fix(installer): allow choosing the Windows installation scope

fix(debugger): debug Python with python, not python3, on Windows (#2159 )
Debugging a Python configuration with no interpreter path (a global `pytest`, `uv run`, `poetry run`) set debugpy's adapter Python to a hardcoded `python3`. On Windows that is at most a Store alias, and the debugpy venv the IDE installs has only `python.exe`, so the managed debugpy was skipped. The launch now uses `python` on Windows, based on the host OS so remote sessions follow the server. Other platforms are unchanged. Sibling covered: `debugLauncherPython` uses the same fallback. Co-authored-by: Bortlesboat <[email protected]>
2026-11-08 08:08:16 -10:00 · 2026-11-08 23:11:59 +08:00 · 2026-11-08 22:57:58 +08:00 · 2026-11-08 22:57:44 +08:00 · 2026-11-08 22:46:42 +08:00 · 2026-11-08 22:33:22 +08:00
1010 changed files with 84341 additions and 6094 deletions
@@ -3907,6 +3907,12 @@ version = "1.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6dbf3de79e51f3d586ab4cb9d5c3e2c14aa28ed23d180cf89b4df0454a69cc87"

+[[package]]
+name = "httpdate"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
+
 [[package]]
 name = "hybrid-array"
 version = "0.4.15"
@@ -3933,6 +3939,7 @@ dependencies = [
 "http",
 "http-body",
 "httparse",
+ "httpdate",
 "itoa",
 "pin-project-lite",
 "smallvec",
@@ -4106,12 +4113,13 @@ checksum = "3d3067d79b975e8844ca9eb072e16b31c3c1c36928edf9c6789548c524d0d954"

 [[package]]
 name = "ide-agent"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "dunce",
 "encoding_rs",
 "ide-core",
 "ide-jsonrpc",
+ "ide-mcp",
 "ide-tools",
 "ide-vcs",
 "ide-vfs",
@@ -4129,7 +4137,7 @@ dependencies = [

 [[package]]
 name = "ide-analysis"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ast-grep-core",
 "ide-core",
@@ -4143,7 +4151,7 @@ dependencies = [

 [[package]]
 name = "ide-android"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "serde",
@@ -4154,7 +4162,7 @@ dependencies = [

 [[package]]
 name = "ide-build"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "blake3",
 "dirs 6.0.0",
@@ -4168,9 +4176,23 @@ dependencies = [
 "zip",
 ]

+[[package]]
+name = "ide-cli"
+version = "0.1.39"
+dependencies = [
+ "dirs 6.0.0",
+ "serde",
+ "serde_json",
+ "tempfile",
+ "tokio",
+ "tracing",
+ "windows-sys 0.61.2",
+ "winreg 0.56.0",
+]
+
 [[package]]
 name = "ide-clipboard"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "objc2 0.6.5",
 "objc2-app-kit 0.3.2",
@@ -4179,7 +4201,7 @@ dependencies = [

 [[package]]
 name = "ide-core"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "dunce",
 "encoding_rs",
@@ -4196,7 +4218,7 @@ dependencies = [

 [[package]]
 name = "ide-coverage"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "ide-run",
@@ -4210,7 +4232,7 @@ dependencies = [

 [[package]]
 name = "ide-dap"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "futures",
 "ide-core",
@@ -4231,7 +4253,7 @@ dependencies = [

 [[package]]
 name = "ide-db"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "bb8",
 "dirs 6.0.0",
@@ -4258,7 +4280,7 @@ dependencies = [

 [[package]]
 name = "ide-docker"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "serde",
@@ -4271,7 +4293,7 @@ dependencies = [

 [[package]]
 name = "ide-extension"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "base64 0.22.1",
 "blake3",
@@ -4291,7 +4313,7 @@ dependencies = [

 [[package]]
 name = "ide-fonts"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "objc2-core-foundation",
 "objc2-core-text",
@@ -4303,7 +4325,7 @@ dependencies = [

 [[package]]
 name = "ide-github"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "ide-vcs",
@@ -4316,13 +4338,15 @@ dependencies = [

 [[package]]
 name = "ide-host"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "base64 0.22.1",
+ "blake3",
 "criterion",
 "dirs 6.0.0",
 "dunce",
 "encoding_rs",
+ "futures",
 "getrandom 0.3.4",
 "globset",
 "ide-agent",
@@ -4339,6 +4363,7 @@ dependencies = [
 "ide-jsonrpc",
 "ide-language",
 "ide-lsp",
+ "ide-mcp",
 "ide-notebook",
 "ide-plugin",
 "ide-remote",
@@ -4357,6 +4382,7 @@ dependencies = [
 "ignore",
 "parking_lot",
 "quick-xml 0.42.0",
+ "regex-lite",
 "regex-syntax",
 "reqwest",
 "rustix",
@@ -4377,7 +4403,7 @@ dependencies = [

 [[package]]
 name = "ide-http"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "parking_lot",
@@ -4395,7 +4421,7 @@ dependencies = [

 [[package]]
 name = "ide-index"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "blake3",
 "criterion",
@@ -4417,7 +4443,7 @@ dependencies = [

 [[package]]
 name = "ide-jsonrpc"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "encoding_rs",
 "futures",
@@ -4434,7 +4460,7 @@ dependencies = [

 [[package]]
 name = "ide-language"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "blake3",
 "criterion",
@@ -4490,7 +4516,7 @@ dependencies = [

 [[package]]
 name = "ide-lsp"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "dunce",
 "futures",
@@ -4514,9 +4540,28 @@ dependencies = [
 "zip",
 ]

+[[package]]
+name = "ide-mcp"
+version = "0.1.39"
+dependencies = [
+ "bytes",
+ "dunce",
+ "getrandom 0.3.4",
+ "http-body-util",
+ "hyper",
+ "hyper-util",
+ "percent-encoding",
+ "serde",
+ "serde_json",
+ "tempfile",
+ "tokio",
+ "tokio-util",
+ "tracing",
+]
+
 [[package]]
 name = "ide-notebook"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "futures",
 "ide-core",
@@ -4539,7 +4584,7 @@ dependencies = [

 [[package]]
 name = "ide-plugin"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "blake3",
 "ide-core",
@@ -4560,7 +4605,7 @@ dependencies = [

 [[package]]
 name = "ide-profiler"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "ide-run",
@@ -4573,7 +4618,7 @@ dependencies = [

 [[package]]
 name = "ide-remote"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "globset",
 "ide-core",
@@ -4591,12 +4636,13 @@ dependencies = [

 [[package]]
 name = "ide-run"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "dunce",
 "encoding_rs",
 "ide-build",
 "ide-core",
+ "ide-language",
 "libc",
 "parking_lot",
 "portable-pty",
@@ -4614,7 +4660,7 @@ dependencies = [

 [[package]]
 name = "ide-sdk"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "dunce",
 "ide-core",
@@ -4633,7 +4679,7 @@ dependencies = [

 [[package]]
 name = "ide-search"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "criterion",
 "globset",
@@ -4653,7 +4699,7 @@ dependencies = [

 [[package]]
 name = "ide-spell"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "parking_lot",
@@ -4666,7 +4712,7 @@ dependencies = [

 [[package]]
 name = "ide-ssh"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "dirs 6.0.0",
 "flate2",
@@ -4675,7 +4721,6 @@ dependencies = [
 "keyring-core",
 "parking_lot",
 "russh",
- "russh-config",
 "russh-sftp",
 "serde",
 "serde_json",
@@ -4688,7 +4733,7 @@ dependencies = [

 [[package]]
 name = "ide-syntax"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "ide-language",
@@ -4703,7 +4748,7 @@ dependencies = [

 [[package]]
 name = "ide-terminal"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "libc",
@@ -4716,7 +4761,7 @@ dependencies = [

 [[package]]
 name = "ide-text"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "criterion",
 "ide-core",
@@ -4729,7 +4774,7 @@ dependencies = [

 [[package]]
 name = "ide-tools"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "flate2",
 "hex",
@@ -4750,7 +4795,7 @@ dependencies = [

 [[package]]
 name = "ide-vcs"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "blake3",
 "dunce",
@@ -4771,7 +4816,7 @@ dependencies = [

 [[package]]
 name = "ide-vfs"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "chardetng",
 "dunce",
@@ -4782,18 +4827,20 @@ dependencies = [
 "ignore",
 "notify",
 "parking_lot",
+ "rustix",
 "serde",
 "serde_json",
 "specta",
 "tempfile",
 "tracing",
 "trash",
+ "windows-sys 0.61.2",
 "zip",
 ]

 [[package]]
 name = "ide-web"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "ide-core",
 "open",
@@ -4809,7 +4856,7 @@ dependencies = [

 [[package]]
 name = "ide-workspace"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "blake3",
 "dunce",
@@ -5425,10 +5472,7 @@ version = "0.1.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "61ff90caf6077a803a240f62fdbe88645a890bbca49ef8174c3cb0404362171d"
 dependencies = [
- "bitflags 2.13.2",
 "libc",
- "plain",
- "redox_syscall 0.9.5",
 ]

 [[package]]
@@ -6358,7 +6402,7 @@ dependencies = [

 [[package]]
 name = "openidea"
-version = "0.1.38"
+version = "0.1.39"
 dependencies = [
 "base64 0.22.1",
 "blake3",
@@ -6370,6 +6414,7 @@ dependencies = [
 "ide-analysis",
 "ide-android",
 "ide-build",
+ "ide-cli",
 "ide-clipboard",
 "ide-core",
 "ide-coverage",
@@ -6385,6 +6430,7 @@ dependencies = [
 "ide-jsonrpc",
 "ide-language",
 "ide-lsp",
+ "ide-mcp",
 "ide-notebook",
 "ide-plugin",
 "ide-profiler",
@@ -6603,7 +6649,7 @@ checksum = "2621685985a2ebf1c516881c026032ac7deafcda1a2c9b7850dc81e3dfcb64c1"
 dependencies = [
 "cfg-if",
 "libc",
- "redox_syscall 0.5.18",
+ "redox_syscall",
 "smallvec",
 "windows-link",
 ]
@@ -6773,12 +6819,6 @@ version = "0.3.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f6b464fbc74e149a392436b17d523f769e057cb6877f6a5c4618bc6f11800548"

-[[package]]
-name = "plain"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"
-
 [[package]]
 name = "plist"
 version = "1.10.2"
@@ -7236,15 +7276,6 @@ dependencies = [
 "bitflags 2.13.2",
 ]

-[[package]]
-name = "redox_syscall"
-version = "0.9.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "580c875845b41ecb1564ad1ae4703044cef774145e3d7a94dc2b3fa7c97868fd"
-dependencies = [
- "bitflags 2.13.2",
-]
-
 [[package]]
 name = "redox_users"
 version = "0.5.3"
@@ -7529,20 +7560,6 @@ dependencies = [
 "zeroize",
 ]

-[[package]]
-name = "russh-config"
-version = "0.58.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "993346101d4741a59c82bafc6b645c52ce3e7b0820f13e4b5d48cdb591e3d955"
-dependencies = [
- "futures",
- "globset",
- "log",
- "thiserror 2.0.21",
- "tokio",
- "whoami 1.6.1",
-]
-
 [[package]]
 name = "russh-cryptovec"
 version = "0.62.0"
@@ -8360,7 +8377,7 @@ dependencies = [
 "objc2-foundation 0.3.2",
 "objc2-quartz-core 0.3.2",
 "raw-window-handle",
- "redox_syscall 0.5.18",
+ "redox_syscall",
 "tracing",
 "wasm-bindgen",
 "web-sys",
@@ -8624,7 +8641,7 @@ dependencies = [
 "stringprep",
 "thiserror 2.0.21",
 "tracing",
- "whoami 2.1.3",
+ "whoami",
 ]

 [[package]]
@@ -10566,12 +10583,6 @@ dependencies = [
 "wit-bindgen",
 ]

-[[package]]
-name = "wasite"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8dad83b4f25e74f184f64c43b150b91efe7647395b42289f38e50566d82855b"
-
 [[package]]
 name = "wasm-bindgen"
 version = "0.2.129"
@@ -11146,17 +11157,6 @@ dependencies = [
 "libc",
 ]

-[[package]]
-name = "whoami"
-version = "1.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d4a4db5077702ca3015d3d02d74974948aba2ad9e12ab7df718ee64ccd7e97d"
-dependencies = [
- "libredox",
- "wasite",
- "web-sys",
-]
-
 [[package]]
 name = "whoami"
 version = "2.1.3"
@@ -5,7 +5,7 @@ members = ["crates/*", "src-tauri"]
 exclude = ["sdk", "plugins"]

 [workspace.package]
-version = "0.1.38"
+version = "0.1.39"
 edition = "2024"
 rust-version = "1.96"
 license = "Apache-2.0"
@@ -42,9 +42,11 @@ ide-fonts = { path = "crates/ide-fonts" }
 ide-ssh = { path = "crates/ide-ssh" }
 ide-remote = { path = "crates/ide-remote" }
 ide-host = { path = "crates/ide-host" }
+ide-mcp = { path = "crates/ide-mcp" }
 ide-notebook = { path = "crates/ide-notebook" }
 ide-extension = { path = "crates/ide-extension" }
 ide-plugin = { path = "crates/ide-plugin" }
+ide-cli = { path = "crates/ide-cli" }

 # serialization & IPC typing
 serde = { version = "1", features = ["derive"] }
@@ -76,8 +76,4 @@ the [official plugins](plugins/official). The plugin API is still a preview.

 [Apache 2.0](LICENSE). Bundled third-party assets are listed in [`THIRD_PARTY_LICENSES.md`](THIRD_PARTY_LICENSES.md).

-Database tool window notes, including Oracle Instant Client setup, are in
-[`docs/databases.md`](docs/databases.md).
-Java language server choices and their capabilities are in [`docs/java.md`](docs/java.md).
-
 <sub>Not affiliated with JetBrains. IntelliJ IDEA is a trademark of JetBrains s.r.o.</sub>
@@ -9,6 +9,7 @@ license.workspace = true
 encoding_rs.workspace = true
 ide-vfs.workspace = true
 ide-core.workspace = true
+ide-mcp.workspace = true
 ide-jsonrpc.workspace = true
 ide-vcs.workspace = true
 ide-tools = { path = "../ide-tools" }
@@ -21,7 +22,5 @@ tracing.workspace = true
 parking_lot.workspace = true
 dunce.workspace = true
 uuid.workspace = true
-which = "8"
-
-[dev-dependencies]
 tempfile.workspace = true
+which = "8"
@@ -27,6 +27,29 @@ use std::sync::Arc;
 use std::sync::atomic::{AtomicU8, Ordering};
 use tokio::sync::oneshot;

+/// ACP's error code for a request that needs the user to sign in.
+pub(crate) const AUTH_REQUIRED: i64 = -32000;
+
+// Covers signed-out users and refused accounts (Claude Code: "API Error: 403").
+pub(crate) fn auth_required(code: i64, message: &str) -> bool {
+    if code == AUTH_REQUIRED {
+        return true;
+    }
+    let lower = message.to_lowercase();
+    let words: Vec<&str> = lower.split(|c: char| !c.is_alphanumeric()).filter(|w| !w.is_empty()).collect();
+    words.iter().any(|w| {
+        *w == "auth"
+            || w.starts_with("authenticat")
+            || w.starts_with("authoriz")
+            || w.starts_with("unauthenticat")
+            || w.starts_with("unauthoriz")
+            || w.starts_with("oauth")
+    }) || words.windows(3).any(|w| w == ["not", "logged", "in"])
+        || words
+            .windows(2)
+            .any(|w| w == ["logged", "out"] || w == ["sign", "in"] || w == ["log", "in"] || w == ["login", "required"])
+}
+
 /// The capabilities this client offers, in v1 form.
 fn client_capabilities() -> Value {
    json!({
@@ -69,6 +92,11 @@ pub(crate) struct Negotiated {
 }

 impl Negotiated {
+    pub fn mcp_stdio(&self) -> bool {
+        // Stdio is the ACP v1 baseline; v2 negotiates each transport explicitly.
+        self.capabilities.pointer("/mcpCapabilities/stdio").and_then(Value::as_bool).unwrap_or(self.generation == 1)
+    }
+
    /// Reads an `initialize` response. The shape decides, not `protocolVersion`: some v1
    /// agents report version 2 with v1 fields (`agentInfo`, `agentCapabilities`); only a
    /// v2 response has `info`.
@@ -97,7 +125,7 @@ impl Negotiated {
                "audio": has(prompt, "audio"),
                "embeddedContext": has(prompt, "embeddedContext"),
            },
-            "mcpCapabilities": { "http": has(mcp, "http"), "sse": false },
+            "mcpCapabilities": { "http": has(mcp, "http"), "sse": false, "stdio": has(mcp, "stdio") },
        });
        if session.is_some() {
            let mut sc = json!({ "list": {}, "resume": {}, "close": {} });
@@ -16,6 +16,42 @@ const CANCEL: &str = include_str!("../../tests/fixtures/acp-v2/cancel.jsonl");
 const RESUME: &str = include_str!("../../tests/fixtures/acp-v2/resume.jsonl");
 const INITIALIZE_V1: &str = include_str!("../../tests/fixtures/acp-v2/initialize-v1.jsonl");

+#[test]
+fn auth_required_matches_authentication_words_and_sign_in_phrases() {
+    for (code, message, expected) in [
+        (AUTH_REQUIRED, "This account is not eligible.", true),
+        (codes::INTERNAL_ERROR, "Auth required", true),
+        (codes::INTERNAL_ERROR, "Authentication failed", true),
+        (codes::INTERNAL_ERROR, "Failed to authenticate. API Error: 401", true),
+        (codes::INTERNAL_ERROR, "Failed to authenticate. API Error: 403", true),
+        (codes::INTERNAL_ERROR, "Not authenticated", true),
+        (codes::INTERNAL_ERROR, "Authorization failed", true),
+        (codes::INTERNAL_ERROR, "Authorize your account", true),
+        (codes::INTERNAL_ERROR, "Unauthenticated", true),
+        (codes::INTERNAL_ERROR, "Unauthentication error", true),
+        (codes::INTERNAL_ERROR, "Unauthorized", true),
+        (codes::INTERNAL_ERROR, "Unauthorization error", true),
+        (codes::INTERNAL_ERROR, "OAuth token has expired", true),
+        (codes::INTERNAL_ERROR, "OAuth2 token has expired", true),
+        (codes::INTERNAL_ERROR, "You are not logged in", true),
+        (codes::INTERNAL_ERROR, "You are logged out", true),
+        (codes::INTERNAL_ERROR, "Please sign in", true),
+        (codes::INTERNAL_ERROR, "Please log in", true),
+        (codes::INTERNAL_ERROR, "Login required", true),
+        (codes::INTERNAL_ERROR, "author", false),
+        (codes::INTERNAL_ERROR, "authors", false),
+        (codes::INTERNAL_ERROR, "authority", false),
+        (codes::INTERNAL_ERROR, "authored", false),
+        (codes::INTERNAL_ERROR, "reauthenticate", false),
+        (codes::INTERNAL_ERROR, "preauthorized", false),
+        (codes::INTERNAL_ERROR, "signal input failed", false),
+        (codes::INTERNAL_ERROR, "catalog index failed", false),
+        (codes::INTERNAL_ERROR, "login succeeded", false),
+    ] {
+        assert_eq!(auth_required(code, message), expected, "code={code}, message={message:?}");
+    }
+}
+
 /// The messages of a fixture going `dir` (`in` or `out`).
 pub(crate) fn frames(fixture: &str, dir: &str) -> Vec<Value> {
    fixture
@@ -527,3 +563,13 @@ async fn v1_requests_are_sent_in_v2() {
        .collect();
    assert_eq!(commands, [&json!("28846a4c-c3e8-4a45-a3d0-c19f10d19d1a"), &json!("s1")]);
 }
+
+#[test]
+fn stdio_mcp_is_v1_baseline_and_negotiated_in_v2() {
+    assert!(super::Negotiated::from_initialize(&json!({"protocolVersion":1,"agentCapabilities":{}})).mcp_stdio());
+    assert!(!super::Negotiated::from_initialize(&json!({"info":{},"capabilities":{"session":{}}})).mcp_stdio());
+    assert!(
+        super::Negotiated::from_initialize(&json!({"info":{},"capabilities":{"session":{"mcp":{"stdio":{}}}}}))
+            .mcp_stdio()
+    );
+}
@@ -35,20 +35,32 @@ pub(crate) fn add_client_options(provider: &str, config: &mut Vec<AgentConfigOpt
    });
 }

-pub(crate) fn bypass_approvals(provider: &str, config: &[AgentConfigOption]) -> bool {
-    provider == "cursor" && config.iter().any(|o| o.id == CURSOR_APPROVAL && o.current.as_deref() == Some("bypass"))
+/// Whether the current settings approve tool requests without asking: a bypass mode,
+/// an allow-all permissions option, or a bypass approval policy.
+pub(crate) fn bypass_approvals(config: &[AgentConfigOption]) -> bool {
+    let selected = |category: &str| {
+        config.iter().find(|o| o.category.as_deref() == Some(category)).and_then(|o| o.current.as_deref())
+    };
+    selected("mode").is_some_and(is_bypass_mode)
+        || selected("permissions").is_some_and(|v| matches!(v.to_ascii_lowercase().as_str(), "on" | "true"))
+        || selected("approval").is_some_and(|v| v.eq_ignore_ascii_case("bypass"))
 }

 /// The mode that approves everything without asking (`bypassPermissions`, `yolo`, `full-access`…), if the agent has one.
 pub(crate) fn bypass_mode(options: &[AgentConfigOption]) -> Option<(&AgentConfigOption, &AgentConfigValue)> {
    let option = options.iter().find(|o| o.category.as_deref() == Some("mode"))?;
-    let value = option.values.iter().find(|v| {
-        let m: String = v.value.to_lowercase().chars().filter(char::is_ascii_lowercase).collect();
-        m.contains("bypass") || m == "yolo" || m.contains("fullaccess") || m == "dangerous"
-    })?;
+    let value = option.values.iter().find(|v| is_bypass_mode(&v.value))?;
    Some((option, value))
 }

+fn is_bypass_mode(mode: &str) -> bool {
+    // Mode ids can be URL-like (`…/session-modes#yolo`), as the composer's mode icon also assumes.
+    let lower = mode.to_lowercase();
+    let m: String =
+        lower.rsplit(['#', '/']).next().unwrap_or_default().chars().filter(char::is_ascii_lowercase).collect();
+    m.contains("bypass") || m == "yolo" || m.contains("fullaccess") || m == "dangerous"
+}
+
 /// The settings in a `session/new` or `session/load` result: its select `configOptions`,
 /// plus the older `modes` / `models` fields for what those don't cover.
 pub(crate) fn options_of(result: &Value) -> Vec<AgentConfigOption> {
@@ -267,6 +279,52 @@ mod tests {
        assert_eq!(ids(&c), [("model", Some("b")), ("mode", Some("code"))]);
    }

+    #[test]
+    fn selected_bypass_settings_approve_without_asking() {
+        let full_access = options_of(&json!({
+            "modes": {"currentModeId": "full-access", "availableModes": [
+                {"id": "ask", "name": "Ask"}, {"id": "full-access", "name": "Full Access"}
+            ]}
+        }));
+        assert!(bypass_approvals(&full_access));
+        assert_eq!(bypass_mode(&full_access).map(|(_, v)| v.value.as_str()), Some("full-access"));
+
+        let asking = options_of(&json!({
+            "modes": {"currentModeId": "ask", "availableModes": [
+                {"id": "ask", "name": "Ask"}, {"id": "full-access", "name": "Full Access"}
+            ]}
+        }));
+        assert!(!bypass_approvals(&asking));
+        assert_eq!(
+            bypass_mode(&asking).map(|(_, v)| v.value.as_str()),
+            Some("full-access"),
+            "the offered bypass mode stays available"
+        );
+
+        let permissions = |current: &str| {
+            options_of(&json!({"configOptions": [{
+                "id": "allow_all", "name": "Allow All", "category": "permissions", "type": "select",
+                "currentValue": current, "options": [{"value": "off"}, {"value": "on"}]
+            }]}))
+        };
+        assert!(bypass_approvals(&permissions("on")));
+        assert!(bypass_approvals(&permissions("TRUE")));
+        assert!(!bypass_approvals(&permissions("off")));
+
+        let approval = options_of(&json!({"configOptions": [{
+            "id": "approval", "name": "Approvals", "category": "approval", "type": "select",
+            "currentValue": "bypass", "options": [{"value": "ask"}, {"value": "bypass"}]
+        }]}));
+        assert!(bypass_approvals(&approval));
+
+        // The composer's mode icon splits URL-like ids on `#` / `/`; the backend must agree.
+        let url_mode = options_of(&json!({
+            "modes": {"currentModeId": "https://agentclientprotocol.com/protocol/session-modes#yolo",
+                      "availableModes": [{"id": "https://agentclientprotocol.com/protocol/session-modes#yolo"}]}
+        }));
+        assert!(bypass_approvals(&url_mode));
+    }
+
    #[test]
    fn commands_and_usage() {
        let cmds = commands_of(&json!({"availableCommands": [
@@ -109,6 +109,9 @@ struct Shared {
 struct Known {
    #[serde(default)]
    config: Vec<AgentConfigOption>,
+    /// Thinking levels reported for each model value, including its last choice.
+    #[serde(default, rename = "thoughtLevels")]
+    thought_levels: BTreeMap<String, Vec<AgentConfigOption>>,
    /// By project root: skills and custom commands differ per project.
    #[serde(default, rename = "projectCommands")]
    commands: HashMap<String, Vec<AgentCommand>>,
@@ -128,10 +131,7 @@ impl Shared {

    fn known_config(&self, provider: &str) -> Vec<AgentConfigOption> {
        let mut config = self.known.lock().get(provider).map(|k| k.config.clone()).unwrap_or_default();
-        // A thinking level's values depend on the model (low/medium/high on one, none or a
-        // different set on another), but what ran last is remembered wholesale — after a
-        // model switch the New Task page would offer the previous model's levels. Until the
-        // session reports the new model's own, don't show the option at all.
+        // Model-specific options are offered separately, never as provider-wide defaults.
        config.retain(|o| o.category.as_deref() != Some("thought_level"));
        config::add_client_options(provider, &mut config);
        if let Some((o, v)) = config::bypass_mode(&config).map(|(o, v)| (o.id.clone(), v.value.clone()))
@@ -155,14 +155,31 @@ impl Shared {
        self.paths.project_root.to_string_lossy().into_owned()
    }

-    fn remember(&self, provider: &str, config: Option<&[AgentConfigOption]>, commands: Option<&[AgentCommand]>) {
+    /// Cache levels only when `model` confirms which model the session reported them for.
+    fn remember(
+        &self,
+        provider: &str,
+        config: Option<&[AgentConfigOption]>,
+        commands: Option<&[AgentCommand]>,
+        model: Option<&str>,
+    ) {
        let snapshot = {
            let mut cache = self.known.lock();
            let known = cache.entry(provider.to_owned()).or_default();
            let mut changed = false;
-            if let Some(c) = config.filter(|c| !c.is_empty() && known.config != *c) {
-                known.config = c.to_vec();
-                changed = true;
+            if let Some(c) = config {
+                if let Some(model) = model {
+                    let levels: Vec<_> =
+                        c.iter().filter(|o| o.category.as_deref() == Some("thought_level")).cloned().collect();
+                    if known.thought_levels.get(model) != Some(&levels) {
+                        known.thought_levels.insert(model.to_owned(), levels);
+                        changed = true;
+                    }
+                }
+                if !c.is_empty() && known.config != c {
+                    known.config = c.to_vec();
+                    changed = true;
+                }
            }
            let root = self.root_key();
            if let Some(c) =
@@ -201,6 +218,9 @@ struct TaskFile {
    /// Turns to drop from the session once it is loaded (a fork of an earlier point).
    #[serde(default, skip_serializing_if = "is_zero")]
    pending_rollback: u32,
+    /// The user named the task: its agent's own title updates no longer replace it.
+    #[serde(default, skip_serializing_if = "is_false")]
+    title_renamed: bool,
 }

 struct TaskState {
@@ -210,6 +230,8 @@ struct TaskState {
    wanted: Vec<AgentConfigChoice>,
    before: Arc<BTreeMap<String, worktree::Stamp>>,
    pending_rollback: u32,
+    /// The user named the task; see `TaskFile::title_renamed`.
+    title_renamed: bool,
    /// A turn is running or about to (prompts arriving now are queued).
    busy: bool,
    /// Background tasks the agent reported as running (`run_in_background` commands and
@@ -221,6 +243,7 @@ struct TaskState {
 /// A running agent and its session.
 #[derive(Clone)]
 struct Live {
+    sign_in_message: String,
    peer: acp::Conn,
    session: String,
    capabilities: AgentCapabilities,
@@ -228,6 +251,7 @@ struct Live {
    embedded: bool,
    /// `session/load`: the process can be stopped between turns and the session reloaded.
    resumable: bool,
+    mcp_stdio: bool,
 }

 struct Task {
@@ -339,6 +363,8 @@ impl AgentManager {
            .map(|p| {
                let mut info = provider::describe(p);
                info.config = self.shared.known_config(&p.id);
+                info.thought_levels =
+                    self.shared.known.lock().get(&p.id).map(|k| k.thought_levels.clone()).unwrap_or_default();
                info.commands = self.shared.known_commands(&p.id);
                info
            })
@@ -458,6 +484,18 @@ impl AgentManager {
                o.current = Some(choice.value.clone());
            }
        }
+        if let Some(model) = model_of(&config)
+            && let Some(levels) = self.shared.known.lock().get(&spec.id).and_then(|k| k.thought_levels.get(&model))
+        {
+            config.extend(levels.iter().cloned().map(|mut o| {
+                if let Some(choice) =
+                    req.config.iter().find(|c| c.id == o.id && o.values.iter().any(|v| v.value == c.value))
+                {
+                    o.current = Some(choice.value.clone());
+                }
+                o
+            }));
+        }
        let now = now_ms();
        let task = AgentTask {
            project_root,
@@ -491,6 +529,7 @@ impl AgentManager {
            before,
            subagents: Vec::new(),
            pending_rollback: 0,
+            title_renamed: false,
        };
        let handle = Task::restore(file, self.shared.clone());
        handle.state.lock().busy = true;
@@ -605,6 +644,8 @@ impl AgentManager {
            o.clone()
        };
        let live = task.live.lock().clone().filter(|l| !l.peer.is_closed());
+        let mut model_options =
+            target.category.as_deref() != Some("model") || target.current.as_deref() == Some(value.as_str());
        if let Some(live) = live.filter(|_| option != config::CURSOR_APPROVAL) {
            let (method, mut params) = config::set_request(&target, &value);
            params["sessionId"] = json!(live.session);
@@ -612,10 +653,14 @@ impl AgentManager {
                live.peer.request(method, params, None).await.map_err(|e| IdeError::internal(task.describe(e)))?;
            if let Some(options) = reply.get("configOptions") {
                config::merge_update(&mut task.state.lock().task.config, options);
+                model_options = true;
            }
        }
        {
            let mut s = task.state.lock();
+            if !model_options {
+                s.task.config.retain(|o| o.category.as_deref() != Some("thought_level"));
+            }
            s.wanted.retain(|c| c.id != option);
            s.wanted.push(AgentConfigChoice { id: option.to_owned(), value: value.clone() });
            if let Some(o) = s.task.config.iter_mut().find(|o| o.id == option) {
@@ -624,8 +669,9 @@ impl AgentManager {
            s.task.model = model_of(&s.task.config).or(s.task.model.take());
            let provider = s.task.provider.clone();
            let config = s.task.config.clone();
+            let model = s.task.model.clone().filter(|_| model_options);
            drop(s);
-            task.shared.remember(&provider, Some(&config), None);
+            task.shared.remember(&provider, Some(&config), None, model.as_deref());
        }
        task.approve_pending();
        task.persist();
@@ -651,7 +697,7 @@ impl AgentManager {
        let cwd_s = dunce::canonicalize(&cwd).unwrap_or(cwd).to_string_lossy().into_owned();
        let reply: Value = live
            .peer
-            .request("session/fork", json!({ "sessionId": live.session, "cwd": cwd_s, "mcpServers": [] }), None)
+            .request("session/fork", json!({ "sessionId": live.session, "cwd": cwd_s, "mcpServers": mcp_servers_for(live.mcp_stdio, &source.shared.paths.project_root) }), None)
            .await
            .map_err(|e| IdeError::internal(source.describe(e)))?;
        let session = reply
@@ -687,6 +733,7 @@ impl AgentManager {
                before: (*s.before).clone(),
                subagents: s.conversation.saved_subagents(),
                pending_rollback: total - keep,
+                title_renamed: s.title_renamed,
            }
        };
        let task = Task::restore(file, self.shared.clone());
@@ -705,12 +752,38 @@ impl AgentManager {
        if task.state.lock().busy {
            return Err(IdeError::invalid("wait until the agent is done"));
        }
+        let starts = turn_starts(&task.state.lock().conversation.main.entries);
+        let Some(&cut) = starts.get(turns as usize) else { return Ok(None) };
+        // Dropping every turn starts the conversation over, which needs no agent-side
+        // rewind — and some agents cannot rewind past their first turn (a resumed
+        // Claude Code session). A fresh session avoids both.
+        if turns == 0 {
+            task.kill();
+            let first = {
+                let mut s = task.state.lock();
+                let first = match s.conversation.main.entries.get(cut) {
+                    Some(AgentEntry::User { text, .. }) => {
+                        Some(AgentPrompt { text: text.clone(), ..Default::default() })
+                    }
+                    _ => None,
+                };
+                s.session_id = None;
+                s.conversation = Conversation::default();
+                // The fresh session reports its own usage; nothing carries over.
+                s.task.usage = None;
+                s.pending_rollback = 0;
+                s.task.updated_ms = now_ms();
+                first
+            };
+            task.persist();
+            self.shared.emit(AgentEvent::Truncated { task: id.to_owned(), length: 0 });
+            task.emit_task();
+            return Ok(first);
+        }
        let live = task.ensure_session().await.map_err(IdeError::internal)?;
        if !live.capabilities.rollback {
            return Err(IdeError::invalid("this agent can't undo turns"));
        }
-        let starts = turn_starts(&task.state.lock().conversation.main.entries);
-        let Some(&cut) = starts.get(turns as usize) else { return Ok(None) };
        let drop = (starts.len() - turns as usize) as u32;
        let _: Value = live
            .peer
@@ -871,6 +944,28 @@ impl AgentManager {
        Ok(())
    }

+    /// Renames the task; the agent's own later title updates keep the user's choice.
+    pub fn rename(&self, id: &str, title: &str) -> IdeResult<()> {
+        let title = title.trim();
+        if title.is_empty() {
+            return Err(IdeError::invalid("the title is empty"));
+        }
+        let title: String = title.chars().take(200).collect();
+        let task = self.task(id)?;
+        {
+            let mut s = task.state.lock();
+            if s.task.title == title && s.title_renamed {
+                return Ok(());
+            }
+            s.task.title = title;
+            s.title_renamed = true;
+            s.task.updated_ms = now_ms();
+        }
+        task.persist();
+        task.emit_task();
+        Ok(())
+    }
+
    /// Forgets the task; with `remove_worktree` also deletes its worktree (the branch stays).
    pub async fn delete(&self, id: &str, remove_worktree: bool) -> IdeResult<()> {
        let task = self.task(id)?;
@@ -941,6 +1036,7 @@ impl Task {
                wanted: file.wanted,
                before: Arc::new(file.before),
                pending_rollback: file.pending_rollback,
+                title_renamed: file.title_renamed,
                busy: false,
                background_tasks: Vec::new(),
            }),
@@ -1052,6 +1148,7 @@ impl Task {
                before: (*s.before).clone(),
                subagents: s.conversation.saved_subagents(),
                pending_rollback: s.pending_rollback,
+                title_renamed: s.title_renamed,
            })
        };
        let path = self.shared.paths.store_dir.join(format!("{}.json", self.id));
@@ -1298,17 +1395,22 @@ impl Task {
            };
            return Failure { message, limit: Some(resets) };
        }
-        match e {
-            // Signed out, or the account was refused (Claude Code: "API Error: 403").
-            RpcError::Server { message, .. } if message.to_lowercase().contains("auth") => {
-                let provider = self.state.lock().task.provider.clone();
-                Failure::from(match self.shared.spec(&provider) {
-                    Some(spec) => format!("{} needs you to sign in. {}", spec.name, spec.login_hint),
-                    None => message,
-                })
-            }
-            e => Failure::from(self.describe(e)),
+        let guidance = self.live.lock().as_ref().map(|live| live.sign_in_message.clone());
+        Failure::from(self.sign_in_error(&e, guidance.as_deref()).unwrap_or_else(|| self.describe(e)))
+    }
+
+    fn sign_in_error(&self, e: &RpcError, guidance: Option<&str>) -> Option<String> {
+        let RpcError::Server { code, message, .. } = e else { return None };
+        if !acp::auth_required(*code, message) {
+            return None;
        }
+        tracing::warn!(task = %self.id, code, %message, "agent sign-in failed");
+        let Some(guidance) = guidance else { return Some(message.clone()) };
+        Some(if message.trim().is_empty() || guidance.contains(message) {
+            guidance.to_owned()
+        } else {
+            format!("{guidance}\n\n{message}")
+        })
    }

    async fn ensure_session(self: &Arc<Self>) -> Result<Live, String> {
@@ -1323,6 +1425,10 @@ impl Task {
            (s.task.provider.clone(), s.task.cwd.0.clone(), s.session_id.clone())
        };
        let spec = self.shared.spec(&provider_id).ok_or_else(|| format!("unknown agent {provider_id}"))?;
+        let launch_cwd = cwd.clone();
+        let spec = tokio::task::spawn_blocking(move || spec.resolve_for_launch(&launch_cwd))
+            .await
+            .map_err(|e| e.to_string())?;
        self.stderr.lock().clear();
        self.config_sent.lock().clear();
        let weak = Arc::downgrade(self);
@@ -1342,7 +1448,9 @@ impl Task {
            .map_err(|e| format!("Couldn't start {} (`{}`): {e}", spec.name, spec.command))?;

        let init = peer.initialize(&client_info()).await.map_err(|e| self.describe(e))?;
+        let sign_in_message = spec.sign_in_message(&init.auth_methods);
        let can_load = init.load_session();
+        let mcp_stdio = init.mcp_stdio();
        let (capabilities, embedded) = capabilities_of(&init);
        // Agents that compare canonical paths fail in a symlinked directory (macOS `/tmp`).
        let cwd_s = dunce::canonicalize(&cwd).unwrap_or(cwd).to_string_lossy().into_owned();
@@ -1351,7 +1459,7 @@ impl Task {
        if let (Some(id), true) = (saved, can_load) {
            self.replaying.store(true, Ordering::Release);
            let loaded: Result<Value, RpcError> =
-                peer.request("session/load", json!({ "sessionId": id, "cwd": cwd_s, "mcpServers": [] }), None).await;
+                peer.request("session/load", json!({ "sessionId": id, "cwd": cwd_s, "mcpServers": mcp_servers_for(mcp_stdio, &self.shared.paths.project_root) }), None).await;
            tokio::time::sleep(REPLAY_GRACE).await;
            self.replaying.store(false, Ordering::Release);
            match loaded {
@@ -1364,14 +1472,13 @@ impl Task {
            Some(s) => s,
            None => {
                let v: Value = peer
-                    .request("session/new", json!({ "cwd": cwd_s, "mcpServers": [] }), None)
+                    .request(
+                        "session/new",
+                        json!({ "cwd": cwd_s, "mcpServers": mcp_servers_for(mcp_stdio, &self.shared.paths.project_root) }),
+                        None,
+                    )
                    .await
-                    .map_err(|e| match e {
-                        RpcError::Server { ref message, .. } if message.to_lowercase().contains("auth") => {
-                            format!("{} needs you to sign in. {}", spec.name, spec.login_hint)
-                        }
-                        e => self.describe(e),
-                    })?;
+                    .map_err(|e| self.sign_in_error(&e, Some(&sign_in_message)).unwrap_or_else(|| self.describe(e)))?;
                let id = v.get("sessionId").and_then(Value::as_str).ok_or("the agent returned no session")?.to_owned();
                (id, v)
            }
@@ -1394,11 +1501,21 @@ impl Task {
        // A session that reports none keeps the last known ones, but what is set is unknown.
        let reported = config::options_of(&result);
        let known = !reported.is_empty();
-        let (mut options, wanted) = {
+        if known {
+            self.shared.remember(&provider_id, Some(&reported), None, model_of(&reported).as_deref());
+        }
+        let (mut options, mut wanted) = {
            let s = self.state.lock();
            (if known { reported } else { s.task.config.clone() }, s.wanted.clone())
        };
        config::add_client_options(&provider_id, &mut options);
+        // Changing model can replace the effort choices; validate those only afterwards.
+        wanted.sort_by_key(|c| match options.iter().find(|o| o.id == c.id).and_then(|o| o.category.as_deref()) {
+            Some("model") => 0,
+            Some("thought_level") => 2,
+            _ => 1,
+        });
+        let mut model_options = known;
        for choice in &wanted {
            // An option the session doesn't offer yet is set once it does (`apply_late_choices`).
            let Some(o) = options.iter().find(|o| o.id == choice.id).cloned() else { continue };
@@ -1408,6 +1525,9 @@ impl Task {
                }
                continue;
            }
+            if o.category.as_deref() == Some("thought_level") && !model_options {
+                continue;
+            }
            let already = known && o.current.as_deref() == Some(choice.value.as_str());
            if already || !o.values.iter().any(|v| v.value == choice.value) {
                continue;
@@ -1419,6 +1539,12 @@ impl Task {
                Ok(reply) => {
                    if let Some(fresh) = reply.get("configOptions") {
                        config::merge_update(&mut options, fresh);
+                        model_options = true;
+                    } else if o.category.as_deref() == Some("model") {
+                        if o.current.as_deref() != Some(choice.value.as_str()) {
+                            options.retain(|o| o.category.as_deref() != Some("thought_level"));
+                        }
+                        model_options = false;
                    }
                    if let Some(o) = options.iter_mut().find(|o| o.id == choice.id) {
                        o.current = Some(choice.value.clone());
@@ -1427,7 +1553,8 @@ impl Task {
                Err(e) => tracing::warn!("agent task {}: setting {} to {} failed: {e}", self.id, o.id, choice.value),
            }
        }
-        self.shared.remember(&provider_id, Some(&options), None);
+        let model = model_of(&options).filter(|_| model_options);
+        self.shared.remember(&provider_id, Some(&options), None, model.as_deref());
        {
            let mut s = self.state.lock();
            s.task.model = model_of(&options).or(s.task.model.take());
@@ -1440,7 +1567,8 @@ impl Task {
        }
        self.persist();
        self.emit_task();
-        let live = Live { peer, session: session_id, capabilities, embedded, resumable: can_load };
+        let live =
+            Live { sign_in_message, peer, session: session_id, capabilities, embedded, resumable: can_load, mcp_stdio };
        *self.live.lock() = Some(live.clone());
        Ok(live)
    }
@@ -1464,6 +1592,7 @@ impl Task {
                .collect()
        };
        if due.is_empty() {
+            self.approve_pending();
            return;
        }
        let task = self.clone();
@@ -1476,15 +1605,24 @@ impl Task {
                        let mut s = task.state.lock();
                        if let Some(fresh) = reply.get("configOptions") {
                            config::merge_update(&mut s.task.config, fresh);
+                        } else if option.category.as_deref() == Some("model") {
+                            s.task.config.retain(|o| o.category.as_deref() != Some("thought_level"));
                        }
                        if let Some(o) = s.task.config.iter_mut().find(|o| o.id == option.id) {
                            o.current = Some(value);
                        }
                        s.task.model = model_of(&s.task.config).or(s.task.model.take());
+                        let model = s.task.model.clone().filter(|_| {
+                            reply.get("configOptions").is_some() || option.category.as_deref() != Some("model")
+                        });
+                        let (provider, options) = (s.task.provider.clone(), s.task.config.clone());
+                        drop(s);
+                        task.shared.remember(&provider, Some(&options), None, model.as_deref());
                    }
                    Err(e) => tracing::warn!("agent task {}: setting {} to {value} failed: {e}", task.id, option.id),
                }
            }
+            task.approve_pending();
            task.persist();
            task.emit_task();
        });
@@ -1540,12 +1678,18 @@ impl Task {
            return;
        }
        if kind == "session_info_update" {
-            // The agent's own title for the session replaces the first line of the prompt.
+            // The agent's own title for the session replaces the first line of the prompt,
+            // unless the user named the task.
            let title = update.get("title").and_then(Value::as_str).map(str::trim).filter(|t| !t.is_empty());
            if let Some(title) = title {
-                self.state.lock().task.title = title.to_owned();
-                self.persist();
-                self.emit_task();
+                // Check and write under one lock: a rename landing between them would be lost.
+                let mut s = self.state.lock();
+                if !s.title_renamed && s.task.title != title {
+                    s.task.title = title.to_owned();
+                    drop(s);
+                    self.persist();
+                    self.emit_task();
+                }
            }
            return;
        }
@@ -1579,11 +1723,15 @@ impl Task {
            }
        };
        if task_changed {
-            let (config, commands) = {
+            let (config, commands, model) = {
                let s = self.state.lock();
-                (s.task.config.clone(), s.task.commands.clone())
+                (
+                    s.task.config.clone(),
+                    s.task.commands.clone(),
+                    s.task.model.clone().filter(|_| kind == "config_option_update"),
+                )
            };
-            self.shared.remember(&provider, Some(&config), Some(&commands));
+            self.shared.remember(&provider, Some(&config), Some(&commands), model.as_deref());
            if kind != "usage_update" {
                self.persist();
            }
@@ -1591,6 +1739,9 @@ impl Task {
            if kind == "config_option_update" && !self.replaying.load(Ordering::Acquire) {
                self.apply_late_choices();
            }
+            if !self.replaying.load(Ordering::Acquire) && kind == "current_mode_update" {
+                self.approve_pending();
+            }
            return;
        }
        if self.replaying.load(Ordering::Acquire) {
@@ -1620,12 +1771,12 @@ impl Task {
    /// Blocks the calling (blocking-pool) thread until the user answers.
    fn ask_permission(self: &Arc<Self>, params: &Value) -> Value {
        let id = self.next_permission.fetch_add(1, Ordering::Relaxed);
-        let title = params
-            .pointer("/toolCall/title")
-            .and_then(Value::as_str)
-            .filter(|t| !t.is_empty())
-            .unwrap_or("The agent asks for permission")
-            .to_owned();
+        let (questions, by_index) = asked_questions(params);
+        let title = permission_title(params);
+        // An agent that answers by index titles its request "Ask user N question(s)"; its
+        // first question says what it wants, as the Claude Code adapter titles its own.
+        let title =
+            if by_index { questions.first().map(|question| question.question.clone()).unwrap_or(title) } else { title };
        // A subagent's request is answered in the task's conversation, named after the subagent.
        let session = params.get("sessionId").and_then(Value::as_str);
        let title = match session.and_then(|s| self.state.lock().conversation.label(s)) {
@@ -1647,11 +1798,10 @@ impl Task {
                    .collect()
            })
            .unwrap_or_default();
-        let questions: Vec<AgentQuestion> = params
-            .pointer("/toolCall/_meta/questions")
-            .and_then(|questions| serde_json::from_value(questions.clone()).ok())
-            .unwrap_or_default();
-        let asked: Vec<String> = questions.iter().map(|question| question.question.clone()).collect();
+        let asked: Vec<String> = questions
+            .iter()
+            .map(|question| question.answer_key.clone().unwrap_or_else(|| question.question.clone()))
+            .collect();
        let (tx, rx) = std::sync::mpsc::channel();
        let entry =
            self.push_entry(AgentEntry::Permission { id, title, options: options.clone(), questions, chosen: None });
@@ -1664,7 +1814,7 @@ impl Task {
            .as_deref()
            .filter(|_| !asked.is_empty())
            .and_then(|reply| serde_json::from_str::<serde_json::Map<String, Value>>(reply).ok());
-        let name = match answers {
+        let name = match &answers {
            Some(answers) => asked
                .iter()
                .filter_map(|question| answers.get(question))
@@ -1690,6 +1840,31 @@ impl Task {
        if !still_asking && self.state.lock().task.status == AgentStatus::NeedsInput {
            self.set_status(AgentStatus::Running, None);
        }
+        // An agent that answers by index reads the answers beside the outcome, keyed by
+        // question index, with its Submit option chosen; anything less cancels the request.
+        if by_index {
+            let submit = options.iter().find(|option| option.kind == "allow_once").or_else(|| options.first());
+            return match (answers.as_ref(), submit) {
+                (Some(answers), Some(submit)) => {
+                    let picked: serde_json::Map<String, Value> = asked
+                        .iter()
+                        .enumerate()
+                        .filter_map(|(index, question)| {
+                            let items = answers.get(question)?;
+                            let answer = match items {
+                                Value::Array(items) => {
+                                    items.iter().filter_map(Value::as_str).collect::<Vec<_>>().join(", ")
+                                }
+                                item => item.as_str().unwrap_or_default().to_owned(),
+                            };
+                            Some((index.to_string(), json!(answer)))
+                        })
+                        .collect();
+                    json!({ "outcome": { "outcome": "selected", "optionId": submit.id }, "answers": picked })
+                }
+                _ => json!({ "outcome": { "outcome": "cancelled" } }),
+            };
+        }
        match answer {
            Some(option) => json!({ "outcome": { "outcome": "selected", "optionId": option } }),
            None => json!({ "outcome": { "outcome": "cancelled" } }),
@@ -1698,12 +1873,15 @@ impl Task {

    fn approve_pending(&self) {
        let s = self.state.lock();
-        if self.cancel_pending.load(Ordering::Acquire) || !config::bypass_approvals(&s.task.provider, &s.task.config) {
+        if self.cancel_pending.load(Ordering::Acquire) || !config::bypass_approvals(&s.task.config) {
            return;
        }
        let mut pending = self.permissions.lock();
        for entry in s.conversation.main.entries.iter().rev() {
-            if let AgentEntry::Permission { id, options, chosen: None, .. } = entry
+            // A request with questions is never satisfied by a bypass: its Submit option
+            // would answer with no answers.
+            if let AgentEntry::Permission { id, options, questions, chosen: None, .. } = entry
+                && questions.is_empty()
                && let Some(option) = options.iter().find(|o| o.kind == "allow_once")
                && let Some(reply) = pending.remove(id)
            {
@@ -1768,6 +1946,82 @@ fn clean(mut prompt: AgentPrompt) -> Option<AgentPrompt> {
    (!prompt.text.is_empty() || !prompt.images.is_empty() || !prompt.files.is_empty()).then_some(prompt)
 }

+fn permission_title(params: &Value) -> String {
+    let call = &params["toolCall"];
+    let title = call.get("title").and_then(Value::as_str).filter(|t| !t.is_empty());
+    if call.get("kind").and_then(Value::as_str) == Some("execute") {
+        if let Some(command) = call.pointer("/rawInput/command").and_then(Value::as_str).filter(|c| !c.is_empty()) {
+            // Network approvals describe the host rather than approving command execution.
+            if !title.is_some_and(|t| t.starts_with("Allow network access to ")) {
+                return format!("Run {}", shell_script(command).unwrap_or_else(|| command.to_owned()));
+            }
+        }
+        if title.is_none()
+            && let Some(content) = call.get("content").and_then(Value::as_array)
+            && let Some(text) = content.iter().find_map(|c| c.pointer("/content/text").and_then(Value::as_str))
+        {
+            return format!("Run {text}");
+        }
+    }
+    title.unwrap_or("The agent asks for permission").to_owned()
+}
+
+/// The script of a `<shell> -c <quoted script>` command line, when the whole line is exactly that.
+pub(crate) fn shell_script(command: &str) -> Option<String> {
+    let (shell, rest) = command.split_once(' ')?;
+    if !matches!(shell.rsplit('/').next(), Some("sh" | "bash" | "zsh")) {
+        return None;
+    }
+    let quoted = rest.strip_prefix("-lc ").or_else(|| rest.strip_prefix("-c "))?;
+    let mut out = String::new();
+    let mut chars = quoted.chars();
+    // Adjacent quoted words, e.g. 'a'\''b' or "a \"b\"".
+    while let Some(c) = chars.next() {
+        match c {
+            '\'' => loop {
+                match chars.next()? {
+                    '\'' => break,
+                    c => out.push(c),
+                }
+            },
+            '"' => loop {
+                match chars.next()? {
+                    '"' => break,
+                    '\\' => match chars.next()? {
+                        c @ ('"' | '\\' | '$' | '`') => out.push(c),
+                        '\n' => {}
+                        c => {
+                            out.push('\\');
+                            out.push(c);
+                        }
+                    },
+                    c => out.push(c),
+                }
+            },
+            '\\' => out.push(chars.next()?),
+            _ => return None,
+        }
+    }
+    Some(out)
+}
+
+/// The questions a permission request asks, and whether they answer by question index.
+/// The Claude Code adapter carries them as `_meta.questions`, answered as the option id;
+/// Qwen Code (ACP) as `_meta.qwenQuestions`, answered with `answers` keyed by index beside
+/// the id of its Submit option.
+fn asked_questions(params: &Value) -> (Vec<AgentQuestion>, bool) {
+    for (pointer, by_index) in [("/toolCall/_meta/questions", false), ("/toolCall/_meta/qwenQuestions", true)] {
+        if let Some(questions) = params
+            .pointer(pointer)
+            .and_then(|questions| serde_json::from_value::<Vec<AgentQuestion>>(questions.clone()).ok())
+            .filter(|questions| !questions.is_empty())
+        {
+            return (questions, by_index);
+        }
+    }
+    (Vec::new(), false)
+}
+
 /// ACP content blocks: the text, each file (embedded when its text is in `contents`, else
 /// a `resource_link`), then the images.
 fn blocks(prompt: &AgentPrompt, contents: &[Option<String>]) -> Vec<Value> {
@@ -1883,6 +2137,10 @@ fn turn_starts(entries: &[AgentEntry]) -> Vec<usize> {
        .collect()
 }

+fn is_false(b: &bool) -> bool {
+    !*b
+}
+
 fn is_zero(n: &u32) -> bool {
    *n == 0
 }
@@ -1964,3 +2222,20 @@ mod replay;
 mod replay_tests;
 #[cfg(test)]
 mod tests;
+
+// The desktop advertises its relay only while the built-in server is listening.
+static MCP_EXECUTABLE: parking_lot::RwLock<Option<std::path::PathBuf>> = parking_lot::RwLock::new(None);
+
+pub fn set_mcp_executable(executable: Option<std::path::PathBuf>) {
+    *MCP_EXECUTABLE.write() = executable;
+}
+
+fn mcp_servers_for(supported: bool, root: &std::path::Path) -> Vec<Value> {
+    stdio_mcp_servers(MCP_EXECUTABLE.read().as_deref(), supported, root)
+}
+
+fn stdio_mcp_servers(executable: Option<&std::path::Path>, supported: bool, root: &std::path::Path) -> Vec<Value> {
+    let Some(executable) = executable.filter(|_| supported) else { return Vec::new() };
+    let command = ide_mcp::stdio_command(executable, root);
+    vec![json!({ "name": "OpenIDEA", "command": command[0], "args": command[1..], "env": [] })]
+}
@@ -282,6 +282,9 @@ pub struct AgentPermissionOption {
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 pub struct AgentQuestion {
+    /// Stable answer identity when the provider supplies question ids.
+    #[serde(default)]
+    pub answer_key: Option<String>,
    #[serde(default)]
    pub header: String,
    pub question: String,
@@ -406,6 +409,9 @@ pub struct AgentProvider {
    pub env: BTreeMap<String, String>,
    /// Settings (models, modes…) the agent offered last time it ran; empty before its first session.
    pub config: Vec<AgentConfigOption>,
+    /// Thinking-level options by model value; absent models have not reported their levels.
+    #[serde(default)]
+    pub thought_levels: BTreeMap<String, Vec<AgentConfigOption>>,
    /// Slash commands it offered last time.
    pub commands: Vec<AgentCommand>,
    pub source: AgentSource,
@@ -98,6 +98,7 @@ pub(super) struct Shim {
 struct Session {
    id: String,
    cwd: PathBuf,
+    mcp_config: Option<tempfile::TempPath>,
    shim: Weak<Shim>,
    st: Mutex<State>,
    /// Serializes (re)starting the process.
@@ -264,9 +265,24 @@ impl Shim {
        Ok(history::chain(&entries, at.as_deref()).into_iter().cloned().collect())
    }

-    fn add_session(self: &Arc<Self>, id: &str, cwd: PathBuf, start: Start, pending: bool) -> Arc<Session> {
+    fn add_session(
+        self: &Arc<Self>,
+        id: &str,
+        cwd: PathBuf,
+        start: Start,
+        pending: bool,
+        mcp_config: Option<String>,
+    ) -> Arc<Session> {
+        let mcp_config = mcp_config.and_then(|json| match write_mcp_config(&json) {
+            Ok(path) => Some(path),
+            Err(e) => {
+                tracing::warn!("Claude Code session {id}: cannot write its MCP configuration: {e}");
+                None
+            }
+        });
        let session = Arc::new(Session {
            id: id.to_owned(),
+            mcp_config,
            shim: Arc::downgrade(self),
            st: Mutex::new(State {
                proc: None,
@@ -312,6 +328,7 @@ impl Shim {
                        "loadSession": true,
                        "promptCapabilities": { "image": true, "embeddedContext": true },
                        "sessionCapabilities": { "fork": {} },
+                        "mcpCapabilities": { "stdio": true, "http": true, "sse": true },
                        "_meta": { "openidea": { "rollback": true, "steer": true, "backgroundTasks": true } },
                    },
                    "agentInfo": { "name": "claude", "title": "Claude Code", "version": self.version() },
@@ -320,7 +337,13 @@ impl Shim {
            }
            "session/new" => {
                let id = new_uuid(false);
-                let session = self.add_session(&id, self.cwd_of(&params), Start::New { id: id.clone() }, false);
+                let session = self.add_session(
+                    &id,
+                    self.cwd_of(&params),
+                    Start::New { id: id.clone() },
+                    false,
+                    mcp_config(&params),
+                );
                rt.block_on(session.ensure()).map_err(|e| self.start_error(&session, e))?;
                session.announce_commands();
                Ok(json!({ "sessionId": id, "configOptions": session.st.lock().settings.options() }))
@@ -336,7 +359,7 @@ impl Shim {
                    None => return Err(invalid(format!("no Claude Code session {id} in {}", cwd.display()))),
                };
                let chain = self.base_chain(&cwd, &start).map_err(internal)?;
-                let session = self.add_session(id, cwd, start, pending);
+                let session = self.add_session(id, cwd, start, pending, mcp_config(&params));
                rt.block_on(session.ensure()).map_err(|e| self.start_error(&session, e))?;
                if method == "session/load" {
                    session.replay(&chain);
@@ -362,7 +385,7 @@ impl Shim {
                    (start, st.settings.clone())
                };
                self.save_pending(&id, Some(&start));
-                let session = self.add_session(&id, source.cwd.clone(), start, true);
+                let session = self.add_session(&id, source.cwd.clone(), start, true, mcp_config(&params));
                session.st.lock().settings = settings;
                let options = session.st.lock().settings.options();
                Ok(json!({ "sessionId": id, "configOptions": options }))
@@ -556,6 +579,9 @@ impl Session {
            old.end();
        }
        let mut args = shim.config.args.clone();
+        if let Some(config) = &self.mcp_config {
+            args.extend(["--mcp-config".to_owned(), config.to_string_lossy().into_owned()]);
+        }
        args.extend(start.args());
        let launch =
            Launch { program: shim.config.program.clone(), args, cwd: self.cwd.clone(), env: shim.config.env.clone() };
@@ -1345,3 +1371,38 @@ fn start_from_json(v: &Value) -> Option<Start> {
    }
    Some(Start::Fork { from: s("fork")?, id: s("id")?, at: s("at") })
 }
+
+/// Writes `json` to a new file only this user can read (removed when the path is dropped).
+fn write_mcp_config(json: &str) -> std::io::Result<tempfile::TempPath> {
+    let mut file = tempfile::Builder::new().prefix("openidea-mcp-").suffix(".json").tempfile()?;
+    std::io::Write::write_all(&mut file, json.as_bytes())?;
+    Ok(file.into_temp_path())
+}
+
+/// ACP `mcpServers` as Claude Code's `--mcp-config` JSON (`None` when there are none).
+fn mcp_config(params: &Value) -> Option<String> {
+    let servers = params.get("mcpServers")?.as_array()?;
+    let pairs = |v: Option<&Value>| -> serde_json::Map<String, Value> {
+        v.and_then(Value::as_array)
+            .into_iter()
+            .flatten()
+            .filter_map(|p| Some((p.get("name")?.as_str()?.to_owned(), p.get("value")?.clone())))
+            .collect()
+    };
+    let mut out = serde_json::Map::new();
+    for server in servers {
+        let Some(name) = server.get("name").and_then(Value::as_str) else { continue };
+        let entry = match server.get("type").and_then(Value::as_str) {
+            Some(kind @ ("http" | "sse")) => {
+                json!({ "type": kind, "url": server.get("url"), "headers": pairs(server.get("headers")) })
+            }
+            _ => json!({
+                "command": server.get("command"),
+                "args": server.get("args").cloned().unwrap_or_else(|| json!([])),
+                "env": pairs(server.get("env")),
+            }),
+        };
+        out.insert(name.to_owned(), entry);
+    }
+    (!out.is_empty()).then(|| json!({ "mcpServers": out }).to_string())
+}
@@ -1170,3 +1170,29 @@ async fn skipped_questions_have_no_answers() {
    let cancelled = ask_questions(&input, &json!({}), |_, _| async { None }).await;
    assert_eq!(cancelled, None);
 }
+
+#[test]
+fn mcp_servers_become_an_mcp_config() {
+    assert_eq!(mcp_config(&json!({ "mcpServers": [] })), None);
+    assert_eq!(mcp_config(&json!({})), None);
+    let config = mcp_config(&json!({ "mcpServers": [
+        { "type": "http", "name": "openidea", "url": "http://127.0.0.1:1/mcp",
+          "headers": [{ "name": "Authorization", "value": "Bearer t" }] },
+        { "name": "local", "command": "srv", "args": ["-x"], "env": [{ "name": "K", "value": "V" }] },
+    ] }))
+    .unwrap();
+    let v: Value = serde_json::from_str(&config).unwrap();
+    assert_eq!(
+        v["mcpServers"]["openidea"],
+        json!({ "type": "http", "url": "http://127.0.0.1:1/mcp", "headers": { "Authorization": "Bearer t" } })
+    );
+    assert_eq!(v["mcpServers"]["local"], json!({ "command": "srv", "args": ["-x"], "env": { "K": "V" } }));
+
+    let path = write_mcp_config(&config).unwrap();
+    assert_eq!(std::fs::read_to_string(&path).unwrap(), config);
+    #[cfg(unix)]
+    assert_eq!(std::os::unix::fs::PermissionsExt::mode(&std::fs::metadata(&path).unwrap().permissions()) & 0o077, 0);
+    let kept = path.to_path_buf();
+    drop(path);
+    assert!(!kept.exists());
+}
@@ -8,6 +8,7 @@ mod translate;
 mod tests;

 use super::Shim;
+use crate::acp::AUTH_REQUIRED;
 use crate::provider::ProviderSpec;
 use ide_jsonrpc::{Framing, Handler, Peer, RpcError, codes};
 use parking_lot::Mutex;
@@ -27,8 +28,6 @@ const OUTPUT_EVERY: Duration = Duration::from_millis(200);
 const EARLY_CANCEL: Duration = Duration::from_secs(1);
 /// How long the client's connection outlives codex.
 const EXIT_GRACE: Duration = Duration::from_millis(100);
-/// ACP's error code for a request that needs the user to sign in.
-const AUTH_REQUIRED: i64 = -32000;

 pub(crate) fn connect(
    spec: &ProviderSpec,
@@ -204,7 +203,7 @@ fn from_codex(e: RpcError) -> ResponseError {
                code,
                codes::PARSE_ERROR | codes::INVALID_REQUEST | codes::METHOD_NOT_FOUND | codes::INVALID_PARAMS
            );
-            let code = if !protocol && message.to_lowercase().contains("auth") { AUTH_REQUIRED } else { code };
+            let code = if !protocol && crate::acp::auth_required(code, &message) { AUTH_REQUIRED } else { code };
            ResponseError { code, message, data }
        }
        RpcError::Closed => error(codes::INTERNAL_ERROR, "Codex exited"),
@@ -264,7 +263,7 @@ impl CodexShim {
            "agentCapabilities": {
                "loadSession": true,
                "promptCapabilities": { "image": true, "audio": false, "embeddedContext": true },
-                "mcpCapabilities": { "http": false, "sse": false },
+                "mcpCapabilities": { "http": false, "sse": false, "stdio": true },
                "sessionCapabilities": { "fork": {}, "close": {} },
                "_meta": { "openidea": { "rollback": true, "steer": true } },
            },
@@ -318,7 +317,11 @@ impl CodexShim {

    async fn new_session(&self, params: &Value) -> Result<Value, ResponseError> {
        let models = self.models().await;
-        let result = self.call("thread/start", json!({ "cwd": params.get("cwd") })).await?;
+        let mut request = json!({ "cwd": params.get("cwd") });
+        if let Some(config) = translate::mcp_config(params) {
+            request["config"] = config;
+        }
+        let result = self.call("thread/start", request).await?;
        let (id, options) = self.open_thread(&result, &models, None);
        if id.is_empty() {
            return Err(error(codes::INTERNAL_ERROR, "codex started no thread"));
@@ -330,7 +333,11 @@ impl CodexShim {
    async fn load_session(&self, params: &Value) -> Result<Value, ResponseError> {
        let id = str_param(params, "sessionId")?;
        let models = self.models().await;
-        let result = self.call("thread/resume", json!({ "threadId": id, "cwd": params.get("cwd") })).await?;
+        let mut request = json!({ "threadId": id, "cwd": params.get("cwd") });
+        if let Some(config) = translate::mcp_config(params) {
+            request["config"] = config;
+        }
+        let result = self.call("thread/resume", request).await?;
        let (_, options) = self.open_thread(&result, &models, None);
        let cwd = self.state.lock().threads.get(id).and_then(|t| t.cwd.clone());
        let thread = result.get("thread").unwrap_or(&Value::Null);
@@ -345,6 +352,9 @@ impl CodexShim {
        let models = self.models().await;
        let settings = self.state.lock().threads.get(source).and_then(|t| t.settings.clone());
        let mut request = json!({ "threadId": source, "cwd": params.get("cwd") });
+        if let Some(config) = translate::mcp_config(params) {
+            request["config"] = config;
+        }
        if let Some(s) = &settings {
            request["model"] = json!(s.model_slug(&models));
            request["approvalPolicy"] = json!(s.mode.approval_policy());
@@ -822,7 +832,7 @@ impl CodexShim {
        match method {
            "item/commandExecution/requestApproval" => {
                let choices = translate::decisions(params, true);
-                let title = translate::command_approval_title(params, item.as_ref(), cwd);
+                let title = translate::command_approval_title(params, item.as_ref());
                let call = tool_call_of(
                    &item_id,
                    &title,
@@ -871,31 +881,55 @@ impl CodexShim {
                Ok(self.ask(&thread, call, &choices, json!({ "permissions": {}, "scope": "turn" })))
            }
            "item/tool/requestUserInput" => {
-                let mut answers = serde_json::Map::new();
-                for q in params.get("questions").and_then(Value::as_array).into_iter().flatten() {
-                    let Some(qid) = q.get("id").and_then(Value::as_str) else { continue };
-                    let choices: Vec<Choice> = q
-                        .get("options")
-                        .and_then(Value::as_array)
-                        .into_iter()
-                        .flatten()
-                        .enumerate()
-                        .filter_map(|(i, o)| {
-                            let label = o.get("label")?.as_str()?;
-                            Some(Choice {
-                                option: json!({ "optionId": i.to_string(), "name": label, "kind": "allow_once" }),
-                                answer: json!({ "answers": [label] }),
+                let questions = params.get("questions").and_then(Value::as_array).cloned().unwrap_or_default();
+                // One permission request carrying all the questions, so the client shows
+                // them as a card (as it does for Claude's `AskUserQuestion`).
+                let asked: Vec<Value> = questions
+                    .iter()
+                    .filter_map(|q| {
+                        let id = q.get("id").and_then(Value::as_str)?;
+                        let question = q.get("question").and_then(Value::as_str)?;
+                        let options: Vec<Value> = q
+                            .get("options")
+                            .and_then(Value::as_array)
+                            .into_iter()
+                            .flatten()
+                            .filter_map(|o| {
+                                let label = o.get("label").and_then(Value::as_str)?;
+                                Some(json!({
+                                    "label": label,
+                                    "description": o.get("description").and_then(Value::as_str).unwrap_or_default(),
+                                }))
                            })
-                        })
-                        .collect();
-                    if choices.is_empty() {
-                        continue;
-                    }
-                    let title = q.get("question").and_then(Value::as_str).unwrap_or("Codex has a question");
-                    let call = tool_call_of(&item_id, title, "other", None, None);
-                    let answer = self.ask(&thread, call, &choices, Value::Null);
-                    if !answer.is_null() {
-                        answers.insert(qid.to_owned(), answer);
+                            .collect();
+                        Some(json!({
+                            "answerKey": id,
+                            "header": q.get("header").and_then(Value::as_str).unwrap_or_default(),
+                            "question": question,
+                            "multiSelect": q.get("multiSelect").and_then(Value::as_bool).unwrap_or(false),
+                            "options": options,
+                        }))
+                    })
+                    .collect();
+                if asked.is_empty() {
+                    return Ok(json!({ "answers": {} }));
+                }
+                let title = asked[0].get("question").and_then(Value::as_str).unwrap_or("Codex has a question");
+                let mut call = tool_call_of(&item_id, title, "other", None, None);
+                call["_meta"] = json!({ "questions": asked });
+                let options = [json!({ "optionId": "submit", "name": "Submit", "kind": "allow_once" })];
+                let picked: serde_json::Map<String, Value> = self
+                    .ask_option(&thread, call, &options)
+                    .and_then(|reply| serde_json::from_str(&reply).ok())
+                    .unwrap_or_default();
+                let mut answers = serde_json::Map::new();
+                for q in &questions {
+                    let Some(qid) = q.get("id").and_then(Value::as_str) else { continue };
+                    if let Some(labels) = picked
+                        .get(qid)
+                        .filter(|labels| labels.as_array().is_some_and(|labels| labels.iter().all(Value::is_string)))
+                    {
+                        answers.insert(qid.to_owned(), json!({ "answers": labels }));
                    }
                }
                Ok(json!({ "answers": answers }))
@@ -928,6 +962,25 @@ impl CodexShim {
        }
    }

+    /// Asks the client; returns the selected option id (`None` when cancelled).
+    fn ask_option(&self, session: &str, tool_call: Value, options: &[Value]) -> Option<String> {
+        let client = self.client.get().cloned()?;
+        let params = json!({ "sessionId": session, "toolCall": tool_call, "options": options });
+        let outcome: Result<Value, RpcError> =
+            self.runtime.block_on(client.request("session/request_permission", params, None));
+        match outcome {
+            Ok(outcome) => outcome
+                .pointer("/outcome/outcome")
+                .and_then(Value::as_str)
+                .filter(|outcome| *outcome == "selected")
+                .and_then(|_| outcome.pointer("/outcome/optionId").and_then(Value::as_str).map(str::to_owned)),
+            Err(e) => {
+                tracing::debug!("codex: question request failed: {e}");
+                None
+            }
+        }
+    }
+
    /// Asks the client; returns the answer for codex (`otherwise` when cancelled).
    fn ask(&self, session: &str, tool_call: Value, choices: &[Choice], otherwise: Value) -> Value {
        let Some(client) = self.client.get().cloned() else { return otherwise };
@@ -247,13 +247,39 @@ fn approvals_offer_what_codex_offers_and_always_a_decline() {
    assert_eq!(
        command_approval_title(
            &json!({"command": "/bin/zsh -lc 'ls'", "commandActions": [{"type": "unknown", "command": "touch b"}]}),
-            None,
            None
        ),
-        "Run touch b"
+        "Run ls"
    );
 }

+#[test]
+fn approval_title_shows_the_script_inside_a_shell_wrapper() {
+    let title = |command: &str| command_approval_title(&json!({ "command": command }), None);
+    assert_eq!(
+        title(r#"/bin/zsh -lc "python3 -c 'import pathlib\np = pathlib.Path(\"a.txt\")'""#),
+        "Run python3 -c 'import pathlib\\np = pathlib.Path(\"a.txt\")'"
+    );
+    assert_eq!(title(r#"bash -lc 'echo '\''hi'\'''"#), "Run echo 'hi'");
+    assert_eq!(title("/bin/zsh -lc ls"), "Run /bin/zsh -lc ls");
+    assert_eq!(title("/bin/zsh -lc 'ls' && rm x"), "Run /bin/zsh -lc 'ls' && rm x");
+    assert_eq!(title("python3 -c 'print(1)'"), "Run python3 -c 'print(1)'");
+}
+
+#[test]
+fn approval_command_uses_its_request_and_matching_item_only() {
+    let command = "python3 -c 'import pathlib\np = pathlib.Path(\"note.txt\")\np.write_text(\"hi\\n\")'";
+    let pending_read = json!({"id": "read", "type": "commandExecution", "command": "ls",
+        "commandActions": [{"type": "listFiles", "path": "."}]});
+    let request = json!({"itemId": "write", "command": command});
+    assert_eq!(command_approval_title(&request, Some(&pending_read)), format!("Run {command}"));
+    let item = json!({"id": "write", "command": command});
+    let request = json!({"itemId": "write"});
+    assert_eq!(command_approval_title(&request, Some(&item)), format!("Run {command}"));
+    assert_eq!(command_approval_title(&request, Some(&pending_read)), "Run a command");
+    assert_eq!(command_approval_title(&request, None), "Run a command");
+}
+
 #[test]
 fn history_replays_turns() {
    let thread = json!({"turns": [{"id": "t", "status": "completed", "items": [
@@ -316,6 +342,39 @@ impl Client {
    }
 }

+#[tokio::test(flavor = "multi_thread")]
+async fn questions_share_one_card_and_keep_their_ids() {
+    let client = Arc::new(Client::default());
+    client.answers.lock().extend([Some(r#"{"first":["One"],"second":["Two","Custom"]}"#), None, Some("invalid")]);
+    let (ours, theirs) = tokio::io::duplex(1 << 16);
+    let (read, write) = tokio::io::split(theirs);
+    let codex = Peer::connect_framed(read, write, Arc::new(ide_jsonrpc::NoopHandler), Framing::Lines);
+    let acp = attach(client.clone(), |events| {
+        let (read, write) = tokio::io::split(ours);
+        Ok(Peer::connect_framed(read, write, events, Framing::Lines))
+    })
+    .unwrap();
+    let params = json!({"threadId": "s", "itemId": "q", "questions": [
+        {"id": "first", "question": "Which?", "options": [{"label": "One", "description": "First"}]},
+        {"id": "second", "question": "Which?", "multiSelect": true, "options": [{"label": "Two"}]}
+    ]});
+    for expected in
+        [json!({"first": {"answers": ["One"]}, "second": {"answers": ["Two", "Custom"]}}), json!({}), json!({})]
+    {
+        let reply: Value = codex.request("item/tool/requestUserInput", params.clone(), None).await.unwrap();
+        assert_eq!(reply, json!({"answers": expected}));
+    }
+    let asked = client.asked.lock();
+    assert_eq!(asked.len(), 3);
+    let questions = &asked[0]["toolCall"]["_meta"]["questions"];
+    assert_eq!(questions.as_array().unwrap().len(), 2);
+    assert_eq!(questions[0]["answerKey"], "first");
+    assert_eq!(questions[1]["answerKey"], "second");
+    assert_eq!(questions[0]["options"][0]["description"], "First");
+    acp.kill();
+    codex.kill();
+}
+
 #[derive(Clone, Copy, Debug, PartialEq)]
 enum Scenario {
    AuthFailure,
@@ -564,6 +623,23 @@ async fn auth_failure_names_auth() {
    assert!(start.get("jsonrpc").is_some(), "codex accepts the jsonrpc field");
 }

+#[test]
+fn request_errors_classify_authentication_without_matching_author_or_protocol_errors() {
+    for (code, message, expected) in [
+        (codes::INTERNAL_ERROR, "Missing author field", codes::INTERNAL_ERROR),
+        (codes::INTERNAL_ERROR, "Unknown authority", codes::INTERNAL_ERROR),
+        (codes::INTERNAL_ERROR, "Authentication failed: expired token", AUTH_REQUIRED),
+        (codes::INTERNAL_ERROR, "Unauthorized", AUTH_REQUIRED),
+        (codes::METHOD_NOT_FOUND, "authentication method not found", codes::METHOD_NOT_FOUND),
+        (AUTH_REQUIRED, "Account is not eligible", AUTH_REQUIRED),
+    ] {
+        let response = from_codex(RpcError::Server { code, message: message.into(), data: Some(json!({"detail": 1})) });
+        assert_eq!(response.code, expected, "{message}");
+        assert_eq!(response.message, message);
+        assert_eq!(response.data, Some(json!({"detail": 1})));
+    }
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn a_stop_sent_right_after_the_prompt_interrupts_the_turn() {
    let (results, _client, frames, _) = replay(Scenario::Interrupt).await;
@@ -968,3 +1044,15 @@ fn v_method(line: &str) -> Option<&str> {
    let at = line.find("\"method\":\"")? + 10;
    line[at..].split('"').next()
 }
+
+#[test]
+fn session_mcp_servers_become_thread_configuration() {
+    assert!(mcp_config(&json!({"mcpServers":[]})).is_none());
+    assert_eq!(
+        mcp_config(&json!({"mcpServers":[{"name":"OpenIDEA","command":"/app/openidea",
+        "args":["--mcp-stdio","--project","/project"],"env":[{"name":"K","value":"V"}]}]})),
+        Some(
+            json!({"mcp_servers":{"OpenIDEA":{"command":"/app/openidea","args":["--mcp-stdio","--project","/project"],"env":{"K":"V"}}}})
+        )
+    );
+}
@@ -733,18 +733,19 @@ pub(super) fn answer_of(choices: &[Choice], outcome: &Value, decline: Value) ->
 }

 /// The ACP title of a command approval.
-pub(super) fn command_approval_title(params: &Value, item: Option<&Value>, cwd: Option<&str>) -> String {
+pub(super) fn command_approval_title(params: &Value, item: Option<&Value>) -> String {
    if let Some(host) = params.pointer("/networkApprovalContext/host").and_then(Value::as_str) {
        return format!("Allow network access to {host}");
    }
-    let from_item = item.and_then(|i| tool_call(i, false, cwd, None)).and_then(|c| str_of(&c, "title"));
-    let title = from_item.or_else(|| {
-        let synthetic = json!({ "id": "", "type": "commandExecution", "command": params.get("command"),
-            "commandActions": params.get("commandActions").cloned().unwrap_or(json!([])) });
-        tool_call(&synthetic, false, cwd, None).and_then(|c| str_of(&c, "title"))
-    });
-    match title.filter(|t| !t.is_empty()) {
-        Some(t) => format!("Run {t}"),
+    // Approval payloads can describe a different command from the item's earlier summary.
+    let item = item.filter(|i| i.get("id") == params.get("itemId"));
+    let command = params
+        .get("command")
+        .and_then(Value::as_str)
+        .filter(|c| !c.is_empty())
+        .or_else(|| item.and_then(|i| i.get("command")).and_then(Value::as_str).filter(|c| !c.is_empty()));
+    match command {
+        Some(command) => format!("Run {}", crate::shell_script(command).unwrap_or_else(|| command.to_owned())),
        None => "Run a command".to_owned(),
    }
 }
@@ -835,3 +836,31 @@ pub(super) fn tail(text: &str) -> String {
 fn str_of(v: &Value, key: &str) -> Option<String> {
    v.get(key).and_then(Value::as_str).map(str::to_owned)
 }
+
+/// Session-scoped MCP configuration, carried in thread/start, resume and fork.
+pub(super) fn mcp_config(params: &Value) -> Option<Value> {
+    let mut servers = serde_json::Map::new();
+    for server in params.get("mcpServers")?.as_array()? {
+        if server.get("type").and_then(Value::as_str).is_some_and(|t| t != "stdio") {
+            continue;
+        }
+        let (Some(name), Some(command)) =
+            (server.get("name").and_then(Value::as_str), server.get("command").and_then(Value::as_str))
+        else {
+            continue;
+        };
+        let env: serde_json::Map<String, Value> = server
+            .get("env")
+            .and_then(Value::as_array)
+            .into_iter()
+            .flatten()
+            .filter_map(|v| Some((v.get("name")?.as_str()?.to_owned(), v.get("value")?.clone())))
+            .collect();
+        servers.insert(
+            name.into(),
+            json!({"command":command,
+            "args":server.get("args").cloned().unwrap_or_else(||json!([])),"env":env}),
+        );
+    }
+    (!servers.is_empty()).then(|| json!({"mcp_servers":servers}))
+}
@@ -5,6 +5,7 @@
 use crate::{AgentCommandReadOnlyReason, AgentProvider, AgentSource};
 use ide_core::{IdeError, IdeResult};
 use serde::{Deserialize, Serialize};
+use serde_json::Value;
 use std::collections::BTreeMap;
 use std::path::{Path, PathBuf};

@@ -81,6 +82,91 @@ fn builtins() -> Vec<ProviderSpec> {
        .collect()
 }

+impl ProviderSpec {
+    pub(crate) fn login_hint(&self, program: &Path) -> String {
+        if !program.is_absolute() {
+            return self.login_hint.clone();
+        }
+        let search = ide_core::process::host_var_os("PATH").unwrap_or_default();
+        let builtin = builtin_spec(&self.id);
+        let on_path = builtin.as_ref().and_then(|b| ide_core::process::find_executable(&b.command, &search));
+        render_login_hint(self, program, on_path.as_deref(), cfg!(windows))
+    }
+
+    pub(crate) fn sign_in_message(&self, auth_methods: &[Value]) -> String {
+        let name = &self.name;
+        let program = Path::new(&self.command);
+        let terminal_args = matches!(self.source, AgentSource::Registry { .. })
+            .then(|| {
+                auth_methods.iter().find_map(|method| {
+                    if method.get("type").and_then(Value::as_str) != Some("terminal") {
+                        return None;
+                    }
+                    method.get("args")?.as_array()?.iter().map(Value::as_str).collect::<Option<Vec<_>>>()
+                })
+            })
+            .flatten();
+        let hint = match terminal_args {
+            Some(args) => {
+                let command = render_login_command(program, args, cfg!(windows));
+                format!("Run `{command}` in a terminal.")
+            }
+            None => self.login_hint(program),
+        };
+        format!("{name} needs you to sign in. {hint}")
+    }
+
+    /// Resolve once before connecting, so authentication guidance names that same install.
+    pub(crate) fn resolve_for_launch(mut self, cwd: &Path) -> Self {
+        if self.driver != Driver::Acp {
+            self.command = crate::native::newest_install(&self.command);
+        }
+        let program = ide_jsonrpc::resolve_spawn_program(&self.command, &self.env);
+        self.command =
+            if program.components().count() > 1 && !program.is_absolute() { cwd.join(program) } else { program }
+                .to_string_lossy()
+                .into_owned();
+        self
+    }
+}
+
+fn render_login_hint(spec: &ProviderSpec, program: &Path, on_path: Option<&Path>, windows: bool) -> String {
+    let Some(builtin) = builtin_spec(&spec.id) else { return spec.login_hint.clone() };
+    let prefix = format!("Run `{}", builtin.command);
+    let Some(rest) = spec.login_hint.strip_prefix(&prefix).filter(|rest| rest.starts_with([' ', '`'])) else {
+        return spec.login_hint.clone();
+    };
+    let same_path = |a: &Path, b: &Path| {
+        a == b || dunce::canonicalize(a).ok().zip(dunce::canonicalize(b).ok()).is_some_and(|(a, b)| a == b)
+    };
+    if on_path.is_some_and(|path| same_path(path, program)) {
+        return spec.login_hint.clone();
+    }
+    let (args, suffix) = rest.split_once('`').expect("built-in login hints delimit their command");
+    let command = render_login_command(program, args.split_whitespace(), windows);
+    match suffix {
+        " in a terminal." => format!("Run `{command}` in a terminal."),
+        " in a terminal and sign in." => format!("Run `{command}` in a terminal and sign in."),
+        _ => spec.login_hint.clone(),
+    }
+}
+
+fn render_login_command<'a>(program: &Path, args: impl IntoIterator<Item = &'a str>, windows: bool) -> String {
+    let quote = |word: &str| {
+        if windows { format!("'{}'", word.replace('\'', "''")) } else { format!("'{}'", word.replace('\'', "'\\''")) }
+    };
+    let mut command = format!("{}{}", if windows { "& " } else { "" }, quote(&program.to_string_lossy()));
+    for arg in args {
+        command.push(' ');
+        if !arg.is_empty() && arg.chars().all(|c| c.is_ascii_alphanumeric() || "-_=./".contains(c)) {
+            command.push_str(arg);
+        } else {
+            command.push_str(&quote(arg));
+        }
+    }
+    command
+}
+
 /// Whether `id` names a built-in agent that needs no registry install (native drivers
 /// and `npx -y` adapters). CLI built-ins (`copilot`, `gemini`, …) can be installed and
 /// updated from the ACP Registry into `<config>/agents/<id>.toml`.
@@ -119,13 +205,14 @@ pub(crate) fn describe(spec: &ProviderSpec) -> AgentProvider {
        args: spec.args.clone(),
        default_program: builtin.as_ref().map(|b| b.command.clone()),
        default_args: builtin.as_ref().map(|b| b.args.clone()).unwrap_or_default(),
-        login_hint: Some(spec.login_hint.clone()),
+        login_hint: Some(spec.login_hint(&ide_jsonrpc::resolve_spawn_program(&spec.command, &spec.env))),
        command_overridden: builtin.as_ref().is_some_and(|b| b.command != spec.command),
        command_editable: reason.is_none(),
        command_read_only_reason: reason,
        installed: installed(&spec.command),
        env: spec.env.iter().cloned().collect(),
        config: vec![],
+        thought_levels: BTreeMap::new(),
        commands: vec![],
        source: spec.source.clone(),
    }
@@ -311,6 +398,113 @@ fn is_executable(p: &Path) -> bool {
 #[cfg(test)]
 mod tests {
    use super::*;
+    use serde_json::json;
+
+    #[test]
+    fn login_hints_cover_all_builtin_commands_and_preserve_separate_login_tools() {
+        for spec in builtins() {
+            let separate = matches!(spec.id.as_str(), "claude-acp" | "codex-acp" | "vibe");
+            for windows in [false, true] {
+                let program =
+                    if windows { Path::new(r"C:\Agent Tools\renamed.cmd") } else { Path::new("/agent tools/renamed") };
+                let hint = render_login_hint(&spec, program, None, windows);
+                if separate {
+                    assert_eq!(hint, spec.login_hint, "{}", spec.id);
+                } else {
+                    let prefix =
+                        if windows { "Run `& 'C:\\Agent Tools\\renamed.cmd'" } else { "Run `'/agent tools/renamed'" };
+                    assert!(hint.starts_with(prefix), "{}: {hint}", spec.id);
+                    assert_eq!(
+                        render_login_hint(&spec, program, Some(program), windows),
+                        spec.login_hint,
+                        "a PATH-resolved command stays bare: {}",
+                        spec.id
+                    );
+                    assert_eq!(render_login_hint(&spec, program, Some(Path::new("/other/install")), windows), hint);
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn login_commands_quote_shell_metacharacters_and_keep_arguments() {
+        let cursor = builtin_spec("cursor").unwrap();
+        assert_eq!(
+            render_login_hint(&cursor, Path::new("/agent's tools/$cli"), None, false),
+            "Run `'/agent'\\''s tools/$cli' login` in a terminal."
+        );
+        assert_eq!(
+            render_login_hint(&cursor, Path::new(r"C:\agent's tools\$cli.cmd"), None, true),
+            r"Run `& 'C:\agent''s tools\$cli.cmd' login` in a terminal."
+        );
+        let opencode = builtin_spec("opencode").unwrap();
+        assert_eq!(
+            render_login_hint(&opencode, Path::new("/registry/opencode"), None, false),
+            "Run `'/registry/opencode' auth login` in a terminal."
+        );
+        let mut custom = cursor;
+        custom.id = "custom".into();
+        custom.login_hint = "Sign in with the agent's own command line first.".into();
+        assert_eq!(render_login_hint(&custom, Path::new("/custom"), None, false), custom.login_hint);
+    }
+
+    #[test]
+    fn launch_resolution_uses_the_child_path_and_absolutizes_relative_overrides() {
+        let dir = tempfile::tempdir().unwrap();
+        let mut cursor = builtin_spec("cursor").unwrap();
+        let command = if cfg!(windows) { "cursor-agent.cmd" } else { "cursor-agent" };
+        let program = dir.path().join(command);
+        std::fs::write(&program, "").unwrap();
+        cursor.env.push(("PATH".into(), dir.path().to_string_lossy().into_owned()));
+        let resolved = cursor.clone().resolve_for_launch(dir.path());
+        assert_eq!(Path::new(&resolved.command), program);
+        assert!(resolved.sign_in_message(&[]).contains(&*program.to_string_lossy()));
+        cursor.command = format!("tools/{command}");
+        let resolved = cursor.resolve_for_launch(dir.path());
+        assert_eq!(Path::new(&resolved.command), dir.path().join("tools").join(command));
+    }
+
+    #[test]
+    fn terminal_login_commands_quote_the_binary_and_each_argument() {
+        for (windows, expected) in [
+            (false, "'/agent'\\''s tools/$cli' auth login --account 'user name' 'a'\\''b' '$token' ''"),
+            (true, "& '/agent''s tools/$cli' auth login --account 'user name' 'a''b' '$token' ''"),
+        ] {
+            assert_eq!(
+                render_login_command(
+                    Path::new("/agent's tools/$cli"),
+                    ["auth", "login", "--account", "user name", "a'b", "$token", ""],
+                    windows
+                ),
+                expected
+            );
+        }
+        let mut spec = builtin_spec("cursor").unwrap();
+        spec.id = "custom".into();
+        spec.source = AgentSource::Registry { version: "1.4.5".into(), update: None };
+        spec.login_hint = "Sign in with the agent's own command line first.".into();
+        for method in [
+            json!({"type": "terminal"}),
+            json!({"type": "terminal", "args": ["login", null]}),
+            json!({"type": "agent", "args": ["login"]}),
+        ] {
+            assert_eq!(
+                spec.sign_in_message(&[method]),
+                "Cursor needs you to sign in. Sign in with the agent's own command line first."
+            );
+        }
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn registry_login_hint_names_the_installed_executable() {
+        let mut spec = builtin_spec("cursor").unwrap();
+        spec.command = "/registry path/dist-package/cursor-agent".into();
+        assert_eq!(
+            describe(&spec).login_hint.as_deref(),
+            Some("Run `'/registry path/dist-package/cursor-agent' login` in a terminal.")
+        );
+    }

    #[test]
    fn launch_metadata_distinguishes_defaults_overrides_and_read_only_agents() {
@@ -290,7 +290,8 @@ impl Timeline {
    /// and records when the turn ended (`done`) on the message that started it.
    pub fn end_turn(&mut self, done: Option<f64>) -> Vec<usize> {
        let mut changed = Vec::new();
-        let started = self.entries.iter().rposition(|e| matches!(e, AgentEntry::User { .. }));
+        // A steered message rides along in a running turn; the one that started it owns its end.
+        let started = self.entries.iter().rposition(|e| matches!(e, AgentEntry::User { steered: false, .. }));
        for (i, e) in self.entries.iter_mut().enumerate() {
            match e {
                AgentEntry::User { done_ms, .. } if Some(i) == started && done.is_some() && done_ms.is_none() => {
@@ -468,6 +469,27 @@ mod tests {
        assert_eq!(t.end_turn(Some(9.0)), Vec::<usize>::new());
    }

+    #[test]
+    fn end_turn_records_on_the_message_that_started_the_turn() {
+        let user = |sent: f64, steered: bool| AgentEntry::User {
+            text: "q".into(),
+            attachments: vec![],
+            images: vec![],
+            sent_ms: Some(sent),
+            done_ms: None,
+            steered,
+        };
+        let mut t = Timeline::default();
+        t.push(user(1.0, false));
+        t.push(AgentEntry::Agent { text: "a".into() });
+        t.push(user(2.0, true));
+        // The steered message rides along in the turn: the reply's time belongs to the
+        // message that started it.
+        assert_eq!(t.end_turn(Some(5.0)), vec![0]);
+        assert!(matches!(t.entries[0], AgentEntry::User { done_ms: Some(5.0), .. }));
+        assert!(matches!(t.entries[2], AgentEntry::User { done_ms: None, .. }));
+    }
+
    #[test]
    fn long_output_keeps_its_tail() {
        let s = tail("é".repeat(MAX_OUTPUT));
@@ -67,6 +67,11 @@ impl BuildStep {
        }
    }

+    /// A CMake configure/build invocation, parsed as compiler output in the Build view.
+    pub fn cmake(program: &str, args: Vec<String>, cwd: PathBuf, env: BTreeMap<String, String>) -> Self {
+        Self { program: program.into(), args, cwd, env, format: Format::Gcc }
+    }
+
    /// The command line as echoed in the console.
    pub fn display(&self) -> String {
        let program = Path::new(&self.program).file_name().map_or(self.program.clone(), |n| n.to_string_lossy().into());
@@ -153,7 +158,7 @@ fn detect_dir(dir: &Path, model: &BuildModel, root: &Path) -> Option<BuildSystem
        Some(BuildSystem::Gradle)
    } else if has(dir, &["Cargo.toml"]) {
        Some(BuildSystem::Cargo)
-    } else if has(dir, &["go.mod"]) {
+    } else if has(dir, &["go.mod", "go.work"]) {
        Some(BuildSystem::Go)
    } else if has(dir, &["tsconfig.json", "package.json"]) {
        Some(BuildSystem::TypeScript)
@@ -227,7 +232,7 @@ pub fn plan(
        BuildSystem::Gradle => gradle_steps(root, model, kind, module_dir.as_deref())?,
        BuildSystem::Cargo => cargo_steps(&dir, kind),
        // Go builds the file's package (a module holds many).
-        BuildSystem::Go => go_steps(file.and_then(Path::parent).unwrap_or(&dir), kind),
+        BuildSystem::Go => go_steps(file.and_then(Path::parent).unwrap_or(&dir), kind)?,
        BuildSystem::TypeScript => ts_steps(&dir, kind),
        BuildSystem::CMake => cmake_steps(&dir, kind, cmake.and_then(<[_]>::first)),
    };
@@ -374,7 +379,33 @@ fn cmake_steps(dir: &Path, kind: BuildKind, profile: Option<&CMakeProfile>) -> V
    steps
 }

-fn go_steps(dir: &Path, kind: BuildKind) -> Vec<BuildStep> {
+fn go_steps(dir: &Path, kind: BuildKind) -> IdeResult<Vec<BuildStep>> {
+    if dir.join("go.work").is_file() {
+        let work_file = dunce::canonicalize(dir.join("go.work"))?;
+        let modules = ide_core::go::work_modules(&std::fs::read_to_string(dir.join("go.work"))?);
+        if modules.is_empty() {
+            return Err(IdeError::invalid("The Go workspace contains no modules"));
+        }
+        let mut steps = Vec::new();
+        for module in modules {
+            let module = dir.join(module);
+            if !module.join("go.mod").is_file() {
+                return Err(IdeError::not_found(format!("Go workspace module has no go.mod: {}", module.display())));
+            }
+            // Go compares workspace membership against cwd paths lexically.
+            let module = dunce::canonicalize(module)?;
+            let mut module_steps = go_module_steps(&module, kind);
+            for step in &mut module_steps {
+                step.env.insert("GOWORK".into(), work_file.to_string_lossy().into_owned());
+            }
+            steps.extend(module_steps);
+        }
+        return Ok(steps);
+    }
+    Ok(go_module_steps(dir, kind))
+}
+
+fn go_module_steps(dir: &Path, kind: BuildKind) -> Vec<BuildStep> {
    let module_root = dir.ancestors().find(|d| d.join("go.mod").is_file()).unwrap_or(dir);
    let target = if module_root == dir { "./...".to_owned() } else { format!("./{}/...", rel_str(module_root, dir)) };
    let mut args = vec!["build"];
@@ -813,6 +844,79 @@ fn launch_class_dirs(system: BuildSystem, module: &Path, test: bool) -> Vec<Path

 #[cfg(test)]
 mod tests {
+    #[test]
+    fn go_workspace_build_commands_compile_members_with_local_dependencies() {
+        let Some(go) = ide_core::process::find_executable("go", &ide_core::tool_path::search_path()) else {
+            return;
+        };
+        let tmp = tempfile::tempdir().unwrap();
+        let root = &tmp.path().join("workspace");
+        write(root, "go.work", "go 1.22\nuse (\n ./app\n ./lib\n ../external\n)\n");
+        write(root, "lib/go.mod", "module example.com/lib\ngo 1.22\n");
+        write(root, "lib/lib.go", "package lib\nfunc Value() int { return 1 }\n");
+        write(root, "app/go.mod", "module example.com/app\ngo 1.22\nrequire example.com/lib v0.0.0\n");
+        write(root, "app/main.go", "package main\nimport \"example.com/lib\"\nfunc main(){_ = lib.Value()}\n");
+        write(root, "../external/go.mod", "module example.com/external\ngo 1.22\nrequire example.com/lib v0.0.0\n");
+        write(root, "../external/main.go", "package main\nimport \"example.com/lib\"\nfunc main(){_ = lib.Value()}\n");
+        // std canonicalization also exercises verbatim paths on Windows.
+        for root in [root.to_path_buf(), std::fs::canonicalize(root).unwrap()] {
+            let plan = plan(&root, &BuildModel::default(), BuildKind::Build, None, None).unwrap();
+            for step in plan.steps {
+                let result = std::process::Command::new(&go)
+                    .args(&step.args)
+                    .envs(&step.env)
+                    .env("GOPROXY", "off")
+                    .current_dir(&step.cwd)
+                    .output()
+                    .unwrap();
+                assert!(result.status.success(), "{step:?}: {}", String::from_utf8_lossy(&result.stderr));
+            }
+        }
+    }
+
+    #[test]
+    fn go_workspace_builds_every_use_module() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path().join("workspace");
+        write(&root, "go.work", "go 1.22\nuse (\n  ./api\n  \"./lib with spaces\"\n  ../shared\n)\n");
+        for module in ["api", "lib with spaces", "../shared"] {
+            write(&root.join(module), "go.mod", "module example.com/p\ngo 1.22\n");
+        }
+        // Cover native paths, Windows verbatim paths and non-normalized module paths.
+        let canonical = std::fs::canonicalize(&root).unwrap();
+        for root in [&root, &canonical, &canonical.join("..").join("workspace")] {
+            for kind in [BuildKind::Build, BuildKind::Rebuild, BuildKind::Artifacts] {
+                let p = plan(root, &BuildModel::default(), kind, None, None).unwrap();
+                assert_eq!(p.system, BuildSystem::Go);
+                assert_eq!(p.steps.len(), 3);
+                for (step, module) in p.steps.iter().zip(["api", "lib with spaces", "../shared"]) {
+                    assert_eq!(step.cwd, dunce::canonicalize(root.join(module)).unwrap());
+                    assert_eq!(
+                        step.env["GOWORK"],
+                        dunce::canonicalize(root.join("go.work")).unwrap().to_string_lossy()
+                    );
+                    let expected =
+                        if kind == BuildKind::Rebuild { vec!["build", "-a", "./..."] } else { vec!["build", "./..."] };
+                    assert_eq!(step.args, expected);
+                }
+            }
+        }
+        let member =
+            plan(&root, &BuildModel::default(), BuildKind::Build, Some(&root.join("api/pkg/a.go")), None).unwrap();
+        assert_eq!(member.steps.len(), 1);
+        assert_eq!(member.steps[0].cwd, root.join("api"));
+        assert_eq!(member.steps[0].args, ["build", "./pkg/..."]);
+        write(&root, "go.work", "use ./missing\n");
+        assert!(
+            plan(&root, &BuildModel::default(), BuildKind::Build, None, None)
+                .unwrap_err()
+                .to_string()
+                .contains("go.mod")
+        );
+        write(&root, "go.work", "go 1.22\n");
+        assert!(plan(&root, &BuildModel::default(), BuildKind::Build, None, None).is_err());
+    }
+
    #[test]
    fn independent_gradle_builds_keep_their_launchers_and_task_paths() {
        let wrapper = if cfg!(windows) { "gradlew.bat" } else { "gradlew" };
@@ -0,0 +1,20 @@
+[package]
+name = "ide-cli"
+description = "The `openidea` command: arguments, the request it sends a running app over a local socket, and installing it on PATH"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+serde.workspace = true
+serde_json.workspace = true
+dirs.workspace = true
+tracing.workspace = true
+
+[target.'cfg(windows)'.dependencies]
+tokio = { workspace = true, features = ["net"] }
+winreg = "0.56"
+windows-sys = { version = "0.61", features = ["Win32_Foundation", "Win32_Storage_FileSystem", "Win32_System_Console", "Win32_UI_WindowsAndMessaging"] }
+
+[dev-dependencies]
+tempfile.workspace = true
@@ -0,0 +1,234 @@
+//! Command-line arguments of `openidea`.
+
+use crate::Target;
+use std::path::Path;
+
+pub const USAGE: &str = "\
+Usage: openidea [options] [[--line <n>] [--column <n>] path[:line[:column]] ...]
+       openidea diff <left> <right>
+
+Opens folders as projects and files in the editor of the running OpenIDEA,
+starting it if needed. Without paths, brings OpenIDEA to the front.
+Lines and columns start at 1; --line and --column apply to the next path.
+
+Options:
+  --line <n>     Put the caret on line <n> of the next file
+  --column <n>   Put the caret in column <n> of that line
+  -h, --help     Show this help
+  -v, --version  Show the version
+";
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum Command {
+    Help,
+    Version,
+    Open(Vec<Target>),
+    Diff(Vec<Target>),
+}
+
+/// Parses `args` (without the program name); relative paths resolve against `cwd`.
+pub fn parse(args: &[String], cwd: &Path) -> Result<Command, String> {
+    parse_with(args, cwd, &|p| p.exists())
+}
+
+fn parse_with(args: &[String], cwd: &Path, exists: &dyn Fn(&Path) -> bool) -> Result<Command, String> {
+    if args.first().is_some_and(|arg| arg == "diff") {
+        return match parse_paths(&args[1..], cwd, exists)? {
+            Command::Open(targets) if targets.len() == 2 => Ok(Command::Diff(targets)),
+            Command::Help => Ok(Command::Help),
+            _ => Err("diff needs two files".into()),
+        };
+    }
+    parse_paths(args, cwd, exists)
+}
+
+fn parse_paths(args: &[String], cwd: &Path, exists: &dyn Fn(&Path) -> bool) -> Result<Command, String> {
+    let mut targets = Vec::new();
+    let mut options = true;
+    let (mut line, mut column) = (None, None);
+    let mut args = args.iter();
+    while let Some(arg) = args.next() {
+        let (flag, inline) = match arg.split_once('=') {
+            Some((flag, value)) if options && flag.starts_with("--") => (flag, Some(value.to_owned())),
+            _ => (arg.as_str(), None),
+        };
+        match flag {
+            "--" if options => options = false,
+            "-h" | "--help" if options => return Ok(Command::Help),
+            "-v" | "--version" if options => return Ok(Command::Version),
+            "--line" | "--column" if options => {
+                let value = inline.or_else(|| args.next().cloned()).ok_or(format!("{flag} needs a number"))?;
+                let n = position(&value).ok_or(format!("{flag}: not a number from 1: {value}"))?;
+                *if flag == "--line" { &mut line } else { &mut column } = Some(n);
+            }
+            a if options && a.starts_with('-') && a != "-" => return Err(format!("unknown option: {a}")),
+            _ => {
+                let mut target = target(arg, cwd, exists)?;
+                if line.is_some() || column.is_some() {
+                    target.line = line.take().or(target.line).or(Some(1));
+                    target.column = column.take();
+                }
+                targets.push(target);
+            }
+        }
+    }
+    if line.is_some() || column.is_some() {
+        return Err("--line and --column need a file after them".into());
+    }
+    Ok(Command::Open(targets))
+}
+
+/// `arg` as a path, else as `path:line[:column]` when `path` exists.
+fn target(arg: &str, cwd: &Path, exists: &dyn Fn(&Path) -> bool) -> Result<Target, String> {
+    let path = cwd.join(arg);
+    if exists(&path) {
+        return Ok(Target { path, line: None, column: None });
+    }
+    for (base, line, column) in split_position(arg) {
+        let path = cwd.join(base);
+        if exists(&path) {
+            return Ok(Target { path, line: Some(line), column });
+        }
+    }
+    Err(format!("{arg}: no such file or directory"))
+}
+
+/// The readings of `arg` as `path:line:column`, then as `path:line`.
+fn split_position(arg: &str) -> Vec<(&str, u32, Option<u32>)> {
+    let Some((rest, last)) = arg.rsplit_once(':') else { return Vec::new() };
+    let Some(last) = position(last) else { return Vec::new() };
+    let mut readings = Vec::new();
+    if let Some((base, line)) = rest.rsplit_once(':')
+        && let Some(line) = position(line)
+        && !base.is_empty()
+    {
+        readings.push((base, line, Some(last)));
+    }
+    if !rest.is_empty() {
+        readings.push((rest, last, None));
+    }
+    readings
+}
+
+fn position(s: &str) -> Option<u32> {
+    if s.is_empty() || !s.bytes().all(|b| b.is_ascii_digit()) {
+        return None;
+    }
+    s.parse().ok().filter(|n| *n > 0)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::path::PathBuf;
+
+    fn args(list: &[&str]) -> Vec<String> {
+        list.iter().map(|s| (*s).to_owned()).collect()
+    }
+
+    fn parse_in(list: &[&str], existing: &[&str]) -> Result<Command, String> {
+        let existing: Vec<PathBuf> = existing.iter().map(PathBuf::from).collect();
+        parse_with(&args(list), Path::new("/work"), &|p| existing.iter().any(|e| e == p))
+    }
+
+    fn at(path: &str, line: Option<u32>, column: Option<u32>) -> Target {
+        Target { path: path.into(), line, column }
+    }
+
+    #[test]
+    fn paths_resolve_against_cwd() {
+        assert_eq!(
+            parse_in(&["src", "/abs/a.rs"], &["/work/src", "/abs/a.rs"]),
+            Ok(Command::Open(vec![at("/work/src", None, None), at("/abs/a.rs", None, None)]))
+        );
+        assert_eq!(parse_in(&[], &[]), Ok(Command::Open(vec![])));
+    }
+
+    #[test]
+    fn positions_split_only_when_the_whole_arg_is_missing() {
+        let files = ["/work/a.rs"];
+        assert_eq!(parse_in(&["a.rs:12"], &files), Ok(Command::Open(vec![at("/work/a.rs", Some(12), None)])));
+        assert_eq!(parse_in(&["a.rs:12:5"], &files), Ok(Command::Open(vec![at("/work/a.rs", Some(12), Some(5))])));
+        assert!(parse_in(&["a.rs:0"], &files).is_err());
+        assert!(parse_in(&["a.rs:x"], &files).is_err());
+        assert!(parse_in(&["missing.rs:3"], &files).is_err());
+    }
+
+    // Windows file names cannot contain `:`, and `b:2` reads as a path on drive B.
+    #[cfg(unix)]
+    #[test]
+    fn an_existing_name_with_a_colon_wins_over_a_position() {
+        let files = ["/work/b:2"];
+        assert_eq!(parse_in(&["b:2"], &files), Ok(Command::Open(vec![at("/work/b:2", None, None)])));
+        assert_eq!(parse_in(&["b:2:7"], &files), Ok(Command::Open(vec![at("/work/b:2", Some(7), None)])));
+    }
+
+    #[test]
+    fn windows_drive_colon_is_not_a_position() {
+        assert_eq!(split_position(r"C:\a.rs:10"), vec![(r"C:\a.rs", 10, None)]);
+        assert_eq!(split_position(r"C:\a.rs:10:2"), vec![(r"C:\a.rs", 10, Some(2)), (r"C:\a.rs:10", 2, None)]);
+        assert!(split_position(r"C:\a.rs").is_empty());
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn windows_absolute_and_unc_targets_keep_spaces_and_unicode() {
+        let local = PathBuf::from(r"C:\项目\my file.rs");
+        let network = PathBuf::from(r"\\server\share\folder name");
+        let command = parse_with(
+            &args(&[r"C:\项目\my file.rs:12:5", r"\\server\share\folder name"]),
+            Path::new(r"D:\work"),
+            &|path| path == local || path == network,
+        );
+        assert_eq!(
+            command,
+            Ok(Command::Open(vec![
+                Target { path: local, line: Some(12), column: Some(5) },
+                Target { path: network, line: None, column: None },
+            ]))
+        );
+    }
+
+    #[test]
+    fn line_and_column_flags_apply_to_the_next_path() {
+        let files = ["/work/a.rs", "/work/b.rs"];
+        assert_eq!(
+            parse_in(&["--line", "12", "--column=5", "a.rs", "b.rs"], &files),
+            Ok(Command::Open(vec![at("/work/a.rs", Some(12), Some(5)), at("/work/b.rs", None, None)]))
+        );
+        assert_eq!(
+            parse_in(&["--line=3", "a.rs:9:9"], &files),
+            Ok(Command::Open(vec![at("/work/a.rs", Some(3), None)]))
+        );
+        assert!(parse_in(&["--line", "0", "a.rs"], &files).is_err());
+        assert!(parse_in(&["--line"], &files).is_err());
+        assert!(parse_in(&["a.rs", "--line", "2"], &files).is_err());
+    }
+
+    #[test]
+    fn options() {
+        assert_eq!(parse_in(&["-h"], &[]), Ok(Command::Help));
+        assert_eq!(parse_in(&["--version"], &[]), Ok(Command::Version));
+        assert!(parse_in(&["--nope"], &[]).is_err());
+        assert_eq!(parse_in(&["--", "-h"], &["/work/-h"]), Ok(Command::Open(vec![at("/work/-h", None, None)])));
+    }
+
+    #[test]
+    fn existing_diff_command_is_supported() {
+        let files = ["/work/a.rs", "/work/b.rs"];
+        assert_eq!(
+            parse_in(&["diff", "a.rs", "b.rs"], &files),
+            Ok(Command::Diff(vec![at("/work/a.rs", None, None), at("/work/b.rs", None, None),]))
+        );
+        assert!(parse_in(&["diff", "a.rs"], &files).is_err());
+        assert_eq!(
+            parse_in(&["diff", "diff", "b.rs"], &["/work/diff", "/work/b.rs"]),
+            Ok(Command::Diff(vec![at("/work/diff", None, None), at("/work/b.rs", None, None),]))
+        );
+        assert_eq!(parse_in(&["--", "diff"], &["/work/diff"]), Ok(Command::Open(vec![at("/work/diff", None, None)])));
+        assert_eq!(
+            parse_in(&["--column=4", "a.rs", "b.rs"], &files),
+            Ok(Command::Open(vec![at("/work/a.rs", Some(1), Some(4)), at("/work/b.rs", None, None),]))
+        );
+    }
+}
@@ -0,0 +1,476 @@
+//! Installing the `openidea` command: a symlink on `PATH` to the launcher
+//! script in a macOS bundle, or a wrapper in a user's bin directory.
+
+use std::ffi::OsStr;
+use std::io;
+use std::path::{Path, PathBuf};
+
+pub const COMMAND: &str = "openidea";
+const LAUNCHER: &str = "Contents/Resources/bin/openidea";
+const SYSTEM_DIR: &str = "/usr/local/bin";
+
+/// The launcher script of the bundle whose executable is `exe`; `None` outside a bundle.
+pub fn bundled_launcher(exe: &Path) -> Option<PathBuf> {
+    let launcher = exe.parent()?.parent()?.parent()?.join(LAUNCHER);
+    launcher.is_file().then_some(launcher)
+}
+
+/// macOS runs a quarantined app from a random read-only copy until it is moved:
+/// a link there would break on the next launch.
+pub fn translocated(path: &Path) -> bool {
+    path.to_string_lossy().contains("/AppTranslocation/")
+}
+
+/// Where the link goes: `~/.local/bin` when it is on `path_var` (no administrator
+/// rights needed), else `/usr/local/bin`.
+pub fn link_dir(path_var: Option<&OsStr>, home: Option<&Path>) -> PathBuf {
+    let local = home.map(|h| h.join(".local/bin"));
+    match (path_var, local) {
+        (Some(var), Some(local)) if std::env::split_paths(var).any(|p| p == local) => local,
+        _ => PathBuf::from(SYSTEM_DIR),
+    }
+}
+
+/// Directories an earlier install may have used.
+pub fn link_dirs(home: Option<&Path>) -> Vec<PathBuf> {
+    home.map(|h| h.join(".local/bin")).into_iter().chain([PathBuf::from(SYSTEM_DIR)]).collect()
+}
+
+/// The installed links among `dirs` (any OpenIDEA bundle's launcher).
+pub fn installed(dirs: &[PathBuf]) -> Vec<PathBuf> {
+    dirs.iter().map(|d| d.join(COMMAND)).filter(|l| is_launcher_link(l)).collect()
+}
+
+fn is_launcher_link(link: &Path) -> bool {
+    std::fs::read_link(link).is_ok_and(|target| target.ends_with(LAUNCHER))
+}
+
+/// Links `dir/openidea` to `launcher`, asking for administrator rights when `dir`
+/// is not writable. Refuses to replace an `openidea` that is not ours.
+pub fn install(launcher: &Path, dir: &Path) -> io::Result<PathBuf> {
+    let link = dir.join(COMMAND);
+    if link.symlink_metadata().is_ok() && !is_launcher_link(&link) {
+        return Err(io::Error::new(
+            io::ErrorKind::AlreadyExists,
+            format!("{} already exists and is not an OpenIDEA command", link.display()),
+        ));
+    }
+    let direct = std::fs::create_dir_all(dir).and_then(|()| {
+        if link.symlink_metadata().is_ok() {
+            std::fs::remove_file(&link)?;
+        }
+        symlink(launcher, &link)
+    });
+    match direct {
+        Err(e) if e.kind() == io::ErrorKind::PermissionDenied => {
+            privileged(&format!("mkdir -p {} && ln -sfn {} {}", quote(dir), quote(launcher), quote(&link)))?
+        }
+        result => result?,
+    }
+    Ok(link)
+}
+
+/// Removes `links`, asking for administrator rights where needed.
+pub fn uninstall(links: &[PathBuf]) -> io::Result<()> {
+    for link in links {
+        match std::fs::remove_file(link) {
+            Err(e) if e.kind() == io::ErrorKind::PermissionDenied => privileged(&format!("rm -f {}", quote(link)))?,
+            result => result?,
+        }
+    }
+    Ok(())
+}
+
+#[cfg(unix)]
+fn symlink(target: &Path, link: &Path) -> io::Result<()> {
+    std::os::unix::fs::symlink(target, link)
+}
+
+#[cfg(not(unix))]
+fn symlink(_target: &Path, _link: &Path) -> io::Result<()> {
+    Err(io::Error::new(io::ErrorKind::Unsupported, "not supported on this platform"))
+}
+
+/// Runs `command` as root after the system's password prompt. Cancelling it is
+/// [`io::ErrorKind::Interrupted`].
+fn privileged(command: &str) -> io::Result<()> {
+    if !cfg!(target_os = "macos") {
+        return Err(io::Error::new(io::ErrorKind::PermissionDenied, "administrator rights required"));
+    }
+    let script = format!("do shell script \"{}\" with administrator privileges", applescript_escape(command));
+    let output = std::process::Command::new("/usr/bin/osascript").arg("-e").arg(script).output()?;
+    if output.status.success() {
+        return Ok(());
+    }
+    let message = String::from_utf8_lossy(&output.stderr).trim().to_owned();
+    // "User canceled. (-128)"
+    let kind = if message.contains("(-128)") { io::ErrorKind::Interrupted } else { io::ErrorKind::PermissionDenied };
+    Err(io::Error::new(kind, message))
+}
+
+fn quote(path: &Path) -> String {
+    format!("'{}'", path.to_string_lossy().replace('\'', r"'\''"))
+}
+
+fn applescript_escape(s: &str) -> String {
+    s.replace('\\', r"\\").replace('"', "\\\"")
+}
+
+const WRAPPER_MARKER: &str = "OpenIDEA command launcher v1";
+
+/// AppImages remount their executable on every launch. Keep the original image path.
+pub fn stable_executable(exe: &Path, appimage: Option<&Path>) -> io::Result<PathBuf> {
+    let path = appimage.unwrap_or(exe);
+    if !path.is_absolute() || !path.is_file() {
+        return Err(io::Error::new(io::ErrorKind::NotFound, "the OpenIDEA executable must be in a permanent location"));
+    }
+    Ok(path.to_path_buf())
+}
+
+pub fn wrapper_path(dir: &Path, windows: bool) -> PathBuf {
+    dir.join(if windows { "openidea.cmd" } else { COMMAND })
+}
+
+fn wrapper(exe: &Path, windows: bool) -> io::Result<String> {
+    let exe =
+        exe.to_str().ok_or_else(|| io::Error::new(io::ErrorKind::InvalidInput, "the executable path is not UTF-8"))?;
+    if exe.contains(['\r', '\n']) || (windows && exe.contains('"')) {
+        return Err(io::Error::new(io::ErrorKind::InvalidInput, "the executable path contains unsupported characters"));
+    }
+    Ok(if windows {
+        format!(
+            "@echo off\r\nrem {WRAPPER_MARKER}\r\nsetlocal DisableDelayedExpansion\r\nfor /f \"tokens=2 delims=:\" %%c in ('\"%SystemRoot%\\System32\\chcp.com\"') do set \"_openidea_codepage=%%c\"\r\n\"%SystemRoot%\\System32\\chcp.com\" 65001 >nul\r\n\"{}\" --cli %*\r\nset \"_openidea_exit=%errorlevel%\"\r\n\"%SystemRoot%\\System32\\chcp.com\" %_openidea_codepage% >nul\r\nexit /b %_openidea_exit%\r\n",
+            exe.replace('%', "%%")
+        )
+    } else {
+        format!("#!/bin/sh\n# {WRAPPER_MARKER}\nexec {} --cli \"$@\"\n", quote(Path::new(exe)))
+    })
+}
+
+pub fn is_wrapper(path: &Path, windows: bool) -> bool {
+    path.symlink_metadata().is_ok_and(|meta| meta.is_file() && !meta.file_type().is_symlink())
+        && std::fs::read_to_string(path).is_ok_and(|text| {
+            text.lines().nth(1) == Some(&format!("{} {WRAPPER_MARKER}", if windows { "rem" } else { "#" }))
+        })
+}
+
+/// Never follows or overwrites a foreign file, even if it has the same command name.
+pub fn install_wrapper(exe: &Path, dir: &Path, windows: bool) -> io::Result<PathBuf> {
+    use std::io::Write;
+    let text = wrapper(exe, windows)?;
+    let path = wrapper_path(dir, windows);
+    if path.symlink_metadata().is_ok() {
+        if !is_wrapper(&path, windows) {
+            return Err(io::Error::new(
+                io::ErrorKind::AlreadyExists,
+                format!("{} already exists and is not an OpenIDEA command", path.display()),
+            ));
+        }
+        std::fs::remove_file(&path)?;
+    }
+    std::fs::create_dir_all(dir)?;
+    let mut file = std::fs::OpenOptions::new().write(true).create_new(true).open(&path)?;
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        file.set_permissions(std::fs::Permissions::from_mode(0o755))?;
+    }
+    file.write_all(text.as_bytes())?;
+    Ok(path)
+}
+
+pub fn uninstall_wrapper(dir: &Path, windows: bool) -> io::Result<Vec<PathBuf>> {
+    let path = wrapper_path(dir, windows);
+    if !is_wrapper(&path, windows) {
+        return Ok(vec![]);
+    }
+    std::fs::remove_file(&path)?;
+    Ok(vec![path])
+}
+
+/// Preserve every unrelated PATH entry, including expandable environment variables.
+pub fn windows_path(current: &str, dir: &str, add: bool) -> Option<String> {
+    fn equal(a: &str, b: &str) -> bool {
+        a.trim().trim_matches('"').trim_end_matches(['\\', '/']).eq_ignore_ascii_case(b.trim_end_matches(['\\', '/']))
+    }
+    let found = current.split(';').any(|entry| equal(entry, dir));
+    if add {
+        if found {
+            return None;
+        }
+        Some(format!("{dir}{}{current}", if current.is_empty() { "" } else { ";" }))
+    } else if found {
+        Some(current.split(';').filter(|entry| !equal(entry, dir)).collect::<Vec<_>>().join(";"))
+    } else {
+        None
+    }
+}
+
+#[cfg(windows)]
+pub fn update_user_path(dir: &Path, add: bool) -> io::Result<()> {
+    use winreg::{
+        RegKey,
+        enums::{HKEY_CURRENT_USER, REG_EXPAND_SZ},
+        types::{FromRegValue, ToRegValue},
+    };
+    let (environment, _) = RegKey::predef(HKEY_CURRENT_USER).create_subkey("Environment")?;
+    let raw = match environment.get_raw_value("Path") {
+        Ok(raw) => Some(raw),
+        Err(e) if e.kind() == io::ErrorKind::NotFound => None,
+        Err(e) => return Err(e),
+    };
+    let current = raw.as_ref().map(String::from_reg_value).transpose()?.unwrap_or_default();
+    let Some(updated) = windows_path(&current, &dir.to_string_lossy(), add) else { return Ok(()) };
+    let mut value = updated.to_reg_value();
+    value.vtype = raw.as_ref().map_or(REG_EXPAND_SZ, |raw| raw.vtype.clone());
+    environment.set_raw_value("Path", &value)?;
+    let message: Vec<u16> = "Environment\0".encode_utf16().collect();
+    // SAFETY: the terminated string stays alive for this bounded synchronous broadcast.
+    unsafe {
+        windows_sys::Win32::UI::WindowsAndMessaging::SendMessageTimeoutW(
+            windows_sys::Win32::UI::WindowsAndMessaging::HWND_BROADCAST,
+            windows_sys::Win32::UI::WindowsAndMessaging::WM_SETTINGCHANGE,
+            0,
+            message.as_ptr() as isize,
+            windows_sys::Win32::UI::WindowsAndMessaging::SMTO_ABORTIFHUNG,
+            1000,
+            std::ptr::null_mut(),
+        );
+    }
+    Ok(())
+}
+
+pub struct Installation {
+    pub path: PathBuf,
+    /// Some when the user needs to add this directory to their shell's PATH.
+    pub path_directory: Option<PathBuf>,
+}
+
+fn resolves_to(path_var: Option<&OsStr>, command: &Path) -> bool {
+    path_var
+        .and_then(|path| std::env::split_paths(path).map(|dir| dir.join(COMMAND)).find(|candidate| candidate.is_file()))
+        .is_some_and(|candidate| candidate == command)
+}
+
+fn user_bin() -> io::Result<PathBuf> {
+    if cfg!(windows) {
+        dirs::data_local_dir().map(|dir| dir.join("OpenIDEA/bin"))
+    } else {
+        dirs::home_dir().map(|dir| dir.join(".local/bin"))
+    }
+    .ok_or_else(|| io::Error::new(io::ErrorKind::NotFound, "no user directory for the openidea command"))
+}
+
+pub fn install_current() -> io::Result<Installation> {
+    let exe = std::env::current_exe()?;
+    if cfg!(target_os = "macos") {
+        let launcher = bundled_launcher(&exe).ok_or_else(|| {
+            io::Error::new(io::ErrorKind::NotFound, "install the command from the packaged OpenIDEA app")
+        })?;
+        if translocated(&launcher) {
+            return Err(io::Error::new(
+                io::ErrorKind::PermissionDenied,
+                "move OpenIDEA to the Applications folder first",
+            ));
+        }
+        let dir = link_dir(std::env::var_os("PATH").as_deref(), dirs::home_dir().as_deref());
+        return Ok(Installation { path: install(&launcher, &dir)?, path_directory: None });
+    }
+    let image = if cfg!(target_os = "linux") { std::env::var_os("APPIMAGE").map(PathBuf::from) } else { None };
+    let exe = stable_executable(&exe, image.as_deref())?;
+    let dir = user_bin()?;
+    let path = install_wrapper(&exe, &dir, cfg!(windows))?;
+    #[cfg(windows)]
+    update_user_path(&dir, true)?;
+    let on_path = cfg!(windows) || resolves_to(std::env::var_os("PATH").as_deref(), &path);
+    Ok(Installation { path, path_directory: (!on_path).then_some(dir) })
+}
+
+pub fn uninstall_current() -> io::Result<Vec<PathBuf>> {
+    if cfg!(target_os = "macos") {
+        let links = installed(&link_dirs(dirs::home_dir().as_deref()));
+        uninstall(&links)?;
+        return Ok(links);
+    }
+    let dir = user_bin()?;
+    let path = wrapper_path(&dir, cfg!(windows));
+    if is_wrapper(&path, cfg!(windows)) {
+        #[cfg(windows)]
+        update_user_path(&dir, false)?;
+        return uninstall_wrapper(&dir, cfg!(windows));
+    }
+    Ok(vec![])
+}
+
+#[cfg(test)]
+mod wrapper_tests {
+    use super::*;
+
+    #[test]
+    fn wrappers_install_update_and_remove_only_their_own_files() {
+        for windows in [false, true] {
+            let dir = tempfile::tempdir().unwrap();
+            let exe = dir.path().join("App folder/程序 & it's 100%.exe");
+            let path = install_wrapper(&exe, dir.path(), windows).unwrap();
+            assert!(is_wrapper(&path, windows));
+            assert_eq!(install_wrapper(&exe, dir.path(), windows).unwrap(), path);
+            assert_eq!(uninstall_wrapper(dir.path(), windows).unwrap(), vec![path.clone()]);
+            assert!(uninstall_wrapper(dir.path(), windows).unwrap().is_empty());
+            std::fs::write(&path, "foreign command").unwrap();
+            assert_eq!(install_wrapper(&exe, dir.path(), windows).unwrap_err().kind(), io::ErrorKind::AlreadyExists);
+            assert!(uninstall_wrapper(dir.path(), windows).unwrap().is_empty());
+            assert_eq!(std::fs::read_to_string(&path).unwrap(), "foreign command");
+        }
+    }
+
+    #[test]
+    fn path_changes_keep_other_entries_and_do_not_duplicate_the_command_dir() {
+        let dir = r"C:\Users\用户\OpenIDEA\bin";
+        let initial = r"%USERPROFILE%\tools;C:\other";
+        let updated = windows_path(initial, dir, true).unwrap();
+        assert_eq!(updated, format!("{dir};{initial}"));
+        assert_eq!(windows_path(&updated, dir, true), None);
+        assert_eq!(windows_path(&updated, dir, false).as_deref(), Some(initial));
+        assert_eq!(
+            windows_path(&format!("\"{dir}\\\";C:\\other"), &dir.to_uppercase(), false).as_deref(),
+            Some(r"C:\other")
+        );
+        assert_eq!(windows_path(initial, dir, false), None);
+    }
+
+    #[test]
+    fn appimage_uses_the_persistent_image_not_the_mounted_binary() {
+        let dir = tempfile::tempdir().unwrap();
+        let image = dir.path().join("OpenIDEA.AppImage");
+        std::fs::write(&image, "image").unwrap();
+        assert_eq!(stable_executable(Path::new("/tmp/.mount_App/usr/bin/openidea"), Some(&image)).unwrap(), image);
+        assert_eq!(stable_executable(&image, None).unwrap(), image);
+        assert!(stable_executable(Path::new("missing"), None).is_err());
+    }
+
+    #[test]
+    fn detects_a_system_binary_shadowing_the_linux_wrapper() {
+        let dir = tempfile::tempdir().unwrap();
+        let system = dir.path().join("system");
+        let user = dir.path().join("user");
+        for bin in [&system, &user] {
+            std::fs::create_dir_all(bin).unwrap();
+            std::fs::write(bin.join(COMMAND), "command").unwrap();
+        }
+        let path = std::env::join_paths([&system, &user]).unwrap();
+        assert!(!resolves_to(Some(&path), &user.join(COMMAND)));
+        let path = std::env::join_paths([&user, &system]).unwrap();
+        assert!(resolves_to(Some(&path), &user.join(COMMAND)));
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn posix_wrapper_preserves_arguments_and_exit_status() {
+        use std::os::unix::fs::PermissionsExt;
+        let dir = tempfile::tempdir().unwrap();
+        let exe = dir.path().join("app & it's $dollar `quoted` \"double\"");
+        std::fs::write(&exe, "#!/bin/sh\nprintf '%s\\n' \"$@\"\nexit 7\n").unwrap();
+        std::fs::set_permissions(&exe, std::fs::Permissions::from_mode(0o755)).unwrap();
+        let path = install_wrapper(&exe, &dir.path().join("bin"), false).unwrap();
+        let output = std::process::Command::new(path).args(["a b", "中文", "x'$`&"]).output().unwrap();
+        assert_eq!(output.status.code(), Some(7));
+        assert_eq!(String::from_utf8(output.stdout).unwrap(), "--cli\na b\n中文\nx'$`&\n");
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn cmd_wrapper_preserves_arguments_and_exit_status() {
+        use std::os::windows::process::CommandExt;
+        let dir = tempfile::tempdir().unwrap();
+        let exe = dir.path().join("程序 & 100% !special!.exe");
+        let source = dir.path().join("helper.rs");
+        std::fs::write(
+            &source,
+            r#"fn main() { for arg in std::env::args().skip(1) { println!("{arg}"); } std::process::exit(7); }"#,
+        )
+        .unwrap();
+        let compiled = std::process::Command::new("rustc")
+            .args(["--crate-name", "launcher_test"])
+            .arg(&source)
+            .arg("-o")
+            .arg(&exe)
+            .output()
+            .unwrap();
+        assert!(compiled.status.success(), "{}", String::from_utf8_lossy(&compiled.stderr));
+        let path = install_wrapper(&exe, &dir.path().join("bin"), true).unwrap();
+        std::fs::write(dir.path().join("chcp.cmd"), "@echo malicious-chcp\r\nexit /b 99\r\n").unwrap();
+        let output = std::process::Command::new("cmd.exe")
+            .current_dir(dir.path())
+            .args(["/d", "/s", "/c"])
+            .raw_arg(format!("\"\"{}\" \"a b\" \"中文\" \"x&y\"\"", path.display()))
+            .output()
+            .unwrap();
+        assert_eq!(output.status.code(), Some(7));
+        assert_eq!(String::from_utf8(output.stdout).unwrap().replace("\r\n", "\n"), "--cli\na b\n中文\nx&y\n");
+        let check = dir.path().join("check.cmd");
+        std::fs::write(&check, "@echo off\r\nfor /f \"tokens=2 delims=:\" %%c in ('\"%SystemRoot%\\System32\\chcp.com\"') do set \"before=%%c\"\r\ncall \"%~dp0bin\\openidea.cmd\" example\r\nset \"code=%errorlevel%\"\r\nfor /f \"tokens=2 delims=:\" %%c in ('\"%SystemRoot%\\System32\\chcp.com\"') do set \"after=%%c\"\r\nif not \"%before%\"==\"%after%\" exit /b 99\r\nexit /b %code%\r\n").unwrap();
+        let output = std::process::Command::new("cmd.exe")
+            .current_dir(dir.path())
+            .args(["/d", "/s", "/c"])
+            .raw_arg(format!("\"\"{}\"\"", check.display()))
+            .output()
+            .unwrap();
+        assert_eq!(output.status.code(), Some(7));
+        assert!(!String::from_utf8_lossy(&output.stdout).contains("malicious-chcp"));
+    }
+}
+
+#[cfg(all(test, unix))]
+mod tests {
+    use super::*;
+
+    fn bundle(root: &Path) -> (PathBuf, PathBuf) {
+        let app = root.join("OpenIDEA.app");
+        let exe = app.join("Contents/MacOS/openidea");
+        let launcher = app.join(LAUNCHER);
+        std::fs::create_dir_all(exe.parent().unwrap()).unwrap();
+        std::fs::create_dir_all(launcher.parent().unwrap()).unwrap();
+        std::fs::write(&exe, "").unwrap();
+        std::fs::write(&launcher, "").unwrap();
+        (exe, launcher)
+    }
+
+    #[test]
+    fn finds_the_launcher_of_a_bundle_only() {
+        let dir = tempfile::tempdir().unwrap();
+        let (exe, launcher) = bundle(dir.path());
+        assert_eq!(bundled_launcher(&exe), Some(launcher));
+        assert_eq!(bundled_launcher(&dir.path().join("target/debug/openidea")), None);
+        assert!(translocated(Path::new("/private/var/folders/x/AppTranslocation/ABC/d/OpenIDEA.app")));
+    }
+
+    #[test]
+    fn prefers_local_bin_on_path() {
+        let home = Path::new("/Users/u");
+        let path = std::env::join_paths(["/usr/bin", "/Users/u/.local/bin"]).unwrap();
+        assert_eq!(link_dir(Some(&path), Some(home)), home.join(".local/bin"));
+        assert_eq!(link_dir(Some(OsStr::new("/usr/bin")), Some(home)), PathBuf::from(SYSTEM_DIR));
+        assert_eq!(link_dir(None, Some(home)), PathBuf::from(SYSTEM_DIR));
+    }
+
+    #[test]
+    fn install_replaces_its_own_link_but_not_other_files() {
+        let dir = tempfile::tempdir().unwrap();
+        let (_, launcher) = bundle(dir.path());
+        let bin = dir.path().join("bin");
+        let link = install(&launcher, &bin).unwrap();
+        assert_eq!(std::fs::read_link(&link).unwrap(), launcher);
+        assert_eq!(install(&launcher, &bin).unwrap(), link);
+        assert_eq!(installed(std::slice::from_ref(&bin)), vec![link.clone()]);
+        uninstall(&installed(std::slice::from_ref(&bin))).unwrap();
+        assert!(installed(std::slice::from_ref(&bin)).is_empty());
+        std::fs::write(&link, "someone else's").unwrap();
+        assert_eq!(install(&launcher, &bin).unwrap_err().kind(), io::ErrorKind::AlreadyExists);
+    }
+
+    #[test]
+    fn quoting() {
+        assert_eq!(quote(Path::new("/a b/it's")), r"'/a b/it'\''s'");
+        assert_eq!(applescript_escape(r#"ln "a\b""#), r#"ln \"a\\b\""#);
+    }
+}
@@ -0,0 +1,72 @@
+//! The `openidea` command.
+//!
+//! The command is the app's own executable run in CLI mode: it parses its
+//! arguments ([`args`]), sends one [`Request`] to the running app over a local
+//! socket ([`socket`]) and exits. [`install`] links the bundle's launcher
+//! script into a directory on `PATH`.
+
+pub mod args;
+pub mod install;
+pub mod socket;
+
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+
+/// Bumped when [`Request`] changes incompatibly; an app still running an older
+/// version answers with an error instead of misreading it.
+pub const PROTOCOL_VERSION: u32 = 1;
+
+/// A file or folder to open, with an optional 1-based position in a file.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Target {
+    /// Absolute.
+    pub path: PathBuf,
+    pub line: Option<u32>,
+    pub column: Option<u32>,
+}
+
+/// What the command asks the running app to do. No targets: bring the app to the front.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Request {
+    pub version: u32,
+    pub targets: Vec<Target>,
+    #[serde(default)]
+    pub diff: bool,
+}
+
+impl Request {
+    pub fn open(targets: Vec<Target>) -> Self {
+        Self { version: PROTOCOL_VERSION, targets, diff: false }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(tag = "kind", rename_all = "camelCase")]
+pub enum Response {
+    Ok,
+    Error { message: String },
+}
+
+/// A GUI subsystem executable inherits redirected handles, but needs its parent's
+/// console for interactive help and errors. Batch launchers wait for this process.
+#[cfg(windows)]
+pub fn attach_console() {
+    use windows_sys::Win32::Storage::FileSystem::{FILE_TYPE_DISK, FILE_TYPE_PIPE, GetFileType};
+    use windows_sys::Win32::System::Console::{
+        ATTACH_PARENT_PROCESS, AttachConsole, GetStdHandle, STD_ERROR_HANDLE, STD_INPUT_HANDLE, STD_OUTPUT_HANDLE,
+        SetStdHandle,
+    };
+    // SAFETY: attaches only this CLI process, without allocating a new console.
+    unsafe {
+        let redirected = [STD_INPUT_HANDLE, STD_OUTPUT_HANDLE, STD_ERROR_HANDLE].map(|kind| {
+            let handle = GetStdHandle(kind);
+            (kind, handle, matches!(GetFileType(handle), FILE_TYPE_DISK | FILE_TYPE_PIPE))
+        });
+        AttachConsole(ATTACH_PARENT_PROCESS);
+        for (kind, handle, keep) in redirected {
+            if keep {
+                SetStdHandle(kind, handle);
+            }
+        }
+    }
+}
@@ -0,0 +1,266 @@
+//! The local socket the running app listens on: one JSON [`Request`] line in,
+//! one [`Response`] line out. Unix domain sockets or Windows named pipes.
+
+use crate::{Request, Response};
+use std::io;
+use std::path::{Path, PathBuf};
+use std::time::Duration;
+
+const TIMEOUT: Duration = Duration::from_secs(10);
+const MAX_MESSAGE: u64 = 1024 * 1024;
+
+fn answer(line: &str, handle: &dyn Fn(Request) -> Response) -> Response {
+    match serde_json::from_str::<Request>(line) {
+        Ok(request) if request.version == crate::PROTOCOL_VERSION && (!request.diff || request.targets.len() == 2) => {
+            handle(request)
+        }
+        Ok(_) => Response::Error { message: "unsupported or invalid CLI request".into() },
+        Err(e) => Response::Error { message: format!("invalid request: {e}") },
+    }
+}
+
+/// The socket of the app with bundle identifier `identifier`. The name is a hash:
+/// socket paths are limited to about 100 bytes, and development identifiers are long.
+pub fn socket_path(identifier: &str) -> Option<PathBuf> {
+    if cfg!(windows) {
+        let user = dirs::data_local_dir()?;
+        return Some(PathBuf::from(format!(
+            r"\\.\pipe\openidea-{:016x}",
+            fnv1a(&format!("{}:{identifier}", user.display()))
+        )));
+    }
+    let dir = if cfg!(target_os = "macos") { dirs::cache_dir() } else { dirs::runtime_dir().or_else(dirs::cache_dir) };
+    Some(dir?.join(format!("openidea-{:016x}.sock", fnv1a(identifier))))
+}
+
+fn fnv1a(s: &str) -> u64 {
+    s.bytes().fold(0xcbf29ce484222325, |hash, byte| (hash ^ u64::from(byte)).wrapping_mul(0x100000001b3))
+}
+
+#[cfg(unix)]
+mod imp {
+    use super::*;
+    use std::io::{BufRead, BufReader, Read, Write};
+    use std::os::unix::fs::{FileTypeExt, PermissionsExt};
+    use std::os::unix::net::{UnixListener, UnixStream};
+
+    pub fn send(socket: &Path, request: &Request) -> io::Result<Response> {
+        let stream = UnixStream::connect(socket)?;
+        stream.set_read_timeout(Some(TIMEOUT))?;
+        stream.set_write_timeout(Some(TIMEOUT))?;
+        write_line(&stream, request)?;
+        let mut reply = String::new();
+        BufReader::new((&stream).take(MAX_MESSAGE)).read_line(&mut reply)?;
+        Ok(serde_json::from_str(&reply)?)
+    }
+
+    pub fn serve(socket: &Path, handle: impl Fn(Request) -> Response + Send + 'static) -> io::Result<()> {
+        let listener = bind(socket)?;
+        std::thread::Builder::new().name("cli-socket".into()).spawn(move || {
+            for stream in listener.incoming().flatten() {
+                if let Err(e) = serve_one(&stream, &handle) {
+                    tracing::warn!("cli request failed: {e}");
+                }
+            }
+        })?;
+        Ok(())
+    }
+
+    /// Binds `socket`, replacing a stale file no one answers on.
+    fn bind(socket: &Path) -> io::Result<UnixListener> {
+        if let Some(dir) = socket.parent() {
+            std::fs::create_dir_all(dir)?;
+        }
+        let listener = match UnixListener::bind(socket) {
+            Err(e) if e.kind() == io::ErrorKind::AddrInUse => {
+                if !std::fs::symlink_metadata(socket)?.file_type().is_socket() || UnixStream::connect(socket).is_ok() {
+                    return Err(e);
+                }
+                std::fs::remove_file(socket)?;
+                UnixListener::bind(socket)?
+            }
+            bound => bound?,
+        };
+        std::fs::set_permissions(socket, std::fs::Permissions::from_mode(0o600))?;
+        Ok(listener)
+    }
+
+    fn serve_one(stream: &UnixStream, handle: &dyn Fn(Request) -> Response) -> io::Result<()> {
+        stream.set_read_timeout(Some(TIMEOUT))?;
+        stream.set_write_timeout(Some(TIMEOUT))?;
+        let mut line = String::new();
+        BufReader::new(stream.take(MAX_MESSAGE)).read_line(&mut line)?;
+        write_line(stream, &answer(&line, handle))
+    }
+
+    fn write_line(mut stream: &UnixStream, value: &impl serde::Serialize) -> io::Result<()> {
+        let mut line = serde_json::to_string(value)?;
+        line.push('\n');
+        stream.write_all(line.as_bytes())
+    }
+}
+
+#[cfg(windows)]
+mod imp {
+    use super::*;
+    use tokio::io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufReader};
+    use tokio::net::windows::named_pipe::{ClientOptions, ServerOptions};
+
+    fn runtime() -> io::Result<tokio::runtime::Runtime> {
+        tokio::runtime::Builder::new_current_thread().enable_all().build()
+    }
+
+    pub fn send(socket: &Path, request: &Request) -> io::Result<Response> {
+        runtime()?.block_on(async {
+            tokio::time::timeout(TIMEOUT, async {
+                let mut pipe = loop {
+                    match ClientOptions::new().open(socket) {
+                        Ok(pipe) => break pipe,
+                        // All existing instances are busy; wait instead of starting another app.
+                        Err(e) if e.raw_os_error() == Some(231) => tokio::time::sleep(Duration::from_millis(10)).await,
+                        Err(e) => return Err(e),
+                    }
+                };
+                let mut line = serde_json::to_vec(request)?;
+                line.push(b'\n');
+                pipe.write_all(&line).await?;
+                let mut reply = String::new();
+                BufReader::new((&mut pipe).take(MAX_MESSAGE)).read_line(&mut reply).await?;
+                pipe.write_all(b"\n").await?;
+                Ok(serde_json::from_str(&reply)?)
+            })
+            .await
+            .map_err(|_| io::Error::new(io::ErrorKind::TimedOut, "CLI request timed out"))?
+        })
+    }
+
+    pub fn serve(socket: &Path, handle: impl Fn(Request) -> Response + Send + 'static) -> io::Result<()> {
+        let socket = socket.to_owned();
+        let (ready, receiver) = std::sync::mpsc::sync_channel(1);
+        std::thread::Builder::new().name("cli-pipe".into()).spawn(move || {
+            let runtime = match runtime() {
+                Ok(runtime) => runtime,
+                Err(e) => {
+                    let _ = ready.send(Err(e));
+                    return;
+                }
+            };
+            runtime.block_on(async move {
+                let mut pipe = match ServerOptions::new().first_pipe_instance(true).create(&socket) {
+                    Ok(pipe) => pipe,
+                    Err(e) => {
+                        let _ = ready.send(Err(e));
+                        return;
+                    }
+                };
+                let _ = ready.send(Ok(()));
+                loop {
+                    if let Err(e) = pipe.connect().await {
+                        tracing::warn!("CLI pipe connection failed: {e}");
+                        return;
+                    }
+                    // Keep an instance bound while answering, so another process cannot take the name.
+                    let next = match ServerOptions::new().create(&socket) {
+                        Ok(next) => next,
+                        Err(e) => {
+                            tracing::warn!("cannot create CLI pipe: {e}");
+                            return;
+                        }
+                    };
+                    let reply = tokio::time::timeout(TIMEOUT, async {
+                        let mut line = String::new();
+                        BufReader::new((&mut pipe).take(MAX_MESSAGE)).read_line(&mut line).await?;
+                        let mut reply = serde_json::to_vec(&answer(&line, &handle))?;
+                        reply.push(b'\n');
+                        pipe.write_all(&reply).await?;
+                        // Wait until the client has drained the reply before closing its instance.
+                        pipe.read_exact(&mut [0u8; 1]).await.map(|_| ())
+                    })
+                    .await;
+                    if !matches!(reply, Ok(Ok(()))) {
+                        tracing::warn!("CLI pipe request failed: {reply:?}");
+                    }
+                    // Dropping after the write lets the client drain its reply before disconnecting.
+                    drop(pipe);
+                    pipe = next;
+                }
+            });
+        })?;
+        receiver.recv().map_err(|_| io::Error::other("CLI pipe thread stopped"))?
+    }
+}
+
+/// Sends `request` to the app listening on `socket` and waits for its answer.
+pub use imp::send;
+/// Answers requests on `socket` with `handle`, on a thread of its own.
+pub use imp::serve;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn socket_names_separate_identifiers_and_stay_short() {
+        let release = socket_path("ai.l0ng.openidea").unwrap();
+        let dev = socket_path("ai.l0ng.openidea.dev.w158e9c5954b7bf64").unwrap();
+        assert_ne!(release, dev);
+        assert!(dev.as_os_str().len() < 100 || cfg!(unix));
+    }
+
+    #[test]
+    fn answers_only_its_protocol_version() {
+        let ok = |_: Request| Response::Ok;
+        assert_eq!(answer(&serde_json::to_string(&Request::open(vec![])).unwrap(), &ok), Response::Ok);
+        let old = r#"{"version":0,"targets":[]}"#;
+        assert!(matches!(answer(old, &ok), Response::Error { .. }));
+        assert!(matches!(answer("garbage", &ok), Response::Error { .. }));
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn named_pipe_round_trip() {
+        let socket = socket_path(&format!("test-{}", std::process::id())).unwrap();
+        let (tx, rx) = std::sync::mpsc::channel();
+        serve(&socket, move |request| {
+            tx.send(request).unwrap();
+            Response::Ok
+        })
+        .unwrap();
+        for _ in 0..2 {
+            let target = crate::Target { path: r"C:\项目\my file.rs".into(), line: Some(3), column: Some(2) };
+            assert_eq!(send(&socket, &Request::open(vec![target.clone()])).unwrap(), Response::Ok);
+            assert_eq!(rx.recv_timeout(TIMEOUT).unwrap().targets, vec![target]);
+        }
+        assert!(serve(&socket, |_| Response::Ok).is_err());
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn request_round_trip_and_stale_socket() {
+        let dir = tempfile::tempdir().unwrap();
+        let socket = dir.path().join("cli.sock");
+        // A file left by an app that exited without removing it.
+        drop(std::os::unix::net::UnixListener::bind(&socket).unwrap());
+        let (tx, rx) = std::sync::mpsc::channel();
+        serve(&socket, move |request| {
+            tx.send(request).unwrap();
+            Response::Ok
+        })
+        .unwrap();
+        let target = crate::Target { path: "/p/a.rs".into(), line: Some(3), column: None };
+        assert_eq!(send(&socket, &Request::open(vec![target.clone()])).unwrap(), Response::Ok);
+        assert_eq!(rx.recv().unwrap().targets, vec![target]);
+        // A live server keeps its socket.
+        assert_eq!(serve(&socket, |_| Response::Ok).unwrap_err().kind(), io::ErrorKind::AddrInUse);
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn refuses_to_remove_an_unrelated_file() {
+        let dir = tempfile::tempdir().unwrap();
+        let socket = dir.path().join("cli.sock");
+        std::fs::write(&socket, "keep").unwrap();
+        assert!(serve(&socket, |_| Response::Ok).is_err());
+        assert_eq!(std::fs::read_to_string(&socket).unwrap(), "keep");
+    }
+}
@@ -166,6 +166,16 @@ impl Default for CompletionSettings {
 pub struct AutoImportSettings {
    pub add_unambiguous: bool,
    pub optimize_on_the_fly: bool,
+    pub imports_on_paste: ImportsOnPaste,
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum ImportsOnPaste {
+    #[default]
+    Ask,
+    Always,
+    Never,
 }

 /// Editor › General › Code Folding.
@@ -251,6 +261,7 @@ pub struct SmartKeysSettings {
    pub tab_out_of_pair: bool,
    /// Reformat on paste: `none` | `indentBlock` | `indentEachLine`.
    pub reformat_on_paste: String,
+    pub escape_on_paste: bool,
    pub smart_indent: bool,
    /// Enter › Insert documentation comment stub: Enter after `/**` closes the comment.
    pub insert_doc_stub: bool,
@@ -268,6 +279,7 @@ impl Default for SmartKeysSettings {
            surround_selection: true,
            tab_out_of_pair: true,
            reformat_on_paste: "indentEachLine".into(),
+            escape_on_paste: true,
            smart_indent: true,
            insert_doc_stub: true,
            backspace_unindent: "autoindent".into(),
@@ -464,3 +476,24 @@ impl Default for EncodingSettings {
        }
    }
 }
+
+#[cfg(test)]
+mod auto_import_tests {
+    use super::{AutoImportSettings, ImportsOnPaste};
+
+    #[test]
+    fn imports_on_paste_defaults_to_ask_for_existing_settings() {
+        let settings: AutoImportSettings = serde_json::from_str(r#"{"addUnambiguous":true}"#).unwrap();
+        assert!(settings.add_unambiguous);
+        assert_eq!(settings.imports_on_paste, ImportsOnPaste::Ask);
+    }
+
+    #[test]
+    fn imports_on_paste_modes_round_trip() {
+        for mode in ["ask", "always", "never"] {
+            let json = serde_json::json!({ "importsOnPaste": mode });
+            let settings: AutoImportSettings = serde_json::from_value(json).unwrap();
+            assert_eq!(serde_json::to_value(settings).unwrap()["importsOnPaste"], mode);
+        }
+    }
+}
@@ -10,11 +10,27 @@ use serde::{Deserialize, Serialize};
 use specta::Type;
 use std::sync::Arc;

+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(tag = "type", rename_all = "camelCase", rename_all_fields = "camelCase")]
+pub enum McpUiRequest {
+    Confirm { client: String, tool: String, subject: String, project: String, detail: Option<String> },
+    OpenFile { path: crate::IpcPath, line: Option<u32>, column: Option<u32> },
+}
+
 #[derive(Clone, Debug, Serialize, Deserialize, Type)]
 #[serde(tag = "type", rename_all = "camelCase", rename_all_fields = "camelCase")]
 pub enum IdeEvent {
+    McpRequest {
+        id: u32,
+        request: McpUiRequest,
+    },
+    McpRequestClosed {
+        id: u32,
+    },
    /// Project window membership or selection changed.
    WindowGroupsChanged,
+    /// A window entered or left full screen, itself or as a member of a full-screen window group.
+    WindowFullscreenChanged,
    ProjectTrustChanged {
        root: crate::IpcPath,
        trusted: bool,
@@ -0,0 +1,124 @@
+//! Go workspace module paths shared by project builds and run detection.
+use std::path::PathBuf;
+
+/// Module directories from a go.work file. Quoted paths and comments follow Go's file syntax.
+pub fn work_modules(text: &str) -> Vec<PathBuf> {
+    let mut tokens = Vec::new();
+    let mut chars = text.chars().peekable();
+    while let Some(ch) = chars.next() {
+        match ch {
+            '\n' | '(' | ')' => tokens.push(ch.to_string()),
+            ch if ch.is_whitespace() => {}
+            '/' if chars.peek() == Some(&'/') => {
+                for c in chars.by_ref() {
+                    if c == '\n' {
+                        tokens.push("\n".into());
+                        break;
+                    }
+                }
+            }
+            '"' | '`' => {
+                let Some(token) = quoted_work_path(&mut chars, ch) else { return Vec::new() };
+                tokens.push(token);
+            }
+            _ => {
+                let mut token = ch.to_string();
+                while chars.peek().is_some_and(|c| !c.is_whitespace() && *c != '(' && *c != ')') {
+                    token.push(chars.next().unwrap());
+                }
+                tokens.push(token);
+            }
+        }
+    }
+    let mut out = Vec::new();
+    let mut start = true;
+    let mut tokens = tokens.into_iter();
+    while let Some(token) = tokens.next() {
+        if token == "\n" {
+            start = true;
+            continue;
+        }
+        if start
+            && token == "use"
+            && let Some(path) = tokens.next()
+        {
+            if path == "(" {
+                let mut paths = Vec::new();
+                let mut closed = false;
+                for path in tokens.by_ref() {
+                    if path == ")" {
+                        closed = true;
+                        break;
+                    }
+                    if path != "\n" && !path.is_empty() {
+                        paths.push(PathBuf::from(path));
+                    }
+                }
+                if closed {
+                    out.extend(paths);
+                }
+            } else if path != "\n" && !path.is_empty() {
+                out.push(PathBuf::from(path));
+            }
+        }
+        start = false;
+    }
+    let mut seen = std::collections::HashSet::new();
+    out.retain(|path| seen.insert(path.clone()));
+    out
+}
+
+fn quoted_work_path(chars: &mut std::iter::Peekable<std::str::Chars<'_>>, quote: char) -> Option<String> {
+    let mut bytes = Vec::new();
+    while let Some(ch) = chars.next() {
+        if ch == quote {
+            return String::from_utf8(bytes).ok();
+        }
+        if ch == '\\' && quote == '"' {
+            let escaped = chars.next()?;
+            let byte = match escaped {
+                'a' => 7,
+                'b' => 8,
+                'f' => 12,
+                'n' => 10,
+                'r' => 13,
+                't' => 9,
+                'v' => 11,
+                '\\' => b'\\',
+                '"' => b'"',
+                'x' => {
+                    let digits: String = chars.by_ref().take(2).collect();
+                    if digits.len() != 2 {
+                        return None;
+                    }
+                    u8::from_str_radix(&digits, 16).ok()?
+                }
+                'u' | 'U' => {
+                    let width = if escaped == 'u' { 4 } else { 8 };
+                    let digits: String = chars.by_ref().take(width).collect();
+                    if digits.len() != width {
+                        return None;
+                    }
+                    let ch = char::from_u32(u32::from_str_radix(&digits, 16).ok()?)?;
+                    bytes.extend_from_slice(ch.to_string().as_bytes());
+                    continue;
+                }
+                '0'..='7' => {
+                    let digits = format!("{escaped}{}", chars.by_ref().take(2).collect::<String>());
+                    if digits.len() != 3 {
+                        return None;
+                    }
+                    u8::from_str_radix(&digits, 8).ok()?
+                }
+                _ => return None,
+            };
+            bytes.push(byte);
+        } else {
+            if ch == '\n' && quote == '"' {
+                return None;
+            }
+            bytes.extend_from_slice(ch.to_string().as_bytes());
+        }
+    }
+    None
+}
@@ -7,6 +7,7 @@
 pub mod editor_settings;
 pub mod error;
 pub mod event;
+pub mod go;
 pub mod ids;
 pub mod ignored;
 pub mod inspection_settings;
@@ -299,9 +299,11 @@ fn appimage_fixes() -> Vec<(OsString, Option<OsString>)> {
 const APPIMAGE_LAUNCH_VARS: [&str; 4] = ["APPDIR", "APPIMAGE", "ARGV0", "OWD"];

 /// What to change in `vars` (an environment) so a child sees the host's environment rather
-/// than the AppImage's: every `:`-separated entry inside `$APPDIR` is dropped (a saved
-/// `<NAME>_ORIG` wins when present), variables left empty are removed, and so are the
-/// runtime's own launch variables. Nothing changes when `APPDIR` is not set.
+/// than the AppImage's: every `:`-separated entry inside `$APPDIR` — or inside *any*
+/// AppImage mount, since an in-app update restart inherits the previous mount's entries
+/// alongside the new one — is dropped (a saved `<NAME>_ORIG` wins when present),
+/// variables left empty are removed, and so are the runtime's own launch variables.
+/// Nothing changes when `APPDIR` is not set.
 fn appimage_env_fixes(vars: &[(OsString, OsString)]) -> Vec<(OsString, Option<OsString>)> {
    let get = |name: &str| vars.iter().find(|(k, _)| k == name).map(|(_, v)| v);
    let Some(appdir) =
@@ -309,7 +311,12 @@ fn appimage_env_fixes(vars: &[(OsString, OsString)]) -> Vec<(OsString, Option<Os
    else {
        return Vec::new();
    };
-    let inside = |entry: &str| entry.strip_prefix(appdir).is_some_and(|rest| rest.is_empty() || rest.starts_with('/'));
+    let inside = |entry: &str| {
+        let own = entry.strip_prefix(appdir).is_some_and(|rest| rest.is_empty() || rest.starts_with('/'));
+        // AppImages extract to `/tmp/.mount_<name>`; an entry under another mount is
+        // another image's (e.g. the pre-update one a restart inherited), never the host's.
+        own || entry.starts_with("/tmp/.mount_")
+    };
    let mut fixes = Vec::new();
    for (key, value) in vars {
        let (Some(name), Some(value)) = (key.to_str(), value.to_str()) else { continue };
@@ -715,7 +722,7 @@ mod tests {
            ("PATH", "/tmp/.mount_OpenIDabc/usr/bin/:/tmp/.mount_OpenIDabc/usr/sbin/:/usr/local/bin:/usr/bin"),
            ("XDG_DATA_DIRS", "/tmp/.mount_OpenIDabc/usr/share:/usr/share:/usr/local/share:/usr/share"),
            ("HOME", "/home/me"),
-            ("JAVA_HOME", "/tmp/.mount_OpenIDabcdef/jdk"),
+            ("JAVA_HOME", "/opt/jdk"),
        ]);
        assert_eq!(
            got,
@@ -728,6 +735,27 @@ mod tests {
        );
    }

+    #[test]
+    fn entries_of_a_previous_updates_mount_are_dropped() {
+        // An in-app update restart inherits the old mount's entries: a child's curl
+        // must not load the old image's libraries (they can still be mounted).
+        let got = fixes(&[
+            ("APPDIR", "/tmp/.mount_OpenIDjIlFFA"),
+            ("LD_LIBRARY_PATH", "/tmp/.mount_OpenIDjIlFFA/usr/lib/:/tmp/.mount_OpenIDdaNGfM/usr/lib/:/usr/local/lib"),
+            ("PATH", "/tmp/.mount_OpenIDjIlFFA/usr/bin/:/tmp/.mount_OpenIDdaNGfM/usr/bin/:/usr/bin"),
+            ("GIO_MODULE_DIR", "/tmp/.mount_OpenIDdaNGfM/usr/lib/gio/modules"),
+        ]);
+        assert_eq!(
+            got,
+            [
+                fix("APPDIR", None),
+                fix("LD_LIBRARY_PATH", Some("/usr/local/lib")),
+                fix("PATH", Some("/usr/bin")),
+                fix("GIO_MODULE_DIR", None),
+            ]
+        );
+    }
+
    #[test]
    fn variables_left_empty_are_removed() {
        // AppRun prepends to an unset variable, leaving a trailing `:`; hooks set single paths.
@@ -1,5 +1,6 @@
 //! Shared filesystem rules for discovering builds and resolving their owners.

+use std::collections::HashSet;
 use std::path::{Component, Path, PathBuf};

 pub const SEARCH_DEPTH: usize = 3;
@@ -35,10 +36,23 @@ pub fn discover_matching(
    max_depth: usize,
    stop_at_match: bool,
    marked: impl Fn(&Path) -> bool,
+) -> Vec<PathBuf> {
+    discover_matching_cancellable(root, max_depth, stop_at_match, &crate::CancellationToken::new(), marked)
+}
+
+pub fn discover_matching_cancellable(
+    root: &Path,
+    max_depth: usize,
+    stop_at_match: bool,
+    cancel: &crate::CancellationToken,
+    marked: impl Fn(&Path) -> bool,
 ) -> Vec<PathBuf> {
    let mut found = Vec::new();
    let mut pending = vec![(root.to_path_buf(), 0)];
    while let Some((dir, depth)) = pending.pop() {
+        if cancel.is_cancelled() {
+            break;
+        }
        if marked(&dir) {
            found.push(dir.clone());
            if stop_at_match {
@@ -66,6 +80,70 @@ pub fn discover_matching(
    found
 }

+/// Expands workspace member patterns one level deep: `dir`, `dir/*`, `dir/**`.
+pub fn expand_members(root: &Path, patterns: &[String], marker: &str) -> Vec<PathBuf> {
+    let mut dirs = Vec::new();
+    for pattern in patterns {
+        let pattern = pattern.trim().trim_start_matches("./").trim_end_matches('/');
+        if pattern.is_empty() || pattern.starts_with('!') {
+            continue;
+        }
+        let base = pattern.strip_suffix("/**").or_else(|| pattern.strip_suffix("/*"));
+        match base {
+            Some(base) if !base.contains('*') => {
+                dirs.extend(children(&root.join(base)).into_iter().filter(|d| d.join(marker).is_file()))
+            }
+            None if !pattern.contains('*') => {
+                let dir = root.join(pattern);
+                if dir.join(marker).is_file() {
+                    dirs.push(dir);
+                }
+            }
+            _ => {}
+        }
+    }
+    let mut seen = HashSet::new();
+    dirs.retain(|d| seen.insert(d.clone()));
+    dirs
+}
+
+pub fn node_workspace_members(root: &Path) -> Vec<PathBuf> {
+    let package = std::fs::read(root.join("package.json"))
+        .ok()
+        .and_then(|bytes| serde_json::from_slice::<serde_json::Value>(&bytes).ok())
+        .unwrap_or_default();
+    expand_members(root, &node_workspace_patterns(root, &package), "package.json")
+}
+
+fn node_workspace_patterns(root: &Path, pkg: &serde_json::Value) -> Vec<String> {
+    let mut patterns: Vec<String> = Vec::new();
+    let ws = pkg.get("workspaces");
+    let list = ws
+        .and_then(serde_json::Value::as_array)
+        .or_else(|| ws.and_then(|w| w.get("packages")).and_then(serde_json::Value::as_array));
+    if let Some(list) = list {
+        patterns.extend(list.iter().filter_map(serde_json::Value::as_str).map(str::to_owned));
+    }
+    if let Ok(yaml) = std::fs::read_to_string(root.join("pnpm-workspace.yaml")) {
+        let mut in_packages = false;
+        for line in yaml.lines() {
+            let trimmed = line.trim();
+            if trimmed.is_empty() || trimmed.starts_with('#') {
+                continue;
+            }
+            if !line.starts_with([' ', '\t', '-']) {
+                in_packages = trimmed.starts_with("packages:");
+                continue;
+            }
+            if in_packages && let Some(item) = trimmed.strip_prefix('-') {
+                let item = item.split(" #").next().unwrap_or_default().trim().trim_matches(['"', '\'']);
+                patterns.push(item.to_owned());
+            }
+        }
+    }
+    patterns
+}
+
 /// The closest package manager declaration or lockfile, shared by build and run.
 pub fn package_manager(root: &Path) -> &'static str {
    for dir in root.ancestors() {
@@ -61,6 +61,8 @@ pub struct Settings {
    pub cmake: CMakeSettings,
    /// Tools › Agents › Chat.
    pub agents: AgentSettings,
+    /// Tools › MCP Server (global only).
+    pub mcp_server: McpServerSettings,
    /// Plugin settings (`[contributes.settings]`): plugin id → its values by key.
    #[specta(type = BTreeMap<String, BTreeMap<String, specta_typescript::Unknown>>)]
    pub plugins: BTreeMap<String, serde_json::Map<String, serde_json::Value>>,
@@ -86,6 +88,14 @@ impl Default for AgentSettings {
    }
 }

+/// Tools › MCP Server: agents use the IDE's built-in tools.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct McpServerSettings {
+    /// Serve the tools on 127.0.0.1 while the IDE runs.
+    pub enabled: bool,
+}
+
 /// Absent profiles retain automatic discovery for existing projects.
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
@@ -230,6 +240,7 @@ impl Default for Settings {
            run_targets: Vec::new(),
            cmake: CMakeSettings::default(),
            agents: AgentSettings::default(),
+            mcp_server: McpServerSettings::default(),
            plugins: BTreeMap::new(),
        }
    }
@@ -850,6 +861,8 @@ pub struct JavaSettings {
    /// Project JDK home; empty = per module, the installed JDK matching the
    /// Java version it targets.
    pub jdk: String,
+    /// Project Java language level (`8`, `11`, `17`, `21`, `25`); empty = SDK default.
+    pub language_level: String,
    /// JDK home the Java language server (jdtls) runs on, apart from the project
    /// JDK (IDEA's "JDK for importer"); empty = the project JDK when new enough,
    /// else the first installed one that is.
@@ -903,6 +916,8 @@ pub enum GradleDistribution {
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct MavenSettings {
+    /// JDK home used to run Maven; empty = Project JDK, else the POM's Java version.
+    pub runner_jre: String,
    /// Project-relative root POMs removed from the Maven project model.
    pub unlinked_projects: Vec<String>,
    /// Project-relative POMs outside the root reactor added as independent top-level projects.
@@ -953,6 +968,98 @@ impl Default for TypeScriptSettings {
    }
 }

+/// Dependency scope for a module dependency or project library (IDEA's Modules › Dependencies).
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum DependencyScope {
+    #[default]
+    Compile,
+    Test,
+    Runtime,
+    Provided,
+}
+
+/// A project-level library (Project Structure › Libraries).
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct ProjectLibrary {
+    pub name: String,
+    /// Class archives (`.jar`) or class directories.
+    pub classes: Vec<String>,
+    /// Source archives (`-sources.jar`, `.zip`) or source directories.
+    pub sources: Vec<String>,
+    /// Documentation archives (`-javadoc.jar`) or directories.
+    pub javadocs: Vec<String>,
+    pub scope: DependencyScope,
+}
+
+/// Dependency entry of a module (Project Structure › Modules › Dependencies).
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct ModuleDependency {
+    /// `"library"` (references a `ProjectLibrary` by name or path) or `"module"` (references another module).
+    pub kind: String,
+    pub target: String,
+    pub scope: DependencyScope,
+    pub exported: bool,
+}
+
+/// Per-module Project Structure overrides (SDK, language level, output paths, dependencies).
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct ModuleStructureSettings {
+    /// Module SDK home override; empty = inherit Project SDK.
+    pub jdk: String,
+    /// Module language level override; empty = inherit Project language level.
+    pub language_level: String,
+    /// Module compiler output directory override; empty = inherit Project compiler output.
+    pub compiler_output: String,
+    /// Module test compiler output directory override; empty = default.
+    pub test_compiler_output: String,
+    /// Additional module dependencies.
+    pub dependencies: Vec<ModuleDependency>,
+}
+
+/// Framework facet attached to a module (Project Structure › Facets).
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct FacetConfig {
+    /// `"web"` | `"spring"` | `"jpa"`.
+    pub kind: String,
+    /// Module relative path (`"."` for root module).
+    pub module: String,
+    /// Deployment descriptor path (e.g. `src/main/webapp/WEB-INF/web.xml`, `src/main/resources/META-INF/persistence.xml`).
+    pub descriptor: String,
+    /// Web resource root directory for Web facets (e.g. `src/main/webapp`).
+    pub web_root: String,
+}
+
+/// Packaging type of a Project Structure artifact.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum ArtifactKind {
+    #[default]
+    Jar,
+    War,
+    WarExploded,
+}
+
+/// Packaging artifact definition (Project Structure › Artifacts).
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct ArtifactConfig {
+    pub name: String,
+    pub kind: ArtifactKind,
+    /// Module relative path (`"."` for root module).
+    pub module: String,
+    /// Output directory (relative to project root or absolute).
+    pub output_directory: String,
+    /// Main class for executable JAR artifacts.
+    pub main_class: String,
+    /// Project library names included in the packaged artifact (`WEB-INF/lib` or JAR manifest).
+    pub include_libraries: Vec<String>,
+}
+
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct ProjectStructureSettings {
@@ -969,9 +1076,28 @@ pub struct ProjectStructureSettings {
    pub content_roots: Vec<String>,
    /// "Exclude files": `;`-separated name patterns (`*.log;tmp*`) excluded at any depth.
    pub exclude_files: String,
+    /// Project compiler output directory (relative to project root or absolute; empty = default).
+    pub compiler_output: String,
+    /// Per-module SDK, language level, output paths and dependency overrides, keyed by module relative path (`"."` for root).
+    pub modules: BTreeMap<String, ModuleStructureSettings>,
+    /// Project-level libraries (`JAR`s / class folders / source archives).
+    pub libraries: Vec<ProjectLibrary>,
+    /// Module framework facets (`web`, `spring`, `jpa`).
+    pub facets: Vec<FacetConfig>,
+    /// Packaging artifacts (`jar`, `war`, `warExploded`).
+    pub artifacts: Vec<ArtifactConfig>,
 }

 impl ProjectStructureSettings {
+    /// Overrides belong to the module's full path, never just its directory name.
+    pub fn module_settings(
+        &self,
+        root: &std::path::Path,
+        module: &std::path::Path,
+    ) -> Option<&ModuleStructureSettings> {
+        self.modules.iter().find_map(|(key, settings)| (root.join(key) == module).then_some(settings))
+    }
+
    /// The "Exclude files" name patterns.
    pub fn exclude_file_patterns(&self) -> Vec<String> {
        self.exclude_files.split(';').map(str::trim).filter(|p| !p.is_empty()).map(str::to_owned).collect()
@@ -1152,12 +1278,81 @@ mod tests {
        assert_eq!(s.file_excludes(), vec!["*.log", "tmp*"]);
        assert!(Settings::default().files.file_types.is_empty());
    }
+
+    #[test]
+    fn project_structure_modules_libraries_facets_and_artifacts_round_trip() {
+        let old: Settings = serde_json::from_str(r#"{"projectStructure":{"sourceRoots":["src"]}}"#).unwrap();
+        assert!(old.project_structure.compiler_output.is_empty());
+        assert!(old.project_structure.modules.is_empty());
+        assert!(old.project_structure.libraries.is_empty());
+        assert!(old.project_structure.facets.is_empty());
+        assert!(old.project_structure.artifacts.is_empty());
+        assert!(old.languages.java.language_level.is_empty());
+
+        let mut settings = Settings::default();
+        settings.languages.java.language_level = "21".into();
+        settings.project_structure.compiler_output = "out/production".into();
+        settings.project_structure.modules.insert(
+            "backend".into(),
+            ModuleStructureSettings {
+                jdk: "/opt/jdk-21".into(),
+                language_level: "21".into(),
+                compiler_output: "backend/target/classes".into(),
+                test_compiler_output: "backend/target/test-classes".into(),
+                dependencies: vec![ModuleDependency {
+                    kind: "library".into(),
+                    target: "custom-lib".into(),
+                    scope: DependencyScope::Compile,
+                    exported: true,
+                }],
+            },
+        );
+        settings.project_structure.libraries.push(ProjectLibrary {
+            name: "custom-lib".into(),
+            classes: vec!["lib/custom.jar".into()],
+            sources: vec!["lib/custom-sources.jar".into()],
+            javadocs: Vec::new(),
+            scope: DependencyScope::Compile,
+        });
+        settings.project_structure.facets.push(FacetConfig {
+            kind: "web".into(),
+            module: "backend".into(),
+            descriptor: "src/main/webapp/WEB-INF/web.xml".into(),
+            web_root: "src/main/webapp".into(),
+        });
+        settings.project_structure.artifacts.push(ArtifactConfig {
+            name: "backend:war exploded".into(),
+            kind: ArtifactKind::WarExploded,
+            module: "backend".into(),
+            output_directory: "out/artifacts/backend_war_exploded".into(),
+            main_class: String::new(),
+            include_libraries: vec!["custom-lib".into()],
+        });
+
+        let value = serde_json::to_value(&settings).unwrap();
+        assert_eq!(value["languages"]["java"]["languageLevel"], "21");
+        assert_eq!(value["projectStructure"]["compilerOutput"], "out/production");
+        assert_eq!(value["projectStructure"]["artifacts"][0]["kind"], "warExploded");
+        let restored: Settings = serde_json::from_value(value).unwrap();
+        assert_eq!(restored, settings);
+    }
 }

 #[cfg(test)]
 mod maven_linkage_tests {
    use super::*;

+    #[test]
+    fn maven_runner_jre_defaults_and_round_trips() {
+        let old: MavenSettings = serde_json::from_str(r#"{"home":"/opt/maven"}"#).unwrap();
+        assert!(old.runner_jre.is_empty());
+        assert!(MavenSettings::default().runner_jre.is_empty());
+        let settings = MavenSettings { runner_jre: "/opt/jdk-21".into(), ..old };
+        let encoded = serde_json::to_string(&settings).unwrap();
+        assert!(encoded.contains(r#""runnerJre":"/opt/jdk-21""#));
+        assert_eq!(serde_json::from_str::<MavenSettings>(&encoded).unwrap(), settings);
+    }
+
    #[test]
    fn maven_linkage_defaults_and_round_trips() {
        let old: MavenSettings = serde_json::from_str(r#"{"home":"/opt/maven"}"#).unwrap();
@@ -12,14 +12,17 @@ use ide_core::{CancellationToken, IdeError, IdeResult, error::ErrorKind};
 use serde::{Deserialize, Serialize};
 use specta::Type;
 use sqlx::{
-    Column, ColumnIndex, Connection, Decode, Executor, MySql, Postgres, Row, SqlSafeStr, Sqlite, TypeInfo, ValueRef,
-    mysql::{MySqlConnectOptions, MySqlPool, MySqlPoolOptions, MySqlSslMode},
+    Column, ColumnIndex, Connection, Decode, Executor, Row, SqlSafeStr, Sqlite, TypeInfo, ValueRef,
+    mysql::{MySqlConnectOptions, MySqlConnection, MySqlSslMode},
    pool::PoolConnection,
-    postgres::{PgConnectOptions, PgPool, PgPoolOptions, PgSslMode},
+    postgres::{PgConnectOptions, PgConnection, PgSslMode},
    sqlite::{SqliteConnectOptions, SqlitePool, SqlitePoolOptions},
 };
 use std::path::{Path, PathBuf};
-use std::sync::Arc;
+use std::sync::{
+    Arc,
+    atomic::{AtomicBool, Ordering},
+};
 use std::time::{Duration, Instant};

 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Type)]
@@ -47,12 +50,135 @@ pub struct QueryResult {
    pub execution_ms: f64,
 }

+/// Session context belongs to the physical connection, including across pool checkouts.
+#[derive(Debug, Clone)]
+pub struct Context {
+    default: Option<String>,
+    current: Option<String>,
+    known: bool,
+}
+
+impl Context {
+    pub(crate) fn new(default: Option<String>) -> Self {
+        Self { current: default.clone(), default, known: true }
+    }
+
+    pub(crate) fn set_current(&mut self, current: Option<String>) {
+        self.current = current;
+    }
+
+    fn wanted(&self, driver: DbDriver, schema: Option<&str>) -> Option<String> {
+        schema
+            .filter(|s| !s.is_empty())
+            .and_then(|s| crate::sql::use_schema(driver, s))
+            .or_else(|| self.default.clone())
+    }
+}
+
+macro_rules! sqlx_pool {
+    ($manager:ident, $handle:ident, $options:ty, $connection:ty, $driver:expr, $query:expr) => {
+        pub struct $manager {
+            options: $options,
+            init: Arc<Vec<String>>,
+            timeout: Duration,
+        }
+
+        pub struct $handle {
+            conn: Option<$connection>,
+            context: Context,
+            options: $options,
+            init: Arc<Vec<String>>,
+            timeout: Duration,
+            in_transaction: bool,
+        }
+
+        impl std::ops::Deref for $handle {
+            type Target = $connection;
+            fn deref(&self) -> &Self::Target {
+                self.conn.as_ref().expect("live connection")
+            }
+        }
+
+        impl std::ops::DerefMut for $handle {
+            fn deref_mut(&mut self) -> &mut Self::Target {
+                self.conn.as_mut().expect("live connection")
+            }
+        }
+
+        impl ManageConnection for $manager {
+            type Connection = $handle;
+            type Error = sqlx::Error;
+
+            async fn connect(&self) -> Result<Self::Connection, Self::Error> {
+                tokio::time::timeout(self.timeout, async {
+                    let mut conn = <$connection>::connect_with(&self.options).await?;
+                    let context_sql = |value: Option<String>| {
+                        value.map(|v| {
+                            if $driver == DbDriver::Postgres {
+                                format!("SET search_path TO {v}")
+                            } else {
+                                crate::sql::use_schema($driver, &v).expect("switchable driver")
+                            }
+                        })
+                    };
+                    for sql in self.init.iter() {
+                        sqlx::raw_sql(sqlx::AssertSqlSafe(sql.clone())).execute(&mut conn).await?;
+                    }
+                    let row = sqlx::raw_sql(sqlx::AssertSqlSafe($query.to_owned())).fetch_one(&mut conn).await?;
+                    let context = Context::new(context_sql(row.try_get(0)?));
+                    Ok($handle {
+                        conn: Some(conn),
+                        context,
+                        options: self.options.clone(),
+                        init: self.init.clone(),
+                        timeout: self.timeout,
+                        in_transaction: false,
+                    })
+                })
+                .await
+                .map_err(|_| sqlx::Error::PoolTimedOut)?
+            }
+
+            async fn is_valid(&self, conn: &mut Self::Connection) -> Result<(), Self::Error> {
+                conn.ping().await
+            }
+
+            fn has_broken(&self, conn: &mut Self::Connection) -> bool {
+                conn.conn.is_none()
+            }
+        }
+    };
+}
+
+sqlx_pool!(PgManager, PgHandle, PgConnectOptions, PgConnection, DbDriver::Postgres, "SHOW search_path");
+sqlx_pool!(MysqlManager, MysqlHandle, MySqlConnectOptions, MySqlConnection, DbDriver::Mysql, "SELECT DATABASE()");
+
+pub struct ServerPool<M: ManageConnection> {
+    inner: Bb8Pool<M>,
+    closed: AtomicBool,
+}
+
+impl<M: ManageConnection> ServerPool<M> {
+    async fn get(&self) -> IdeResult<bb8::PooledConnection<'static, M>>
+    where
+        M::Error: std::fmt::Display,
+    {
+        if self.closed.load(Ordering::Relaxed) {
+            return Err(IdeError::new(ErrorKind::Io, "database connection is closed"));
+        }
+        self.inner.get_owned().await.map_err(|e| match e {
+            bb8::RunError::User(e) => IdeError::new(ErrorKind::Io, e.to_string()),
+            bb8::RunError::TimedOut => IdeError::new(ErrorKind::Io, "timed out connecting to the database"),
+        })
+    }
+}
+
 // Keep an empty slot when a connection is discarded after cancellation or rollback failure.
 pub struct MssqlConnectionManager(tiberius::Config);

 type MssqlClient = tiberius::Client<tokio_util::compat::Compat<tokio::net::TcpStream>>;

-pub struct MssqlConnection(Option<MssqlClient>);
+pub struct MssqlConnection(Option<MssqlClient>, Context);

 impl std::ops::Deref for MssqlConnection {
    type Target = MssqlClient;
@@ -76,7 +202,7 @@ impl ManageConnection for MssqlConnectionManager {

        let tcp = tokio::net::TcpStream::connect(self.0.get_addr()).await?;
        tcp.set_nodelay(true)?;
-        let client = match MssqlClient::connect(self.0.clone(), tcp.compat_write()).await {
+        let mut client = match MssqlClient::connect(self.0.clone(), tcp.compat_write()).await {
            // Preserve the single redirect supported by the previous pool adapter.
            Err(tiberius::error::Error::Routing { host, port }) => {
                let mut config = self.0.clone();
@@ -88,7 +214,11 @@ impl ManageConnection for MssqlConnectionManager {
            }
            result => result?,
        };
-        Ok(MssqlConnection(Some(client)))
+        let row = client.simple_query("SELECT DB_NAME()").await?.into_row().await?;
+        let default = row
+            .and_then(|r| r.get::<&str, _>(0).map(str::to_owned))
+            .and_then(|db| crate::sql::use_schema(DbDriver::SqlServer, &db));
+        Ok(MssqlConnection(Some(client), Context::new(default)))
    }

    async fn is_valid(&self, conn: &mut Self::Connection) -> Result<(), Self::Error> {
@@ -103,25 +233,13 @@ impl ManageConnection for MssqlConnectionManager {

 pub enum Pool {
    Sqlite(SqlitePool),
-    Postgres(PgPool),
-    Mysql(MySqlPool),
+    Postgres(ServerPool<PgManager>),
+    Mysql(ServerPool<MysqlManager>),
    SqlServer(Bb8Pool<MssqlConnectionManager>),
    Clickhouse(crate::clickhouse::ClickhousePool),
    Oracle(crate::oracle::OraclePool),
 }

-/// Runs `$body` with `$p` bound to the concrete pool of each driver.
-macro_rules! with_pool {
-    ($pool:expr, $p:ident => $body:expr) => {
-        match $pool {
-            Pool::Sqlite($p) => $body,
-            Pool::Postgres($p) => $body,
-            Pool::Mysql($p) => $body,
-            Pool::SqlServer(_) | Pool::Clickhouse(_) | Pool::Oracle(_) => unreachable!(),
-        }
-    };
-}
-
 pub(crate) fn db_err(e: sqlx::Error) -> IdeError {
    match &e {
        sqlx::Error::Database(d) => {
@@ -438,6 +556,19 @@ macro_rules! backend_id {
    }};
 }

+// Session control, scripts and PostgreSQL set_config can invalidate the tracked context.
+fn context_may_change(sql: &str) -> bool {
+    let text = sql.trim().trim_end_matches(';');
+    text.contains(';')
+        || text.to_ascii_lowercase().contains("set_config")
+        || !text.split_whitespace().next().is_some_and(|s| {
+            matches!(
+                s.to_ascii_uppercase().as_str(),
+                "SELECT" | "INSERT" | "UPDATE" | "DELETE" | "CREATE" | "DROP" | "TRUNCATE" | "SHOW" | "EXPLAIN"
+            )
+        })
+}
+
 fn looks_like_query(sql: &str) -> bool {
    let first = sql
        .lines()
@@ -535,7 +666,13 @@ impl Setup {
                    return Err(IdeError::invalid("ClickHouse HTTP does not support statement caching"));
                }
                (_, "statement_cache_capacity") => s.statement_cache = Some(number(&name)? as usize),
-                (_, "connect_timeout") => s.connect_timeout = Some(Duration::from_secs(number(&name)?)),
+                (_, "connect_timeout") => {
+                    let seconds = number(&name)?;
+                    if seconds == 0 {
+                        return Err(IdeError::invalid("connect_timeout must be greater than zero"));
+                    }
+                    s.connect_timeout = Some(Duration::from_secs(seconds));
+                }
                (DbDriver::Postgres, "application_name") => s.application_name = Some(value.to_owned()),
                (DbDriver::Mysql, "charset") => s.charset = Some(value.to_owned()),
                (DbDriver::Mysql, "collation") => s.collation = Some(value.to_owned()),
@@ -662,14 +799,12 @@ impl Pool {
                if let Some(n) = setup.statement_cache {
                    opts = opts.statement_cache_capacity(n);
                }
-                let pool = PgPoolOptions::new()
-                    .max_connections(MAX)
-                    .acquire_timeout(timeout)
-                    .after_connect(after_connect!())
-                    .connect_with(opts)
-                    .await
-                    .map_err(db_err)?;
-                Ok(Pool::Postgres(pool))
+                let manager = PgManager { options: opts, init: init.clone(), timeout };
+                // Open once directly so authentication failures retain their database error.
+                let first = manager.connect().await.map_err(db_err)?;
+                let pool = Bb8Pool::builder().max_size(MAX).connection_timeout(timeout).build_unchecked(manager);
+                let _ = pool.add(first);
+                Ok(Pool::Postgres(ServerPool { inner: pool, closed: AtomicBool::new(false) }))
            }
            DbDriver::Mysql => {
                let mut opts = MySqlConnectOptions::new()
@@ -711,14 +846,12 @@ impl Pool {
                if !tz.is_empty() {
                    opts = opts.timezone(Some(tz.to_owned()));
                }
-                let pool = MySqlPoolOptions::new()
-                    .max_connections(MAX)
-                    .acquire_timeout(timeout)
-                    .after_connect(after_connect!())
-                    .connect_with(opts)
-                    .await
-                    .map_err(db_err)?;
-                Ok(Pool::Mysql(pool))
+                let manager = MysqlManager { options: opts, init: init.clone(), timeout };
+                // Open once directly so authentication failures retain their database error.
+                let first = manager.connect().await.map_err(db_err)?;
+                let pool = Bb8Pool::builder().max_size(MAX).connection_timeout(timeout).build_unchecked(manager);
+                let _ = pool.add(first);
+                Ok(Pool::Mysql(ServerPool { inner: pool, closed: AtomicBool::new(false) }))
            }
            DbDriver::SqlServer => {
                use tiberius::Config;
@@ -757,7 +890,9 @@ impl Pool {
        match self {
            Pool::SqlServer(_) | Pool::Oracle(_) => {}
            Pool::Clickhouse(p) => p.close(),
-            _ => with_pool!(self, p => p.close().await),
+            Pool::Sqlite(p) => p.close().await,
+            Pool::Postgres(p) => p.closed.store(true, Ordering::Relaxed),
+            Pool::Mysql(p) => p.closed.store(true, Ordering::Relaxed),
        }
    }

@@ -766,7 +901,9 @@ impl Pool {
            Pool::SqlServer(_) => false,
            Pool::Oracle(p) => p.is_closed(),
            Pool::Clickhouse(p) => p.is_closed(),
-            _ => with_pool!(self, p => p.is_closed()),
+            Pool::Sqlite(p) => p.is_closed(),
+            Pool::Postgres(p) => p.closed.load(Ordering::Relaxed),
+            Pool::Mysql(p) => p.closed.load(Ordering::Relaxed),
        }
    }

@@ -775,18 +912,9 @@ impl Pool {
        if let Pool::Clickhouse(p) = self {
            return Ok(p.execute(sql, max, &CancellationToken::new()).await?.rows);
        }
-        if let Pool::Oracle(p) = self {
-            let mut conn = p.get().await?;
-            let fetched = crate::oracle::run(&mut conn, sql, 0, max, Cells::Text, &CancellationToken::new()).await?;
-            return Ok(fetched.1);
-        }
-        let fetched: IdeResult<Fetched> = match self {
-            Pool::SqlServer(p) => {
-                let mut conn = p.get_owned().await.map_err(mssql_pool_err)?;
-                mssql_fetch(&mut conn, sql, 0, max).await
-            }
-            _ => with_pool!(self, p => fetch!(p, sql, max, Cells::Text)),
-        };
+        let mut conn = Held::acquire(self).await?;
+        conn.apply_context(None).await?;
+        let fetched = conn.fetch_rows(sql, max).await;
        Ok(fetched?.1)
    }

@@ -809,7 +937,10 @@ impl Pool {
            return p.execute_from(sql, skip, max_rows, cancel).await;
        }
        let mut conn = Held::acquire(self).await?;
-        let r = conn.execute_from(self, sql, skip, max_rows, cancel).await;
+        let r = match conn.apply_context(None).await {
+            Ok(()) => conn.execute_from(self, sql, skip, max_rows, cancel).await,
+            Err(e) => Err(e),
+        };
        if cancel.is_cancelled() {
            conn.discard().await;
            return Err(IdeError::cancelled());
@@ -822,8 +953,10 @@ impl Pool {
    pub async fn transaction(&self, statements: &[(String, bool)]) -> IdeResult<u64> {
        match self {
            Pool::Clickhouse(_) => Err(crate::clickhouse::transaction_error()),
-            Pool::SqlServer(p) => {
-                let mut conn = p.get_owned().await.map_err(mssql_pool_err)?;
+            Pool::SqlServer(_) => {
+                let mut held = Held::acquire(self).await?;
+                held.apply_context(None).await?;
+                let Held::SqlServer(mut conn) = held else { unreachable!() };
                let result = async {
                    mssql_command(&mut conn, "BEGIN TRAN").await?;
                    let mut total = 0;
@@ -846,8 +979,10 @@ impl Pool {
                }
                result
            }
-            Pool::Oracle(p) => {
-                let mut conn = p.get().await?;
+            Pool::Oracle(_) => {
+                let mut held = Held::acquire(self).await?;
+                held.apply_context(None).await?;
+                let Held::Oracle(mut conn) = held else { unreachable!() };
                let result = crate::oracle::transaction(&mut conn, statements).await;
                if result.is_err() {
                    // An open transaction must never return to the pool with the connection.
@@ -855,21 +990,37 @@ impl Pool {
                }
                result
            }
-            _ => with_pool!(self, p => {
-                let mut tx = p.begin().await.map_err(db_err)?;
-                let mut total = 0;
-                for (sql, expect_one) in statements {
-                    let done = sqlx::raw_sql(sqlx::AssertSqlSafe(sql.clone())).execute(&mut *tx).await.map_err(db_err)?;
-                    let n = done.rows_affected();
-                    // MySQL reports 0 for an UPDATE that leaves the row unchanged.
-                    if *expect_one && (n > 1 || (n == 0 && !matches!(self, Pool::Mysql(_)))) {
-                        return Err(IdeError::invalid(format!("{sql}: expected to change 1 row, changed {n}; nothing was saved")));
-                    }
-                    total += n;
+            _ => {
+                let mut conn = Held::acquire(self).await?;
+                conn.apply_context(None).await?;
+                macro_rules! transaction {
+                    ($c:expr) => {{
+                        let mut tx = (&mut **$c).begin().await.map_err(db_err)?;
+                        let mut total = 0;
+                        for (sql, expect_one) in statements {
+                            let done = sqlx::raw_sql(sqlx::AssertSqlSafe(sql.clone()))
+                                .execute(&mut *tx)
+                                .await
+                                .map_err(db_err)?;
+                            let n = done.rows_affected();
+                            if *expect_one && (n > 1 || (n == 0 && !matches!(self, Pool::Mysql(_)))) {
+                                return Err(IdeError::invalid(format!(
+                                    "{sql}: expected to change 1 row, changed {n}; nothing was saved"
+                                )));
+                            }
+                            total += n;
+                        }
+                        tx.commit().await.map_err(db_err)?;
+                        Ok(total)
+                    }};
                }
-                tx.commit().await.map_err(db_err)?;
-                Ok(total)
-            }),
+                match &mut conn {
+                    Held::Sqlite(c) => transaction!(c),
+                    Held::Postgres(c) => transaction!(&mut ***c),
+                    Held::Mysql(c) => transaction!(&mut ***c),
+                    _ => unreachable!(),
+                }
+            }
        }
    }
 }
@@ -878,8 +1029,8 @@ impl Pool {
 /// manual-commit console across statements with its transaction open.
 pub enum Held {
    Sqlite(PoolConnection<Sqlite>),
-    Postgres(PoolConnection<Postgres>),
-    Mysql(PoolConnection<MySql>),
+    Postgres(Box<bb8::PooledConnection<'static, PgManager>>),
+    Mysql(Box<bb8::PooledConnection<'static, MysqlManager>>),
    SqlServer(Box<bb8::PooledConnection<'static, MssqlConnectionManager>>),
    Clickhouse(crate::clickhouse::ClickhousePool),
    Oracle(crate::oracle::OracleConnection),
@@ -889,8 +1040,8 @@ impl Held {
    pub async fn acquire(pool: &Pool) -> IdeResult<Self> {
        Ok(match pool {
            Pool::Sqlite(p) => Held::Sqlite(p.acquire().await.map_err(db_err)?),
-            Pool::Postgres(p) => Held::Postgres(p.acquire().await.map_err(db_err)?),
-            Pool::Mysql(p) => Held::Mysql(p.acquire().await.map_err(db_err)?),
+            Pool::Postgres(p) => Held::Postgres(Box::new(p.get().await?)),
+            Pool::Mysql(p) => Held::Mysql(Box::new(p.get().await?)),
            Pool::SqlServer(p) => Held::SqlServer(Box::new(p.get_owned().await.map_err(mssql_pool_err)?)),
            Pool::Clickhouse(p) => {
                if p.is_closed() {
@@ -902,8 +1053,121 @@ impl Held {
        })
    }

+    fn context(&mut self) -> Option<&mut Context> {
+        match self {
+            Held::Postgres(c) => Some(&mut c.context),
+            Held::Mysql(c) => Some(&mut c.context),
+            Held::SqlServer(c) => Some(&mut c.1),
+            Held::Oracle(c) => Some(c.context()),
+            _ => None,
+        }
+    }
+
+    fn invalidate_context(&mut self) {
+        if let Some(context) = self.context() {
+            context.known = false;
+        }
+    }
+
+    fn before_statement(&mut self, sql: &str) {
+        let control = sql.trim().trim_end_matches(';').trim().to_ascii_uppercase();
+        if let Held::Mysql(c) = self {
+            if matches!(control.as_str(), "BEGIN" | "START TRANSACTION") {
+                c.in_transaction = true;
+                return;
+            }
+            if matches!(control.as_str(), "COMMIT" | "ROLLBACK") {
+                return;
+            }
+        }
+        if context_may_change(sql) {
+            self.invalidate_context();
+        }
+    }
+
+    fn after_statement(&mut self, sql: &str) {
+        if let Held::Mysql(c) = self
+            && matches!(sql.trim().trim_end_matches(';').trim().to_ascii_uppercase().as_str(), "COMMIT" | "ROLLBACK")
+        {
+            c.in_transaction = false;
+        }
+    }
+
+    pub async fn apply_context(&mut self, schema: Option<&str>) -> IdeResult<()> {
+        let driver = match self {
+            Held::Postgres(_) => DbDriver::Postgres,
+            Held::Mysql(_) => DbDriver::Mysql,
+            Held::SqlServer(_) => DbDriver::SqlServer,
+            Held::Oracle(_) => DbDriver::Oracle,
+            _ => return Ok(()),
+        };
+        let context = self.context().expect("switchable connection");
+        let wanted = context.wanted(driver, schema);
+        if context.known && context.current == wanted {
+            return Ok(());
+        }
+        context.known = false;
+        if let Some(sql) = &wanted {
+            self.raw_command(sql).await?;
+        } else {
+            // MySQL cannot USE an absent database. Re-open with the original options.
+            macro_rules! reopen {
+                ($c:expr, $manager:ident) => {{
+                    let manager = $manager { options: $c.options.clone(), init: $c.init.clone(), timeout: $c.timeout };
+                    if $c.in_transaction {
+                        return Err(IdeError::invalid("commit or roll back before clearing the selected database"));
+                    }
+                    let fresh = manager.connect().await.map_err(db_err)?;
+                    if let Some(raw) = $c.conn.take() {
+                        let _ = raw.close().await;
+                    }
+                    ***$c = fresh;
+                }};
+            }
+            match self {
+                Held::Mysql(c) => reopen!(c, MysqlManager),
+                Held::Postgres(c) => reopen!(c, PgManager),
+                _ => unreachable!("server context has a default"),
+            }
+        }
+        let context = self.context().expect("switchable connection");
+        context.current = wanted;
+        context.known = true;
+        Ok(())
+    }
+
+    /// Restore before a manual session returns its physical connection to the pool.
+    pub async fn restore_default(&mut self) -> IdeResult<()> {
+        self.apply_context(None).await
+    }
+
+    async fn fetch_rows(&mut self, sql: &str, max: usize) -> IdeResult<Fetched> {
+        self.before_statement(sql);
+        let result = match self {
+            Held::Sqlite(c) => fetch!(&mut **c, sql, max, Cells::Text),
+            Held::Postgres(c) => fetch!(&mut ****c, sql, max, Cells::Text),
+            Held::Mysql(c) => fetch!(&mut ****c, sql, max, Cells::Text),
+            Held::SqlServer(c) => mssql_fetch(c, sql, 0, max).await,
+            Held::Oracle(c) => crate::oracle::run(c, sql, 0, max, Cells::Text, &CancellationToken::new()).await,
+            Held::Clickhouse(_) => unreachable!(),
+        };
+        if result.is_ok() {
+            self.after_statement(sql);
+        }
+        result
+    }
+
    /// Runs a statement without results (`BEGIN`, `COMMIT`, `ROLLBACK`).
    pub async fn command(&mut self, sql: &str) -> IdeResult<()> {
+        self.before_statement(sql);
+        let result = self.raw_command(sql).await;
+        if result.is_ok() {
+            self.after_statement(sql);
+        }
+        result
+    }
+
+    async fn raw_command(&mut self, sql: &str) -> IdeResult<()> {
        match self {
            Held::SqlServer(c) => mssql_command(c, sql).await,
            Held::Clickhouse(_) => Err(crate::clickhouse::transaction_error()),
@@ -918,8 +1182,8 @@ impl Held {
                let sql = sqlx::AssertSqlSafe(sql.to_owned());
                match other {
                    Held::Sqlite(c) => sqlx::raw_sql(sql).execute(&mut **c).await.map(drop),
-                    Held::Postgres(c) => sqlx::raw_sql(sql).execute(&mut **c).await.map(drop),
-                    Held::Mysql(c) => sqlx::raw_sql(sql).execute(&mut **c).await.map(drop),
+                    Held::Postgres(c) => sqlx::raw_sql(sql).execute(&mut ****c).await.map(drop),
+                    Held::Mysql(c) => sqlx::raw_sql(sql).execute(&mut ****c).await.map(drop),
                    Held::SqlServer(_) | Held::Clickhouse(_) | Held::Oracle(_) => unreachable!(),
                }
                .map_err(db_err)
@@ -932,11 +1196,15 @@ impl Held {
    pub async fn discard(self) {
        match self {
            Held::Sqlite(c) => drop(c.detach()),
-            Held::Postgres(c) => {
-                let _ = c.detach().close().await;
+            Held::Postgres(mut c) => {
+                if let Some(raw) = c.conn.take() {
+                    let _ = raw.close().await;
+                }
            }
-            Held::Mysql(c) => {
-                let _ = c.detach().close().await;
+            Held::Mysql(mut c) => {
+                if let Some(raw) = c.conn.take() {
+                    let _ = raw.close().await;
+                }
            }
            Held::SqlServer(mut c) => {
                c.0.take();
@@ -971,6 +1239,7 @@ impl Held {
        if let Held::Clickhouse(c) = self {
            return c.execute_from(sql, skip, max_rows, cancel).await;
        }
+        self.before_statement(sql);
        let started = Instant::now();
        // `$id`: the query naming the server process, `$kill`: how another connection stops it.
        macro_rules! run {
@@ -1003,9 +1272,9 @@ impl Held {
        let fetched: Fetched = match self {
            Held::Sqlite(c) => run!(c, None::<&str>, |_: String| String::new()),
            Held::Postgres(c) => {
-                run!(c, Some("SELECT pg_backend_pid()"), |b: String| format!("SELECT pg_cancel_backend({b})"))
+                run!(&mut ***c, Some("SELECT pg_backend_pid()"), |b: String| format!("SELECT pg_cancel_backend({b})"))
            }
-            Held::Mysql(c) => run!(c, Some("SELECT CONNECTION_ID()"), |b: String| format!("KILL QUERY {b}")),
+            Held::Mysql(c) => run!(&mut ***c, Some("SELECT CONNECTION_ID()"), |b: String| format!("KILL QUERY {b}")),
            Held::SqlServer(c) => {
                // Tiberius has no attention/cancel API; stop reading and discard the connection.
                tokio::select! {
@@ -1016,6 +1285,7 @@ impl Held {
            Held::Oracle(c) => crate::oracle::run(c, sql, skip, max_rows, Cells::Display, cancel).await?,
            Held::Clickhouse(_) => unreachable!(),
        };
+        self.after_statement(sql);
        let (columns, rows, affected, has_more, first) = fetched;
        let elapsed_ms = started.elapsed().as_secs_f64() * 1000.0;
        Ok(QueryResult {
@@ -1055,7 +1325,7 @@ mod tests {
    #[test]
    fn discarded_sqlserver_connections_are_broken() {
        let manager = MssqlConnectionManager(tiberius::Config::new());
-        assert!(manager.has_broken(&mut MssqlConnection(None)));
+        assert!(manager.has_broken(&mut MssqlConnection(None, Context::new(None))));
    }

    #[tokio::test]
@@ -1191,6 +1461,7 @@ mod tests {
        assert_eq!(setup.charset.as_deref(), Some("utf8mb4"));
        assert_eq!(setup.connect_timeout, Some(Duration::from_secs(5)));
        assert!(Setup::of(&DataSource { properties: vec![prop("a; drop", "1")], ..s.clone() }).is_err());
+        assert!(Setup::of(&DataSource { properties: vec![prop("connect_timeout", "0")], ..s.clone() }).is_err());
        assert!(Setup::of(&DataSource { properties: vec![prop("connect_timeout", "soon")], ..s }).is_err());
    }

@@ -315,7 +315,7 @@ fn keep_alive(pool: &Arc<Pool>, every: Duration) {
 async fn end_session(session: &Session) {
    let held = session.lock().await.take();
    if let Some(mut conn) = held
-        && conn.command("ROLLBACK").await.is_err()
+        && (conn.command("ROLLBACK").await.is_err() || conn.restore_default().await.is_err())
    {
        conn.discard().await;
    }
@@ -704,8 +704,15 @@ impl DbManager {
        let introspection = self.source(id)?.introspection;
        let system = introspection.show_system;
        let pool = self.pool(id).await?;
+        if pool.driver() == DbDriver::SqlServer {
+            let first =
+                |rows: Vec<Vec<Option<String>>>| rows.into_iter().filter_map(|r| r.into_iter().next().flatten());
+            let current = first(pool.rows("SELECT DB_NAME()", 1).await?).next().unwrap_or_default();
+            let names = first(pool.rows(sql::sqlserver_databases(), MAX_META_ROWS).await?).collect();
+            return Ok(Databases { current, names });
+        }
        if pool.driver() != DbDriver::Postgres {
-            return Err(IdeError::invalid("only PostgreSQL data sources list databases"));
+            return Err(IdeError::invalid("this data source does not list databases"));
        }
        let first = |rows: Vec<Vec<Option<String>>>| rows.into_iter().filter_map(|r| r.into_iter().next().flatten());
        let current = first(pool.rows("SELECT current_database()", 1).await?).next().unwrap_or_default();
@@ -1038,11 +1045,13 @@ impl DbManager {
        max_rows: usize,
        cancel: &CancellationToken,
    ) -> IdeResult<QueryResult> {
-        self.execute_from(id, statement, 0, max_rows, cancel).await
+        self.execute_from(id, statement, 0, max_rows, cancel, None).await
    }

    /// [`execute`](Self::execute), reading past the first `skip` rows without keeping
    /// them: a later page of a result, where only that page is decoded and returned.
+    /// `schema` is a query console's active context: the connection that runs the
+    /// statement is put in it first, so unqualified names resolve there.
    pub async fn execute_from(
        &self,
        id: &str,
@@ -1050,8 +1059,9 @@ impl DbManager {
        skip: usize,
        max_rows: usize,
        cancel: &CancellationToken,
+        schema: Option<&str>,
    ) -> IdeResult<QueryResult> {
-        let r = self.run(id, statement, skip, max_rows, cancel).await;
+        let r = self.run(id, statement, skip, max_rows, cancel, schema).await;
        let ran = match &r {
            Ok(_) => true,
            Err(e) => !matches!(e.kind, ErrorKind::Cancelled | ErrorKind::PermissionDenied),
@@ -1083,8 +1093,15 @@ impl DbManager {
            .map_err(|e| IdeError::internal(e.to_string()))?
    }

-    /// The execution plan of `statement` (explained, not run).
-    pub async fn explain(&self, id: &str, statement: &str, cancel: &CancellationToken) -> IdeResult<Vec<PlanNode>> {
+    /// The execution plan of `statement` (explained, not run), in the console's
+    /// active `schema` when it has one.
+    pub async fn explain(
+        &self,
+        id: &str,
+        statement: &str,
+        cancel: &CancellationToken,
+        schema: Option<&str>,
+    ) -> IdeResult<Vec<PlanNode>> {
        let driver = self.pool(id).await?.driver();
        if driver == DbDriver::Oracle {
            // EXPLAIN PLAN writes PLAN_TABLE; the plan is read (and cleaned up) separately.
@@ -1102,14 +1119,16 @@ impl DbManager {
                0,
                MAX_META_ROWS,
                cancel,
+                schema,
            )
            .await?;
-            let result = self.run(id, &plan::oracle_plan_query(&plan_id), 0, MAX_META_ROWS, cancel).await?;
+            let result = self.run(id, &plan::oracle_plan_query(&plan_id), 0, MAX_META_ROWS, cancel, None).await?;
            let nodes = plan::parse(driver, &result);
-            let _ = self.run(id, &plan::oracle_plan_cleanup(&plan_id), 0, 0, cancel).await;
+            let _ = self.run(id, &plan::oracle_plan_cleanup(&plan_id), 0, 0, cancel, None).await;
            return nodes;
        }
-        let result = self.run(id, &plan::explain_statement(driver, statement), 0, MAX_META_ROWS, cancel).await?;
+        let result =
+            self.run(id, &plan::explain_statement(driver, statement), 0, MAX_META_ROWS, cancel, schema).await?;
        plan::parse(driver, &result)
    }

@@ -1120,11 +1139,25 @@ impl DbManager {
        skip: usize,
        max_rows: usize,
        cancel: &CancellationToken,
+        schema: Option<&str>,
    ) -> IdeResult<QueryResult> {
        let pool = self.pool(id).await?;
        let session = self.sessions.lock().get(id).cloned();
        let Some(session) = session else {
-            return pool.execute_from(statement, skip, max_rows, cancel).await;
+            if schema.is_none() {
+                return pool.execute_from(statement, skip, max_rows, cancel).await;
+            }
+            // Like `Pool::execute_from`, with the schema applied to the connection first.
+            let mut conn = Held::acquire(&pool).await?;
+            let r = match conn.apply_context(schema).await {
+                Ok(()) => conn.execute_from(&pool, statement, skip, max_rows, cancel).await,
+                Err(e) => Err(e),
+            };
+            if cancel.is_cancelled() {
+                conn.discard().await;
+                return Err(IdeError::cancelled());
+            }
+            return r;
        };
        if pool.driver() == DbDriver::Clickhouse {
            return Err(IdeError::invalid("ClickHouse manual transactions are unsupported"));
@@ -1132,10 +1165,12 @@ impl DbManager {
        let mut held = session.lock().await;
        if held.is_none() {
            let mut conn = Held::acquire(&pool).await?;
+            conn.apply_context(schema).await?;
            conn.command(conn::begin_statement(pool.driver())).await?;
            *held = Some(conn);
        }
        let conn = held.as_mut().expect("opened above");
+        conn.apply_context(schema).await?;
        let r = conn.execute_from(&pool, statement, skip, max_rows, cancel).await;
        if cancel.is_cancelled() {
            // The server rolls the transaction back with the connection.
@@ -1171,7 +1206,12 @@ impl DbManager {
        let Some(session) = session else { return Ok(()) };
        let mut held = session.lock().await;
        let Some(mut conn) = held.take() else { return Ok(()) };
-        match conn.command(if commit { "COMMIT" } else { "ROLLBACK" }).await {
+        let result = async {
+            conn.command(if commit { "COMMIT" } else { "ROLLBACK" }).await?;
+            conn.restore_default().await
+        }
+        .await;
+        match result {
            Ok(()) => Ok(()),
            Err(e) => {
                conn.discard().await;
@@ -181,7 +181,7 @@ impl OraclePool {
        .await
        .map_err(|e| IdeError::internal(format!("Oracle connect task: {e}")))?
        .map_err(oracle_err)?;
-        let _ = pool.add(OracleHandle { conn: Some(opened) });
+        let _ = pool.add(opened);
        Ok(Self { state, pool: Arc::new(pool) })
    }

@@ -208,6 +208,7 @@ fn pool_err(e: bb8::RunError<OracleError>) -> OracleError {
 /// discarded (a cancelled statement leaves it in the blocking task).
 pub struct OracleHandle {
    conn: Option<oracle::Connection>,
+    context: crate::conn::Context,
 }

 pub struct OracleConnectionManager(Arc<State>);
@@ -222,7 +223,7 @@ impl ManageConnection for OracleConnectionManager {
            .await
            .map_err(|e| OracleError::message(format!("Oracle connect task: {e}")))?;
        let conn = opened.map_err(OracleError::new)?;
-        Ok(OracleHandle { conn: Some(conn) })
+        Ok(conn)
    }

    async fn is_valid(&self, conn: &mut Self::Connection) -> Result<(), Self::Error> {
@@ -271,6 +272,10 @@ pub struct OracleConnection {
 }

 impl OracleConnection {
+    pub(crate) fn context(&mut self) -> &mut crate::conn::Context {
+        &mut self.pooled.context
+    }
+
    pub fn is_closed(&self) -> bool {
        self.pooled.conn.is_none()
    }
@@ -282,7 +287,7 @@ impl OracleConnection {
    }
 }

-fn open(state: &State) -> oracle::Result<oracle::Connection> {
+fn open(state: &State) -> oracle::Result<OracleHandle> {
    let mut connector = oracle::Connector::new(state.user.clone(), state.password.clone(), state.connect.clone());
    connector.driver_name("OpenIDEA");
    if let Some(n) = state.statement_cache {
@@ -293,7 +298,12 @@ fn open(state: &State) -> oracle::Result<oracle::Connection> {
    for sql in &state.init {
        statement(&mut conn, sql, 0, 0, Cells::Text).map_err(|e| message_error(&e.message))?;
    }
-    Ok(conn)
+    let user: String = conn.query_row_as("SELECT SYS_CONTEXT('USERENV', 'SESSION_USER') FROM DUAL", &[])?;
+    let default = crate::sql::use_schema(DbDriver::Oracle, &user);
+    let current: String = conn.query_row_as("SELECT SYS_CONTEXT('USERENV', 'CURRENT_SCHEMA') FROM DUAL", &[])?;
+    let mut context = crate::conn::Context::new(default);
+    context.set_current(crate::sql::use_schema(DbDriver::Oracle, &current));
+    Ok(OracleHandle { conn: Some(conn), context })
 }

 /// Runs `f` with the connection on the blocking pool. Cancelling drops the
@@ -558,7 +568,7 @@ mod tests {
            )
            .unwrap(),
        ));
-        let mut broken = OracleHandle { conn: None };
+        let mut broken = OracleHandle { conn: None, context: crate::conn::Context::new(None) };
        assert!(manager.has_broken(&mut broken));
        // A connection that cannot be opened reports the failure without panicking
        // (a client-load error, or ORA-12541 when a client is available).
@@ -63,6 +63,11 @@ pub const ORACLE_SYSTEM_SCHEMAS: &[&str] = &[
    "XS$NULL",
 ];

+/// Databases available to this login; offline/restoring databases cannot be selected.
+pub fn sqlserver_databases() -> &'static str {
+    "SELECT name FROM sys.databases WHERE state = 0 AND HAS_DBACCESS(name) = 1 ORDER BY name"
+}
+
 pub fn schemas(driver: DbDriver, system: bool) -> &'static str {
    match driver {
        DbDriver::Sqlite => "SELECT name FROM pragma_database_list WHERE name <> 'temp' ORDER BY seq",
@@ -396,6 +401,18 @@ pub fn current_schema(driver: DbDriver) -> Option<&'static str> {
    }
 }

+/// The statement that makes unqualified names resolve in `schema` on the
+/// connection that runs it (a query console's active schema; `None`: the driver
+/// has no schema to switch — SQLite's `main`, ClickHouse's `USE` differs).
+pub fn use_schema(driver: DbDriver, schema: &str) -> Option<String> {
+    match driver {
+        DbDriver::Sqlite | DbDriver::Clickhouse => None,
+        DbDriver::Postgres => Some(format!("SET search_path TO {}", quote_ident(driver, schema))),
+        DbDriver::Mysql | DbDriver::SqlServer => Some(format!("USE {}", quote_ident(driver, schema))),
+        DbDriver::Oracle => Some(format!("ALTER SESSION SET CURRENT_SCHEMA = {}", quote_ident(driver, schema))),
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 #[serde(rename = "DbSortKey")]
@@ -994,6 +1011,20 @@ mod tests {
        assert!(object_ddl(DbDriver::Postgres, "s", K::Sequence, "q").unwrap().0.contains("sequencename = 'q'"));
    }

+    #[test]
+    fn schema_switch_statement_per_dialect() {
+        assert_eq!(use_schema(DbDriver::Postgres, "app data"), Some("SET search_path TO \"app data\"".into()));
+        assert_eq!(use_schema(DbDriver::Mysql, "a`b"), Some("USE `a``b`".into()));
+        assert_eq!(use_schema(DbDriver::SqlServer, "app] data"), Some("USE [app]] data]".into()));
+        assert_eq!(use_schema(DbDriver::Postgres, "a\"b"), Some("SET search_path TO \"a\"\"b\"".into()));
+        assert_eq!(use_schema(DbDriver::Oracle, "a\"b"), Some("ALTER SESSION SET CURRENT_SCHEMA = \"a\"\"b\"".into()));
+        assert!(sqlserver_databases().contains("state = 0 AND HAS_DBACCESS(name) = 1"));
+        assert_eq!(use_schema(DbDriver::Oracle, "hr"), Some("ALTER SESSION SET CURRENT_SCHEMA = \"hr\"".into()));
+        // Single-schema (SQLite) and not-yet-supported drivers: no dropdown, no switch.
+        assert_eq!(use_schema(DbDriver::Sqlite, "main"), None);
+        assert_eq!(use_schema(DbDriver::Clickhouse, "default"), None);
+    }
+
    #[test]
    fn postgres_ddl() {
        let cols = [
@@ -103,7 +103,7 @@ async fn clickhouse_cloud_manager_catalogs_and_session_table() -> IdeResult<()>
                "completion columns differ from catalog",
            )?;
        }
-        let plan = db.explain("clickhouse", &format!("SELECT id FROM {table}"), &cancel).await?;
+        let plan = db.explain("clickhouse", &format!("SELECT id FROM {table}"), &cancel, None).await?;
        check(!plan.is_empty(), "query plan missing")?;
        let value = r"path\O'Brien";
        let result = db
@@ -85,3 +85,101 @@ async fn metadata_names_are_text_whatever_the_column_collation() -> IdeResult<()
    let raw = manager(&tmp, "SET character_set_results = binary").await.unwrap();
    assert_metadata_is_text(&raw).await
 }
+
+// A console's active schema: the connection that runs each autocommit statement
+// is put in it first, so unqualified names resolve there (and not elsewhere).
+// Its own schema names: tests of this file share one server but run in parallel.
+#[tokio::test]
+async fn active_schema_context_drives_the_executing_connection() -> IdeResult<()> {
+    const A: &str = "oi_ctx_meta";
+    const B: &str = "oi_ctx_data";
+    let tmp = tempfile::tempdir().unwrap();
+    let Some(db) = manager(&tmp, "").await else { return Ok(()) };
+    let c = CancellationToken::new();
+    for s in [A, B] {
+        for stmt in [
+            format!("DROP DATABASE IF EXISTS `{s}`"),
+            format!("CREATE DATABASE `{s}` CHARACTER SET utf8mb4 COLLATE utf8mb4_bin"),
+            format!("CREATE TABLE `{s}`.`用户` (id INT PRIMARY KEY, name VARCHAR(20))"),
+            format!("INSERT INTO `{s}`.`用户` VALUES (1, '{s}')"),
+        ] {
+            db.execute("m", &stmt, 10, &c).await.unwrap();
+        }
+    }
+
+    // The source connects with no default database; the console's pick decides.
+    let r = db.execute_from("m", "SELECT DATABASE()", 0, 1, &c, Some(A)).await?;
+    assert_eq!(r.rows, vec![vec![Some(A.into())]]);
+    // Both schemas hold `用户`; the context resolves the unqualified name in its own,
+    // on every pooled connection the autocommit statements may land on.
+    for _ in 0..6 {
+        for (schema, name) in [(A, A), (B, B)] {
+            let r = db.execute_from("m", "SELECT name FROM 用户", 0, 1, &c, Some(schema)).await?;
+            assert_eq!(r.rows, vec![vec![Some(name.into())]], "of {schema}");
+            let r = db.execute_from("m", "SELECT DATABASE()", 0, 1, &c, Some("")).await?;
+            assert_eq!(r.rows, vec![vec![None]]);
+            assert_eq!(db.completion("m").await?.default_schema, "");
+        }
+    }
+    // A statement without a selection returns to the source's absent default.
+    let r = db.execute_from("m", "SELECT DATABASE()", 0, 1, &c, None).await?;
+    assert_eq!(r.rows, vec![vec![None]]);
+
+    // A manual-commit console switches schemas on its session connection.
+    db.set_manual_commit("m", true).await?;
+    // Starting a no-database manual session must keep its transaction open.
+    db.execute("m", &format!("INSERT INTO `{A}`.`用户` VALUES (2, 'rollback')"), 1, &c).await?;
+    db.finish_transaction("m", false).await?;
+    assert!(db.execute("m", &format!("SELECT name FROM `{A}`.`用户` WHERE id = 2"), 1, &c).await?.rows.is_empty());
+    let r = db.execute_from("m", "SELECT name FROM 用户", 0, 1, &c, Some(A)).await?;
+    assert_eq!(r.rows, vec![vec![Some(A.into())]]);
+    let r = db.execute_from("m", "SELECT DATABASE()", 0, 1, &c, Some(B)).await?;
+    assert_eq!(r.rows, vec![vec![Some(B.into())]]);
+    assert!(db.execute("m", "SELECT DATABASE()", 1, &c).await.is_err());
+    // The rejected clear keeps the transaction and selection intact.
+    assert_eq!(db.execute_from("m", "SELECT DATABASE()", 0, 1, &c, Some(B)).await?.rows, vec![vec![Some(B.into())]]);
+    db.finish_transaction("m", true).await?;
+    for commit in [false, true] {
+        db.execute_from("m", "SELECT 1", 0, 1, &c, Some(A)).await?;
+        db.finish_transaction("m", commit).await?;
+        let r = db.execute("m", "SELECT DATABASE()", 1, &c).await?;
+        assert_eq!(r.rows, vec![vec![None]]);
+    }
+    db.execute_from("m", "SELECT 1", 0, 1, &c, Some(A)).await?;
+    db.set_manual_commit("m", false).await?;
+    db.execute("m", &format!("USE `{B}`"), 1, &c).await?;
+    let r = db.execute("m", "SELECT DATABASE()", 1, &c).await?;
+    assert_eq!(r.rows, vec![vec![None]]);
+
+    // An unknown schema fails the statement instead of running it somewhere else.
+    let error = db.execute_from("m", "SELECT 1", 0, 1, &c, Some("oi_missing")).await.unwrap_err();
+    assert!(error.message.contains("oi_missing"), "{}", error.message);
+    Ok(())
+}
+
+#[tokio::test]
+async fn a_reused_physical_connection_restores_the_configured_database() -> IdeResult<()> {
+    use ide_db::{Held, Pool};
+    let Some((host, port, user, password)) = server() else { return Ok(()) };
+    let source = DataSource {
+        driver: DbDriver::Mysql,
+        host,
+        port: Some(port),
+        user,
+        database: "mysql".into(),
+        ..Default::default()
+    };
+    let pool = Pool::connect(&source, Some(&password), None).await?;
+    let c = CancellationToken::new();
+    let _other = [Held::acquire(&pool).await?, Held::acquire(&pool).await?, Held::acquire(&pool).await?];
+    let mut conn = Held::acquire(&pool).await?;
+    let backend = conn.execute(&pool, "SELECT CONNECTION_ID()", 1, &c).await?.rows;
+    for schema in ["information_schema", "mysql", "information_schema"] {
+        conn.apply_context(Some(schema)).await?;
+        assert_eq!(conn.execute(&pool, "SELECT DATABASE()", 1, &c).await?.rows, vec![vec![Some(schema.into())]]);
+    }
+    drop(conn);
+    assert_eq!(pool.rows("SELECT DATABASE()", 1).await?, vec![vec![Some("mysql".into())]]);
+    assert_eq!(pool.execute("SELECT CONNECTION_ID()", 1, &c).await?.rows, backend);
+    Ok(())
+}
@@ -0,0 +1,135 @@
+//! The active schema context against a real PostgreSQL server, skipped unless
+//! `OPENIDEA_TEST_POSTGRES=host:port:user:password` names a throwaway server.
+
+use ide_core::{CancellationToken, IdeResult};
+use ide_db::{DataSource, DbDriver, DbManager};
+
+fn server() -> Option<(String, u16, String, String)> {
+    let v = std::env::var("OPENIDEA_TEST_POSTGRES").ok()?;
+    let mut it = v.splitn(4, ':');
+    Some((it.next()?.into(), it.next()?.parse().ok()?, it.next()?.into(), it.next().unwrap_or("").into()))
+}
+
+async fn manager(tmp: &tempfile::TempDir) -> Option<DbManager> {
+    let (host, port, user, password) = server()?;
+    let root = tmp.path().to_path_buf();
+    let ssh = std::sync::Arc::new(ide_ssh::SshManager::new(root.join("ssh-passwords.json")));
+    let db = DbManager::new(root.clone(), root.join("passwords.json"), root.join("history.json"), ssh);
+    db.save_sources(vec![DataSource {
+        id: "p".into(),
+        name: "postgres".into(),
+        driver: DbDriver::Postgres,
+        host,
+        port: Some(port),
+        user,
+        ..Default::default()
+    }])
+    .await
+    .unwrap();
+    db.set_password("p", Some(password), false).await.unwrap();
+    Some(db)
+}
+
+async fn create_schemas(db: &DbManager) {
+    let c = CancellationToken::new();
+    for (schema, tag) in [("oi_a", "from a"), ("oi_b", "from b")] {
+        for stmt in [
+            format!("DROP SCHEMA IF EXISTS \"{schema}\" CASCADE"),
+            format!("CREATE SCHEMA \"{schema}\""),
+            format!("CREATE TABLE \"{schema}\".items (id INT PRIMARY KEY, tag TEXT)"),
+            format!("INSERT INTO \"{schema}\".items VALUES (1, '{tag}')"),
+        ] {
+            db.execute("p", &stmt, 10, &c).await.unwrap();
+        }
+    }
+}
+
+#[tokio::test]
+async fn active_schema_context_drives_the_executing_connection() -> IdeResult<()> {
+    let tmp = tempfile::tempdir().unwrap();
+    let Some(db) = manager(&tmp).await else { return Ok(()) };
+    create_schemas(&db).await;
+    let c = CancellationToken::new();
+
+    // The connection default stays untouched before any console picks a schema.
+    let r = db.execute("p", "SHOW search_path", 1, &c).await?;
+    assert!(r.rows[0][0].as_deref().unwrap_or("").contains("public"), "{:?}", r.rows);
+
+    // Both schemas hold `items`; the context resolves the unqualified name in its own,
+    // on every pooled connection the autocommit statements may land on.
+    for _ in 0..6 {
+        for (schema, tag) in [("oi_a", "from a"), ("oi_b", "from b")] {
+            let r = db.execute_from("p", "SELECT tag FROM items", 0, 1, &c, Some(schema)).await?;
+            assert_eq!(r.rows, vec![vec![Some(tag.into())]], "of {schema}");
+            let r = db.execute_from("p", "SHOW search_path", 0, 1, &c, Some("")).await?;
+            assert_eq!(r.rows, vec![vec![Some("\"$user\", public".into())]]);
+            assert_eq!(db.completion("p").await?.default_schema, "public");
+        }
+    }
+
+    // A manual-commit console switches schemas on its session connection.
+    db.set_manual_commit("p", true).await?;
+    let r = db.execute_from("p", "SELECT tag FROM items", 0, 1, &c, Some("oi_a")).await?;
+    assert_eq!(r.rows, vec![vec![Some("from a".into())]]);
+    let r = db.execute_from("p", "SELECT tag FROM items", 0, 1, &c, Some("oi_b")).await?;
+    assert_eq!(r.rows, vec![vec![Some("from b".into())]]);
+    db.finish_transaction("p", true).await?;
+    for commit in [false, true] {
+        db.execute_from("p", "SELECT 1", 0, 1, &c, Some("oi_a")).await?;
+        db.finish_transaction("p", commit).await?;
+        let r = db.execute("p", "SHOW search_path", 1, &c).await?;
+        assert_eq!(r.rows, vec![vec![Some("\"$user\", public".into())]]);
+    }
+    db.set_manual_commit("p", false).await?;
+    db.execute("p", "SET search_path TO oi_b", 1, &c).await?;
+    let r = db.execute("p", "SHOW search_path", 1, &c).await?;
+    assert_eq!(r.rows, vec![vec![Some("\"$user\", public".into())]]);
+
+    // An unknown schema never resolves the statement's tables (`SET search_path`
+    // itself does not validate names; resolution against it does).
+    let error = db.execute_from("p", "SELECT tag FROM items", 0, 1, &c, Some("oi_missing")).await.unwrap_err();
+    assert!(error.message.to_lowercase().contains("does not exist"), "{}", error.message);
+    Ok(())
+}
+
+#[tokio::test]
+async fn a_reused_physical_connection_restores_the_full_default_path() -> IdeResult<()> {
+    use ide_db::{DbOptions, Held, Pool};
+    let Some((host, port, user, password)) = server() else { return Ok(()) };
+    let source = DataSource {
+        driver: DbDriver::Postgres,
+        host,
+        port: Some(port),
+        user,
+        options: DbOptions { default_schema: "public, pg_catalog".into(), ..Default::default() },
+        ..Default::default()
+    };
+    let pool = Pool::connect(&source, Some(&password), None).await?;
+    let c = CancellationToken::new();
+    // Occupy the other three slots: every operation below must reuse the fourth.
+    let _other = [Held::acquire(&pool).await?, Held::acquire(&pool).await?, Held::acquire(&pool).await?];
+    let mut conn = Held::acquire(&pool).await?;
+    let backend = conn.execute(&pool, "SELECT pg_backend_pid()", 1, &c).await?.rows;
+    for schema in ["pg_catalog", "public", "pg_catalog"] {
+        conn.apply_context(Some(schema)).await?;
+        let r = conn.execute(&pool, "SELECT current_schema()", 1, &c).await?;
+        assert_eq!(r.rows, vec![vec![Some(schema.into())]]);
+    }
+    conn.apply_context(Some("public")).await?;
+    conn.execute(&pool, "SELECT set_config('search_path', 'pg_catalog', false)", 1, &c).await?;
+    conn.apply_context(Some("public")).await?;
+    assert_eq!(conn.execute(&pool, "SELECT current_schema()", 1, &c).await?.rows, vec![vec![Some("public".into())]]);
+    drop(conn);
+    assert_eq!(pool.rows("SHOW search_path", 1).await?, vec![vec![Some("public, pg_catalog".into())]]);
+    assert_eq!(pool.execute("SELECT pg_backend_pid()", 1, &c).await?.rows, backend);
+    let mut conn = Held::acquire(&pool).await?;
+    conn.command("BEGIN").await?;
+    conn.apply_context(Some("pg_catalog")).await?;
+    conn.command("ROLLBACK").await?;
+    conn.restore_default().await?;
+    assert_eq!(
+        conn.execute(&pool, "SHOW search_path", 1, &c).await?.rows,
+        vec![vec![Some("public, pg_catalog".into())]]
+    );
+    Ok(())
+}
@@ -132,16 +132,16 @@ async fn a_later_page_returns_only_its_rows() -> IdeResult<()> {
    let sql = "SELECT id FROM users ORDER BY id";
    let ids = |r: &QueryResult| r.rows.iter().map(|row| row[0].clone().unwrap()).collect::<Vec<_>>();

-    let second = db.execute_from("s1", sql, 1, 1, &c).await?;
+    let second = db.execute_from("s1", sql, 1, 1, &c, None).await?;
    assert_eq!(ids(&second), vec!["2"]);
    assert!(second.has_more);
    assert_eq!(second.columns.len(), 1);

-    let last = db.execute_from("s1", sql, 2, 5, &c).await?;
+    let last = db.execute_from("s1", sql, 2, 5, &c, None).await?;
    assert_eq!(ids(&last), vec!["3"]);
    assert!(!last.has_more);

-    let past = db.execute_from("s1", sql, 9, 5, &c).await?;
+    let past = db.execute_from("s1", sql, 9, 5, &c, None).await?;
    assert!(past.rows.is_empty() && !past.has_more);
    assert_eq!(past.columns.len(), 1, "columns of a page past the end come from the prepared statement");
    Ok(())
@@ -276,11 +276,11 @@ async fn ddl_of_tables_and_views() -> IdeResult<()> {
 async fn explains_queries_without_running_them() -> IdeResult<()> {
    let (_tmp, db) = setup().await;
    let c = CancellationToken::new();
-    let plan = db.explain("s1", "SELECT * FROM users WHERE id > 1 ORDER BY note;", &c).await?;
+    let plan = db.explain("s1", "SELECT * FROM users WHERE id > 1 ORDER BY note;", &c, None).await?;
    let ops: Vec<_> = plan.iter().map(|n| n.operation.as_str()).collect();
    assert_eq!(ops, vec!["Index Scan", "Order By"]);
    assert!(plan[0].params.starts_with("table: users;"), "{}", plan[0].params);
-    db.explain("s1", "DELETE FROM users", &c).await?;
+    db.explain("s1", "DELETE FROM users", &c, None).await?;
    assert_eq!(count(&db).await, "3");
    Ok(())
 }
@@ -443,7 +443,7 @@ pub fn compose_op(

 /// Whether `ep` is a daemon on this machine, where a bind mount of the project
 /// is this machine's folder. The CLI's default daemon and a context are looked
-/// up (`DOCKER_HOST`, else the context's endpoint).
+/// up (`DOCKER_CONTEXT`, then `DOCKER_HOST`, else the current context).
 pub fn endpoint_is_local(ep: &DockerEndpoint) -> IdeResult<bool> {
    let url = match ep {
        DockerEndpoint::Socket { path } => path.trim().to_owned(),
@@ -451,17 +451,31 @@ pub fn endpoint_is_local(ep: &DockerEndpoint) -> IdeResult<bool> {
            let host = host.trim();
            if host.contains("://") { host.to_owned() } else { format!("tcp://{host}") }
        }
-        DockerEndpoint::Default => {
-            match ide_core::process::host_var_os("DOCKER_HOST").map(|v| v.to_string_lossy().trim().to_owned()) {
-                Some(url) if !url.is_empty() => url,
-                _ => context_host(ep, None)?,
-            }
-        }
+        DockerEndpoint::Default => default_daemon_url(
+            ide_core::process::host_var_os("DOCKER_CONTEXT").as_deref().and_then(|v| v.to_str()),
+            ide_core::process::host_var_os("DOCKER_HOST").as_deref().and_then(|v| v.to_str()),
+            |name| context_host(&DockerEndpoint::Default, name),
+        )?,
        DockerEndpoint::Context { name } => context_host(&DockerEndpoint::Default, Some(name.trim()))?,
    };
    Ok(daemon_url_is_local(&url))
 }

+fn default_daemon_url(
+    context: Option<&str>,
+    host: Option<&str>,
+    lookup: impl FnOnce(Option<&str>) -> IdeResult<String>,
+) -> IdeResult<String> {
+    let context = context.filter(|v| !v.is_empty());
+    if context.is_some() {
+        return lookup(context);
+    }
+    match host.filter(|v| !v.is_empty()) {
+        Some(host) => Ok(host.to_owned()),
+        None => lookup(None),
+    }
+}
+
 /// The daemon URL of context `name` (the current one with `None`).
 fn context_host(ep: &DockerEndpoint, name: Option<&str>) -> IdeResult<String> {
    let mut args = vec!["context", "inspect", "--format", "{{.Endpoints.docker.Host}}"];
@@ -506,6 +520,34 @@ pub fn compose_config(ep: &DockerEndpoint, dir: &Path, files: &[String]) -> IdeR
 mod local_tests {
    use super::*;

+    #[test]
+    fn the_selected_context_overrides_docker_host() {
+        let local = "unix:///var/run/docker.sock";
+        let remote = "ssh://me@build";
+        for host in [None, Some(""), Some(local)] {
+            let url = default_daemon_url(Some("build"), host, |name| {
+                assert_eq!(name, Some("build"));
+                Ok(remote.into())
+            })
+            .unwrap();
+            assert!(!daemon_url_is_local(&url));
+        }
+        for context in [None, Some("")] {
+            assert_eq!(
+                default_daemon_url(context, Some(local), |_| panic!("host overrides current context")).unwrap(),
+                local
+            );
+            assert_eq!(
+                default_daemon_url(context, None, |name| {
+                    assert_eq!(name, None);
+                    Ok(remote.into())
+                })
+                .unwrap(),
+                remote
+            );
+        }
+    }
+
    #[test]
    fn local_daemon_urls() {
        for url in [
@@ -18,13 +18,15 @@ pub enum Capability {
    EditorRead,
    /// Edit the focused editor (versioned edits).
    EditorWrite,
+    /// Create and replace files inside the project root.
+    ProjectWrite,
    VcsRead,
    VcsWrite,
    /// The plugin's own key-value store and data directory.
    Storage,
    /// The plugin's own secrets (kept in the client's OS keychain).
    Secrets,
-    /// Workbench events (file opened, saved, focus…), not keystrokes.
+    /// Workbench events (files, focus, VCS), not keystrokes.
    Events,
    /// Keystrokes and editor input events.
    InputEvents,
@@ -36,6 +38,8 @@ pub enum Capability {
    Process(String),
    /// Read files outside the project under one path.
    FsRead(String),
+    /// Write files outside the project under one path.
+    FsWrite(String),
 }

 /// How a grant is presented (plan 4.2).
@@ -54,10 +58,14 @@ impl Capability {
    pub fn risk(&self) -> Risk {
        match self {
            Self::ProjectRead | Self::EditorRead | Self::Storage | Self::Events | Self::VcsRead => Risk::Low,
-            Self::EditorWrite | Self::VcsWrite | Self::Net(_) | Self::Secrets | Self::InputEvents | Self::Clipboard => {
-                Risk::Medium
-            }
-            Self::Process(_) | Self::FsRead(_) => Risk::High,
+            Self::EditorWrite
+            | Self::ProjectWrite
+            | Self::VcsWrite
+            | Self::Net(_)
+            | Self::Secrets
+            | Self::InputEvents
+            | Self::Clipboard => Risk::Medium,
+            Self::Process(_) | Self::FsRead(_) | Self::FsWrite(_) => Risk::High,
        }
    }

@@ -73,11 +81,12 @@ impl Capability {
            Self::ProjectRead => "Read files in the open project".into(),
            Self::EditorRead => "Read the focused editor's file and selection".into(),
            Self::EditorWrite => "Change text in the editor".into(),
+            Self::ProjectWrite => "Create and change files in the open project".into(),
            Self::VcsRead => "Read version control state".into(),
            Self::VcsWrite => "Change version control state (commit, fetch, checkout)".into(),
            Self::Storage => "Store its own data".into(),
            Self::Secrets => "Store secrets in the system keychain".into(),
-            Self::Events => "Observe workbench events (files opened, saved, focus)".into(),
+            Self::Events => "Observe editor, filesystem and version control events".into(),
            Self::InputEvents => "Observe keystrokes and editor input".into(),
            Self::Clipboard => {
                "Copy to the clipboard from its commands, and read and write it from its web views".into()
@@ -85,6 +94,7 @@ impl Capability {
            Self::Net(host) => format!("Connect to {host} (from the machine the project is on)"),
            Self::Process(bin) => format!("Run {bin} — equivalent to running arbitrary code on this machine"),
            Self::FsRead(path) => format!("Read files under {path}, outside the project"),
+            Self::FsWrite(path) => format!("Change files under {path}, outside the project"),
        }
    }

@@ -92,7 +102,7 @@ impl Capability {
    pub fn covers(&self, wanted: &Capability) -> bool {
        match (self, wanted) {
            (Self::Net(pattern), Self::Net(host)) => host_matches(pattern, host),
-            (Self::FsRead(base), Self::FsRead(path)) => {
+            (Self::FsRead(base), Self::FsRead(path)) | (Self::FsWrite(base), Self::FsWrite(path)) => {
                std::path::Path::new(path).starts_with(std::path::Path::new(base))
            }
            _ => self == wanted,
@@ -116,6 +126,7 @@ impl fmt::Display for Capability {
            Self::ProjectRead => f.write_str("project.read"),
            Self::EditorRead => f.write_str("editor.read"),
            Self::EditorWrite => f.write_str("editor.write"),
+            Self::ProjectWrite => f.write_str("project.write"),
            Self::VcsRead => f.write_str("vcs.read"),
            Self::VcsWrite => f.write_str("vcs.write"),
            Self::Storage => f.write_str("storage"),
@@ -126,6 +137,7 @@ impl fmt::Display for Capability {
            Self::Net(h) => write!(f, "net:{h}"),
            Self::Process(b) => write!(f, "process:{b}"),
            Self::FsRead(p) => write!(f, "fs.read:{p}"),
+            Self::FsWrite(p) => write!(f, "fs.write:{p}"),
        }
    }
 }
@@ -158,11 +170,11 @@ impl FromStr for Capability {
                    }
                    Ok(Self::Process(arg.to_owned()))
                }
-                "fs.read" => {
+                "fs.read" | "fs.write" => {
                    if !std::path::Path::new(arg).is_absolute() && !arg.starts_with('~') {
                        return Err(format!("{s:?}: use an absolute path (or ~/…)"));
                    }
-                    Ok(Self::FsRead(arg.to_owned()))
+                    Ok(if kind == "fs.read" { Self::FsRead(arg.to_owned()) } else { Self::FsWrite(arg.to_owned()) })
                }
                _ => Err(format!("unknown capability {s:?}")),
            };
@@ -171,6 +183,7 @@ impl FromStr for Capability {
            "project.read" | "project-read" => Self::ProjectRead,
            "editor.read" | "editor-read" => Self::EditorRead,
            "editor.write" | "editor-write" => Self::EditorWrite,
+            "project.write" => Self::ProjectWrite,
            "vcs.read" => Self::VcsRead,
            "vcs.write" => Self::VcsWrite,
            "storage" => Self::Storage,
@@ -224,6 +237,7 @@ mod tests {
        for s in [
            "project.read",
            "editor.write",
+            "project.write",
            "vcs.write",
            "storage",
            "secrets",
@@ -236,12 +250,12 @@ mod tests {
            assert_eq!(s.parse::<Capability>().unwrap().to_string(), s);
        }
        // Absolute paths are the platform's.
-        let (git, etc) = if cfg!(windows) {
-            (r"process:C:\Program Files\Git\bin\git.exe", r"fs.read:C:\Windows")
+        let (git, etc, out) = if cfg!(windows) {
+            (r"process:C:\Program Files\Git\bin\git.exe", r"fs.read:C:\Windows", r"fs.write:C:\out")
        } else {
-            ("process:/usr/bin/git", "fs.read:/etc")
+            ("process:/usr/bin/git", "fs.read:/etc", "fs.write:/out")
        };
-        for s in [git, etc] {
+        for s in [git, etc, out] {
            assert_eq!(s.parse::<Capability>().unwrap().to_string(), s);
        }
        assert_eq!("project-read".parse::<Capability>().unwrap(), Capability::ProjectRead);
@@ -249,6 +263,7 @@ mod tests {
        assert!("net:a b".parse::<Capability>().is_err());
        assert!("process:./evil".parse::<Capability>().is_err());
        assert!("fs.read:rel".parse::<Capability>().is_err());
+        assert!("fs.write:rel".parse::<Capability>().is_err());
        assert!("network".parse::<Capability>().is_err());
    }

@@ -308,6 +308,13 @@ pub fn by_risk(caps: &[Capability]) -> Vec<(Risk, Vec<Capability>)> {

 /// Resolves a `process:` program to an absolute path once, at grant time:
 /// absolute names are taken as is, others are looked up in `path_var`.
+/// The directory is canonicalized but the file name kept as found: `cargo`,
+/// `rustc` and friends are often links to a multicall shim (rustup, asdf,
+/// mise) that picks the tool by the name it was invoked under — resolving the
+/// link itself would start the shim with the tool's arguments. The grant
+/// still pins the target's content: a hash read through a link reads the file
+/// it points to, so relinking or replacing either still fails the
+/// approved-file check.
 pub fn resolve_program(name: &str, path_var: Option<&OsStr>) -> Result<PathBuf, String> {
    let candidate = Path::new(name);
    if candidate.is_absolute() {
@@ -325,15 +332,21 @@ pub fn resolve_program(name: &str, path_var: Option<&OsStr>) -> Result<PathBuf,
        for ext in &exts {
            let p = dir.join(format!("{name}{ext}"));
            if is_executable(&p) {
-                return Ok(dunce_canonical(&p));
+                return Ok(canonical_dir(&p));
            }
        }
    }
    Err(format!("{name} was not found on PATH"))
 }

-fn dunce_canonical(p: &Path) -> PathBuf {
-    std::fs::canonicalize(p).unwrap_or_else(|_| p.to_path_buf())
+/// `p` with its parent canonicalized but the file name as found: PATH
+/// entries like `/var` → `/private/var` (macOS) or `~` links collapse to
+/// their real directory, while a linked program (`cargo` → rustup) keeps
+/// its link name so the shim still dispatches on argv[0].
+fn canonical_dir(p: &Path) -> PathBuf {
+    let Some(dir) = p.parent() else { return p.to_path_buf() };
+    let Some(name) = p.file_name() else { return p.to_path_buf() };
+    std::fs::canonicalize(dir).map(|d| d.join(name)).unwrap_or_else(|_| p.to_path_buf())
 }

 fn is_executable(p: &Path) -> bool {
@@ -474,6 +487,42 @@ mod tests {
        assert!(l.check_binary(&r.subject, &cap).unwrap_err().contains("changed"));
    }

+    /// A program found as a link stays the link: multicall shims (rustup,
+    /// asdf, mise) pick the tool by the name they were invoked under, so
+    /// `Command::new` must see the link. The hash still covers the target —
+    /// reading through the link reads it — so replacing either still trips
+    /// the approved-file check.
+    #[cfg(unix)]
+    #[test]
+    fn linked_programs_resolve_to_the_link() {
+        use std::os::unix::fs::PermissionsExt;
+        let tmp = tempfile::tempdir().unwrap();
+        let bin_dir = tmp.path().join("bin");
+        let real_dir = tmp.path().join("real");
+        std::fs::create_dir(&bin_dir).unwrap();
+        std::fs::create_dir(&real_dir).unwrap();
+        let target = real_dir.join("shim");
+        std::fs::write(&target, "#!/bin/sh\necho v1\n").unwrap();
+        std::fs::set_permissions(&target, std::fs::Permissions::from_mode(0o755)).unwrap();
+        std::os::unix::fs::symlink(&target, bin_dir.join("cargo")).unwrap();
+
+        let path_var = std::env::join_paths([bin_dir.clone()]).unwrap();
+        let resolved = resolve_program("cargo", Some(&path_var)).unwrap();
+        // Directory canonicalized, file name kept — still the link.
+        let want = std::fs::canonicalize(&bin_dir).unwrap().join("cargo");
+        assert_eq!(resolved, want);
+        assert!(resolved.symlink_metadata().unwrap().file_type().is_symlink());
+
+        let mut l = Ledger::in_memory();
+        let r = req("1.0.0", "h", &["process:cargo"], &[]);
+        let cap: Capability = "process:cargo".parse().unwrap();
+        let bin = BinaryGrant { path: resolved.clone(), hash: file_hash(&resolved).unwrap() };
+        l.confirm(&r, &[], [(cap.to_string(), bin)].into());
+        assert_eq!(l.check_binary(&r.subject, &cap).unwrap(), resolved);
+        std::fs::write(&target, "#!/bin/sh\necho evil\n").unwrap();
+        assert!(l.check_binary(&r.subject, &cap).unwrap_err().contains("changed"));
+    }
+
    #[test]
    fn hashes_and_grouping() {
        let tmp = tempfile::tempdir().unwrap();
@@ -31,6 +31,6 @@ pub use manifest::{
    Manifest, check_relative, engine_compatible, validate_item_id, validate_plugin_id, validate_point_id,
 };
 pub use point::{Commit, Disposable, ExtensionPoint, MAX_PACKAGE_FILE, Package, Placement, Prepared, decode};
-pub use registry::{ContributionInfo, ExtensionRegistry, PreparedSet};
+pub use registry::{ContributionInfo, ExtensionRegistry, LOCALES_DIR, LOCALES_POINT, PreparedSet};
 pub use ui::{UiContribution, UiDecl, UiPoint, UiStore, to_json};
 pub use when::validate_when;
@@ -144,7 +144,8 @@ impl ActivationEvent {

 /// Workbench event kinds (`on-event:<kind>`, WIT `events.event-kind`).
 /// `scheduled` comes from `on-schedule` instead.
-pub const EVENT_KINDS: &[&str] = &["file-opened", "file-saved", "editor-focused", "action-performed", "vcs-changed"];
+pub const EVENT_KINDS: &[&str] =
+    &["file-opened", "file-saved", "files-changed", "editor-focused", "action-performed", "vcs-changed"];

 impl std::fmt::Display for ActivationEvent {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -315,6 +316,11 @@ impl Manifest {
            self.needs_api("`icon`", 2)?;
            check_relative(icon, "icon")?;
        }
+        for cap in self.capabilities.required.iter().chain(&self.capabilities.optional) {
+            if matches!(cap, Capability::ProjectWrite | Capability::FsWrite(_)) {
+                self.needs_api(&format!("capability `{cap}`"), 3)?;
+            }
+        }
        if let Some(dark) = &self.icon_dark {
            if self.icon.is_none() {
                return Err("`icon-dark` needs `icon`".into());
@@ -326,6 +332,9 @@ impl Manifest {
        }
        let mut seen = BTreeSet::new();
        for event in &self.activation {
+            if matches!(event, ActivationEvent::Event(kind) if kind == "files-changed") {
+                self.needs_api("`on-event:files-changed`", 3)?;
+            }
            if !seen.insert(event) {
                return Err(format!("duplicate activation event {event}"));
            }
@@ -490,6 +499,10 @@ mod tests {
    fn event_activation() {
        assert_eq!(ActivationEvent::parse("on-event:file-saved"), Ok(ActivationEvent::Event("file-saved".into())));
        assert_eq!(ActivationEvent::Event("vcs-changed".into()).to_string(), "on-event:vcs-changed");
+        assert_eq!(
+            ActivationEvent::parse("on-event:files-changed"),
+            Ok(ActivationEvent::Event("files-changed".into()))
+        );
        let err = ActivationEvent::parse("on-event:keystroke").unwrap_err();
        assert!(err.contains("unknown event kind") && err.contains("action-performed"), "{err}");
        assert!(ActivationEvent::parse("on-event:scheduled").is_err(), "declared with on-schedule");
@@ -583,6 +596,29 @@ mod tests {

    const BASE: &str = "id = \"ok\"\nname = \"N\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.2\"\n";

+    #[test]
+    fn files_changed_activation_needs_api_1_3() {
+        let activation = "wasm = \"plugin.wasm\"\nactivation = [\"on-event:files-changed\"]\n";
+        for engine in ["^1.0", "^1.2", ">=1.1, <2"] {
+            let base = BASE.replace("^1.2", engine);
+            assert!(err(&format!("{base}{activation}")).contains("new in plugin API 1.3"), "{engine}");
+        }
+        for engine in ["^1.3", ">=1.3, <2"] {
+            Manifest::parse(&format!("{}{activation}", BASE.replace("^1.2", engine))).unwrap();
+        }
+        Manifest::parse(&format!("{BASE}{}", activation.replace("files-changed", "file-saved"))).unwrap();
+    }
+
+    #[test]
+    fn write_capabilities_need_api_1_3() {
+        for cap in ["project.write", "fs.write:~/tool"] {
+            let caps = format!("[capabilities]\noptional = [\"{cap}\"]\n");
+            assert!(err(&format!("{BASE}{caps}")).contains("new in plugin API 1.3"), "{cap}");
+            let m = Manifest::parse(&format!("{}{caps}", BASE.replace("^1.2", "^1.3"))).unwrap();
+            assert_eq!(m.capabilities.optional[0].to_string(), cap);
+        }
+    }
+
    #[test]
    fn parses_icons() {
        let m = Manifest::parse(&format!("{BASE}icon = \"icon.svg\"\nicon-dark = \"icon_dark.svg\"\n")).unwrap();
@@ -9,6 +9,11 @@ use std::collections::BTreeMap;
 use std::path::PathBuf;
 use std::sync::Arc;

+/// The point behind a package's `locales/<tag>.json` catalogs: it has no
+/// `[[contributes.locales]]` table, the directory declares it.
+pub const LOCALES_POINT: &str = "locales";
+pub const LOCALES_DIR: &str = "locales";
+
 /// A contribution as the plugin details page lists it.
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
@@ -127,6 +132,20 @@ impl ExtensionRegistry {
                set.items.push((point.id(), prepared));
            }
        }
+        if let Some(point) = self.point(LOCALES_POINT)
+            && !pkg.manifest.contributes.contains_key(LOCALES_POINT)
+            && pkg.dir.join(LOCALES_DIR).is_dir()
+        {
+            let prepared = point
+                .prepare(pkg, toml::Value::Table(Default::default()))
+                .map_err(|e| format!("{LOCALES_DIR}: {}", strip_prefix(&e, LOCALES_POINT)))?;
+            for f in &prepared.files {
+                if !set.files.contains(f) {
+                    set.files.push(f.clone());
+                }
+            }
+            set.items.push((point.id(), prepared));
+        }
        Ok(set)
    }

@@ -12,11 +12,15 @@ path = "src/bin/server.rs"
 [dependencies]
 encoding_rs.workspace = true
 ide-core.workspace = true
+ide-mcp.workspace = true
+futures.workspace = true
 ide-text.workspace = true
 ide-vfs.workspace = true
 regex-syntax.workspace = true
+regex-lite = "0.1"
 ide-workspace.workspace = true
 ide-language.workspace = true
+blake3.workspace = true
 ide-index.workspace = true
 ide-syntax.workspace = true
 ide-search.workspace = true
@@ -48,7 +52,7 @@ ide-tools = { path = "../ide-tools" }
 ide-docker = { path = "../ide-docker" }
 semver = "1"
 serde.workspace = true
-serde_json.workspace = true
+serde_json = { workspace = true, features = ["raw_value"] }
 toml.workspace = true
 specta.workspace = true
 specta-typescript.workspace = true
@@ -15,8 +15,22 @@ fn main() {
        println!("openidea-server {} (protocol {})", env!("CARGO_PKG_VERSION"), rpc::PROTOCOL_VERSION);
        return;
    }
+    if args.first().is_some_and(|a| a == "--connect") {
+        // One forwarded connection (see `ide_host::relay`): stdout carries its bytes.
+        let code = match ide_host::relay::parse_args(&args[1..]).and_then(|(host, port)| {
+            ide_host::relay::relay(&host, port, std::io::stdin(), std::io::stdout().lock())
+                .map_err(|e| format!("cannot connect to {host}:{port}: {e}"))
+        }) {
+            Ok(()) => 0,
+            Err(e) => {
+                eprintln!("{e}");
+                1
+            }
+        };
+        std::process::exit(code);
+    }
    if !args.iter().any(|a| a == "--stdio") {
-        eprintln!("usage: openidea-server --stdio | --version");
+        eprintln!("usage: openidea-server --stdio | --connect <host> <port> | --version");
        std::process::exit(2);
    }
    // stdout carries the protocol: logs go to stderr.
@@ -78,6 +92,11 @@ async fn run(base: PathBuf) -> i32 {
            None
        }
    };
+    if let Some(root) = std::env::var_os(ide_host::trust::TRUSTED_ROOT_ENV)
+        && let Err(e) = host.trust.inherit(std::path::Path::new(&root))
+    {
+        tracing::warn!("cannot trust {}: {e}", root.to_string_lossy());
+    }
    tracing::info!("openidea-server {} ready", env!("CARGO_PKG_VERSION"));
    let mut dispatcher = Dispatcher::standard();
    if let Some(plugins) = &plugins {
@@ -22,6 +22,10 @@ use std::time::Duration;

 type Changes = Vec<(OsString, Option<OsString>)>;

+/// Set by the desktop when the Dev Containers CLI already ran the lifecycle commands
+/// (`devcontainer up`): the server then doesn't run `postStartCommand` again.
+pub const LIFECYCLE_DONE_ENV: &str = "OPENIDEA_LIFECYCLE_DONE";
+
 /// What Reload Environment changed.
 #[derive(Debug, Clone, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
@@ -72,7 +76,7 @@ impl Environment {
            return None;
        }
        let config = self.load_project(root, sink);
-        let post_start = config.and_then(|c| c.post_start);
+        let post_start = config.and_then(|c| c.post_start).filter(|_| std::env::var_os(LIFECYCLE_DONE_ENV).is_none());
        let first = self.state.lock().post_started.insert(root.to_path_buf());
        post_start.filter(|_| first)
    }
@@ -8,12 +8,14 @@ pub mod environment;
 mod formatter;
 mod java_runtime;
 mod kotlin_bridge;
+pub mod mcp;
 pub mod notebook;
 pub mod ops;
 mod phpstan;
 pub mod plugins;
 mod project;
 mod proxy;
+pub mod relay;
 mod requests;
 pub mod rpc;
 pub mod shell_env;
@@ -53,6 +55,8 @@ pub struct HostConfig {
 }

 pub struct Host {
+    pub mcp_reports: mcp::Reports,
+    pub mcp_requests: mcp::Requests,
    pub trust: trust::TrustStore,
    pub config_dir: PathBuf,
    /// Persistent user state, including credentials and recovery history.
@@ -111,6 +115,8 @@ impl Host {
        let ssh = Arc::new(ide_ssh::SshManager::new(data_dir.join("ssh-passwords.json")));
        ssh.set_configs(global_settings.effective().ssh.configs);
        let host = Self {
+            mcp_reports: Default::default(),
+            mcp_requests: Default::default(),
            trust: trust::TrustStore::load(&config_dir, &data_dir),
            proxy_password: ide_ssh::secrets::SecretFile::new(data_dir.join("proxy-password.json")),
            proxy_session_password: Mutex::default(),
@@ -218,11 +224,15 @@ impl Host {
    /// so the window can open another project at once. Returns the thread that
    /// finishes shutting down its workers.
    fn begin_close(&self, window: &str) -> Option<std::thread::JoinHandle<()>> {
+        self.mcp_reports.forget_window(window);
+        self.mcp_requests.forget_window(window);
        self.external_logs.write().remove(self.owner_window(window));
        for request in self.project_requests.write().remove(self.owner_window(window)).unwrap_or_default() {
            self.cancel_request(request);
        }
        let project = self.projects.write().remove(window)?;
+        project.files_events_active.store(false, std::sync::atomic::Ordering::Release);
+        project.plugin_diagnostics.close();
        if let Some(plugins) = plugins::editor_plugin_host() {
            plugins.invalidate_client_navigation(&project.root, Some(window), None);
            plugins.set_active_file(window, None);
@@ -373,6 +383,10 @@ impl Host {
        self.terminals.kill_all();
        let projects: Vec<_> = self.projects.write().drain().map(|(_, p)| p).collect();
        for project in &projects {
+            project.files_events_active.store(false, std::sync::atomic::Ordering::Release);
+        }
+        for project in &projects {
+            project.plugin_diagnostics.close();
            if let Some(bridge) = &project.kotlin_bridge {
                bridge.stop();
            }
@@ -0,0 +1,448 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (mcpserver.toolsets/src/general/PatchToolset.kt, FileToolset.kt), Apache-2.0.
+//! Changing the project and the editor: new files, patches, formatting and imports,
+//! rename, open editors.
+//!
+//! Text changes go through the document layer: an open editor's buffer is
+//! patched in place and remains unsaved. Other files are opened transiently,
+//! saved and closed. Saves record Local History like the IDE's own edits.
+
+mod diff;
+mod format;
+mod patch;
+mod rename;
+
+use crate::Project;
+use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
+use ide_core::event::McpUiRequest;
+use ide_core::{DocId, FileEdit, IdeError, IdeResult, Pos, Range, TextEdit, WorkspaceEdit};
+use patch::FileOp;
+use std::fmt::Write as _;
+use std::path::{Path, PathBuf};
+
+pub fn tools() -> Vec<Tool> {
+    vec![create_new_file(), apply_patch(), format::reformat_file(), rename::rename_refactoring(), open_file_in_editor()]
+}
+
+/// What tools without a result value answer (JetBrains renders `Unit` so).
+const SUCCESS: &str = "[success]";
+
+// --- the document layer ----------------------------------------------------------
+
+/// Whether the file is open with unsaved changes.
+fn is_dirty(project: &Project, path: &Path) -> bool {
+    project.documents.by_path(path).is_some_and(|d| project.documents.is_dirty(d).unwrap_or(false))
+}
+
+async fn create_or_replace(call: &Call, path: PathBuf, text: Option<String>, overwrite: bool) -> IdeResult<()> {
+    let project = call.project.clone();
+    let edit = call
+        .host
+        .blocking(move || {
+            let mut files = Vec::new();
+            if path.exists() {
+                if !overwrite {
+                    return Err(IdeError::invalid("File already exists"));
+                }
+                if let Some(text) = text {
+                    let info = project.documents.open(&path)?;
+                    let result: IdeResult<()> = (|| {
+                        let snap = project.documents.text_snapshot(info.id)?;
+                        let doc = ide_text::Document::new(&snap.text);
+                        let edits = doc
+                            .diff(&text)
+                            .changes
+                            .into_iter()
+                            .map(|c| TextEdit {
+                                range: Range::new(doc.offset_to_pos(c.from), doc.offset_to_pos(c.to)),
+                                new_text: c.insert,
+                            })
+                            .collect();
+                        files.push(FileEdit::Edit {
+                            path: path.into(),
+                            edits,
+                            version: Some(
+                                i32::try_from(snap.version)
+                                    .map_err(|_| IdeError::invalid("document version is out of range"))?,
+                            ),
+                        });
+                        Ok(())
+                    })();
+                    project.documents.close(info.id);
+                    result?;
+                }
+            } else {
+                files.push(FileEdit::Create { path: path.clone().into(), overwrite: false });
+                if let Some(text) = text {
+                    files.push(FileEdit::Edit {
+                        path: path.into(),
+                        edits: vec![TextEdit { range: Range::point(Pos::new(0, 0)), new_text: text }],
+                        version: None,
+                    });
+                }
+            }
+            Ok(WorkspaceEdit { files, preconditions: Vec::new() })
+        })
+        .await?;
+    if edit.files.is_empty() {
+        return Ok(());
+    }
+    let edit = crate::ops::lsp::prepare_workspace_edit(&call.host, call.window(), edit).await?;
+    crate::ops::lsp::apply_workspace_edit(&call.host, call.window(), edit).await
+}
+
+/// The open document of `path`, or a transient one (`true`: close it after use).
+fn open_document(project: &Project, path: &Path) -> IdeResult<(DocId, bool)> {
+    match project.documents.by_path(path) {
+        Some(doc) => Ok((doc, false)),
+        None => Ok((project.documents.open(path)?.id, true)),
+    }
+}
+
+fn normalize_newlines(text: &str) -> String {
+    text.replace("\r\n", "\n").replace('\r', "\n")
+}
+
+/// The range of a whole text.
+fn whole_range(text: &str) -> Range {
+    let count = text.split('\n').count();
+    let last = text.rsplit('\n').next().unwrap_or("");
+    Range::new(Pos::new(0, 0), Pos::new(count.saturating_sub(1) as u32, last.encode_utf16().count() as u32))
+}
+
+/// Whether two paths name the same file (language servers report canonical paths; on a
+/// case-insensitive file system `a.txt` and `A.txt` are one file).
+fn same_file(a: &Path, b: &Path) -> bool {
+    if a == b || matches!((dunce::canonicalize(a), dunce::canonicalize(b)), (Ok(x), Ok(y)) if x == y) {
+        return true;
+    }
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::MetadataExt;
+        if let (Ok(x), Ok(y)) = (std::fs::metadata(a), std::fs::metadata(b)) {
+            return x.dev() == y.dev() && x.ino() == y.ino();
+        }
+    }
+    false
+}
+
+/// The text edits of `edit` for `path`.
+fn edits_for(edit: &WorkspaceEdit, path: &Path) -> Vec<TextEdit> {
+    edit.files
+        .iter()
+        .filter_map(|f| match f {
+            ide_core::FileEdit::Edit { path: p, edits, .. } if same_file(p, path) => Some(edits.clone()),
+            _ => None,
+        })
+        .flatten()
+        .collect()
+}
+
+/// Re-reads the open, unmodified documents of `paths` whose files changed on disk, before
+/// a tool reads or changes them: an agent that just wrote a file itself must not have
+/// that write undone from a stale buffer because the file watcher has not caught up yet
+/// (JetBrains refreshes the VFS first). Documents with unsaved changes are left alone.
+fn refresh_from_disk(project: &Project, paths: &[PathBuf]) {
+    project.documents.on_disk_changed(paths);
+}
+
+/// Project files a tool works on: `files` resolved inside the project, existing,
+/// regular, without duplicates (the first spelling is kept), changeable
+/// ([`Call::check_writable`]) and with their open documents up to date with the disk.
+async fn requested_files(call: &Call) -> IdeResult<Vec<(String, PathBuf)>> {
+    let files = call.str_list("files")?;
+    if files.is_empty() {
+        return Err(IdeError::invalid("files must contain at least one path"));
+    }
+    let mut out: Vec<(String, PathBuf)> = Vec::new();
+    for raw in files {
+        let raw = raw.trim();
+        if raw.is_empty() {
+            return Err(IdeError::invalid("files must not contain blank paths"));
+        }
+        let path = call.resolve_inside(raw)?;
+        if !path.exists() {
+            return Err(IdeError::not_found(format!("File not found: {raw}")));
+        }
+        if !path.is_file() {
+            return Err(IdeError::invalid(format!("Not a file: {raw}")));
+        }
+        if !out.iter().any(|(_, p)| *p == path) {
+            out.push((raw.to_owned(), path));
+        }
+    }
+    for (_, path) in &out {
+        call.check_writable(path).await?;
+    }
+    let (project, paths) = (call.project().clone(), out.iter().map(|(_, p)| p.clone()).collect::<Vec<_>>());
+    call.host()
+        .blocking(move || {
+            refresh_from_disk(&project, &paths);
+            Ok(())
+        })
+        .await?;
+    Ok(out)
+}
+
+// --- create_new_file ----------------------------------------------------------------
+
+fn create_new_file() -> Tool {
+    Tool::new(
+        "create_new_file",
+        "Creates a new file at the specified path within the project directory and optionally populates it with \
+text if provided.
+Use this tool to generate new files in your project structure.
+Note: Creates any necessary parent directories automatically",
+        |call| async move {
+            let raw = call.str("pathInProject")?;
+            let path = call.resolve_writable(&raw).await?;
+            let text = call.opt_str("text")?.map(|t| normalize_newlines(&t));
+            let overwrite = call.flag("overwrite", false)?;
+            let cannot =
+                |e: &dyn std::fmt::Display| IdeError::invalid(format!("Can't create file: {}: {e}", path.display()));
+            if path.is_dir() {
+                return Err(cannot(&"it is a directory"));
+            }
+            if path.exists() && !overwrite {
+                return Err(IdeError::new(
+                    ide_core::error::ErrorKind::AlreadyExists,
+                    format!("File already exists: {raw}. Specify 'overwrite=true' to overwrite it"),
+                ));
+            }
+            create_or_replace(&call, path, text, overwrite).await?;
+            Ok(Output::text(SUCCESS))
+        },
+    )
+    .write()
+    .param(Param::required(
+        "pathInProject",
+        ParamType::String,
+        "Path where the file should be created relative to the project root",
+    ))
+    .param(Param::optional("text", ParamType::String, "Content to write into the new file"))
+    .param(Param::optional(
+        "overwrite",
+        ParamType::Boolean,
+        "Whether to overwrite an existing file if exists. If false, an exception is thrown in case of a conflict.",
+    ))
+}
+
+// --- apply_patch --------------------------------------------------------------------
+
+fn apply_patch() -> Tool {
+    Tool::new(
+        "apply_patch",
+        "Apply a patch using the Codex apply_patch format or unified git diff format.
+Supports Add, Delete, and Update operations with optional Move to path for updates.
+Paths must stay inside the project directory.",
+        |call| async move {
+            let input = [call.opt_str("input")?, call.opt_str("patch")?]
+                .into_iter()
+                .flatten()
+                .find(|s| !s.trim().is_empty())
+                .ok_or_else(|| IdeError::invalid("input must be a non-empty string"))?;
+            let ops = patch::parse(&input).map_err(IdeError::invalid)?;
+            let total = ops.iter().filter(|op| !matches!(op, FileOp::Skip { .. })).count();
+            let mut applied = 0usize;
+            let mut errors = Vec::new();
+            let mut notes = Vec::new();
+            // Each operation stands alone, as in JetBrains: a failed one leaves the others applied.
+            for op in ops {
+                if let FileOp::Skip { path, note } = op {
+                    notes.push(format!("{path}: {note}"));
+                    continue;
+                }
+                let path = op.path().to_owned();
+                match apply_op(&call, op, &mut notes).await {
+                    Ok(()) => applied += 1,
+                    Err(e) if e.kind == ide_core::error::ErrorKind::Cancelled => return Err(e),
+                    Err(e) => errors.push(format!("{path}: {}", e.message)),
+                }
+            }
+            let mut out = format!("{applied} out of {total} operations applied.");
+            if !errors.is_empty() {
+                let _ = write!(
+                    out,
+                    " {} operations failed to be applied due to errors:\n{}",
+                    errors.len(),
+                    errors.join("\n")
+                );
+            }
+            if !notes.is_empty() {
+                out.push_str("\nNotes:");
+                for n in notes {
+                    let _ = write!(out, "\n- {n}");
+                }
+            }
+            Ok(Output::text(out))
+        },
+    )
+    .write()
+    .param(Param::optional(
+        "input",
+        ParamType::String,
+        "Patch text in the apply_patch format or unified git diff format.",
+    ))
+    .param(Param::optional(
+        "patch",
+        ParamType::String,
+        "Alias of `input` for compatibility with clients that send `{patch: ...}`.",
+    ))
+}
+
+/// Applies one operation of a patch; its checks come first, so a failed operation changes nothing.
+async fn apply_op(call: &Call, op: FileOp, notes: &mut Vec<String>) -> IdeResult<()> {
+    let host = call.host();
+    let project = call.project().clone();
+    match op {
+        // Noted by the caller.
+        FileOp::Skip { .. } => Ok(()),
+        FileOp::Add { path: raw, text } => {
+            let path = call.resolve_writable(&raw).await?;
+            if path.exists() {
+                return Err(IdeError::invalid(format!("File already exists: {raw}")));
+            }
+            create_or_replace(call, path, Some(text), false).await
+        }
+        FileOp::Delete { path: raw } => {
+            let path = call.resolve_writable(&raw).await?;
+            if !path.is_file() {
+                return Err(IdeError::not_found(format!("File not found: {raw}")));
+            }
+            if is_dirty(&project, &path) {
+                return Err(IdeError::invalid("cannot delete a file with unsaved editor changes"));
+            }
+            let edit = WorkspaceEdit {
+                files: vec![FileEdit::Delete { path: path.into(), recursive: false }],
+                preconditions: Vec::new(),
+            };
+            let edit = crate::ops::lsp::prepare_workspace_edit(&host, call.window(), edit).await?;
+            crate::ops::lsp::apply_workspace_edit(&host, call.window(), edit).await
+        }
+        FileOp::Update { path: first, move_to, hunks, or } => {
+            // A plain diff's other names count when its `+++` path does not exist.
+            let mut raw = first.clone();
+            let mut path = call.resolve_inside(&raw)?;
+            for other in &or {
+                if path.exists() {
+                    break;
+                }
+                let candidate = call.resolve_inside(other)?;
+                if candidate.exists() {
+                    (raw, path) = (other.clone(), candidate);
+                }
+            }
+            if !path.exists() {
+                let tried = if or.is_empty() { String::new() } else { format!(" (also tried {})", or.join(", ")) };
+                return Err(IdeError::not_found(format!("File not found: {first}{tried}")));
+            }
+            if !path.is_file() {
+                return Err(IdeError::invalid(format!("Path is not a file: {raw}")));
+            }
+            if !hunks.is_empty() || move_to.is_some() {
+                call.check_writable(&path).await?;
+            }
+            let to = match &move_to {
+                Some(m) => {
+                    let to = call.resolve_writable(m).await?;
+                    // A move that changes only the case on a case-insensitive file system finds itself.
+                    if to != path && to.exists() && !same_file(&to, &path) {
+                        return Err(IdeError::new(
+                            ide_core::error::ErrorKind::AlreadyExists,
+                            format!("File already exists: {m}"),
+                        ));
+                    }
+                    Some(to).filter(|t| *t != path)
+                }
+                None => None,
+            };
+            let shown = call.display(&path);
+            let (p, target) = (project.clone(), path.clone());
+            let (mut edit, fuzzy, dirty) = host
+                .blocking(move || {
+                    refresh_from_disk(&p, std::slice::from_ref(&target));
+                    let info = p.documents.open(&target)?;
+                    let result = (|| {
+                        let snap = p.documents.text_snapshot(info.id)?;
+                        let dirty = p.documents.is_dirty(info.id)?;
+                        let applied = patch::apply(&snap.text, &hunks).map_err(IdeError::invalid)?;
+                        let text = ide_text::Document::new(&snap.text);
+                        let edits = text
+                            .diff(&applied.text)
+                            .changes
+                            .into_iter()
+                            .map(|c| TextEdit {
+                                range: Range::new(text.offset_to_pos(c.from), text.offset_to_pos(c.to)),
+                                new_text: c.insert,
+                            })
+                            .collect();
+                        Ok((
+                            WorkspaceEdit {
+                                files: vec![FileEdit::Edit {
+                                    path: target.clone().into(),
+                                    edits,
+                                    version: Some(
+                                        i32::try_from(snap.version)
+                                            .map_err(|_| IdeError::invalid("document version is out of range"))?,
+                                    ),
+                                }],
+                                preconditions: Vec::new(),
+                            },
+                            applied.fuzzy,
+                            dirty,
+                        ))
+                    })();
+                    p.documents.close(info.id);
+                    result
+                })
+                .await?;
+            if let Some(to) = to {
+                edit.files.push(FileEdit::Rename { from: path.into(), to: to.into() });
+            }
+            let edit = crate::ops::lsp::prepare_workspace_edit(&host, call.window(), edit).await?;
+            crate::ops::lsp::apply_workspace_edit(&host, call.window(), edit).await?;
+            if dirty {
+                notes.push(format!("{shown}: patched the unsaved editor buffer"));
+            }
+            for (hunk, fuzz) in fuzzy {
+                notes.push(format!("{shown}: hunk {hunk} matched only {}", fuzz.describe()));
+            }
+            Ok(())
+        }
+    }
+}
+
+// --- the editor ------------------------------------------------------------------------
+
+fn open_file_in_editor() -> Tool {
+    Tool::new(
+        "open_file_in_editor",
+        "Opens the specified file in the IDE editor.
+Requires a filePath parameter containing the path to the file to open.
+The file path can be absolute or relative to the project root.
+Optionally puts the caret at a 1-based line and column.",
+        |call| async move {
+            let raw = call.str("filePath")?;
+            // Opening shows the file to the user: outside the project the user agrees first.
+            let path = call.resolve_readable(&raw).await?;
+            if !path.is_file() {
+                return Err(IdeError::not_found(format!("File {raw} doesn't exist or can't be opened")));
+            }
+            let positive = |name: &str| -> IdeResult<Option<u32>> {
+                match call.opt_i64(name)? {
+                    None => Ok(None),
+                    Some(n) if n < 1 || n > u32::MAX as i64 => {
+                        Err(IdeError::invalid(format!("`{name}` is 1-based and must be at least 1")))
+                    }
+                    Some(n) => Ok(Some(n as u32)),
+                }
+            };
+            let (line, column) = (positive("line")?, positive("column")?);
+            call.ask(McpUiRequest::OpenFile { path: path.into(), line, column }).await?;
+            Ok(Output::text(SUCCESS))
+        },
+    )
+    .write()
+    .param(Param::required("filePath", ParamType::String, "Path relative to the project root"))
+    .param(Param::optional("line", ParamType::Integer, "1-based line to put the caret on"))
+    .param(Param::optional("column", ParamType::Integer, "1-based column on that line"))
+}
@@ -0,0 +1,380 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (mcpserver.toolsets/src/general/UnifiedDiffSupport.kt), Apache-2.0.
+//! The unified diff tools answer with, so an agent sees what the IDE changed
+//! without reading the files again. Capped, so a large change cannot flood the
+//! agent's context.
+
+/// Unchanged lines kept around each change, as in a standard unified diff.
+const CONTEXT_LINES: usize = 3;
+
+/// The default cap on diff lines.
+pub const MAX_DIFF_LINES: usize = 200;
+
+/// The smallest useful hunk: the `@@` header line and one line under it.
+const MIN_HUNK_LINES: usize = 2;
+
+/// Beyond this many differing lines (after the common head and tail) the
+/// diff is not computed: the file is reported as too large to diff.
+const MAX_EDIT_DISTANCE: usize = 2000;
+
+/// One file a tool processed: the requested path, the text before and after.
+/// `None` texts are reported as unavailable, never as "nothing changed".
+pub struct ChangedFileText {
+    pub path: String,
+    pub before: Option<String>,
+    pub after: Option<String>,
+}
+
+/// A unified diff of the changes in `files`, at most `max_lines` diff lines;
+/// `None` when nothing changed. A file goes in whole, or the footer names it.
+pub fn build_unified_diff(files: &[ChangedFileText], max_lines: usize) -> Option<String> {
+    let mut lines: Vec<String> = Vec::new();
+    let mut omitted_files = Vec::new();
+    let mut omitted_lines = 0usize;
+    for file in files {
+        let Some(diff) = file_diff(file) else { continue };
+        // A header with no hunk under it helps nobody.
+        if !lines.is_empty() && max_lines.saturating_sub(lines.len()) < diff.header.len() + MIN_HUNK_LINES {
+            omitted_files.push(diff.path.clone());
+            omitted_lines += diff.line_count();
+            continue;
+        }
+        lines.extend(diff.header.iter().cloned());
+        for (index, hunk) in diff.hunks.iter().enumerate() {
+            let room = max_lines as isize - lines.len() as isize - 1;
+            if room < 1 && index > 0 {
+                omitted_lines += diff.hunks[index..].iter().map(Hunk::line_count).sum::<usize>();
+                break;
+            }
+            // The first hunk always keeps one line, so its file header never stands alone.
+            let body = room.max(1) as usize;
+            lines.extend(hunk.render(body));
+            omitted_lines += hunk.body.len().saturating_sub(body);
+        }
+    }
+    if lines.is_empty() {
+        return None;
+    }
+    let mut out = lines.join("\n");
+    if omitted_lines > 0 {
+        out.push_str(&format!("\n… and {omitted_lines} more diff line(s) omitted."));
+    }
+    if !omitted_files.is_empty() {
+        out.push_str(&format!("\n… The diff leaves out these file(s): {}.", omitted_files.join(", ")));
+    }
+    Some(out)
+}
+
+struct FileDiff {
+    path: String,
+    header: Vec<String>,
+    hunks: Vec<Hunk>,
+}
+
+impl FileDiff {
+    fn line_count(&self) -> usize {
+        self.header.len() + self.hunks.iter().map(Hunk::line_count).sum::<usize>()
+    }
+}
+
+/// One hunk: where it starts on each side (0-based), and its `-`, `+` and context lines.
+struct Hunk {
+    start0: usize,
+    start1: usize,
+    body: Vec<String>,
+}
+
+impl Hunk {
+    fn line_count(&self) -> usize {
+        self.body.len() + 1
+    }
+
+    /// The hunk with at most `max_body` body lines; the header counts the lines it prints.
+    fn render(&self, max_body: usize) -> Vec<String> {
+        let printed = &self.body[..self.body.len().min(max_body)];
+        let count0 = printed.iter().filter(|l| l.starts_with(' ') || l.starts_with('-')).count();
+        let count1 = printed.iter().filter(|l| l.starts_with(' ') || l.starts_with('+')).count();
+        // An empty range names the line before it, so it keeps the 0-based value.
+        let start = |s: usize, count: usize| if count == 0 { s } else { s + 1 };
+        let mut out =
+            vec![format!("@@ -{},{count0} +{},{count1} @@", start(self.start0, count0), start(self.start1, count1))];
+        out.extend(printed.iter().cloned());
+        out
+    }
+}
+
+/// A line of the text, and whether it ends without a line separator (the last line).
+type DiffLine<'a> = (&'a str, bool);
+
+fn file_diff(file: &ChangedFileText) -> Option<FileDiff> {
+    let path = file.path.replace('\\', "/");
+    let header = vec![format!("--- a/{path}"), format!("+++ b/{path}")];
+    let note = |text: &str| {
+        let mut header = header.clone();
+        header.push(format!("({text})"));
+        Some(FileDiff { path: path.clone(), header, hunks: Vec::new() })
+    };
+    let (Some(before), Some(after)) = (&file.before, &file.after) else {
+        return note(
+            "the content of this file is not available, so the diff cannot report what changed; read the file again",
+        );
+    };
+    if before == after {
+        return None;
+    }
+    let old = split_lines(before);
+    let new = split_lines(after);
+    let Some(changes) = changes(&old, &new) else { return note("this file changed, but it is too large to diff") };
+    // The texts differ but the lines are equal: only the line separators changed.
+    if changes.is_empty() {
+        return note("only the line separators of this file changed");
+    }
+    let hunks = group(&changes).into_iter().map(|g| build_hunk(g, &old, &new)).collect();
+    Some(FileDiff { path, header, hunks })
+}
+
+/// The lines a diff compares: no extra empty line after a final separator; a
+/// last line without one is marked, so a change of the final separator alone counts.
+fn split_lines(text: &str) -> Vec<DiffLine<'_>> {
+    if text.is_empty() {
+        return Vec::new();
+    }
+    let ends_with_newline = text.ends_with('\n');
+    let mut lines: Vec<DiffLine> = text.split('\n').map(|l| (l.strip_suffix('\r').unwrap_or(l), false)).collect();
+    if ends_with_newline {
+        lines.pop();
+    } else if let Some(last) = lines.last_mut() {
+        last.1 = true;
+    }
+    lines
+}
+
+/// A run of changed lines: at `line0` in the old text `deleted` lines, at `line1` in the new one `inserted`.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+struct Change {
+    line0: usize,
+    line1: usize,
+    deleted: usize,
+    inserted: usize,
+}
+
+/// The changes from `a` to `b` (Myers' algorithm), `None` when they differ too much.
+fn changes(a: &[DiffLine], b: &[DiffLine]) -> Option<Vec<Change>> {
+    let head = a.iter().zip(b).take_while(|(x, y)| x == y).count();
+    let tail = a[head..].iter().rev().zip(b[head..].iter().rev()).take_while(|(x, y)| x == y).count();
+    let (a_mid, b_mid) = (&a[head..a.len() - tail], &b[head..b.len() - tail]);
+    let script = myers(a_mid, b_mid)?;
+    // `script`: per step, true = equal (both advance), Some side otherwise.
+    let mut out: Vec<Change> = Vec::new();
+    let (mut i, mut j) = (head, head);
+    for step in script {
+        match step {
+            Step::Equal => {
+                i += 1;
+                j += 1;
+                continue;
+            }
+            Step::Delete => {
+                match out.last_mut() {
+                    Some(c) if c.line0 + c.deleted == i && c.line1 + c.inserted == j => c.deleted += 1,
+                    _ => out.push(Change { line0: i, line1: j, deleted: 1, inserted: 0 }),
+                }
+                i += 1;
+            }
+            Step::Insert => {
+                match out.last_mut() {
+                    Some(c) if c.line0 + c.deleted == i && c.line1 + c.inserted == j => c.inserted += 1,
+                    _ => out.push(Change { line0: i, line1: j, deleted: 0, inserted: 1 }),
+                }
+                j += 1;
+            }
+        }
+    }
+    Some(out)
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+enum Step {
+    Equal,
+    Delete,
+    Insert,
+}
+
+/// The shortest edit script from `a` to `b`, deletions before insertions in each run.
+fn myers(a: &[DiffLine], b: &[DiffLine]) -> Option<Vec<Step>> {
+    let (n, m) = (a.len() as isize, b.len() as isize);
+    let max = (n + m) as usize;
+    let limit = max.min(MAX_EDIT_DISTANCE) as isize;
+    let off = max as isize + 1;
+    let mut v = vec![0isize; 2 * max + 3];
+    // V after each round d, for diagonals -d..=d.
+    let mut trace: Vec<Vec<isize>> = Vec::new();
+    let mut end = None;
+    'rounds: for d in 0..=limit {
+        for k in (-d..=d).step_by(2) {
+            let at = |k: isize| (off + k) as usize;
+            let mut x =
+                if k == -d || (k != d && v[at(k - 1)] < v[at(k + 1)]) { v[at(k + 1)] } else { v[at(k - 1)] + 1 };
+            let mut y = x - k;
+            while x < n && y < m && a[x as usize] == b[y as usize] {
+                x += 1;
+                y += 1;
+            }
+            v[at(k)] = x;
+            if x >= n && y >= m {
+                trace.push(v[at(-d)..=at(d)].to_vec());
+                end = Some(d);
+                break 'rounds;
+            }
+        }
+        trace.push(v[(off - d) as usize..=(off + d) as usize].to_vec());
+    }
+    let d_end = end?;
+    let mut steps = Vec::new();
+    let (mut x, mut y) = (n, m);
+    for d in (1..=d_end).rev() {
+        let prev = &trace[(d - 1) as usize];
+        let get = |k: isize| prev[(k + d - 1) as usize];
+        let k = x - y;
+        let insert = k == -d || (k != d && get(k - 1) < get(k + 1));
+        let prev_k = if insert { k + 1 } else { k - 1 };
+        let prev_x = get(prev_k);
+        let prev_y = prev_x - prev_k;
+        let (mid_x, mid_y) = if insert { (prev_x, prev_y + 1) } else { (prev_x + 1, prev_y) };
+        while x > mid_x && y > mid_y {
+            steps.push(Step::Equal);
+            x -= 1;
+            y -= 1;
+        }
+        steps.push(if insert { Step::Insert } else { Step::Delete });
+        (x, y) = (prev_x, prev_y);
+    }
+    steps.extend(std::iter::repeat_n(Step::Equal, x as usize));
+    steps.reverse();
+    // Within a run of changes, deletions first (as `-` lines precede `+` lines).
+    let mut i = 0;
+    while i < steps.len() {
+        if steps[i] == Step::Equal {
+            i += 1;
+            continue;
+        }
+        let end = steps[i..].iter().position(|s| *s == Step::Equal).map_or(steps.len(), |p| i + p);
+        steps[i..end].sort_by_key(|s| *s == Step::Insert);
+        i = end;
+    }
+    Some(steps)
+}
+
+/// Changes whose context lines touch share a hunk.
+fn group(changes: &[Change]) -> Vec<&[Change]> {
+    let mut out: Vec<&[Change]> = Vec::new();
+    let mut start = 0;
+    for i in 1..changes.len() {
+        let prev = changes[i - 1];
+        if changes[i].line0 - (prev.line0 + prev.deleted) > CONTEXT_LINES * 2 {
+            out.push(&changes[start..i]);
+            start = i;
+        }
+    }
+    if !changes.is_empty() {
+        out.push(&changes[start..]);
+    }
+    out
+}
+
+fn build_hunk(group: &[Change], old: &[DiffLine], new: &[DiffLine]) -> Hunk {
+    let (first, last) = (group[0], group[group.len() - 1]);
+    // One clamp for both sides, so the two starts in the header stay in step.
+    let leading = CONTEXT_LINES.min(first.line0).min(first.line1);
+    let (start0, start1) = (first.line0 - leading, first.line1 - leading);
+    let (end0, end1) = (last.line0 + last.deleted, last.line1 + last.inserted);
+    let trailing = CONTEXT_LINES.min(old.len() - end0).min(new.len() - end1);
+    let mut body = Vec::new();
+    let push = |body: &mut Vec<String>, prefix: char, (text, no_newline): DiffLine| {
+        body.push(format!("{prefix}{text}"));
+        if no_newline {
+            body.push("\\ No newline at end of file".into());
+        }
+    };
+    let mut line0 = start0;
+    for c in group {
+        while line0 < c.line0 {
+            push(&mut body, ' ', old[line0]);
+            line0 += 1;
+        }
+        for &l in &old[c.line0..c.line0 + c.deleted] {
+            push(&mut body, '-', l);
+        }
+        for &l in &new[c.line1..c.line1 + c.inserted] {
+            push(&mut body, '+', l);
+        }
+        line0 = c.line0 + c.deleted;
+    }
+    while line0 < end0 + trailing {
+        push(&mut body, ' ', old[line0]);
+        line0 += 1;
+    }
+    Hunk { start0, start1, body }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn diff(before: &str, after: &str) -> Option<String> {
+        build_unified_diff(
+            &[ChangedFileText { path: "src/A.java".into(), before: Some(before.into()), after: Some(after.into()) }],
+            MAX_DIFF_LINES,
+        )
+    }
+
+    #[test]
+    fn diffs_a_reformat_like_jetbrains() {
+        let out = diff("public class DiffTarget {\nint a;\n}\n", "public class DiffTarget {\n    int a;\n}\n").unwrap();
+        assert_eq!(
+            out,
+            "--- a/src/A.java\n+++ b/src/A.java\n@@ -1,3 +1,3 @@\n public class DiffTarget {\n-int a;\n+    int a;\n }"
+        );
+        assert_eq!(diff("same\n", "same\n"), None);
+    }
+
+    #[test]
+    fn splits_far_changes_into_hunks_and_marks_the_final_newline() {
+        let before: String = (1..=20).map(|i| format!("{i}\n")).collect();
+        let after: String = (1..=20)
+            .map(|i| match i {
+                2 => "two\n".to_owned(),
+                19 => "nineteen\n".to_owned(),
+                i => format!("{i}\n"),
+            })
+            .collect();
+        let out = diff(&before, &after).unwrap();
+        assert!(out.contains("@@ -1,5 +1,5 @@\n 1\n-2\n+two\n 3\n 4\n 5\n"), "{out}");
+        assert!(out.contains("@@ -16,5 +16,5 @@\n 16\n 17\n 18\n-19\n+nineteen\n 20"), "{out}");
+        let out = diff("a\nb", "a\nb\n").unwrap();
+        assert!(out.ends_with("@@ -1,2 +1,2 @@\n a\n-b\n\\ No newline at end of file\n+b"), "{out}");
+        let out = diff("a\r\n", "a\n").unwrap();
+        assert!(out.ends_with("(only the line separators of this file changed)"), "{out}");
+        let out = diff("", "x\n").unwrap();
+        assert!(out.ends_with("@@ -0,0 +1,1 @@\n+x"), "{out}");
+        let out = diff("import a;\n\nclass X {}\n", "\nclass X {}\n").unwrap();
+        assert!(out.ends_with("@@ -1,3 +1,2 @@\n-import a;\n \n class X {}"), "{out}");
+    }
+
+    #[test]
+    fn caps_the_diff_and_names_what_it_leaves_out() {
+        let before: String = (0..300).map(|i| format!("{i}\n")).collect();
+        let after: String = (0..300).map(|i| format!("x{i}\n")).collect();
+        let files = [
+            ChangedFileText { path: "a.txt".into(), before: Some(before.clone()), after: Some(after.clone()) },
+            ChangedFileText { path: "b.txt".into(), before: Some(before), after: Some(after) },
+            ChangedFileText { path: "c.bin".into(), before: None, after: None },
+        ];
+        let out = build_unified_diff(&files, 50).unwrap();
+        assert_eq!(out.lines().filter(|l| !l.starts_with('…')).count(), 50, "{out}");
+        // 553 lines of a.txt's hunk, 603 of b.txt, 3 of c.bin's note.
+        assert!(out.contains("… and 1159 more diff line(s) omitted."), "{out}");
+        assert!(out.ends_with("… The diff leaves out these file(s): b.txt, c.bin."), "{out}");
+        // The cut hunk's header counts what it prints.
+        assert!(out.contains("@@ -1,47 +0,0 @@"), "{out}");
+    }
+}
@@ -0,0 +1,199 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (mcpserver.toolsets/src/general/FormattingToolset.kt), Apache-2.0.
+//! `reformat_file` and `optimize_imports` with the language servers: document
+//! formatting and the `source.organizeImports` code action. Both answer with a
+//! unified diff of what changed, or `ok`.
+//!
+//! JetBrains always has a formatter and an import optimizer; here a file whose
+//! language server offers none is reported after the diff (the whole call fails
+//! only when no file could be processed).
+
+use super::diff::{ChangedFileText, MAX_DIFF_LINES, build_unified_diff};
+use super::{edits_for, open_document, requested_files, whole_range};
+use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
+use ide_core::{DocId, IdeError, IdeResult};
+use std::path::Path;
+
+const ORGANIZE_IMPORTS: &str = "source.organizeImports";
+
+pub(super) fn reformat_file() -> Tool {
+    Tool::new(
+        "reformat_file",
+        "Reformats the specified files in the IDE.
+Use this tool to apply code formatting rules to files identified by their project-relative paths.
+Returns a unified diff of the changes that the formatter applied, or \"ok\" when the files already match the code \
+style.
+The diff shows the formatter changes only. It never repeats the edit that you applied yourself.
+The diff stops at 200 lines. A footer names the file(s) that it leaves out.
+To remove unused imports without reformatting, use optimize_imports.",
+        |call| async move {
+            let organize = call.flag("optimizeImports", false)?;
+            run(&call, Job { organize, format: true }).await
+        },
+    )
+    .write()
+    .param(Param::required(
+        "files",
+        ParamType::StringList,
+        "List of project-relative files to reformat. Duplicate paths are ignored after normalization.",
+    ))
+    .param(Param::optional(
+        "optimizeImports",
+        ParamType::Boolean,
+        "If true, also remove unused imports and order the remaining ones before reformatting.",
+    ))
+}
+
+#[derive(Clone, Copy)]
+struct Job {
+    organize: bool,
+    format: bool,
+}
+
+async fn run(call: &Call, job: Job) -> IdeResult<Output> {
+    let files = requested_files(call).await?;
+    let mut changed = Vec::new();
+    let mut problems = Vec::new();
+    for (raw, path) in &files {
+        match process(call, path, job).await {
+            Ok(outcome) => {
+                changed.push(ChangedFileText {
+                    path: raw.clone(),
+                    before: Some(outcome.before),
+                    after: Some(outcome.after),
+                });
+                problems.extend(outcome.notes.into_iter().map(|n| format!("{raw}: {n}")));
+            }
+            Err(e) if e.kind == ide_core::error::ErrorKind::Cancelled => return Err(e),
+            Err(e) => {
+                let what = if job.format { "not formatted" } else { "imports not optimized" };
+                problems.push(format!("{raw}: {what}: {}", e.message));
+            }
+        }
+    }
+    if changed.is_empty() {
+        return Err(IdeError::unavailable(problems.join("\n")));
+    }
+    let mut out = build_unified_diff(&changed, MAX_DIFF_LINES).unwrap_or_else(|| "ok".into());
+    if !problems.is_empty() {
+        out.push_str("\n\n");
+        out.push_str(&problems.join("\n"));
+    }
+    Ok(Output::text(out))
+}
+
+struct Outcome {
+    before: String,
+    after: String,
+    /// What went wrong without failing the file (imports not optimized before a reformat).
+    notes: Vec<String>,
+}
+
+/// Runs the job on one file's document (opened transiently when it is not open) and saves it.
+async fn process(call: &Call, path: &Path, job: Job) -> IdeResult<Outcome> {
+    let host = call.host();
+    let project = call.project().clone();
+    let (p, target) = (project.clone(), path.to_path_buf());
+    let (doc, transient) = host.blocking(move || open_document(&p, &target)).await?;
+    let result = async {
+        let info = project.documents.snapshot(doc)?;
+        if info.read_only {
+            return Err(IdeError::invalid("the file is read-only"));
+        }
+        let before = project.documents.text_snapshot(doc)?.text;
+        let mut notes = Vec::new();
+        if job.organize {
+            match organize_imports(call, doc, path).await {
+                Ok(()) => {}
+                Err(e) if job.format && e.kind != ide_core::error::ErrorKind::Cancelled => {
+                    notes.push(format!("imports not optimized: {}", e.message));
+                }
+                Err(e) => return Err(e),
+            }
+        }
+        if job.format {
+            format(call, doc, &info).await?;
+        }
+        let p = project.clone();
+        let after = host
+            .blocking(move || {
+                if !info.dirty && p.documents.is_dirty(doc)? {
+                    p.documents.save(doc)?;
+                }
+                Ok(p.documents.text_snapshot(doc)?.text)
+            })
+            .await?;
+        Ok(Outcome { before, after, notes })
+    }
+    .await;
+    if transient {
+        project.documents.close(doc);
+    }
+    result
+}
+
+/// Formats the whole document with its language server; indentation from EditorConfig, else the settings.
+async fn format(call: &Call, doc: DocId, info: &ide_workspace::DocumentInfo) -> IdeResult<()> {
+    let host = call.host();
+    let project = call.project().clone();
+    let editor = project.settings.effective().editor;
+    let ec = info.editorconfig.as_ref();
+    let insert_spaces = match ec.and_then(|e| e.indent_style) {
+        Some(style) => style != ide_workspace::editorconfig::IndentStyle::Tab,
+        None => editor.insert_spaces,
+    };
+    let tab_size = ec.and_then(|e| e.indent_size.or(e.tab_width)).unwrap_or(editor.tab_size);
+    let options = ide_lsp::types::FormatOptions { tab_size, insert_spaces, on_save: false, tool: None };
+    let version = project.documents.text_snapshot(doc)?.version;
+    let edits = tokio::select! {
+        r = crate::ops::lsp::lsp_format(&host, call.window(), doc, None, options) => r?,
+        _ = call.cancel.cancelled() => return Err(IdeError::cancelled()),
+    };
+    host.blocking(move || {
+        if project.documents.text_snapshot(doc)?.version != version {
+            return Err(IdeError::unavailable("the file changed while it was being formatted; try again"));
+        }
+        project.documents.apply_edits(doc, &edits).map(|_| ())
+    })
+    .await
+}
+
+/// Runs the `source.organizeImports` code action of the document's language server.
+/// Nothing offered: nothing to do, unless the server says it has no such action at all.
+pub(super) async fn organize_imports(call: &Call, doc: DocId, path: &Path) -> IdeResult<()> {
+    let host = call.host();
+    let window = call.window();
+    let text = call.project().documents.text_snapshot(doc)?.text;
+    let request = crate::mcp::tool::request_id();
+    let only = vec![ORGANIZE_IMPORTS.to_owned()];
+    let query = tokio::select! {
+        r = crate::ops::lsp::lsp_code_action_query(&host, window, request, doc, whole_range(&text), only) => r?,
+        _ = call.cancel.cancelled() => {
+            host.cancel_request(request);
+            return Err(IdeError::cancelled());
+        }
+    };
+    let organizes = |kind: &str| kind == ORGANIZE_IMPORTS || kind.starts_with("source.organizeImports.");
+    let action = query
+        .actions
+        .into_iter()
+        .filter(|a| a.disabled_reason.is_none() && a.kind.as_deref().is_some_and(organizes))
+        .max_by_key(|a| a.is_preferred);
+    let Some(action) = action else {
+        let offered = query.advertised_kinds.is_none_or(|kinds| kinds.iter().any(|k| k == "source" || organizes(k)));
+        return if offered {
+            Ok(())
+        } else {
+            Err(IdeError::unavailable("the language server of this file offers no organize imports action"))
+        };
+    };
+    let action = crate::ops::lsp::lsp_resolve_code_action(&host, window, doc, action).await?;
+    match &action.edit {
+        Some(edit) => {
+            let edits = edits_for(edit, path);
+            let project = call.project().clone();
+            host.blocking(move || project.documents.apply_edits(doc, &edits).map(|_| ())).await
+        }
+        // The server applies the change itself (`workspace/applyEdit` during the command).
+        None => crate::ops::lsp::lsp_apply_code_action(&host, window, doc, action).await,
+    }
+}
@@ -0,0 +1,949 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (mcpserver.toolsets/src/general/PatchApplyEngine.kt), Apache-2.0.
+//! Patches as AI agents write them: the Codex `apply_patch` format (with the
+//! strict `@@` pair blocks some models write) and unified (git) diffs, bare or
+//! inside `*** Begin Patch`. Parsing and applying hunks to a text are pure, so
+//! they are tested here; the tool in `edit.rs` resolves paths and writes through
+//! the documents.
+//!
+//! Beyond JetBrains: stacked `@@` anchors, unified hunk line numbers as hints,
+//! `\ No newline at end of file`, plain `diff -u` / `diff -ru` names, and errors
+//! that show where a hunk went wrong.
+
+use std::fmt::Write as _;
+
+/// One file of a patch, paths as written in it.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum FileOp {
+    Add {
+        path: String,
+        text: String,
+    },
+    Delete {
+        path: String,
+    },
+    /// `or` lists other paths the file may have, tried in order when `path` does
+    /// not exist (a plain diff's `---` name, or its names without their first
+    /// directory, as `patch -p1` reads `diff -ru old/ new/`).
+    Update {
+        path: String,
+        move_to: Option<String>,
+        hunks: Vec<Hunk>,
+        or: Vec<String>,
+    },
+    /// A git section the tool does not apply (a copy): skipped with `note`, the others go on.
+    Skip {
+        path: String,
+        note: String,
+    },
+}
+
+impl FileOp {
+    pub fn path(&self) -> &str {
+        match self {
+            FileOp::Add { path, .. }
+            | FileOp::Delete { path }
+            | FileOp::Update { path, .. }
+            | FileOp::Skip { path, .. } => path,
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct Hunk {
+    /// `@@ <line>` anchors: found in order before the hunk's lines.
+    pub anchors: Vec<String>,
+    /// `@@ -a,b +c,d @@`: the 1-based start in the old file, a hint where to look.
+    pub old_start: Option<usize>,
+    pub lines: Vec<Line>,
+    /// `*** End of File`: the lines end the file.
+    pub at_eof: bool,
+    /// `\ No newline at end of file` after the old / new side.
+    pub old_no_newline: bool,
+    pub new_no_newline: bool,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum Line {
+    Context(String),
+    Remove(String),
+    Add(String),
+}
+
+impl Hunk {
+    fn old_lines(&self) -> Vec<&str> {
+        self.lines
+            .iter()
+            .filter_map(|l| match l {
+                Line::Context(s) | Line::Remove(s) => Some(s.as_str()),
+                Line::Add(_) => None,
+            })
+            .collect()
+    }
+
+    fn new_lines(&self) -> Vec<&str> {
+        self.lines
+            .iter()
+            .filter_map(|l| match l {
+                Line::Context(s) | Line::Add(s) => Some(s.as_str()),
+                Line::Remove(_) => None,
+            })
+            .collect()
+    }
+
+    /// How the hunk is named in errors.
+    fn label(&self, n: usize) -> String {
+        match (self.anchors.last(), self.old_start) {
+            (Some(a), _) => format!("hunk {n} (@@ {a})"),
+            (None, Some(s)) => format!("hunk {n} (at line {s})"),
+            _ => format!("hunk {n}"),
+        }
+    }
+}
+
+const BEGIN_PATCH: &str = "*** Begin Patch";
+const END_PATCH: &str = "*** End Patch";
+const ADD: &str = "*** Add File: ";
+const DELETE: &str = "*** Delete File: ";
+const UPDATE: &str = "*** Update File: ";
+const MOVE: &str = "*** Move to: ";
+const END_OF_FILE: &str = "*** End of File";
+const DIFF_GIT: &str = "diff --git ";
+
+/// Parses either format: `*** Begin Patch` … `*** End Patch` (holding the Codex
+/// format or a git diff), else a bare unified diff.
+pub fn parse(input: &str) -> Result<Vec<FileOp>, String> {
+    let lines: Vec<&str> = input.split('\n').map(|l| l.strip_suffix('\r').unwrap_or(l)).collect();
+    let ops = match lines.iter().position(|l| l.trim() == BEGIN_PATCH) {
+        Some(begin) => {
+            let end = lines[begin + 1..]
+                .iter()
+                .position(|l| l.trim() == END_PATCH)
+                .map(|e| begin + 1 + e)
+                .ok_or("patch must include *** End Patch (the patch looks truncated)")?;
+            let body = &lines[begin + 1..end];
+            // `--- x` also removes a `-- x` line (SQL, Lua comments): only a body without
+            // Codex headers is read as a diff.
+            let codex = body.iter().any(|l| {
+                let t = l.trim_start();
+                t.starts_with(ADD) || t.starts_with(DELETE) || t.starts_with(UPDATE)
+            });
+            if !codex && looks_like_git_diff(body) {
+                parse_unified(body, begin + 1)?
+            } else {
+                parse_codex(body, begin + 1)?
+            }
+        }
+        None if looks_like_git_diff(&lines) => parse_unified(&lines, 0)?,
+        None => {
+            return Err("patch must include *** Begin Patch (or be a unified diff with `--- a/path` and \
+`+++ b/path` headers)"
+                .into());
+        }
+    };
+    if ops.is_empty() {
+        return Err("patch did not contain any operations".into());
+    }
+    Ok(ops)
+}
+
+fn looks_like_git_diff(lines: &[&str]) -> bool {
+    let mut markers = false;
+    for line in lines {
+        let t = line.trim_start();
+        if t.starts_with(DIFF_GIT) || t.starts_with("rename from ") || t.starts_with("rename to ") {
+            return true;
+        }
+        markers |= line.starts_with("--- ") || line.starts_with("+++ ");
+    }
+    markers
+}
+
+/// Refuses paths with control characters, or with `\n`-style escapes a model wrote
+/// instead of a real path.
+fn ensure_safe_path(path: &str, label: &str) -> Result<(), String> {
+    let control = path.chars().any(|c| c.is_ascii_control());
+    let escaped = ["\\n", "\\r", "\\t"].iter().any(|e| path.contains(e));
+    if control || escaped {
+        Err(format!("{label} path contains control characters or escape sequences"))
+    } else {
+        Ok(())
+    }
+}
+
+// --- the Codex format -----------------------------------------------------------
+
+fn is_diff_prefix(c: char) -> bool {
+    matches!(c, ' ' | '+' | '-')
+}
+
+/// `*** Add File:` and the like (not `*** End of File`, which belongs to a hunk).
+fn is_patch_header(line: &str) -> bool {
+    match line.chars().next() {
+        None => false,
+        Some(c) if is_diff_prefix(c) => false,
+        Some(_) => {
+            let t = line.trim_start();
+            t.starts_with("*** ") && t.trim_end() != END_OF_FILE
+        }
+    }
+}
+
+fn is_hunk_header(line: &str) -> bool {
+    line.chars().next().is_some_and(|c| !is_diff_prefix(c)) && line.trim_start().starts_with("@@")
+}
+
+fn op_path(rest: &str, label: &str) -> Result<String, String> {
+    let path = rest.trim();
+    if path.is_empty() {
+        return Err(format!("{label} requires a path"));
+    }
+    ensure_safe_path(path, label)?;
+    Ok(path.to_owned())
+}
+
+/// `lines[start..]` is the body after `*** Begin Patch`; `offset` numbers lines in errors.
+fn parse_codex(body: &[&str], offset: usize) -> Result<Vec<FileOp>, String> {
+    let mut ops = Vec::new();
+    let mut i = 0;
+    let n = |i: usize| i + offset + 1;
+    while i < body.len() {
+        let line = body[i];
+        let header = line.trim_start();
+        if let Some(rest) = header.strip_prefix(ADD) {
+            let path = op_path(rest, "Add File")?;
+            i += 1;
+            // (text, written with `+`): blank separator lines before the next header are dropped.
+            let mut content: Vec<(&str, bool)> = Vec::new();
+            while let Some(&l) = body.get(i).filter(|l| !is_patch_header(l)) {
+                match l.strip_prefix('+') {
+                    Some(text) => content.push((text, true)),
+                    None if l.trim().is_empty() => content.push(("", false)),
+                    None => return Err(format!("Add File lines must start with + (line {}: `{l}`)", n(i))),
+                }
+                i += 1;
+            }
+            while content.last().is_some_and(|(_, explicit)| !explicit) {
+                content.pop();
+            }
+            let mut text = content.iter().map(|(t, _)| *t).collect::<Vec<_>>().join("\n");
+            if !content.is_empty() {
+                text.push('\n');
+            }
+            ops.push(FileOp::Add { path, text });
+        } else if let Some(rest) = header.strip_prefix(DELETE) {
+            ops.push(FileOp::Delete { path: op_path(rest, "Delete File")? });
+            i += 1;
+        } else if let Some(rest) = header.strip_prefix(UPDATE) {
+            let path = op_path(rest, "Update File")?;
+            i += 1;
+            let mut move_to = None;
+            if let Some(rest) =
+                body.get(i).filter(|l| is_patch_header(l)).and_then(|l| l.trim_start().strip_prefix(MOVE))
+            {
+                move_to = Some(op_path(rest, "Move to")?);
+                i += 1;
+            }
+            let mut hunks = Vec::new();
+            while i < body.len() && !is_patch_header(body[i]) {
+                if body[i].trim().is_empty() {
+                    i += 1;
+                    continue;
+                }
+                hunks.push(parse_codex_hunk(body, &mut i, hunks.is_empty(), offset)?);
+            }
+            // A move alone needs no hunk (JetBrains requires one).
+            if hunks.is_empty() && move_to.is_none() {
+                return Err("Update File requires at least one hunk".into());
+            }
+            ops.push(FileOp::Update { path, move_to, hunks, or: Vec::new() });
+        } else if line.trim().is_empty() {
+            i += 1;
+        } else {
+            return Err(format!("Unexpected patch line: {line}"));
+        }
+    }
+    Ok(ops)
+}
+
+fn parse_codex_hunk(body: &[&str], i: &mut usize, first: bool, offset: usize) -> Result<Hunk, String> {
+    let mut hunk = Hunk::default();
+    let mut bare = false;
+    let mut headed = false;
+    // Several `@@` lines narrow the place down, as in Codex.
+    while let Some(&line) = body.get(*i).filter(|l| is_hunk_header(l)) {
+        let trimmed = line.trim();
+        match parse_range_header(trimmed) {
+            Some((start, ..)) => hunk.old_start = Some(start),
+            None => {
+                let text = trimmed.trim_start_matches('@').trim();
+                // `@@ fn main() @@` repeats the marker at the end sometimes.
+                let text = text.trim_end_matches('@').trim_end();
+                if !text.is_empty() {
+                    hunk.anchors.push(text.to_owned());
+                }
+            }
+        }
+        bare = trimmed == "@@";
+        headed = true;
+        *i += 1;
+    }
+    let n = |i: usize| i + offset + 1;
+    if !headed {
+        let line = body[*i];
+        if !first || !line.chars().next().is_none_or(is_diff_prefix) {
+            return Err(format!("Expected @@ hunk header (line {}: `{line}`)", n(*i)));
+        }
+    }
+    let is_strict_start =
+        |l: &str| !l.is_empty() && !is_patch_header(l) && !is_hunk_header(l) && !l.starts_with(is_diff_prefix);
+    if bare && body.get(*i).is_some_and(|l| is_strict_start(l)) {
+        return parse_strict_pair(body, i);
+    }
+    // Blank lines at the end of a hunk are usually separators, not context.
+    let mut implicit_blanks = 0usize;
+    while let Some(&line) = body.get(*i).filter(|l| !is_hunk_header(l) && !is_patch_header(l)) {
+        if line.trim_end() == END_OF_FILE {
+            hunk.at_eof = true;
+            *i += 1;
+            break;
+        }
+        let parsed = match line.chars().next() {
+            None => Line::Context(String::new()),
+            Some(' ') => Line::Context(line[1..].to_owned()),
+            Some('-') => Line::Remove(line[1..].to_owned()),
+            Some('+') => Line::Add(line[1..].to_owned()),
+            Some(_) if hunk.lines.is_empty() => {
+                return Err(format!("Hunk lines must start with space, +, or - (line {}: `{line}`)", n(*i)));
+            }
+            Some(_) => break,
+        };
+        implicit_blanks = if line.is_empty() { implicit_blanks + 1 } else { 0 };
+        hunk.lines.push(parsed);
+        *i += 1;
+    }
+    hunk.lines.truncate(hunk.lines.len() - implicit_blanks);
+    if hunk.lines.is_empty() {
+        return Err("Empty hunk in Update File".into());
+    }
+    Ok(hunk)
+}
+
+/// `@@`, the old lines, `@@`, the new lines: whole lines without `-` / `+` prefixes.
+fn parse_strict_pair(body: &[&str], i: &mut usize) -> Result<Hunk, String> {
+    let mut old = Vec::new();
+    let mut closed = false;
+    while let Some(&line) = body.get(*i).filter(|l| !is_patch_header(l)) {
+        *i += 1;
+        if line.trim() == "@@" {
+            closed = true;
+            break;
+        }
+        old.push(line);
+    }
+    if !closed {
+        return Err("Strict @@ pair hunk requires second @@ delimiter".into());
+    }
+    let mut new = Vec::new();
+    while let Some(&line) = body.get(*i).filter(|l| !is_patch_header(l) && !is_hunk_header(l)) {
+        new.push(line);
+        *i += 1;
+    }
+    while new.last().is_some_and(|l| l.trim().is_empty()) {
+        new.pop();
+    }
+    if old.is_empty() && new.is_empty() {
+        return Err("Empty hunk in Update File".into());
+    }
+    let lines = old
+        .into_iter()
+        .map(|l| Line::Remove(l.to_owned()))
+        .chain(new.into_iter().map(|l| Line::Add(l.to_owned())))
+        .collect();
+    Ok(Hunk { lines, ..Hunk::default() })
+}
+
+// --- unified diffs -------------------------------------------------------------
+
+#[derive(Default)]
+struct Section {
+    git_old: Option<String>,
+    git_new: Option<String>,
+    /// `---` / `+++` seen; `None` inside is `/dev/null`.
+    old: Option<Option<String>>,
+    new: Option<Option<String>>,
+    new_file: bool,
+    deleted: bool,
+    rename_from: Option<String>,
+    rename_to: Option<String>,
+    /// `old mode` / `new mode`: a permission change, which the tool leaves alone.
+    mode_change: bool,
+    /// `copy from` / `copy to`.
+    copy_from: Option<String>,
+    copy_to: Option<String>,
+    hunks: Vec<Hunk>,
+    line: usize,
+}
+
+fn is_file_start(lines: &[&str], i: usize) -> bool {
+    let l = lines[i];
+    l.starts_with(DIFF_GIT)
+        || (l.starts_with("--- ") && lines.get(i + 1).is_some_and(|n| n.starts_with("+++ ")) && l != "--- ")
+}
+
+/// `offset` numbers lines in errors (the diff may sit inside `*** Begin Patch`).
+fn parse_unified(lines: &[&str], offset: usize) -> Result<Vec<FileOp>, String> {
+    let mut ops = Vec::new();
+    let mut i = 0;
+    let mut section: Option<Section> = None;
+    while i < lines.len() {
+        let line = lines[i];
+        let n = i + offset + 1;
+        if is_file_start(lines, i) && (line.starts_with(DIFF_GIT) || section.as_ref().is_none_or(|s| s.old.is_some())) {
+            if let Some(s) = section.take() {
+                ops.push(finish_section(s)?);
+            }
+            let mut s = Section { line: n, ..Section::default() };
+            if let Some(rest) = line.strip_prefix(DIFF_GIT) {
+                (s.git_old, s.git_new) = split_git_paths(rest);
+                i += 1;
+            }
+            section = Some(s);
+            continue;
+        }
+        let Some(s) = section.as_mut() else {
+            if line.starts_with("@@ ") {
+                return Err(format!("line {n}: a hunk without a `--- a/path` / `+++ b/path` header before it"));
+            }
+            // Text before the first file (a commit message, `Index:` lines).
+            i += 1;
+            continue;
+        };
+        let trimmed = line.trim_start();
+        if let Some(p) = line.strip_prefix("--- ") {
+            s.old = Some(diff_path(p, "a/"));
+        } else if let Some(p) = line.strip_prefix("+++ ") {
+            s.new = Some(diff_path(p, "b/"));
+        } else if trimmed.starts_with("new file mode") {
+            s.new_file = true;
+        } else if trimmed.starts_with("deleted file mode") {
+            s.deleted = true;
+        } else if let Some(p) = trimmed.strip_prefix("rename from ") {
+            s.rename_from = Some(rename_path(p)?);
+        } else if let Some(p) = trimmed.strip_prefix("rename to ") {
+            s.rename_to = Some(rename_path(p)?);
+        } else if trimmed.starts_with("Binary files ") || trimmed == "GIT binary patch" {
+            return Err(format!("Binary git patch is not supported (line {n})"));
+        } else if let Some(p) = trimmed.strip_prefix("copy from ") {
+            s.copy_from = Some(rename_path(p)?);
+        } else if let Some(p) = trimmed.strip_prefix("copy to ") {
+            s.copy_to = Some(rename_path(p)?);
+        } else if trimmed.starts_with("old mode ") || trimmed.starts_with("new mode ") {
+            s.mode_change = true;
+        } else if line.starts_with("@@") {
+            if s.old.is_none() && s.new.is_none() && s.git_old.is_none() {
+                return Err(format!("line {n}: a hunk without a `--- a/path` / `+++ b/path` header before it"));
+            }
+            i += 1;
+            let hunk = parse_unified_hunk(lines, &mut i, line, n)?;
+            s.hunks.push(hunk);
+            continue;
+        } else if !s.hunks.is_empty() && (line.starts_with('+') || line.starts_with('-') || line.starts_with(' ')) {
+            // Lines after a hunk that its counts left out (`-- ` ends `git format-patch` output).
+            if line != "-- " {
+                return Err(format!(
+                    "line {n}: `{line}` follows a hunk but is not part of it; check the hunk's counts"
+                ));
+            }
+            if let Some(s) = section.take() {
+                ops.push(finish_section(s)?);
+            }
+        }
+        // Other extended headers (`index`, modes, similarity) need nothing.
+        i += 1;
+    }
+    if let Some(s) = section {
+        ops.push(finish_section(s)?);
+    }
+    Ok(ops)
+}
+
+/// `@@ -a,b +c,d @@`: hunk lines until the counts are used up; lines beyond
+/// counts that are too small are taken too, and a bare `@@` reads to the next header.
+fn parse_unified_hunk(lines: &[&str], i: &mut usize, header: &str, n: usize) -> Result<Hunk, String> {
+    let counts = parse_range_header(header);
+    if counts.is_none() && header.starts_with("@@ -") {
+        return Err(format!("line {n}: cannot read the hunk header `{header}`"));
+    }
+    let mut hunk = Hunk { old_start: counts.map(|c| c.0), ..Hunk::default() };
+    let (mut old_left, mut new_left) = counts.map_or((usize::MAX, usize::MAX), |c| (c.1, c.2));
+    let mut implicit_blanks = 0usize;
+    let first = *i;
+    while let Some(&line) = lines.get(*i) {
+        let done = old_left == 0 && new_left == 0;
+        if line.starts_with("@@") || is_file_start(lines, *i) {
+            break;
+        }
+        if line.trim_end() == END_OF_FILE {
+            hunk.at_eof = true;
+            *i += 1;
+            break;
+        }
+        if line.starts_with('\\') {
+            match hunk.lines.last() {
+                Some(Line::Remove(_)) => hunk.old_no_newline = true,
+                Some(Line::Add(_)) => hunk.new_no_newline = true,
+                Some(Line::Context(_)) => {
+                    hunk.old_no_newline = true;
+                    hunk.new_no_newline = true;
+                }
+                None => {}
+            }
+            *i += 1;
+            continue;
+        }
+        let parsed = match line.chars().next() {
+            _ if done && (line.is_empty() || line == "-- ") => break,
+            Some(' ') => Line::Context(line[1..].to_owned()),
+            Some('-') => Line::Remove(line[1..].to_owned()),
+            Some('+') => Line::Add(line[1..].to_owned()),
+            // Editors strip the space of empty context lines.
+            None => Line::Context(String::new()),
+            Some(_) if hunk.lines.is_empty() => {
+                return Err(format!(
+                    "Hunk lines must start with space, +, or - (line {}: `{line}`)",
+                    n + 1 + *i - first
+                ));
+            }
+            Some(_) => break,
+        };
+        match parsed {
+            Line::Context(_) => {
+                old_left = old_left.saturating_sub(1);
+                new_left = new_left.saturating_sub(1);
+            }
+            Line::Remove(_) => old_left = old_left.saturating_sub(1),
+            Line::Add(_) => new_left = new_left.saturating_sub(1),
+        }
+        implicit_blanks = if line.is_empty() { implicit_blanks + 1 } else { 0 };
+        hunk.lines.push(parsed);
+        *i += 1;
+    }
+    if counts.is_none() {
+        hunk.lines.truncate(hunk.lines.len() - implicit_blanks);
+    }
+    if hunk.lines.is_empty() {
+        return Err(format!("Empty hunk in Update File (line {n}: `{header}`)"));
+    }
+    Ok(hunk)
+}
+
+/// (old start, old count, new count) of `@@ -a[,b] +c[,d] @@`; extra `@`s (`@@@`) are accepted.
+fn parse_range_header(header: &str) -> Option<(usize, usize, usize)> {
+    let rest = header.trim_start_matches('@').trim_start().strip_prefix('-')?;
+    let (ranges, _) = rest.split_once(" @@").unwrap_or((rest.trim_end_matches('@'), ""));
+    let (old, new) = ranges.split_once(" +")?;
+    let range = |r: &str| -> Option<(usize, usize)> {
+        match r.trim().split_once(',') {
+            Some((s, c)) => Some((s.parse().ok()?, c.parse().ok()?)),
+            None => Some((r.trim().parse().ok()?, 1)),
+        }
+    };
+    let (start, old_count) = range(old)?;
+    let (_, new_count) = range(new)?;
+    Some((start, old_count, new_count))
+}
+
+/// The two paths of `diff --git a/x b/y` (ambiguous with spaces: equal halves win).
+fn split_git_paths(rest: &str) -> (Option<String>, Option<String>) {
+    let rest = rest.trim();
+    if let Some((a, b)) = rest.strip_prefix('"').and_then(|r| r.split_once("\" ")) {
+        return (Some(strip_prefix(&unquote(&format!("\"{a}\"")), "a/")), Some(strip_prefix(&unquote(b), "b/")));
+    }
+    let splits: Vec<usize> = rest.match_indices(" b/").map(|(i, _)| i).collect();
+    let pick = splits.iter().find(|&&i| rest[..i].strip_prefix("a/") == Some(&rest[i + 3..])).or(splits.first());
+    match pick {
+        Some(&i) => (Some(strip_prefix(&rest[..i], "a/")), Some(rest[i + 3..].to_owned())),
+        None => (None, None),
+    }
+}
+
+/// A `---` / `+++` path: `None` for `/dev/null`; timestamps and the `a/` / `b/` prefix removed.
+fn diff_path(raw: &str, prefix: &str) -> Option<String> {
+    let raw = raw.split('\t').next().unwrap_or(raw).trim_end();
+    let path = unquote(raw);
+    if path == "/dev/null" {
+        return None;
+    }
+    Some(strip_prefix(&path, prefix))
+}
+
+fn rename_path(raw: &str) -> Result<String, String> {
+    let path = unquote(raw.trim());
+    if path.is_empty() { Err("Could not determine file path from git diff".into()) } else { Ok(path) }
+}
+
+fn strip_prefix(path: &str, prefix: &str) -> String {
+    path.strip_prefix(prefix).unwrap_or(path).to_owned()
+}
+
+/// Git quotes paths with special characters: `"a/x \"y\""`.
+fn unquote(s: &str) -> String {
+    let Some(inner) = s.strip_prefix('"').and_then(|s| s.strip_suffix('"')) else { return s.to_owned() };
+    let mut out = String::new();
+    let mut chars = inner.chars();
+    while let Some(c) = chars.next() {
+        if c != '\\' {
+            out.push(c);
+            continue;
+        }
+        match chars.next() {
+            Some('n') => out.push('\n'),
+            Some('t') => out.push('\t'),
+            Some(c) => out.push(c),
+            None => {}
+        }
+    }
+    out
+}
+
+fn finish_section(s: Section) -> Result<FileOp, String> {
+    const NO_PATH: &str = "Could not determine file path from git diff";
+    let n = s.line;
+    let old = match &s.old {
+        Some(p) => p.clone(),
+        None => s.rename_from.clone().or_else(|| s.git_old.clone()),
+    };
+    let new = match &s.new {
+        Some(p) => p.clone(),
+        None => s.rename_to.clone().or_else(|| s.git_new.clone()),
+    };
+    if s.copy_from.is_some() || s.copy_to.is_some() {
+        // Git writes a copy only with `-C`; JetBrains reads it as a change of the source.
+        let to = s.copy_to.clone().or(new).ok_or_else(|| format!("{NO_PATH} (line {n})"))?;
+        let from = s.copy_from.clone().or(old).unwrap_or_default();
+        let note = format!(
+            "the copy of {from} to {to} was skipped: copies are not supported; add the new file with `*** Add File` \
+instead"
+        );
+        return Ok(FileOp::Skip { path: to, note });
+    }
+    if s.new_file || (s.old.as_ref().is_some_and(|o| o.is_none())) {
+        let path = new.ok_or_else(|| format!("{NO_PATH} (line {n})"))?;
+        ensure_safe_path(&path, "Add File")?;
+        let mut lines = Vec::new();
+        let mut no_newline = false;
+        for h in &s.hunks {
+            for l in &h.lines {
+                match l {
+                    Line::Add(t) => lines.push(t.as_str()),
+                    _ => return Err(format!("`{path}` is a new file, but its hunk has context or removed lines")),
+                }
+            }
+            no_newline |= h.new_no_newline;
+        }
+        let mut text = lines.join("\n");
+        if !lines.is_empty() && !no_newline {
+            text.push('\n');
+        }
+        return Ok(FileOp::Add { path, text });
+    }
+    if s.deleted || (s.new.as_ref().is_some_and(|n| n.is_none())) {
+        let path = old.ok_or_else(|| format!("{NO_PATH} (line {n})"))?;
+        ensure_safe_path(&path, "Delete File")?;
+        return Ok(FileOp::Delete { path });
+    }
+    // Only git's rename headers say a file moves: plain diffs often name the sides
+    // differently (`--- a.txt.orig` / `+++ a.txt`, `diff -ru old/ new/`).
+    if s.rename_from.is_some() || s.rename_to.is_some() {
+        let path = old.or(new.clone()).ok_or_else(|| format!("{NO_PATH} (line {n})"))?;
+        ensure_safe_path(&path, "Update File")?;
+        let move_to = new.filter(|p| *p != path);
+        if let Some(m) = &move_to {
+            ensure_safe_path(m, "Move to")?;
+        }
+        if s.hunks.is_empty() && move_to.is_none() && !s.mode_change {
+            return Err(format!("line {n}: `{path}` has no changes"));
+        }
+        return Ok(FileOp::Update { path, move_to, hunks: s.hunks, or: Vec::new() });
+    }
+    let path = new.clone().or(old.clone()).ok_or_else(|| format!("{NO_PATH} (line {n})"))?;
+    ensure_safe_path(&path, "Update File")?;
+    if s.hunks.is_empty() {
+        // Only the file mode changes: nothing to do to the text, as in JetBrains.
+        if s.mode_change {
+            return Ok(FileOp::Update { path, move_to: None, hunks: Vec::new(), or: Vec::new() });
+        }
+        return Err(format!("line {n}: `{path}` has no changes"));
+    }
+    let below_first_dir = |p: &Option<String>| p.as_ref().and_then(|p| p.split_once('/')).map(|(_, r)| r.to_owned());
+    let mut or: Vec<String> = Vec::new();
+    let others =
+        if old == new { [None, None, None] } else { [old.clone(), below_first_dir(&new), below_first_dir(&old)] };
+    for p in others.into_iter().flatten() {
+        if !p.is_empty() && p != path && !or.contains(&p) {
+            or.push(p);
+        }
+    }
+    Ok(FileOp::Update { path, move_to: None, hunks: s.hunks, or })
+}
+
+// --- applying -------------------------------------------------------------------
+
+/// How exactly a hunk's lines matched the file, tried in this order.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub enum Fuzz {
+    Exact,
+    TrailingWhitespace,
+    Whitespace,
+    /// Whitespace, and typographic dashes, quotes and spaces as their ASCII forms.
+    Punctuation,
+}
+
+impl Fuzz {
+    fn same(self, a: &str, b: &str) -> bool {
+        match self {
+            Fuzz::Exact => a == b,
+            Fuzz::TrailingWhitespace => a.trim_end() == b.trim_end(),
+            Fuzz::Whitespace => a.trim() == b.trim(),
+            Fuzz::Punctuation => a.trim().chars().map(normalize_char).eq(b.trim().chars().map(normalize_char)),
+        }
+    }
+
+    pub fn describe(self) -> &'static str {
+        match self {
+            Fuzz::Exact => "exactly",
+            Fuzz::TrailingWhitespace => "ignoring trailing whitespace",
+            Fuzz::Whitespace => "ignoring indentation and whitespace",
+            Fuzz::Punctuation => "ignoring whitespace and typographic punctuation (dashes, quotes, spaces)",
+        }
+    }
+}
+
+fn normalize_char(c: char) -> char {
+    match c {
+        '\u{2010}'..='\u{2015}' | '\u{2212}' => '-',
+        '\u{2018}'..='\u{201B}' => '\'',
+        '\u{201C}'..='\u{201F}' => '"',
+        '\u{00A0}' | '\u{2002}'..='\u{200A}' | '\u{202F}' | '\u{205F}' | '\u{3000}' => ' ',
+        c => c,
+    }
+}
+
+const LEVELS: [Fuzz; 4] = [Fuzz::Exact, Fuzz::TrailingWhitespace, Fuzz::Whitespace, Fuzz::Punctuation];
+
+/// The result of [`apply`]: the new text and the hunks that matched only loosely.
+#[derive(Debug, PartialEq, Eq)]
+pub struct Applied {
+    pub text: String,
+    /// (1-based hunk, how it matched) for hunks that did not match exactly.
+    pub fuzzy: Vec<(usize, Fuzz)>,
+}
+
+/// Applies `hunks` in order to `text` (`\n` line endings). A hunk is searched
+/// after the previous one, then (unless it ends the file) from the top. Errors
+/// name the hunk and the lines that were not found.
+pub fn apply(text: &str, hunks: &[Hunk]) -> Result<Applied, String> {
+    let trailing_newline = text.ends_with('\n');
+    let mut lines: Vec<String> = if text.is_empty() {
+        Vec::new()
+    } else {
+        let mut l: Vec<String> = text.split('\n').map(str::to_owned).collect();
+        if trailing_newline {
+            l.pop();
+        }
+        l
+    };
+    let original_len = lines.len();
+    let mut cursor = 0usize;
+    let mut fuzzy = Vec::new();
+    let mut ends_without_newline = None;
+    for (index, hunk) in hunks.iter().enumerate() {
+        let n = index + 1;
+        let file: Vec<&str> = lines.iter().map(String::as_str).collect();
+        let mut anchor_line = None;
+        for anchor in &hunk.anchors {
+            let find =
+                |from: usize| LEVELS.iter().find_map(|level| (from..file.len()).find(|&i| level.same(file[i], anchor)));
+            let found = find(cursor).or_else(|| find(0)).ok_or_else(|| {
+                format!(
+                    "Hunk context not found: {}: cannot find the line `{anchor}` its `@@` header names",
+                    hunk.label(n)
+                )
+            })?;
+            anchor_line = Some(found);
+            cursor = found + 1;
+        }
+        // Line numbers of a diff count the original file: shift them by what earlier hunks added.
+        let shift = |s: usize| (s as isize + lines.len() as isize - original_len as isize).max(0) as usize;
+        let mut old = hunk.old_lines();
+        if old.is_empty() {
+            let at = if !hunk.anchors.is_empty() {
+                cursor
+            } else if hunk.at_eof {
+                file.len()
+            } else {
+                // `@@ -5,0 +6,2 @@` inserts after line 5; without a position, at the end.
+                hunk.old_start.map_or(file.len(), |s| shift(s).min(file.len()))
+            };
+            let new: Vec<String> = hunk.new_lines().into_iter().map(str::to_owned).collect();
+            cursor = at + new.len();
+            lines.splice(at..at, new);
+            continue;
+        }
+        let hint = hunk.old_start.map(|s| shift(s.saturating_sub(1)));
+        // Models often repeat the `@@` line as the hunk's first context line: then the
+        // block starts at the anchor rather than after it.
+        let find = |old: &[&str]| {
+            find_block(&file, old, cursor, hint, hunk.at_eof)
+                .or_else(|| anchor_line.and_then(|a| find_block(&file, old, a, hint, hunk.at_eof)))
+                .or_else(|| (cursor > 0 && !hunk.at_eof).then(|| find_block(&file, old, 0, hint, false)).flatten())
+        };
+        let mut found = find(&old);
+        // A blank last line in the patch that the file does not have (Codex does the same).
+        if found.is_none() && old.last() == Some(&"") {
+            old.pop();
+            if !old.is_empty() {
+                found = find(&old);
+            }
+        }
+        let Some((at, level)) = found else {
+            return Err(mismatch(&file, &old, hint, &hunk.label(n), hunk.at_eof));
+        };
+        if level != Fuzz::Exact {
+            fuzzy.push((n, level));
+        }
+        if at + old.len() == file.len() {
+            if hunk.new_no_newline {
+                ends_without_newline = Some(true);
+            } else if hunk.old_no_newline {
+                ends_without_newline = Some(false);
+            }
+        }
+        // Context lines keep the file's spelling (a loose match must not re-indent them).
+        let mut new = Vec::new();
+        let mut matched = 0usize;
+        for line in &hunk.lines {
+            match line {
+                Line::Context(_) | Line::Remove(_) if matched >= old.len() => {}
+                Line::Context(_) => {
+                    new.push(file[at + matched].to_owned());
+                    matched += 1;
+                }
+                Line::Remove(_) => matched += 1,
+                Line::Add(s) => new.push(s.clone()),
+            }
+        }
+        let removed = old.len();
+        cursor = at + new.len();
+        lines.splice(at..at + removed, new);
+    }
+    let mut result = lines.join("\n");
+    let newline = match ends_without_newline {
+        Some(no) => !no,
+        None => trailing_newline || text.is_empty(),
+    };
+    if newline && !lines.is_empty() {
+        result.push('\n');
+    }
+    Ok(Applied { text: result, fuzzy })
+}
+
+/// Where `old` occurs at or after `from`, as exactly as possible; with a hint,
+/// the occurrence nearest to it. A hunk that ends the file must match its end.
+fn find_block(lines: &[&str], old: &[&str], from: usize, hint: Option<usize>, at_eof: bool) -> Option<(usize, Fuzz)> {
+    if old.len() > lines.len() {
+        return None;
+    }
+    let last = lines.len() - old.len();
+    let matches = |at: usize, level: Fuzz| old.iter().zip(&lines[at..]).all(|(o, l)| level.same(l, o));
+    for level in LEVELS {
+        if at_eof {
+            if last >= from && matches(last, level) {
+                return Some((last, level));
+            }
+            continue;
+        }
+        let mut best: Option<usize> = None;
+        for at in from..=last {
+            if !matches(at, level) {
+                continue;
+            }
+            match hint {
+                None => return Some((at, level)),
+                Some(h) => {
+                    if best.is_none_or(|b| at.abs_diff(h) < b.abs_diff(h)) {
+                        best = Some(at);
+                    }
+                }
+            }
+        }
+        if let Some(at) = best {
+            return Some((at, level));
+        }
+    }
+    None
+}
+
+/// The error for lines that were not found, with the closest partial match.
+fn mismatch(lines: &[&str], old: &[&str], hint: Option<usize>, label: &str, at_eof: bool) -> String {
+    let mut msg = format!("Hunk context not found: {label} does not apply: these lines were not found:\n");
+    for l in old {
+        let _ = writeln!(msg, "  {l}");
+    }
+    // The start with the longest run of matching lines (ignoring whitespace).
+    let mut best: Option<(usize, usize)> = None;
+    for at in 0..lines.len() {
+        let run = old.iter().zip(&lines[at..]).take_while(|(o, l)| Fuzz::Punctuation.same(o, l)).count();
+        let better = match best {
+            None => run > 0,
+            Some((b, r)) => run > r || (run == r && hint.is_some_and(|h| at.abs_diff(h) < b.abs_diff(h))),
+        };
+        if better {
+            best = Some((at, run));
+        }
+    }
+    match best {
+        Some((at, run)) if run < old.len() => {
+            let actual = lines.get(at + run).map_or("(end of file)".to_owned(), |l| format!("`{l}`"));
+            let _ = write!(
+                msg,
+                "Closest match at line {}: line {} is {actual}, but the patch expects `{}`.",
+                at + 1,
+                at + run + 1,
+                old[run]
+            );
+        }
+        Some((at, _)) if at_eof => {
+            let _ = write!(
+                msg,
+                "They occur at line {}, but the hunk is marked `*** End of File` and they do not end the file.",
+                at + 1
+            );
+        }
+        Some((at, _)) => {
+            let _ = write!(msg, "They occur at line {}.", at + 1);
+        }
+        None => {
+            // A common mistake: only part of a line after `-` / ` `.
+            let partial = old
+                .iter()
+                .filter(|o| !o.trim().is_empty())
+                .find_map(|o| lines.iter().position(|l| l.contains(o.trim())).map(|i| (o.trim(), i)));
+            match partial {
+                Some((o, i)) => {
+                    let _ = write!(
+                        msg,
+                        "Line {} contains `{o}` but is `{}`: patch lines must be whole lines, with their indentation.",
+                        i + 1,
+                        lines[i]
+                    );
+                }
+                None => msg.push_str("No line of them is in the file; read the file again before patching it."),
+            }
+        }
+    }
+    msg
+}
+
+#[cfg(test)]
+mod tests;
@@ -0,0 +1,584 @@
+//! Parser and engine tests, including JetBrains' `PatchApplyEngineTest` cases.
+
+use super::*;
+
+fn update(ops: &[FileOp]) -> &[Hunk] {
+    match &ops[0] {
+        FileOp::Update { hunks, .. } => hunks,
+        other => panic!("not an update: {other:?}"),
+    }
+}
+
+fn apply_patch(text: &str, patch: &str) -> Result<String, String> {
+    let ops = parse(patch)?;
+    apply(text, update(&ops)).map(|a| a.text)
+}
+
+fn patch(lines: &[&str]) -> String {
+    lines.iter().map(|l| format!("{l}\n")).collect()
+}
+
+fn hunk(lines: &[(char, &str)], at_eof: bool) -> Hunk {
+    let lines = lines
+        .iter()
+        .map(|&(p, t)| match p {
+            '-' => Line::Remove(t.into()),
+            '+' => Line::Add(t.into()),
+            _ => Line::Context(t.into()),
+        })
+        .collect();
+    Hunk { lines, at_eof, ..Hunk::default() }
+}
+
+// --- Codex format -------------------------------------------------------
+
+#[test]
+fn parses_every_codex_operation() {
+    let ops = parse(
+        "*** Begin Patch\n*** Add File: new.txt\n+one\n+two\n*** Delete File: old.txt\n*** Update File: a.rs\n\
+*** Move to: b.rs\n@@ fn main\n ctx\n-old\n+new\n*** End Patch\n",
+    )
+    .unwrap();
+    assert_eq!(
+        ops,
+        vec![
+            FileOp::Add { path: "new.txt".into(), text: "one\ntwo\n".into() },
+            FileOp::Delete { path: "old.txt".into() },
+            FileOp::Update {
+                path: "a.rs".into(),
+                move_to: Some("b.rs".into()),
+                hunks: vec![Hunk {
+                    anchors: vec!["fn main".into()],
+                    lines: vec![Line::Context("ctx".into()), Line::Remove("old".into()), Line::Add("new".into())],
+                    ..Hunk::default()
+                }],
+                or: vec![],
+            },
+        ]
+    );
+}
+
+#[test]
+fn codex_tolerates_wrappers_crlf_and_blank_separators() {
+    let ops = parse(
+        "apply_patch <<'EOF'\r\n*** Begin Patch\r\n*** Add File: x\r\n+a\r\n+\r\n\r\n*** Update File: y\r\n-a\r\n+b\r\n\r\n*** End Patch\r\nEOF",
+    )
+    .unwrap();
+    assert_eq!(ops[0], FileOp::Add { path: "x".into(), text: "a\n\n".into() });
+    assert_eq!(update(&ops[1..])[0].lines, vec![Line::Remove("a".into()), Line::Add("b".into())]);
+    // JetBrains: a heredoc around the patch.
+    let ops = parse(&patch(&["<<EOF", "*** Begin Patch", "*** Add File: notes.txt", "+alpha", "*** End Patch", "EOF"]))
+        .unwrap();
+    assert_eq!(ops, vec![FileOp::Add { path: "notes.txt".into(), text: "alpha\n".into() }]);
+}
+
+#[test]
+fn codex_empty_add_and_move_only() {
+    let ops = parse("*** Begin Patch\n*** Add File: e\n*** Update File: a\n*** Move to: b\n*** End Patch").unwrap();
+    assert_eq!(ops[0], FileOp::Add { path: "e".into(), text: String::new() });
+    assert_eq!(ops[1], FileOp::Update { path: "a".into(), move_to: Some("b".into()), hunks: vec![], or: vec![] });
+}
+
+/// JetBrains `PatchApplyEngineTest`: the parse errors.
+#[test]
+fn codex_errors() {
+    let fails = |lines: &[&str], expected: &str| {
+        let e = parse(&patch(lines)).unwrap_err();
+        assert!(e.contains(expected), "expected `{expected}` in: {e}");
+    };
+    fails(&["oops"], "patch must include *** Begin Patch");
+    fails(&["*** Begin Patch", "*** Add File: notes.txt", "+alpha"], "patch must include *** End Patch");
+    fails(&["*** Begin Patch", "*** End Patch"], "patch did not contain any operations");
+    fails(&["*** Begin Patch", "oops", "*** End Patch"], "Unexpected patch line: oops");
+    fails(&["*** Begin Patch", "*** Add File:   ", "*** End Patch"], "Add File requires a path");
+    fails(
+        &["*** Begin Patch", "*** Add File: notes.txt", "alpha", "*** End Patch"],
+        "Add File lines must start with +",
+    );
+    fails(
+        &["*** Begin Patch", "*** Add File: notes.txt", "+alpha", "beta", "*** End Patch"],
+        "Add File lines must start with + (line 4: `beta`)",
+    );
+    fails(&["*** Begin Patch", "*** Delete File:   ", "*** End Patch"], "Delete File requires a path");
+    fails(&["*** Begin Patch", "*** Update File:   ", "*** End Patch"], "Update File requires a path");
+    fails(
+        &["*** Begin Patch", "*** Update File: s.txt", "*** Move to:   ", "*** End Patch"],
+        "Move to requires a path",
+    );
+    fails(&["*** Begin Patch", "*** Update File: s.txt", "*** End Patch"], "Update File requires at least one hunk");
+    fails(&["*** Begin Patch", "*** Update File: s.txt", "oops", "*** End Patch"], "Expected @@ hunk header");
+    fails(
+        &["*** Begin Patch", "*** Update File: s.txt", " alpha", "-beta", "+gamma", "oops", "*** End Patch"],
+        "Expected @@ hunk header",
+    );
+    fails(
+        &["*** Begin Patch", "*** Update File: s.txt", "@@ def sample()", "oops", "*** End Patch"],
+        "Hunk lines must start with space, +, or -",
+    );
+    fails(&["*** Begin Patch", "*** Update File: s.txt", "@@", "*** End Patch"], "Empty hunk in Update File");
+    fails(
+        &["*** Begin Patch", "*** Update File: s.txt", "@@", "## Goals", "*** End Patch"],
+        "Strict @@ pair hunk requires second @@ delimiter",
+    );
+    fails(
+        &["*** Begin Patch", "*** Delete File: bad\\npath.txt", "*** End Patch"],
+        "Delete File path contains control",
+    );
+    fails(
+        &["*** Begin Patch", "*** Add File: bad\\npath.txt", "+alpha", "*** End Patch"],
+        "Add File path contains control characters or escape sequences",
+    );
+    fails(&["*** Begin Patch", "*** Update File: bad\\npath.txt", "*** End Patch"], "Update File path contains");
+    fails(
+        &["*** Begin Patch", "*** Update File: s.txt", "*** Move to: bad\\npath.txt", "*** End Patch"],
+        "Move to path contains",
+    );
+    fails(&["*** Begin Patch", "*** Update File: a", "-x", "*** End of File", "-y", "*** End Patch"], "Expected @@");
+}
+
+#[test]
+fn codex_hunks_split_on_markers_and_stack_anchors() {
+    let ops = parse(
+        "*** Begin Patch\n*** Update File: a\n@@ class A\n@@ def f():\n-x\n+y\n@@\n-p\n+q\n*** End of File\n*** End Patch",
+    )
+    .unwrap();
+    let hunks = update(&ops);
+    assert_eq!(hunks.len(), 2);
+    assert_eq!(hunks[0].anchors, vec!["class A".to_owned(), "def f():".to_owned()]);
+    assert!(!hunks[0].at_eof && hunks[1].at_eof);
+    assert!(hunks[1].anchors.is_empty());
+}
+
+#[test]
+fn codex_headers_with_line_numbers_are_hints_not_anchors() {
+    for header in ["@@@ -48,6 +48,7 @@@", "@@ -48,6 +48,7 @@", "@@ -48,6 +48,7 @@ fn sample()"] {
+        let ops = parse(&patch(&["*** Begin Patch", "*** Update File: s", header, " a", "-b", "+c", "*** End Patch"]))
+            .unwrap();
+        let h = &update(&ops)[0];
+        assert!(h.anchors.is_empty(), "{header}: {:?}", h.anchors);
+        assert_eq!(h.old_start, Some(48), "{header}");
+    }
+    let ops =
+        parse(&patch(&["*** Begin Patch", "*** Update File: s", "@@ def sample()", " a", "*** End Patch"])).unwrap();
+    assert_eq!(update(&ops)[0].anchors, vec!["def sample()".to_owned()]);
+    // JetBrains `applyHunks works with unified-diff style hunk headers`.
+    let p = patch(&[
+        "*** Begin Patch",
+        "*** Update File: s",
+        "@@ -1,3 +1,4 @@",
+        " alpha",
+        "-beta",
+        "+BETA",
+        " gamma",
+        "+delta",
+        "*** End Patch",
+    ]);
+    assert_eq!(apply_patch("alpha\nbeta\ngamma\n", &p).unwrap(), "alpha\nBETA\ngamma\ndelta\n");
+}
+
+#[test]
+fn strict_pair_hunks() {
+    let p = patch(&[
+        "*** Begin Patch",
+        "*** Update File: s",
+        "@@",
+        "## Goals",
+        "- Keep old wording",
+        "@@",
+        "## Goals",
+        "- Keep new wording",
+        "*** End Patch",
+    ]);
+    let ops = parse(&p).unwrap();
+    let h = &update(&ops)[0];
+    assert!(h.anchors.is_empty());
+    assert_eq!(
+        h.lines,
+        vec![
+            Line::Remove("## Goals".into()),
+            Line::Remove("- Keep old wording".into()),
+            Line::Add("## Goals".into()),
+            Line::Add("- Keep new wording".into()),
+        ]
+    );
+    assert_eq!(apply_patch("# T\n## Goals\n- Keep old wording\n", &p).unwrap(), "# T\n## Goals\n- Keep new wording\n");
+}
+
+#[test]
+fn applies_codex_hunks_with_anchors() {
+    let text = "class A:\n    def f():\n        return 1\nclass B:\n    def f():\n        return 1\n";
+    let patch = "*** Begin Patch\n*** Update File: a.py\n@@ class B:\n     def f():\n-        return 1\n+        return 2\n*** End Patch";
+    assert_eq!(
+        apply_patch(text, patch).unwrap(),
+        "class A:\n    def f():\n        return 1\nclass B:\n    def f():\n        return 2\n"
+    );
+}
+
+#[test]
+fn applies_several_hunks_in_order() {
+    let text = "a\nb\nc\nd\ne\nf\n";
+    let patch = "*** Begin Patch\n*** Update File: x\n@@\n a\n-b\n+B\n@@\n e\n-f\n+F\n+G\n*** End Patch";
+    assert_eq!(apply_patch(text, patch).unwrap(), "a\nB\nc\nd\ne\nF\nG\n");
+}
+
+#[test]
+fn same_lines_twice_match_in_order() {
+    let text = "x\ny\nx\ny\n";
+    let patch = "*** Begin Patch\n*** Update File: f\n@@\n-x\n+1\n@@\n-x\n+2\n*** End Patch";
+    assert_eq!(apply_patch(text, patch).unwrap(), "1\ny\n2\ny\n");
+}
+
+#[test]
+fn end_of_file_hunks_must_end_the_file() {
+    let text = "end\nmid\nend\n";
+    let patch = "*** Begin Patch\n*** Update File: f\n@@\n-end\n+END\n*** End of File\n*** End Patch";
+    assert_eq!(apply_patch(text, patch).unwrap(), "end\nmid\nEND\n");
+    let beta = hunk(&[('-', "beta"), ('+', "BETA")], true);
+    assert_eq!(apply("alpha\nbeta\n", std::slice::from_ref(&beta)).unwrap().text, "alpha\nBETA\n");
+    let e = apply("alpha\nbeta\ngamma\n", &[beta]).unwrap_err();
+    assert!(e.starts_with("Hunk context not found") && e.contains("do not end the file"), "{e}");
+}
+
+#[test]
+fn hunks_out_of_order_are_found_from_the_top() {
+    let hunks = [hunk(&[('-', "one"), ('+', "ONE")], true), hunk(&[('-', "two"), ('+', "TWO")], false)];
+    assert_eq!(apply("one\ntwo\nthree\none\n", &hunks).unwrap().text, "one\nTWO\nthree\nONE\n");
+    let text = "fn a() {\n    one();\n    two();\n}\n";
+    let p =
+        "*** Begin Patch\n*** Update File: f\n@@\n-    two();\n+    2();\n@@\n-    one();\n+    1();\n*** End Patch";
+    assert_eq!(apply_patch(text, p).unwrap(), "fn a() {\n    1();\n    2();\n}\n");
+}
+
+#[test]
+fn many_repeated_hunks_apply_deterministically() {
+    let hunks: Vec<Hunk> = (0..80).map(|i| hunk(&[('-', "alpha"), ('+', &format!("alpha-{i}"))], false)).collect();
+    let text = "alpha\n".repeat(600);
+    let expected: String = (0..80).map(|i| format!("alpha-{i}\n")).collect::<String>() + &"alpha\n".repeat(520);
+    assert_eq!(apply(&text, &hunks).unwrap().text, expected);
+}
+
+#[test]
+fn accepts_the_anchor_repeated_as_context() {
+    let text = "package greet\n\nfunc prefix() string {\n\treturn \"Merhaba, \"\n}\n";
+    let patch = "*** Begin Patch\n*** Update File: f\n@@ func prefix() string {\n func prefix() string {\n-\treturn \"Merhaba, \"\n+\treturn \"Selam, \"\n }\n*** End Patch";
+    assert_eq!(apply_patch(text, patch).unwrap(), "package greet\n\nfunc prefix() string {\n\treturn \"Selam, \"\n}\n");
+}
+
+#[test]
+fn pure_additions_go_after_the_anchor_or_at_the_end() {
+    let text = "fn a() {}\nfn b() {}\n";
+    let after = "*** Begin Patch\n*** Update File: f\n@@ fn a() {}\n+fn a2() {}\n*** End Patch";
+    assert_eq!(apply_patch(text, after).unwrap(), "fn a() {}\nfn a2() {}\nfn b() {}\n");
+    let end = "*** Begin Patch\n*** Update File: f\n@@\n+fn c() {}\n*** End Patch";
+    assert_eq!(apply_patch(text, end).unwrap(), "fn a() {}\nfn b() {}\nfn c() {}\n");
+}
+
+#[test]
+fn fuzz_levels_are_tried_in_order_and_reported() {
+    let text = "fn main() {   \n    let x = 1;\n}\n";
+    let ops =
+        parse("*** Begin Patch\n*** Update File: f\n@@\n fn main() {\n-    let x = 1;\n+    let x = 2;\n*** End Patch")
+            .unwrap();
+    let a = apply(text, update(&ops)).unwrap();
+    assert_eq!(a.text, "fn main() {   \n    let x = 2;\n}\n");
+    assert_eq!(a.fuzzy, vec![(1, Fuzz::TrailingWhitespace)]);
+    let ops = parse("*** Begin Patch\n*** Update File: f\n@@\n-let x = 1;\n+    let y = 1;\n*** End Patch").unwrap();
+    let a = apply(text, update(&ops)).unwrap();
+    assert_eq!(a.text, "fn main() {   \n    let y = 1;\n}\n");
+    assert_eq!(a.fuzzy, vec![(1, Fuzz::Whitespace)]);
+
+    // JetBrains: typographic punctuation, exact matches first.
+    let typographic = "import asyncio  # local import \u{2013} avoids top\u{2011}level dep";
+    let ascii = "import asyncio  # local import - avoids top-level dep";
+    let a =
+        apply(&format!("{typographic}\n"), &[hunk(&[('-', ascii), ('+', "import asyncio  # HELLO")], false)]).unwrap();
+    assert_eq!(a.text, "import asyncio  # HELLO\n");
+    assert_eq!(a.fuzzy, vec![(1, Fuzz::Punctuation)]);
+    let both = [hunk(&[('-', ascii), ('+', "# FIRST")], false), hunk(&[('-', ascii), ('+', "# SECOND")], false)];
+    let text = format!("first\n{typographic}\n{typographic}\n");
+    assert_eq!(apply(&text, &both).unwrap().text, "first\n# FIRST\n# SECOND\n");
+    let text = format!("first\n{typographic}\n{ascii}\n");
+    let exact = apply(&text, &[hunk(&[('-', ascii), ('+', "# EXACT")], false)]).unwrap();
+    assert_eq!(exact.text, format!("first\n{typographic}\n# EXACT\n"));
+}
+
+#[test]
+fn a_trailing_blank_context_line_is_optional() {
+    let text = "a\nb";
+    let patch = "*** Begin Patch\n*** Update File: f\n@@\n-b\n+c\n \n*** End Patch";
+    assert_eq!(apply_patch(text, patch).unwrap(), "a\nc");
+}
+
+#[test]
+fn keeps_a_missing_final_newline_and_handles_empty_files() {
+    assert_eq!(apply_patch("a\nb", "*** Begin Patch\n*** Update File: f\n-b\n+c\n*** End Patch").unwrap(), "a\nc");
+    assert_eq!(apply_patch("", "*** Begin Patch\n*** Update File: f\n+x\n*** End Patch").unwrap(), "x\n");
+    assert_eq!(apply_patch("a\n", "*** Begin Patch\n*** Update File: f\n-a\n*** End Patch").unwrap(), "");
+    let h = hunk(&[('-', "alpha"), ('+', "alpha2"), (' ', "beta")], false);
+    assert_eq!(apply("alpha   \nbeta\n", &[h]).unwrap().text, "alpha2\nbeta\n");
+}
+
+#[test]
+fn reports_where_a_hunk_went_wrong() {
+    let text = "fn a() {\n    one();\n    two();\n}\n";
+    let patch =
+        "*** Begin Patch\n*** Update File: f\n@@\n fn a() {\n     one();\n-    three();\n+    four();\n*** End Patch";
+    let e = apply_patch(text, patch).unwrap_err();
+    assert!(e.starts_with("Hunk context not found: hunk 1 does not apply"), "{e}");
+    assert!(e.contains("  fn a() {\n      one();\n      three();\n"), "{e}");
+    assert!(e.contains("Closest match at line 1: line 3 is `    two();`, but the patch expects `    three();`"), "{e}");
+    let e = apply_patch(text, "*** Begin Patch\n*** Update File: f\n@@ fn zzz\n-x\n*** End Patch").unwrap_err();
+    assert!(e.contains("hunk 1 (@@ fn zzz)") && e.contains("`fn zzz`"), "{e}");
+    let e = apply_patch(text, "*** Begin Patch\n*** Update File: f\n-nothing\n*** End Patch").unwrap_err();
+    assert!(e.contains("No line of them"), "{e}");
+    let e = apply_patch(text, "*** Begin Patch\n*** Update File: f\n-two\n+three\n*** End Patch").unwrap_err();
+    assert!(e.contains("Line 3 contains `two` but is `    two();`: patch lines must be whole lines"), "{e}");
+}
+
+// --- unified diffs ------------------------------------------------------
+
+const GIT: &str = "diff --git a/src/lib.rs b/src/lib.rs
+index 3b18e51..a9e0c2f 100644
+--- a/src/lib.rs
+++ b/src/lib.rs
+@@ -1,3 +1,3 @@ mod x;
+ fn a() {}
+-fn b() {}
+fn b() { todo!() }
+ fn c() {}
+@@ -10,2 +10,3 @@
+ fn j() {}
+fn k() {}
+ fn l() {}
+diff --git a/new.txt b/new.txt
+new file mode 100644
+index 0000000..e69de29
+--- /dev/null
+++ b/new.txt
+@@ -0,0 +1,2 @@
+hello
+world
+diff --git a/gone.txt b/gone.txt
+deleted file mode 100644
+--- a/gone.txt
+++ /dev/null
+@@ -1 +0,0 @@
+-bye
+diff --git a/old name.txt b/new name.txt
+similarity index 90%
+rename from old name.txt
+rename to new name.txt
+--- a/old name.txt
+++ b/new name.txt
+@@ -1 +1 @@
+-x
+y
+";
+
+#[test]
+fn parses_git_diffs() {
+    let ops = parse(GIT).unwrap();
+    assert_eq!(ops.len(), 4);
+    match &ops[0] {
+        FileOp::Update { path, move_to: None, hunks, or } => {
+            assert_eq!(path, "src/lib.rs");
+            assert!(or.is_empty(), "{or:?}");
+            assert_eq!(hunks.len(), 2);
+            assert_eq!(hunks[0].old_start, Some(1));
+            assert_eq!(hunks[1].lines.len(), 3);
+        }
+        other => panic!("{other:?}"),
+    }
+    assert_eq!(ops[1], FileOp::Add { path: "new.txt".into(), text: "hello\nworld\n".into() });
+    assert_eq!(ops[2], FileOp::Delete { path: "gone.txt".into() });
+    assert!(matches!(&ops[3], FileOp::Update { path, move_to: Some(to), .. }
+        if path == "old name.txt" && to == "new name.txt"));
+}
+
+#[test]
+fn parses_git_diffs_inside_begin_patch() {
+    let ops = parse(&patch(&[
+        "*** Begin Patch",
+        "diff --git a/s.txt b/s.txt",
+        "--- a/s.txt",
+        "+++ b/s.txt",
+        "@@ -1 +1 @@",
+        "-old",
+        "+new",
+        "*** End Patch",
+    ]))
+    .unwrap();
+    assert!(
+        matches!(&ops[..], [FileOp::Update { path, move_to: None, hunks, .. }] if path == "s.txt" && hunks.len() == 1)
+    );
+    // `--- x` removing a `-- x` line keeps a Codex patch a Codex patch.
+    let ops =
+        parse("*** Begin Patch\n*** Update File: q.sql\n@@\n--- old comment\n+-- new comment\n*** End Patch").unwrap();
+    assert_eq!(update(&ops)[0].lines, vec![Line::Remove("-- old comment".into()), Line::Add("-- new comment".into())]);
+}
+
+#[test]
+fn parses_plain_unified_diffs_and_pure_renames() {
+    let ops =
+        parse("--- a.txt\t2024-01-01 10:00:00\n+++ a.txt\t2024-01-02 10:00:00\n@@ -1,2 +1,2 @@\n-a\n+b\n c\n").unwrap();
+    assert!(
+        matches!(&ops[0], FileOp::Update { path, move_to: None, hunks, .. } if path == "a.txt" && hunks.len() == 1)
+    );
+    // Differently named sides are not a move: the `+++` path, else the others.
+    let ops = parse("--- a.txt.orig\n+++ a.txt\n@@ -1 +1 @@\n-a\n+b\n").unwrap();
+    assert!(matches!(&ops[0], FileOp::Update { path, move_to: None, or, .. }
+        if path == "a.txt" && or == &["a.txt.orig"]));
+    let ops = parse(
+        "diff -ru old/src/a.txt new/src/a.txt\n--- old/src/a.txt\t2024-01-01\n+++ new/src/a.txt\t2024-01-02\n@@ -1 +1 @@\n-a\n+b\n",
+    )
+    .unwrap();
+    assert!(matches!(&ops[0], FileOp::Update { path, move_to: None, or, .. }
+        if path == "new/src/a.txt" && or == &["old/src/a.txt", "src/a.txt"]));
+    let ops = parse("diff --git a/x.rs b/y/x.rs\nsimilarity index 100%\nrename from x.rs\nrename to y/x.rs\n").unwrap();
+    assert_eq!(
+        ops[0],
+        FileOp::Update { path: "x.rs".into(), move_to: Some("y/x.rs".into()), hunks: vec![], or: vec![] }
+    );
+    let ops = parse("diff --git a/e b/e\nnew file mode 100644\nindex 0000000..e69de29\n").unwrap();
+    assert_eq!(ops[0], FileOp::Add { path: "e".into(), text: String::new() });
+    let ops = parse("diff --git \"a/sp ace\" \"b/sp ace\"\ndeleted file mode 100644\n").unwrap();
+    assert_eq!(ops[0], FileOp::Delete { path: "sp ace".into() });
+}
+
+#[test]
+fn unified_counts_are_tolerated() {
+    // Counts too large: the next header ends the hunk.
+    let ops = parse("--- a/f\n+++ b/f\n@@ -1,9 +1,9 @@\n-a\n+b\n--- a/g\n+++ b/g\n@@ -1 +1 @@\n-c\n+d\n").unwrap();
+    assert_eq!(ops.len(), 2);
+    assert_eq!(update(&ops)[0].lines.len(), 2);
+    // Counts too small: following hunk lines still belong to it.
+    let ops = parse("--- a/f\n+++ b/f\n@@ -1,1 +1,1 @@\n-a\n+b\n c\n").unwrap();
+    assert_eq!(update(&ops)[0].lines.len(), 3);
+    // A bare `@@` reads to the next header; empty lines are empty context.
+    let ops = parse("--- a/f\n+++ b/f\n@@\n x\n\n-y\n+z\n\n").unwrap();
+    assert_eq!(
+        update(&ops)[0].lines,
+        vec![Line::Context("x".into()), Line::Context(String::new()), Line::Remove("y".into()), Line::Add("z".into())]
+    );
+    // `git format-patch` signature.
+    let ops = parse("Subject: x\n---\n--- a/f\n+++ b/f\n@@ -1 +1 @@\n-a\n+b\n-- \n2.43.0\n").unwrap();
+    assert_eq!(ops.len(), 1);
+    // `*** End of File` inside a unified hunk.
+    let ops = parse("--- a/f\n+++ b/f\n@@\n-a\n+b\n*** End of File\n").unwrap();
+    assert!(update(&ops)[0].at_eof);
+}
+
+#[test]
+fn unified_errors() {
+    assert!(parse("@@ -1 +1 @@\n-a\n+b\n").unwrap_err().contains("patch must include *** Begin Patch"));
+    assert!(parse("--- a/f\n+++ b/f\n@@ -x +y @@\n-a\n").unwrap_err().contains("cannot read"));
+    let e = parse("diff --git a/f b/f\nBinary files a/f and b/f differ\n").unwrap_err();
+    assert!(e.contains("Binary git patch is not supported"), "{e}");
+    assert!(parse("diff --git a/f b/f\nindex 1..2\n").unwrap_err().contains("no changes"));
+    assert!(parse("--- /dev/null\n+++ b/n\n@@ -1 +1 @@\n x\n").unwrap_err().contains("new file"));
+    let e = parse("--- a/f\n+++ b/f\n@@ -1 +1 @@\nzzz\n").unwrap_err();
+    assert!(e.contains("Hunk lines must start with space, +, or - (line 4: `zzz`)"), "{e}");
+}
+
+#[test]
+fn applies_unified_hunks_near_their_line_numbers() {
+    let text = "x\nsame\nx\nx\nx\nsame\nx\n";
+    let ops = parse("--- a/f\n+++ b/f\n@@ -6,1 +6,1 @@\n-same\n+changed\n").unwrap();
+    assert_eq!(apply(text, update(&ops)).unwrap().text, "x\nsame\nx\nx\nx\nchanged\nx\n");
+    // Wrong line numbers still apply where the context is.
+    let ops = parse("--- a/f\n+++ b/f\n@@ -40,2 +40,2 @@\n x\n-same\n+changed\n").unwrap();
+    assert_eq!(apply(text, update(&ops)).unwrap().text, "x\nsame\nx\nx\nx\nchanged\nx\n");
+    // Insertion after line 2 (`-2,0`).
+    let ops = parse("--- a/f\n+++ b/f\n@@ -2,0 +3,1 @@\n+new\n").unwrap();
+    assert_eq!(apply(text, update(&ops)).unwrap().text, "x\nsame\nnew\nx\nx\nx\nsame\nx\n");
+    // Later line numbers shift by what earlier hunks added.
+    let ops = parse("--- a/f\n+++ b/f\n@@ -0,0 +1,2 @@\n+n1\n+n2\n@@ -6,1 +8,1 @@\n-same\n+changed\n").unwrap();
+    assert_eq!(apply(text, update(&ops)).unwrap().text, "n1\nn2\nx\nsame\nx\nx\nx\nchanged\nx\n");
+}
+
+#[test]
+fn applies_the_git_example() {
+    let text = "fn a() {}\nfn b() {}\nfn c() {}\nfn d() {}\nfn e() {}\nfn f() {}\nfn g() {}\nfn h() {}\nfn i() {}\nfn j() {}\nfn l() {}\n";
+    let ops = parse(GIT).unwrap();
+    let out = apply(text, update(&ops)).unwrap().text;
+    assert_eq!(
+        out,
+        "fn a() {}\nfn b() { todo!() }\nfn c() {}\nfn d() {}\nfn e() {}\nfn f() {}\nfn g() {}\nfn h() {}\nfn i() {}\nfn j() {}\nfn k() {}\nfn l() {}\n"
+    );
+}
+
+#[test]
+fn no_newline_markers() {
+    let add = parse("--- /dev/null\n+++ b/n\n@@ -0,0 +1 @@\n+x\n\\ No newline at end of file\n").unwrap();
+    assert_eq!(add[0], FileOp::Add { path: "n".into(), text: "x".into() });
+    // Adding the final newline.
+    let ops = parse("--- a/f\n+++ b/f\n@@ -1,2 +1,2 @@\n a\n-b\n\\ No newline at end of file\n+b\n").unwrap();
+    assert_eq!(apply("a\nb", update(&ops)).unwrap().text, "a\nb\n");
+    // Removing it.
+    let ops = parse("--- a/f\n+++ b/f\n@@ -1,2 +1,2 @@\n a\n-b\n+b\n\\ No newline at end of file\n").unwrap();
+    assert_eq!(apply("a\nb\n", update(&ops)).unwrap().text, "a\nb");
+}
+
+#[test]
+fn splits_git_paths() {
+    assert_eq!(split_git_paths("a/x y b/x y"), (Some("x y".into()), Some("x y".into())));
+    assert_eq!(split_git_paths("a/x b/y"), (Some("x".into()), Some("y".into())));
+    assert_eq!(parse_range_header("@@ -3 +4,0 @@"), Some((3, 1, 0)));
+    assert_eq!(parse_range_header("@@ -1,2 +1,3 @@ fn x"), Some((1, 2, 3)));
+    assert_eq!(parse_range_header("@@@ -48,6 +48,7 @@@"), Some((48, 6, 7)));
+    assert_eq!(parse_range_header("@@ fn x"), None);
+    assert_eq!(unquote("\"a\\\"b\\\\c\""), "a\"b\\c");
+}
+
+#[test]
+fn mode_changes_and_copies_do_not_fail_the_patch() {
+    // A mode-only section is an update without hunks; the hunks of the others still apply.
+    let diff = patch(&[
+        "diff --git a/run.sh b/run.sh",
+        "old mode 100644",
+        "new mode 100755",
+        "diff --git a/a.txt b/a.txt",
+        "--- a/a.txt",
+        "+++ b/a.txt",
+        "@@ -1 +1 @@",
+        "-x",
+        "+y",
+    ]);
+    let ops = parse(&diff).unwrap();
+    assert_eq!(ops.len(), 2);
+    assert_eq!(ops[0], FileOp::Update { path: "run.sh".into(), move_to: None, hunks: Vec::new(), or: Vec::new() });
+    assert_eq!(update(&ops[1..]).len(), 1);
+
+    // A mode change together with a rename is a move.
+    let ops = parse("diff --git a/x b/y\nold mode 100644\nnew mode 100755\nrename from x\nrename to y\n").unwrap();
+    assert!(matches!(&ops[0], FileOp::Update { move_to: Some(m), .. } if m == "y"));
+
+    // A copy is skipped with a note.
+    let diff = patch(&[
+        "diff --git a/src/a.rs b/src/b.rs",
+        "similarity index 90%",
+        "copy from src/a.rs",
+        "copy to src/b.rs",
+        "--- a/src/a.rs",
+        "+++ b/src/b.rs",
+        "@@ -1 +1 @@",
+        "-a",
+        "+b",
+        "diff --git a/c.txt b/c.txt",
+        "--- a/c.txt",
+        "+++ b/c.txt",
+        "@@ -1 +1 @@",
+        "-1",
+        "+2",
+    ]);
+    let ops = parse(&diff).unwrap();
+    assert_eq!(ops.len(), 2);
+    match &ops[0] {
+        FileOp::Skip { path, note } => {
+            assert_eq!(path, "src/b.rs");
+            assert!(note.contains("copy of src/a.rs to src/b.rs") && note.contains("not supported"), "{note}");
+        }
+        other => panic!("{other:?}"),
+    }
+    assert_eq!(ops[1].path(), "c.txt");
+}
@@ -0,0 +1,950 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (mcpserver.toolsets/src/general/RefactoringToolset.kt, renameTarget.kt), Apache-2.0.
+//! `rename_refactoring` with the language server's rename. The target is given
+//! as in JetBrains: a `contextSnippet`, else `line` + `column`, else the one
+//! declaration of `symbolName` in the file; `targetIndex` picks from the
+//! candidates an earlier call listed. Failures are results (`ok: false` with an
+//! `error.kind`), not tool errors, so the agent can correct the call.
+//!
+//! Symbols are told apart by their definition (go to definition): the language
+//! server has no PSI elements to compare. It renames code references only;
+//! `searchInComments` / `searchInText` add whole-word occurrences found with
+//! Find in Files.
+
+use super::normalize_newlines;
+use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
+use crate::ops::search::SearchEvent;
+use ide_core::{DocId, FileEdit, IdeError, IdeResult, Pos, Range, TextEdit, WorkspaceEdit};
+use ide_lsp::types::GotoKind;
+use ide_search::{SearchContext, SearchQuery, SearchScope};
+use parking_lot::Mutex;
+use serde::Serialize;
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+/// Occurrences of the name whose definition is looked up when no position is given.
+const MAX_LOOKUPS: usize = 50;
+
+/// Files `searchInText` treats as plain text.
+const TEXT_EXTENSIONS: &[&str] = &["txt", "text", "md", "markdown", "rst", "adoc", "asciidoc", "properties"];
+
+pub(super) fn rename_refactoring() -> Tool {
+    Tool::new(
+        "rename_refactoring",
+        "Rename a symbol and every reference to it. Set preview=true to analyze the rename and write nothing.
+The language server resolves the symbol, so it also updates a reference that a text search cannot
+find. Always prefer this tool over a text replacement.
+
+Point at the symbol with ONE of these, in order of preference: contextSnippet, then line and column.
+With neither of them, the file must declare one symbol with this name. symbolName is always required.
+A position that resolves to another name refuses the rename.
+
+targetIndex is not a third way to point at the symbol. It picks from a candidates list an earlier call
+returned, so repeat that call with every argument it had, and add targetIndex.
+
+Read `applied`. It is the only success signal. Nothing is written in part, except after
+error.kind=write_failed, and its hint says what was written.
+ok=false with candidates asks you to pick one with targetIndex. ok=false with conflicts asks for another
+newName. ok=false with error tells you in `hint` what to correct.
+
+applyAutomaticRenamers has no effect here: the language server renames the symbol and its references. A library or \
+compiled symbol cannot be renamed.
+
+By default, the rename changes no comment, no string literal and no plain-text occurrence of the name.
+Set searchInComments or searchInText to change them too.",
+        |call| async move { run(&call).await },
+    )
+    .write()
+    .param(Param::required("pathInProject", ParamType::String, "Path relative to the project root"))
+    .param(Param::required("symbolName", ParamType::String, "Exact, case-sensitive name of the symbol to rename."))
+    .param(Param::required(
+        "newName",
+        ParamType::String,
+        "New name for the symbol. It must be a valid identifier for the symbol's language.",
+    ))
+    .param(Param::optional(
+        "contextSnippet",
+        ParamType::String,
+        "Optional. Exact fragment of the file that shows the symbol. It must match the file once, and contain \
+symbolName.",
+    ))
+    .param(Param::optional(
+        "line",
+        ParamType::Integer,
+        "Optional. 1-based line of the symbol. Copy it from search_symbol output. Needs column too.",
+    ))
+    .param(Param::optional(
+        "column",
+        ParamType::Integer,
+        "Optional. 1-based column of the symbol. Copy it from search_symbol output. Needs line too.",
+    ))
+    .param(Param::optional(
+        "targetIndex",
+        ParamType::Integer,
+        "Optional. 1-based pick from the candidates list an earlier call returned. Repeat every other argument of \
+that call.",
+    ))
+    .param(Param::optional(
+        "preview",
+        ParamType::Boolean,
+        "Optional. Analyze only: report affects and conflicts, and write nothing. The default is false.",
+    ))
+    .param(Param::optional(
+        "applyAutomaticRenamers",
+        ParamType::Boolean,
+        "Optional. Also rename what the IDE renames along with the symbol. The default is false.",
+    ))
+    .param(Param::optional(
+        "searchInComments",
+        ParamType::Boolean,
+        "Optional. Also rename the name in comments and string literals. The default is false.",
+    ))
+    .param(Param::optional(
+        "searchInText",
+        ParamType::Boolean,
+        "Optional. Also rename the name in plain-text occurrences, such as non-code files. The default is false.",
+    ))
+}
+
+// --- the result ------------------------------------------------------------------
+
+#[derive(Serialize, Default)]
+#[serde(rename_all = "camelCase")]
+struct RenameResult {
+    ok: bool,
+    applied: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    resolved_symbol: Option<SymbolInfo>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    affects: Option<Affects>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    renamed_file: Option<RenamedFile>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    candidates: Option<Vec<Candidate>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    conflicts: Option<Vec<Conflict>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    error: Option<RenameError>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    note: Option<String>,
+}
+
+impl RenameResult {
+    fn failed(kind: &'static str, hint: impl Into<String>) -> Self {
+        Self { error: Some(RenameError { kind, hint: hint.into() }), ..Self::default() }
+    }
+
+    fn with_symbol(mut self, symbol: Option<SymbolInfo>) -> Self {
+        self.resolved_symbol = symbol;
+        self
+    }
+}
+
+#[derive(Serialize, Clone)]
+#[serde(rename_all = "camelCase")]
+struct SymbolInfo {
+    name: String,
+    declaration_text: String,
+    declaration_file: String,
+    declaration_line: u32,
+    language: String,
+}
+
+/// The blast radius: files with an edit, and the edits.
+#[derive(Serialize)]
+struct Affects {
+    files: usize,
+    usages: usize,
+}
+
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+struct RenamedFile {
+    previous_path: String,
+    path: String,
+}
+
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+struct Candidate {
+    target_index: usize,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    kind: Option<String>,
+    symbol: SymbolInfo,
+}
+
+#[derive(Serialize)]
+struct Conflict {
+    description: String,
+}
+
+#[derive(Serialize)]
+struct RenameError {
+    kind: &'static str,
+    hint: String,
+}
+
+// --- the call --------------------------------------------------------------------
+
+struct Request {
+    name: String,
+    new_name: String,
+    snippet: Option<String>,
+    position: Option<(i64, i64)>,
+    target_index: Option<i64>,
+    preview: bool,
+    automatic_renamers: bool,
+    in_comments: bool,
+    in_text: bool,
+}
+
+async fn run(call: &Call) -> IdeResult<Output> {
+    let raw = call.str("pathInProject")?;
+    let name = call.str("symbolName")?;
+    let new_name = call.str("newName")?;
+    for (value, arg) in [(&raw, "pathInProject"), (&name, "symbolName"), (&new_name, "newName")] {
+        if value.trim().is_empty() {
+            return Err(IdeError::invalid(format!("{arg} is empty")));
+        }
+    }
+    let (line, column) = (call.opt_i64("line")?, call.opt_i64("column")?);
+    if line.is_some() != column.is_some() {
+        return Err(IdeError::invalid("line and column must be given together"));
+    }
+    let request = Request {
+        name,
+        new_name,
+        snippet: call.opt_str("contextSnippet")?,
+        position: line.zip(column),
+        target_index: call.opt_i64("targetIndex")?,
+        preview: call.flag("preview", false)?,
+        automatic_renamers: call.flag("applyAutomaticRenamers", false)?,
+        in_comments: call.flag("searchInComments", false)?,
+        in_text: call.flag("searchInText", false)?,
+    };
+    let path = call.resolve_inside(&raw)?;
+    if !path.is_file() {
+        return Err(IdeError::not_found(format!("File not found: {raw}")));
+    }
+    let host = call.host();
+    let project = call.project().clone();
+    let (p, target) = (project.clone(), path.clone());
+    let (doc, transient) = host
+        .blocking(move || {
+            // The rename reads and changes files across the project: no buffer may be older than its file.
+            let open: Vec<PathBuf> = p
+                .documents
+                .open_documents()
+                .into_iter()
+                .filter_map(|d| p.documents.snapshot(d).ok().map(|i| i.path.to_path_buf()))
+                .chain(std::iter::once(target.clone()))
+                .collect();
+            super::refresh_from_disk(&p, &open);
+            super::open_document(&p, &target)
+        })
+        .await?;
+    // Closed on every path out, a panic or a dropped call included.
+    let _close = CloseDocument(project.clone(), transient.then_some(doc));
+    Output::json(rename(call, doc, &path, &request).await?)
+}
+
+/// Closes a transient document when dropped.
+struct CloseDocument(Arc<crate::Project>, Option<DocId>);
+
+impl Drop for CloseDocument {
+    fn drop(&mut self) {
+        if let Some(doc) = self.1 {
+            self.0.documents.close(doc);
+        }
+    }
+}
+
+async fn rename(call: &Call, doc: DocId, path: &Path, req: &Request) -> IdeResult<RenameResult> {
+    let snap = call.project().documents.text_snapshot(doc)?;
+    let file = File { call, doc, path, text: &snap.text, language: snap.language.0.clone() };
+    let pos = match resolve_target(&file, req).await? {
+        Resolution::Resolved(pos) => pos,
+        Resolution::Unresolved(kind, hint) => return Ok(RenameResult::failed(kind, hint)),
+        Resolution::Ambiguous(positions) => {
+            let mut candidates = Vec::new();
+            for (i, pos) in positions.iter().enumerate() {
+                let (symbol, kind) = file.symbol_at(&req.name, *pos).await;
+                candidates.push(Candidate { target_index: i + 1, kind, symbol });
+            }
+            let hint = format!(
+                "'{}' matches {} symbols here. Nothing changed. Call again with every argument of this call plus \
+targetIndex, or narrow the call with a contextSnippet that shows the one you mean.",
+                req.name,
+                positions.len()
+            );
+            return Ok(RenameResult { candidates: Some(candidates), ..RenameResult::failed("ambiguous_symbol", hint) });
+        }
+    };
+    let symbol = Some(file.symbol_at(&req.name, pos).await.0);
+    if req.name == req.new_name {
+        let hint = format!("The symbol already has the name '{}'.", req.new_name);
+        return Ok(RenameResult::failed("new_name_matches_current", hint).with_symbol(symbol));
+    }
+    if !plausible_identifier(&req.new_name) {
+        let hint = format!("'{}' is not a valid identifier for {}.", req.new_name, file.language);
+        return Ok(RenameResult::failed("new_name_invalid", hint).with_symbol(symbol));
+    }
+    let host = call.host();
+    let window = call.window();
+    match crate::ops::lsp::lsp_prepare_rename(&host, window, doc, pos).await {
+        Ok(Some(_)) => {}
+        Ok(None) => {
+            let hint = "This symbol cannot be renamed. A library or compiled symbol has to change upstream.";
+            return Ok(RenameResult::failed("not_renamable", hint).with_symbol(symbol));
+        }
+        Err(e) if e.kind == ide_core::error::ErrorKind::Cancelled => return Err(e),
+        Err(e) => return Ok(RenameResult::failed("language_not_supported", no_server_hint(&e)).with_symbol(symbol)),
+    }
+    let request = crate::mcp::tool::request_id();
+    let renamed = tokio::select! {
+        r = crate::ops::lsp::lsp_rename(&host, window, request, doc, pos, req.new_name.clone()) => r,
+        _ = call.cancel.cancelled() => {
+            host.cancel_request(request);
+            return Err(IdeError::cancelled());
+        }
+    };
+    let renamed = match renamed {
+        Ok(r) => r,
+        Err(e) if e.kind == ide_core::error::ErrorKind::Cancelled => return Err(e),
+        // Servers explain a clash with an existing name in the error (gopls: "would conflict with").
+        Err(e) if e.message.to_lowercase().contains("conflict") => {
+            let hint = "A conflict refused the rename and nothing changed. Choose another newName.";
+            let conflicts = Some(vec![Conflict { description: e.message }]);
+            return Ok(RenameResult { conflicts, ..RenameResult::failed("conflicts_found", hint) }.with_symbol(symbol));
+        }
+        Err(e) => return Ok(RenameResult::failed("new_name_refused", e.message).with_symbol(symbol)),
+    };
+    let mut edit = renamed.edit;
+    if edit.files.is_empty() {
+        return Ok(RenameResult::failed("unknown", "The language server found nothing to rename.").with_symbol(symbol));
+    }
+    if req.in_comments || req.in_text {
+        add_text_occurrences(call, &mut edit, req).await?;
+    }
+    for f in &edit.files {
+        let paths: Vec<&Path> = match f {
+            FileEdit::Edit { path, .. } | FileEdit::Create { path, .. } | FileEdit::Delete { path, .. } => vec![path],
+            FileEdit::Rename { from, to } => vec![from, to],
+        };
+        for p in paths {
+            if let Err(e) = super::super::tool::ensure_inside(call.root(), p) {
+                let hint = format!(
+                    "{}. Nothing was renamed. A rename that must change a file outside the project cannot run here.",
+                    e.message
+                );
+                return Ok(RenameResult::failed("read_only_usages", hint).with_symbol(symbol));
+            }
+        }
+    }
+    let mut files: Vec<&Path> = Vec::new();
+    let mut usages = 0;
+    for f in &edit.files {
+        if let FileEdit::Edit { path, edits, .. } = f {
+            usages += edits.len();
+            if !files.contains(&&**path) {
+                files.push(path);
+            }
+        }
+    }
+    let affects = Some(Affects { files: files.len(), usages });
+    let mut notes = Vec::new();
+    if renamed.incomplete.is_some() {
+        notes.push("The language server reported that the references may be incomplete.");
+    }
+    if req.automatic_renamers {
+        notes.push(
+            "applyAutomaticRenamers had no effect: the language server renames the symbol and its references only.",
+        );
+    }
+    let note = (!notes.is_empty()).then(|| notes.join(" "));
+    if req.preview {
+        return Ok(RenameResult { ok: true, affects, resolved_symbol: symbol, note, ..RenameResult::default() });
+    }
+    // The IDE's configuration among the files: the user agrees first.
+    let mut checked: Vec<&Path> = Vec::new();
+    for f in &edit.files {
+        let paths: Vec<&Path> = match f {
+            FileEdit::Edit { path, .. } | FileEdit::Create { path, .. } | FileEdit::Delete { path, .. } => vec![path],
+            FileEdit::Rename { from, to } => vec![from, to],
+        };
+        for p in paths {
+            if !checked.contains(&p) {
+                checked.push(p);
+                call.check_writable(p).await?;
+            }
+        }
+    }
+    let renamed_file = edit.files.iter().find_map(|f| match f {
+        FileEdit::Rename { from, to } if super::same_file(from, path) => {
+            Some(RenamedFile { previous_path: call.display(from), path: call.display(to) })
+        }
+        _ => None,
+    });
+    let (h, w) = (host.clone(), window.to_owned());
+    let written = crate::ops::lsp::apply_workspace_edit(&h, &w, edit).await;
+    if let Err(e) = written {
+        let hint = format!("The rename stopped while it wrote. {} Read the files again before you retry.", e.message);
+        return Ok(RenameResult::failed("write_failed", hint).with_symbol(symbol));
+    }
+    Ok(RenameResult {
+        ok: true,
+        applied: true,
+        resolved_symbol: symbol,
+        affects,
+        renamed_file,
+        note,
+        ..RenameResult::default()
+    })
+}
+
+fn no_server_hint(e: &IdeError) -> String {
+    format!(
+        "No language server can rename in this file ({}), so nothing was renamed. Without one, change the \
+occurrences with apply_patch.",
+        e.message
+    )
+}
+
+/// Refuses only what no language accepts in a name: whitespace, separators, a leading digit.
+fn plausible_identifier(name: &str) -> bool {
+    !name.starts_with(|c: char| c.is_ascii_digit())
+        && !name.chars().any(|c| c.is_whitespace() || c.is_control() || ".,;:()[]{}<>\"'`/\\+*=!?&|^%#~".contains(c))
+}
+
+// --- the target ------------------------------------------------------------------
+
+enum Resolution {
+    Resolved(Pos),
+    /// Several symbols, in document order; `targetIndex` is 1-based.
+    Ambiguous(Vec<Pos>),
+    Unresolved(&'static str, String),
+}
+
+/// The file the rename starts in.
+struct File<'a> {
+    call: &'a Call,
+    doc: DocId,
+    path: &'a Path,
+    text: &'a str,
+    language: String,
+}
+
+impl File<'_> {
+    fn line(&self, line: u32) -> &str {
+        self.text.split('\n').nth(line as usize).unwrap_or("")
+    }
+
+    /// Where the symbol at `pos` is defined; `None` without an answer.
+    async fn definition(&self, pos: Pos) -> Option<(PathBuf, Pos)> {
+        let host = self.call.host();
+        let found = crate::ops::lsp::lsp_goto(&host, self.call.window(), self.doc, pos, GotoKind::Definition).await;
+        let loc = found.ok()?.into_iter().find(|l| l.uri.is_none())?;
+        Some((PathBuf::from(&*loc.path), loc.range.start))
+    }
+
+    /// Whether the language server can rename at `pos`; `Err` without one.
+    async fn renameable(&self, pos: Pos) -> Result<bool, Resolution> {
+        let host = self.call.host();
+        match crate::ops::lsp::lsp_prepare_rename(&host, self.call.window(), self.doc, pos).await {
+            Ok(found) => Ok(found.is_some()),
+            Err(e) => Err(Resolution::Unresolved("language_not_supported", no_server_hint(&e))),
+        }
+    }
+
+    /// The symbol (from its definition when known) and its outline kind.
+    async fn symbol_at(&self, name: &str, pos: Pos) -> (SymbolInfo, Option<String>) {
+        let (file, at) = match self.definition(pos).await {
+            Some((file, at)) if super::same_file(&file, self.path) => (self.path.to_path_buf(), at),
+            Some((file, at)) => (file, at),
+            None => (self.path.to_path_buf(), pos),
+        };
+        let declaration_text = if file == self.path {
+            self.line(at.line).trim().to_owned()
+        } else {
+            let project = self.call.project();
+            project
+                .text_of(&file)
+                .ok()
+                .and_then(|t| t.split('\n').nth(at.line as usize).map(|l| l.trim().to_owned()))
+                .unwrap_or_default()
+        };
+        let kind = if file == self.path { self.kind_at(at).await } else { None };
+        let symbol = SymbolInfo {
+            name: name.to_owned(),
+            declaration_text,
+            declaration_file: self.call.display(&file),
+            declaration_line: at.line + 1,
+            language: self.language.clone(),
+        };
+        (symbol, kind)
+    }
+
+    /// The outline kind (`field`, `method`) of the declaration whose name is at `pos`.
+    async fn kind_at(&self, pos: Pos) -> Option<String> {
+        let host = self.call.host();
+        let outline = crate::ops::doc::doc_outline(&host, self.call.window(), self.doc).await.ok()?;
+        let mut stack: Vec<&ide_core::OutlineItem> = outline.iter().collect();
+        while let Some(item) = stack.pop() {
+            let r = item.selection_range;
+            if r.start <= pos && pos <= r.end {
+                let kind = format!("{:?}", item.kind);
+                return Some(kind[..1].to_lowercase() + &kind[1..]);
+            }
+            stack.extend(item.children.iter());
+        }
+        None
+    }
+
+    /// Positions of `name` as an identifier (outside comments and strings when a grammar knows them).
+    async fn identifiers(&self, name: &str) -> Vec<Pos> {
+        let host = self.call.host();
+        match crate::ops::syntax::syntax_identifiers(&host, self.call.window(), self.doc, name.to_owned(), None).await {
+            Ok(found) if !found.is_empty() => found.into_iter().map(|o| o.range.start).collect(),
+            _ => word_positions(self.text, name),
+        }
+    }
+}
+
+/// The symbol the caller pointed at, or why the tool cannot tell which one it is.
+/// `targetIndex` picks from the list of the branch the other arguments select.
+async fn resolve_target(file: &File<'_>, req: &Request) -> IdeResult<Resolution> {
+    let resolution = if let Some(snippet) = &req.snippet {
+        by_snippet(file, snippet, &req.name).await
+    } else if let Some((line, column)) = req.position {
+        by_position(file, line, column, &req.name).await
+    } else {
+        by_declaration(file, &req.name).await?
+    };
+    let Some(index) = req.target_index else { return Ok(resolution) };
+    Ok(match resolution {
+        Resolution::Ambiguous(candidates) => pick(&candidates, index),
+        // One symbol now: only a pick of the first agrees with it; the code changed since the list.
+        Resolution::Resolved(pos) if index == 1 => Resolution::Resolved(pos),
+        Resolution::Resolved(pos) => pick(&[pos], index),
+        unresolved => unresolved,
+    })
+}
+
+fn pick(candidates: &[Pos], index: i64) -> Resolution {
+    let n = candidates.len();
+    if index < 1 || index as usize > n {
+        return Resolution::Unresolved(
+            "target_index_out_of_range",
+            format!(
+                "targetIndex {index} is outside 1..{n}. This call reports {n} candidate(s). Send the same \
+pathInProject, symbolName and contextSnippet as the call that listed them."
+            ),
+        );
+    }
+    Resolution::Resolved(candidates[index as usize - 1])
+}
+
+async fn by_snippet(file: &File<'_>, snippet: &str, name: &str) -> Resolution {
+    if snippet.trim().is_empty() {
+        return Resolution::Unresolved("snippet_not_found", "contextSnippet is blank.".into());
+    }
+    let needle = normalize_newlines(snippet);
+    if !needle.contains(name) {
+        return Resolution::Unresolved(
+            "name_mismatch",
+            format!("contextSnippet does not contain '{name}'. Pass a snippet that shows the symbol."),
+        );
+    }
+    let start = match find_snippet(file.text, &needle) {
+        SnippetMatch::NotFound => {
+            return Resolution::Unresolved(
+                "snippet_not_found",
+                "contextSnippet is not in this file. Read the file again and copy the snippet from its current text."
+                    .into(),
+            );
+        }
+        SnippetMatch::NotUnique => {
+            return Resolution::Unresolved(
+                "snippet_not_unique",
+                "contextSnippet matches this file more than once. Extend it until it is unique.".into(),
+            );
+        }
+        SnippetMatch::At(start) => start,
+    };
+    let mut symbols: Vec<(Option<(PathBuf, Pos)>, Pos)> = Vec::new();
+    // Why an occurrence could not be asked about; reported only when no other one resolves.
+    let mut refused = None;
+    for pos in snippet_occurrences(file.text, start, needle.len(), name) {
+        match file.renameable(pos).await {
+            Ok(true) => {}
+            Ok(false) => continue,
+            Err(no_server) => {
+                refused.get_or_insert(no_server);
+                continue;
+            }
+        }
+        let definition = file.definition(pos).await;
+        if definition.is_none() || !symbols.iter().any(|(d, _)| *d == definition) {
+            symbols.push((definition, pos));
+        }
+    }
+    if let (true, Some(refused)) = (symbols.is_empty(), refused) {
+        return refused;
+    }
+    match symbols.len() {
+        0 => Resolution::Unresolved(
+            "symbol_not_found",
+            format!("'{name}' inside contextSnippet does not resolve to a symbol that can be renamed."),
+        ),
+        1 => Resolution::Resolved(symbols[0].1),
+        _ => Resolution::Ambiguous(symbols.into_iter().map(|(_, p)| p).collect()),
+    }
+}
+
+async fn by_position(file: &File<'_>, line: i64, column: i64, name: &str) -> Resolution {
+    let line_count = file.text.split('\n').count() as i64;
+    if line < 1 || column < 1 || line > line_count {
+        return Resolution::Unresolved(
+            "position_out_of_bounds",
+            format!("Position {line}:{column} is outside this file. Both numbers are 1-based."),
+        );
+    }
+    let text = file.line(line as u32 - 1);
+    let units: Vec<u16> = text.encode_utf16().collect();
+    // The column has to stay on the named line: past its end it would land further down.
+    if column as usize - 1 > units.len() {
+        return Resolution::Unresolved(
+            "position_out_of_bounds",
+            format!("Column {column} is past the end of line {line}. Both numbers are 1-based."),
+        );
+    }
+    let pos = Pos::new(line as u32 - 1, column as u32 - 1);
+    let word = word_at(&units, pos.col as usize);
+    let in_code = file
+        .identifiers(name)
+        .await
+        .iter()
+        .any(|p| p.line == pos.line && p.col <= pos.col && pos.col <= p.col + units_len(name));
+    match word {
+        Some((start, w)) if w == name && in_code => {
+            let at = Pos::new(pos.line, start as u32);
+            match file.renameable(at).await {
+                Ok(true) => Resolution::Resolved(at),
+                Ok(false) => Resolution::Unresolved(
+                    "symbol_not_found",
+                    format!("No symbol that can be renamed sits at {line}:{column}."),
+                ),
+                Err(no_server) => no_server,
+            }
+        }
+        Some((_, other)) if other != name => Resolution::Unresolved(
+            "name_mismatch",
+            format!("Position {line}:{column} resolves to '{other}', not to '{name}'. Nothing was renamed."),
+        ),
+        _ => Resolution::Unresolved(
+            "symbol_not_found",
+            format!("No symbol that can be renamed sits at {line}:{column}."),
+        ),
+    }
+}
+
+/// The declarations of `name` in this file: the distinct definitions of its occurrences
+/// that lie in this file (declared-looking occurrences without go to definition).
+async fn by_declaration(file: &File<'_>, name: &str) -> IdeResult<Resolution> {
+    let occurrences = file.identifiers(name).await;
+    let mut declarations: Vec<Pos> = Vec::new();
+    let mut answered = false;
+    for pos in occurrences.iter().take(MAX_LOOKUPS) {
+        if file.call.cancel.is_cancelled() {
+            return Err(IdeError::cancelled());
+        }
+        if let Some((path, at)) = file.definition(*pos).await {
+            answered = true;
+            if super::same_file(&path, file.path) && !declarations.contains(&at) {
+                declarations.push(at);
+            }
+        }
+    }
+    if !answered {
+        declarations = occurrences.into_iter().filter(|p| is_declaration(file.text, *p)).collect();
+    }
+    declarations.sort();
+    Ok(match declarations.len() {
+        0 => Resolution::Unresolved(
+            "symbol_not_found",
+            format!("No symbol named '{name}' is declared in this file. Pass the file that declares it."),
+        ),
+        1 => Resolution::Resolved(declarations[0]),
+        _ => Resolution::Ambiguous(declarations),
+    })
+}
+
+fn units_len(s: &str) -> u32 {
+    s.encode_utf16().count() as u32
+}
+
+fn is_word_unit(u: u16) -> bool {
+    char::from_u32(u as u32).is_some_and(|c| c.is_alphanumeric() || c == '_' || c == '$') || u >= 0x80
+}
+
+/// The identifier-like word touching UTF-16 column `col`: (start column, word).
+fn word_at(units: &[u16], col: usize) -> Option<(usize, String)> {
+    let touches = |i: usize| units.get(i).is_some_and(|&u| is_word_unit(u));
+    let at = if touches(col) {
+        col
+    } else if col > 0 && touches(col - 1) {
+        col - 1
+    } else {
+        return None;
+    };
+    let start = (0..=at).rev().take_while(|&i| touches(i)).last().unwrap_or(at);
+    let end = (at..units.len()).take_while(|&i| touches(i)).last().map_or(at, |e| e + 1);
+    Some((start, String::from_utf16_lossy(&units[start..end])))
+}
+
+enum SnippetMatch {
+    NotFound,
+    NotUnique,
+    /// The byte offset of the only occurrence.
+    At(usize),
+}
+
+/// Where `needle` occurs in `text`, overlapping occurrences included.
+fn find_snippet(text: &str, needle: &str) -> SnippetMatch {
+    let Some(start) = text.find(needle) else { return SnippetMatch::NotFound };
+    // One character further, not one byte: the needle may start with a multibyte character.
+    let step = needle.chars().next().map_or(1, char::len_utf8);
+    if text[start + step..].contains(needle) { SnippetMatch::NotUnique } else { SnippetMatch::At(start) }
+}
+
+/// Whole-word occurrences of `name` inside the `len` bytes of `text` from byte `start`
+/// (a snippet's place in the file): the file's text around an occurrence decides whether
+/// it is a whole word, so a snippet cut in the middle of a word does not make one.
+fn snippet_occurrences(text: &str, start: usize, len: usize, name: &str) -> Vec<Pos> {
+    let is_word = |c: char| c.is_alphanumeric() || c == '_' || c == '$';
+    let mut out = Vec::new();
+    for (at, _) in text[start..start + len].match_indices(name) {
+        let at = start + at;
+        let before = text[..at].chars().next_back();
+        let after = text[at + name.len()..].chars().next();
+        if before.is_some_and(is_word) || after.is_some_and(is_word) {
+            continue;
+        }
+        let line_start = text[..at].rfind('\n').map_or(0, |i| i + 1);
+        out.push(Pos::new(text[..at].matches('\n').count() as u32, units_len(&text[line_start..at])));
+    }
+    out
+}
+
+/// Whole-word occurrences of `name` (0-based line, UTF-16 column).
+fn word_positions(text: &str, name: &str) -> Vec<Pos> {
+    let is_word = |c: char| c.is_alphanumeric() || c == '_' || c == '$';
+    let mut out = Vec::new();
+    for (line_no, line) in text.split('\n').enumerate() {
+        for (at, _) in line.match_indices(name) {
+            let before = line[..at].chars().next_back();
+            let after = line[at + name.len()..].chars().next();
+            if before.is_some_and(is_word) || after.is_some_and(is_word) {
+                continue;
+            }
+            out.push(Pos::new(line_no as u32, units_len(&line[..at])));
+        }
+    }
+    out
+}
+
+/// Words that introduce a declaration of the name after them.
+const DECLARATION_KEYWORDS: &[&str] = &[
+    "fn",
+    "def",
+    "class",
+    "struct",
+    "enum",
+    "trait",
+    "interface",
+    "type",
+    "func",
+    "function",
+    "fun",
+    "let",
+    "const",
+    "var",
+    "val",
+    "mod",
+    "module",
+    "object",
+    "record",
+    "typealias",
+    "protocol",
+    "union",
+    "namespace",
+    "package",
+    "static",
+    "macro_rules!",
+];
+
+/// Whether the occurrence at `p` follows a declaration keyword (`fn name`, `let mut name`).
+fn is_declaration(text: &str, p: Pos) -> bool {
+    let Some(line) = text.split('\n').nth(p.line as usize) else { return false };
+    let mut units = 0u32;
+    let byte = line
+        .char_indices()
+        .find(|(_, c)| {
+            let here = units >= p.col;
+            units += c.len_utf16() as u32;
+            here
+        })
+        .map_or(line.len(), |(i, _)| i);
+    let mut words = line[..byte].split_whitespace().rev();
+    match words.next() {
+        Some("mut") => words.next() == Some("let"),
+        Some(w) => DECLARATION_KEYWORDS.contains(&w),
+        None => false,
+    }
+}
+
+// --- comments and text -------------------------------------------------------------
+
+/// Adds whole-word occurrences of the old name to `edit`: in comments and string
+/// literals of the files it changes, and in plain-text files of the project.
+async fn add_text_occurrences(call: &Call, edit: &mut WorkspaceEdit, req: &Request) -> IdeResult<()> {
+    let edited: Vec<PathBuf> = edit
+        .files
+        .iter()
+        .filter_map(|f| match f {
+            FileEdit::Edit { path, .. } => Some(path.to_path_buf()),
+            _ => None,
+        })
+        .collect();
+    let mut found = Vec::new();
+    if req.in_comments {
+        let scope = || SearchScope::Files { paths: edited.iter().cloned().map(Into::into).collect() };
+        found.extend(occurrences(call, &req.name, scope(), SearchContext::InComments).await?);
+        found.extend(occurrences(call, &req.name, scope(), SearchContext::InStringLiterals).await?);
+    }
+    if req.in_text {
+        let text_file = |p: &Path| {
+            p.extension().and_then(|e| e.to_str()).is_some_and(|e| TEXT_EXTENSIONS.contains(&e.to_lowercase().as_str()))
+        };
+        found.extend(
+            occurrences(call, &req.name, SearchScope::Project, SearchContext::Any)
+                .await?
+                .into_iter()
+                .filter(|(p, _)| text_file(p) && !edited.iter().any(|e| super::same_file(e, p))),
+        );
+    }
+    for (path, range) in found {
+        let text_edit = TextEdit { range, new_text: req.new_name.clone() };
+        let entry = edit.files.iter_mut().find_map(|f| match f {
+            FileEdit::Edit { path: p, edits, .. } if super::same_file(p, &path) => Some(edits),
+            _ => None,
+        });
+        match entry {
+            Some(edits) => {
+                let overlaps =
+                    edits.iter().any(|e| e.range.start < range.end && range.start < e.range.end || e.range == range);
+                if !overlaps {
+                    edits.push(text_edit);
+                }
+            }
+            None => edit.files.push(FileEdit::Edit { path: path.into(), edits: vec![text_edit], version: None }),
+        }
+    }
+    Ok(())
+}
+
+/// Whole-word, case-sensitive Find in Files matches of `name`.
+async fn occurrences(
+    call: &Call,
+    name: &str,
+    scope: SearchScope,
+    context: SearchContext,
+) -> IdeResult<Vec<(PathBuf, Range)>> {
+    let query = SearchQuery {
+        pattern: name.to_owned(),
+        is_regex: false,
+        case_sensitive: true,
+        whole_word: true,
+        include: Vec::new(),
+        exclude: Vec::new(),
+        scope,
+        max_matches: 0,
+        context,
+    };
+    let host = call.host();
+    let request = crate::mcp::tool::request_id();
+    let files = Arc::new(Mutex::new(Vec::new()));
+    let emit: crate::ops::Emit<SearchEvent> = {
+        let files = files.clone();
+        Arc::new(move |event| {
+            if let SearchEvent::File { file } = event {
+                files.lock().push(file);
+            }
+        })
+    };
+    let search = crate::ops::search::start(&host, call.window(), request, query, emit);
+    tokio::pin!(search);
+    tokio::select! {
+        r = &mut search => r?,
+        _ = call.cancel.cancelled() => {
+            host.cancel_request(request);
+            let _ = search.await;
+            return Err(IdeError::cancelled());
+        }
+    }
+    let width = units_len(name);
+    let mut out = Vec::new();
+    for file in std::mem::take(&mut *files.lock()) {
+        for m in &file.matches {
+            for &(from, _) in &m.ranges {
+                let start = Pos::new(m.line, m.text_offset + from);
+                out.push((file.path.to_path_buf(), Range::new(start, Pos::new(m.line, start.col + width))));
+            }
+        }
+    }
+    Ok(out)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn finds_whole_words_in_utf16_columns() {
+        let text = "let foo = foo_bar + foo;\n// ä foo\nfoofoo";
+        assert_eq!(word_positions(text, "foo"), vec![Pos::new(0, 4), Pos::new(0, 20), Pos::new(1, 5)]);
+        let units: Vec<u16> = "  int counter;".encode_utf16().collect();
+        assert_eq!(word_at(&units, 6), Some((6, "counter".into())));
+        assert_eq!(word_at(&units, 13), Some((6, "counter".into())));
+        assert_eq!(word_at(&units, 0), None);
+    }
+
+    #[test]
+    fn finds_snippets_starting_with_multibyte_characters() {
+        let text = "let äb = 1;\nlet äb2 = äb;\n";
+        assert!(matches!(find_snippet(text, "äb"), SnippetMatch::NotUnique));
+        assert!(matches!(find_snippet(text, "äb = 1"), SnippetMatch::At(4)));
+        assert!(matches!(find_snippet(text, "ö"), SnippetMatch::NotFound));
+        // Overlapping occurrences are two.
+        assert!(matches!(find_snippet("aaa", "aa"), SnippetMatch::NotUnique));
+    }
+
+    #[test]
+    fn snippet_occurrences_are_whole_words_of_the_file() {
+        let text = "let beta = 1;\nlet x = alphabeta + beta;\n";
+        // The snippet starts inside `alphabeta`: its `beta` is not a word of the file.
+        let needle = "beta + beta";
+        let SnippetMatch::At(start) = find_snippet(text, needle) else { panic!() };
+        assert_eq!(snippet_occurrences(text, start, needle.len(), "beta"), vec![Pos::new(1, 20)]);
+        let text = "ä beta";
+        assert_eq!(snippet_occurrences(text, 0, text.len(), "beta"), vec![Pos::new(0, 2)]);
+    }
+
+    #[test]
+    fn recognizes_declarations_and_identifiers() {
+        let text = "use x;\nprint(count)\nlet mut count = 1;\nfn count() {}\n";
+        assert!(!is_declaration(text, Pos::new(1, 6)));
+        assert!(is_declaration(text, Pos::new(2, 8)) && is_declaration(text, Pos::new(3, 3)));
+        assert!(plausible_identifier("hitCount") && plausible_identifier("kebab-case") && plausible_identifier("$x"));
+        assert!(!plausible_identifier("1abc") && !plausible_identifier("bad name") && !plausible_identifier("a.b"));
+    }
+}
@@ -0,0 +1,98 @@
+use super::tool::{Call, Output, Param, ParamType, Tool};
+use ide_core::{Diagnostic, IdeResult, Severity};
+use serde_json::{Value, json};
+
+pub fn tools() -> Vec<Tool> {
+    vec![
+        Tool::new(
+            "get_all_open_file_paths",
+            "Returns active editor's and other open editors' file paths relative to the project root.
+
+Use this tool to explore current open editors.",
+            open_editors,
+        ),
+        Tool::new(
+            "get_current_file",
+            "Returns the focused editor's file and selection reported by the IDE.
+Selection lines and UTF-16 columns are 1-based, end exclusive.
+Selected text is limited to 65536 UTF-16 units.",
+            current_file,
+        ),
+        Tool::new(
+            "get_file_problems",
+            "Returns the problems for a file as reported by the IDE's Problems view, including language servers
+and inspections after profile filtering. This reflects what the Problems view shows, rather than a fresh analysis.
+Lines and UTF-16 columns are 1-based.",
+            file_problems,
+        )
+        .param(Param::required("filePath", ParamType::String, "Path relative to the project root"))
+        .param(Param::optional(
+            "errorsOnly",
+            ParamType::Boolean,
+            "Whether to include only errors or include both errors and warnings",
+        )),
+        Tool::new(
+            "get_project_problems",
+            "Returns the project's problems as reported by the IDE's Problems view, including language servers
+and inspections after profile filtering. This reflects what the Problems view shows, rather than a fresh analysis.
+Lines and UTF-16 columns are 1-based.",
+            project_problems,
+        ),
+    ]
+}
+
+async fn open_editors(call: Call) -> IdeResult<Output> {
+    let windows = call.host.mcp_windows(call.root());
+    let open = call.host.mcp_reports.editors(&windows);
+    let active = call.host.mcp_reports.focused(call.window());
+    Output::json(json!({
+        "activeFilePath": active.map(|e| call.display(&e.path.0)),
+        "openFiles": open.iter().map(|p| call.display(p)).collect::<Vec<_>>(),
+    }))
+}
+
+async fn current_file(call: Call) -> IdeResult<Output> {
+    let editor = call.host.mcp_reports.focused(call.window());
+    Output::json(match editor {
+        None => json!({}),
+        Some(e) => json!({
+            "filePath": call.display(&e.path.0), "selectedText": e.selected_text,
+            "selection": {
+                "startLine": e.selection.start.line + 1, "startColumn": e.selection.start.col + 1,
+                "endLine": e.selection.end.line + 1, "endColumn": e.selection.end.col + 1,
+            },
+        }),
+    })
+}
+
+fn problem(d: Diagnostic, text: &str) -> Value {
+    json!({
+        "severity": d.severity, "description": d.message,
+        "lineContent": text.lines().nth(d.range.start.line as usize).unwrap_or_default(),
+        "line": d.range.start.line + 1, "column": d.range.start.col + 1, "source": d.source, "code": d.code,
+    })
+}
+
+async fn file_problems(call: Call) -> IdeResult<Output> {
+    let path = call.resolve_readable(&call.str("filePath")?).await?;
+    let errors_only = call.flag("errorsOnly", true)?;
+    let files = call.host.mcp_reports.problems(&call.host.mcp_windows(call.root()));
+    let (project, file) = (call.project.clone(), path.clone());
+    let text = call.host.blocking(move || project.text_of(&file)).await.unwrap_or_default();
+    let errors: Vec<_> = files
+        .into_iter()
+        .filter(|f| f.path.0 == path)
+        .flat_map(|f| f.items)
+        .filter(|d| !errors_only || d.severity == Severity::Error)
+        .map(|d| problem(d, &text))
+        .collect();
+    Output::json(json!({"filePath": call.display(&path), "errors": errors}))
+}
+
+async fn project_problems(call: Call) -> IdeResult<Output> {
+    let files = call.host.mcp_reports.problems(&call.host.mcp_windows(call.root()));
+    let files: Vec<_> = files.into_iter().map(|f| json!({
+        "filePath":call.display(&f.path.0), "problems": f.items.into_iter().map(|d| problem(d, "")).collect::<Vec<_>>()
+    })).collect();
+    Output::json(json!({"files":files}))
+}
@@ -0,0 +1,280 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (mcpserver.toolsets/src/general/ReadToolset.kt,
+// the list_directory_tree part of FileToolset.kt, src/com/intellij/mcpserver/util/fs.util.kt), Apache-2.0.
+//! Reading files and listing directories.
+
+use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
+use crate::mcp::util::{
+    self, RELATIVE_PATH_IN_PROJECT_DESCRIPTION, TIMED_OUT_DESCRIPTION, TIMEOUT_MILLISECONDS_DESCRIPTION,
+};
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use serde::Serialize;
+use serde_json::json;
+use std::path::Path;
+use std::time::{Duration, Instant};
+
+const DEFAULT_READ_LIMIT: i64 = 2000;
+const MAX_READ_LIMIT: i64 = 5000;
+/// Longer lines are cut (minified files would flood the context), in UTF-16 units.
+const MAX_LINE_LENGTH: usize = 2000;
+const DEFAULT_TREE_DEPTH: i64 = 5;
+
+pub fn tools() -> Vec<Tool> {
+    vec![read_file(), list_directory_tree()]
+}
+
+// --- read_file -----------------------------------------------------------------
+
+fn read_file() -> Tool {
+    Tool::new(
+        "read_file",
+        "Reads a file in the project directory or from any project dependency or other project source root.
+Can read text sources inside jar/zip archives; compiled class files are not decompiled.
+Returns numbered lines (1-indexed) as text.
+By default, reads up to 2000 lines starting from the beginning of the file.
+The maximum accepted limit is 5000 lines.",
+        |call| async move {
+            let offset = positive(&call, "offset", 1)?;
+            let limit = positive(&call, "limit", DEFAULT_READ_LIMIT)?;
+            if limit > MAX_READ_LIMIT {
+                return Err(IdeError::invalid(format!("limit must be <= {MAX_READ_LIMIT}")));
+            }
+            let path = util::resolve_read_file(&call, &call.str("file_path")?).await?;
+            if call.project().documents.by_path(&path).is_none()
+                && let probe = ide_vfs::probe(&path)?
+                && probe.binary
+            {
+                return Err(IdeError::invalid(format!(
+                    "{} is a binary file ({} bytes); read_file reads text",
+                    call.display(&path),
+                    probe.size
+                )));
+            }
+            let text = crate::ops::fs::read_text(&call.host(), call.window(), path).await?;
+            Ok(Output::text(render_slice(&text, offset as usize, limit as usize)?))
+        },
+    )
+    .param(Param::required("file_path", ParamType::String, util::FILE_PATH_DESCRIPTION))
+    .param(Param::optional("offset", ParamType::Integer, "1-based line number to start reading from"))
+    .param(Param::optional(
+        "limit",
+        ParamType::Integer,
+        "Maximum number of lines to return (default: 2000, max: 5000)",
+    ))
+}
+
+/// An integer argument that must be > 0.
+fn positive(call: &Call, name: &str, default: i64) -> IdeResult<i64> {
+    match call.opt_i64(name)?.unwrap_or(default) {
+        n if n <= 0 => Err(IdeError::invalid(format!("{name} must be > 0"))),
+        n => Ok(n),
+    }
+}
+
+/// Lines `start..` of `text` as `L<n>: <line>`; when more than `max_lines` remain, the first
+/// and the last halves of the budget with a `…N lines truncated…` marker between them.
+/// Lines are the editor's: a trailing line break starts an empty last line.
+fn render_slice(text: &str, start: usize, max_lines: usize) -> IdeResult<String> {
+    let lines: Vec<&str> = text.split('\n').map(|l| l.strip_suffix('\r').unwrap_or(l)).collect();
+    let count = lines.len();
+    if start > count {
+        return Err(IdeError::invalid("offset exceeds file length"));
+    }
+    let range = |from: usize, to: usize| {
+        (from..=to).map(|n| format!("L{n}: {}", format_line(lines[n - 1]))).collect::<Vec<_>>().join("\n")
+    };
+    let available = count - start + 1;
+    if available <= max_lines {
+        return Ok(range(start, count));
+    }
+    let head = max_lines / 2;
+    let tail = max_lines - head;
+    let head_end = start + head - 1;
+    let tail_start = count - tail + 1;
+    let mut out = String::new();
+    if head > 0 {
+        out.push_str(&range(start, head_end));
+        out.push('\n');
+    }
+    out.push_str(&format!("\u{2026}{} lines truncated\u{2026}", tail_start - head_end - 1));
+    if tail > 0 {
+        out.push('\n');
+        out.push_str(&range(tail_start, count));
+    }
+    Ok(out)
+}
+
+/// `line` cut to [`MAX_LINE_LENGTH`] UTF-16 units, or as many characters when the cut would
+/// split a surrogate pair (as JetBrains does).
+fn format_line(line: &str) -> &str {
+    let mut units = 0;
+    for (i, c) in line.char_indices() {
+        if units >= MAX_LINE_LENGTH {
+            return &line[..i];
+        }
+        if units + c.len_utf16() > MAX_LINE_LENGTH {
+            // A pair across the boundary: keep MAX_LINE_LENGTH characters instead.
+            return match line.char_indices().nth(MAX_LINE_LENGTH) {
+                Some((cut, _)) => &line[..cut],
+                None => line,
+            };
+        }
+        units += c.len_utf16();
+    }
+    line
+}
+
+// --- list_directory_tree -------------------------------------------------------
+
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+struct DirectoryTreeInfo {
+    traversed_directory: String,
+    tree: String,
+    errors: Vec<String>,
+    #[serde(skip_serializing_if = "std::ops::Not::not")]
+    listing_timed_out: bool,
+}
+
+fn list_directory_tree() -> Tool {
+    Tool::new(
+        "list_directory_tree",
+        "Provides a tree representation of the specified directory in the pseudo graphic format like `tree` utility does.
+Use this tool to explore the contents of a directory or the whole project.
+You MUST prefer this tool over listing directories via command line utilities like `ls` or `dir`.",
+        |call| async move {
+            let directory = call.str("directoryPath")?;
+            let max_depth = call.opt_i64("maxDepth")?.unwrap_or(DEFAULT_TREE_DEPTH);
+            let timeout = call.opt_i64("timeout")?.unwrap_or(util::MEDIUM_TIMEOUT.as_millis() as i64);
+            let dir = call.resolve_readable(&directory).await?;
+            if !dir.exists() {
+                return Err(IdeError::not_found(format!("No such directory: {}", dir.display())));
+            }
+            if !dir.is_dir() {
+                return Err(IdeError::invalid(format!("Not a directory: {}", dir.display())));
+            }
+            let deadline = Instant::now() + Duration::from_millis(timeout.max(0) as u64);
+            let cancel = call.cancel.clone();
+            let mut tree =
+                TreeRender { out: String::new(), errors: Vec::new(), timed_out: false, deadline, cancel: cancel.clone() };
+            let tree = call
+                .host()
+                .blocking(move || {
+                    tree.render(&dir, "", true, max_depth, true);
+                    Ok(tree)
+                })
+                .await?;
+            if cancel.is_cancelled() {
+                return Err(IdeError::cancelled());
+            }
+            Output::json(DirectoryTreeInfo {
+                traversed_directory: directory,
+                tree: tree.out,
+                errors: tree.errors,
+                listing_timed_out: tree.timed_out,
+            })
+        },
+    )
+    .param(Param::required("directoryPath", ParamType::String, RELATIVE_PATH_IN_PROJECT_DESCRIPTION))
+    .param(Param::optional("maxDepth", ParamType::Integer, "Maximum recursion depth"))
+    .param(Param::optional("timeout", ParamType::Integer, TIMEOUT_MILLISECONDS_DESCRIPTION))
+    .output(json!({
+        "type": "object",
+        "properties": {
+            "traversedDirectory": { "type": "string" },
+            "tree": { "type": "string" },
+            "errors": { "type": "array", "items": { "type": "string" } },
+            "listingTimedOut": { "type": "boolean", "description": TIMED_OUT_DESCRIPTION },
+        },
+        "required": ["traversedDirectory", "tree", "errors"],
+    }))
+}
+
+/// The `tree`-like listing: the directory's absolute path, then every entry (hidden and
+/// ignored ones too) by lower-cased name, directories marked with `/`.
+struct TreeRender {
+    out: String,
+    errors: Vec<String>,
+    timed_out: bool,
+    deadline: Instant,
+    cancel: CancellationToken,
+}
+
+impl TreeRender {
+    fn render(&mut self, path: &Path, indent: &str, is_last: bool, max_depth: i64, is_root: bool) {
+        if max_depth <= 0 || self.timed_out || self.cancel.is_cancelled() {
+            return;
+        }
+        if Instant::now() >= self.deadline {
+            self.timed_out = true;
+            return;
+        }
+        let prefix = match (is_root, is_last) {
+            (true, _) => "",
+            (false, true) => "└── ",
+            (false, false) => "├── ",
+        };
+        let name = if is_root {
+            path.display().to_string()
+        } else {
+            path.file_name().unwrap_or_default().to_string_lossy().into_owned()
+        };
+        let is_dir = path.is_dir() && !path.is_symlink();
+        self.out.push_str(&format!("{indent}{prefix}{name}{}\n", if is_dir { "/" } else { "" }));
+        if !is_dir {
+            return;
+        }
+        let mut children: Vec<_> = match std::fs::read_dir(path) {
+            Ok(entries) => entries.filter_map(|e| e.ok().map(|e| e.path())).collect(),
+            Err(e) => {
+                self.errors.push(format!("Failed to read {}: {e}", path.display()));
+                return;
+            }
+        };
+        let key = |p: &std::path::PathBuf| p.file_name().unwrap_or_default().to_string_lossy().into_owned();
+        children.sort_by_cached_key(|p| (key(p).to_lowercase(), key(p)));
+        let child_indent = format!("{indent}{}", if is_last { "    " } else { "│   " });
+        let n = children.len();
+        for (i, child) in children.iter().enumerate() {
+            self.render(child, &child_indent, i + 1 == n, max_depth - 1, false);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn slice(text: &str, start: usize, max: usize) -> String {
+        render_slice(text, start, max).unwrap()
+    }
+
+    #[test]
+    fn numbers_lines_like_the_editor() {
+        assert_eq!(slice("a\nb", 1, 10), "L1: a\nL2: b");
+        assert_eq!(slice("a\r\nb\n", 1, 10), "L1: a\nL2: b\nL3: ");
+        assert_eq!(slice("", 1, 10), "L1: ");
+        assert_eq!(slice("a\nb\nc", 2, 10), "L2: b\nL3: c");
+        assert!(render_slice("", 2, 10).unwrap_err().message.contains("offset exceeds file length"));
+        assert!(render_slice("a\nb", 3, 10).unwrap_err().message.contains("offset exceeds file length"));
+    }
+
+    #[test]
+    fn keeps_head_and_tail_of_long_slices() {
+        let text = (1..=11).map(|n| format!("line {n}")).collect::<Vec<_>>().join("\n");
+        assert_eq!(slice(&text, 1, 4), "L1: line 1\nL2: line 2\n…7 lines truncated…\nL10: line 10\nL11: line 11");
+        assert_eq!(slice(&text, 3, 4), "L3: line 3\nL4: line 4\n…5 lines truncated…\nL10: line 10\nL11: line 11");
+        assert_eq!(slice(&text, 1, 1), "…10 lines truncated…\nL11: line 11");
+    }
+
+    #[test]
+    fn cuts_long_lines_at_utf16_units() {
+        let long = "x".repeat(2100);
+        assert_eq!(format_line(&long).len(), MAX_LINE_LENGTH);
+        // A pair across the boundary keeps 2000 characters.
+        let pair = format!("{}😀{}", "x".repeat(1999), "y".repeat(10));
+        assert_eq!(format_line(&pair).chars().count(), MAX_LINE_LENGTH);
+        assert!(format_line(&pair).ends_with('😀'));
+        let short = format!("{}😀", "x".repeat(1998));
+        assert_eq!(format_line(&short), short);
+    }
+}
@@ -0,0 +1,142 @@
+//! Built-in IDE tools. Transport and discovery live in `ide-mcp`.
+mod edit;
+mod editors;
+mod requests;
+mod run;
+mod vcs;
+pub use requests::Requests;
+mod files;
+mod reports;
+mod search;
+mod symbols;
+mod tool;
+mod util;
+
+use crate::Host;
+use ide_core::{CancellationToken, IdeError};
+use ide_mcp::{ToolCallError, ToolRegistry};
+pub use reports::{FileProblems, FocusedEditor, Reports};
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+pub struct Registry(Arc<Host>);
+impl Registry {
+    pub fn new(host: Arc<Host>) -> Self {
+        Self(host)
+    }
+}
+
+fn tools() -> Vec<tool::Tool> {
+    let mut tools = files::tools();
+    tools.extend(search::tools());
+    tools.extend(editors::tools());
+    tools.push(symbols::get_symbol_info());
+    tools.push(symbols::find_references());
+    tools.extend(edit::tools());
+    tools.extend(run::tools());
+    tools.extend(vcs::tools());
+    tools
+}
+
+// Checked both when listing and calling, so a later trust change takes effect immediately.
+fn allowed(tool: &ide_mcp::Tool, trusted: bool) -> bool {
+    trusted || tool.read_only
+}
+
+impl Registry {
+    fn target(&self, root: &Path) -> Result<(String, Arc<crate::Project>), String> {
+        if self.0.mcp_reports.remote_roots().iter().any(|p| p == root) {
+            return Err("not supported for remote projects yet".into());
+        }
+        let mut windows: Vec<_> = self
+            .0
+            .projects
+            .read()
+            .iter()
+            .filter(|(_, p)| p.root == root && !p.light)
+            .map(|(w, p)| (w.clone(), p.clone()))
+            .collect();
+        let focused = self.0.mcp_reports.focused_window();
+        windows.sort_by(|a, b| {
+            (Some(&b.0) == focused.as_ref()).cmp(&(Some(&a.0) == focused.as_ref())).then(a.0.cmp(&b.0))
+        });
+        windows.into_iter().next().ok_or_else(|| "project is no longer open".into())
+    }
+}
+impl ToolRegistry for Registry {
+    fn projects(&self) -> Vec<PathBuf> {
+        self.0
+            .projects()
+            .into_iter()
+            .filter(|p| !p.light)
+            .map(|p| p.root.clone())
+            .chain(self.0.mcp_reports.remote_roots())
+            .collect()
+    }
+    fn tools(&self, root: &Path) -> Result<Vec<ide_mcp::Tool>, String> {
+        let (_, project) = self.target(root)?;
+        Ok(tools().into_iter().map(|t| t.metadata).filter(|t| allowed(t, project.is_trusted())).collect())
+    }
+    fn call(
+        &self,
+        root: &Path,
+        name: &str,
+        arguments: &str,
+        cancel: CancellationToken,
+    ) -> Result<String, ToolCallError> {
+        self.call_with_client(root, name, arguments, cancel, "MCP client")
+    }
+    fn call_with_client(
+        &self,
+        root: &Path,
+        name: &str,
+        arguments: &str,
+        cancel: CancellationToken,
+        client: &str,
+    ) -> Result<String, ToolCallError> {
+        let (window, project) = self.target(root).map_err(ToolCallError::Failed)?;
+        let tool = tools()
+            .into_iter()
+            .find(|t| t.metadata.name == name && allowed(&t.metadata, project.is_trusted()))
+            .ok_or_else(|| ToolCallError::UnknownTool(format!("unknown tool: {name}")))?;
+        let args = serde_json::from_str(arguments).map_err(|e| ToolCallError::Failed(e.to_string()))?;
+        let call = tool::Call {
+            host: self.0.clone(),
+            project,
+            window,
+            args,
+            cancel: cancel.clone(),
+            client: client.to_owned(),
+            tool: name.to_owned(),
+        };
+        if cancel.is_cancelled() {
+            return Err(ToolCallError::Failed(IdeError::cancelled().message));
+        }
+        let result = self.0.runtime.block_on((tool.handler)(call));
+        if cancel.is_cancelled() {
+            return Err(ToolCallError::Failed(IdeError::cancelled().message));
+        }
+        result.map(|out| out.0).map_err(|e| ToolCallError::Failed(e.message))
+    }
+}
+
+impl Host {
+    fn mcp_windows(&self, root: &Path) -> Vec<String> {
+        let mut windows: Vec<_> =
+            self.projects.read().iter().filter(|(_, p)| p.root == root).map(|(w, _)| w.clone()).collect();
+        windows.sort();
+        windows
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn restricted_mode_excludes_execution_tools() {
+        let mut tool = super::tools().remove(0).metadata;
+        assert!(super::allowed(&tool, false));
+        tool.read_only = false;
+        assert!(!super::allowed(&tool, false));
+        assert!(super::allowed(&tool, true));
+    }
+}
@@ -0,0 +1,124 @@
+//! Window-owned snapshots. A project close drops every report from that window.
+use ide_core::{Diagnostic, IpcPath, Range};
+use parking_lot::RwLock;
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::collections::{BTreeMap, HashMap};
+use std::path::PathBuf;
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct FileProblems {
+    pub path: IpcPath,
+    pub items: Vec<Diagnostic>,
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct FocusedEditor {
+    pub path: IpcPath,
+    /// Zero-based lines and UTF-16 columns, end exclusive.
+    pub selection: Range,
+    pub selected_text: String,
+}
+
+#[derive(Default)]
+pub struct Reports(RwLock<State>);
+#[derive(Default)]
+struct State {
+    windows: HashMap<String, Window>,
+    focused: Option<String>,
+    remote: HashMap<String, PathBuf>,
+    libraries: HashMap<String, Vec<PathBuf>>,
+}
+#[derive(Default)]
+struct Window {
+    editors: Vec<PathBuf>,
+    focused: Option<FocusedEditor>,
+    problems: BTreeMap<PathBuf, Vec<Diagnostic>>,
+}
+impl Reports {
+    pub fn set_open_editors(&self, window: &str, paths: Vec<PathBuf>) {
+        self.0.write().windows.entry(window.into()).or_default().editors = paths;
+    }
+    pub fn set_focused_editor(&self, window: &str, editor: Option<FocusedEditor>, focused: bool) {
+        let mut state = self.0.write();
+        state.windows.entry(window.into()).or_default().focused = editor;
+        if focused {
+            state.focused = Some(window.into());
+        }
+    }
+    pub fn report_problems(&self, window: &str, reset: bool, files: Vec<FileProblems>) {
+        let mut state = self.0.write();
+        let problems = &mut state.windows.entry(window.into()).or_default().problems;
+        if reset {
+            problems.clear();
+        }
+        for file in files {
+            let path = file.path.into();
+            if file.items.is_empty() {
+                problems.remove(&path);
+            } else {
+                problems.insert(path, file.items);
+            }
+        }
+    }
+    pub fn forget_window(&self, window: &str) {
+        let mut state = self.0.write();
+        state.windows.remove(window);
+        state.remote.remove(window);
+        state.libraries.remove(window);
+        if state.focused.as_deref() == Some(window) {
+            state.focused = None;
+        }
+    }
+    pub fn set_remote(&self, window: &str, root: PathBuf) {
+        self.0.write().remote.insert(window.into(), root);
+    }
+    pub fn remove_remote(&self, window: &str) {
+        self.0.write().remote.remove(window);
+    }
+    pub(crate) fn set_libraries(&self, window: &str, roots: Vec<PathBuf>) {
+        self.0.write().libraries.insert(window.into(), roots);
+    }
+    pub(super) fn libraries(&self, windows: &[String]) -> Vec<PathBuf> {
+        let state = self.0.read();
+        windows.iter().filter_map(|w| state.libraries.get(w)).flatten().cloned().collect()
+    }
+    pub(super) fn remote_roots(&self) -> Vec<PathBuf> {
+        self.0.read().remote.values().cloned().collect()
+    }
+    pub(super) fn focused_window(&self) -> Option<String> {
+        self.0.read().focused.clone()
+    }
+    pub(super) fn editors(&self, windows: &[String]) -> Vec<PathBuf> {
+        let state = self.0.read();
+        let mut paths = Vec::new();
+        for window in windows.iter().filter_map(|w| state.windows.get(w)) {
+            for path in &window.editors {
+                if !paths.contains(path) {
+                    paths.push(path.clone());
+                }
+            }
+        }
+        paths
+    }
+    pub(super) fn focused(&self, window: &str) -> Option<FocusedEditor> {
+        self.0.read().windows.get(window).and_then(|w| w.focused.clone())
+    }
+    pub(super) fn problems(&self, windows: &[String]) -> Vec<FileProblems> {
+        let state = self.0.read();
+        let mut files: BTreeMap<PathBuf, Vec<Diagnostic>> = BTreeMap::new();
+        for window in windows.iter().filter_map(|w| state.windows.get(w)) {
+            for (path, items) in &window.problems {
+                let found = files.entry(path.clone()).or_default();
+                for item in items {
+                    if !found.contains(item) {
+                        found.push(item.clone());
+                    }
+                }
+            }
+        }
+        files.into_iter().map(|(path, items)| FileProblems { path: path.into(), items }).collect()
+    }
+}
@@ -0,0 +1,71 @@
+//! Window-bound requests; missing windows, cancellation and timeout all fail closed.
+use super::tool::Call;
+use ide_core::{IdeError, IdeEvent, IdeResult, event::McpUiRequest};
+use parking_lot::Mutex;
+use std::collections::{HashMap, HashSet};
+use tokio::sync::oneshot;
+
+#[derive(Default)]
+pub struct Requests(Mutex<State>);
+#[derive(Default)]
+struct State {
+    ready: HashSet<String>,
+    pending: HashMap<u32, Pending>,
+}
+struct Pending {
+    window: String,
+    answer: oneshot::Sender<Result<bool, String>>,
+}
+impl Requests {
+    pub fn set_ready(&self, window: &str, ready: bool) {
+        if ready {
+            self.0.lock().ready.insert(window.into());
+        } else {
+            self.forget_window(window);
+        }
+    }
+    pub fn forget_window(&self, window: &str) {
+        let mut state = self.0.lock();
+        state.ready.remove(window);
+        state.pending.retain(|_, p| p.window != window);
+    }
+    pub fn answer(&self, window: &str, id: u32, allow: bool, error: Option<String>) -> IdeResult<()> {
+        let mut state = self.0.lock();
+        if !state.pending.get(&id).is_some_and(|p| p.window == window) {
+            return Err(IdeError::invalid("MCP request expired or belongs to another window"));
+        }
+        let pending = state.pending.remove(&id).unwrap();
+        let _ = pending.answer.send(error.map_or(Ok(allow), Err));
+        Ok(())
+    }
+    pub(super) async fn ask(&self, call: &Call, request: McpUiRequest) -> IdeResult<()> {
+        let id = super::tool::request_id().0;
+        let (tx, rx) = oneshot::channel();
+        {
+            let mut state = self.0.lock();
+            if !state.ready.contains(call.window()) {
+                return Err(IdeError::unavailable("MCP request denied: no project window is available"));
+            }
+            state.pending.insert(id, Pending { window: call.window.clone(), answer: tx });
+        }
+        struct Close<'a>(&'a Requests, &'a Call, u32);
+        impl Drop for Close<'_> {
+            fn drop(&mut self) {
+                self.0.0.lock().pending.remove(&self.2);
+                self.1.project.sink.emit(IdeEvent::McpRequestClosed { id: self.2 });
+            }
+        }
+        let _close = Close(self, call, id);
+        call.project.sink.emit(IdeEvent::McpRequest { id, request });
+        let result = tokio::select! {
+            result = rx => result.map_err(|_| IdeError::unavailable("MCP request denied: project window closed"))?,
+            _ = tokio::time::sleep(std::time::Duration::from_secs(180)) => return Err(IdeError::unavailable("MCP request denied: confirmation timed out")),
+            _ = call.cancel.cancelled() => return Err(IdeError::cancelled()),
+        };
+        match result {
+            Ok(true) => Ok(()),
+            Ok(false) => Err(IdeError::invalid("MCP request denied by the user")),
+            Err(message) => Err(IdeError::unavailable(message)),
+        }
+    }
+}
@@ -0,0 +1,214 @@
+// Ported from JetBrains intellij-community plugins/mcp-server
+// (mcpserver.toolsets/src/general/AnalysisToolset.kt, build_project), Apache-2.0.
+//! `build_project`.
+
+use super::output::{MAX_TEXT_LENGTH, TRUNCATED_MARKER, truncate_tail};
+use crate::mcp::run::timeout;
+use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
+use ide_build::compile::{BuildEvent, BuildKind, BuildMessage, BuildResult};
+use ide_core::Severity;
+use ide_core::{IdeError, IdeResult};
+use parking_lot::Mutex;
+use serde_json::{Map, Value, json};
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::time::Instant;
+
+const DEFAULT_TIMEOUT_MS: usize = 60_000;
+const MAX_TIMEOUT_MS: usize = 3_600_000;
+const MAX_PROBLEMS: usize = 300;
+/// Console lines attached to a failure whose messages were not parsed.
+const CONSOLE_LINES: usize = 200;
+
+/// A JetBrains `ProjectProblem`: `kind` ERROR or WARNING, the compiler's code as `group`,
+/// 1-based `line` / `column` (JetBrains reports them 0-based).
+fn problem(call: &Call, m: &BuildMessage) -> Value {
+    let mut v = json!({
+        "message": m.text,
+        "kind": if m.severity == Severity::Error { "ERROR" } else { "WARNING" },
+    });
+    if let Some(code) = &m.code {
+        v["group"] = code.clone().into();
+    }
+    if let Some(path) = &m.path {
+        v["file"] = call.display(path).into();
+    }
+    if let Some(range) = m.range {
+        v["line"] = (range.start.line + 1).into();
+        v["column"] = (range.start.col + 1).into();
+    }
+    v
+}
+
+/// Runs the build of `target` (the whole project when `None`), its console into `console`.
+/// Returns `None` when `deadline` passed first (the build is then stopped).
+pub async fn build_once(
+    call: &Call,
+    kind: BuildKind,
+    target: Option<PathBuf>,
+    deadline: Instant,
+    console: &Arc<Mutex<String>>,
+) -> IdeResult<Option<BuildResult>> {
+    let host = call.host();
+    let request = crate::mcp::tool::request_id();
+    let sink = console.clone();
+    let channel = crate::ops::Channel::new(move |e: BuildEvent| match e {
+        BuildEvent::Output { text, .. } => sink.lock().push_str(&text),
+        BuildEvent::Step { command, .. } => sink.lock().push_str(&format!("$ {command}\n")),
+        _ => {}
+    });
+    let build = crate::ops::build::build_run(&host, call.window(), kind, target, None, request, Vec::new(), channel);
+    tokio::pin!(build);
+    let remaining = deadline.saturating_duration_since(Instant::now());
+    tokio::select! {
+        r = &mut build => r.map(Some),
+        _ = tokio::time::sleep(remaining) => {
+            host.cancel_request(request);
+            let _ = build.await;
+            Ok(None)
+        }
+        _ = call.cancel.cancelled() => {
+            host.cancel_request(request);
+            let _ = build.await;
+            Err(IdeError::cancelled())
+        }
+    }
+}
+
+pub fn build_project() -> Tool {
+    Tool::new(
+        "build_project",
+        "Triggers building of the project or specified files, waits for completion, and returns build errors.
+Use this tool to build the project or compile files and get detailed information about compilation errors and warnings.
+You have to use this tool after performing edits to validate if the edits are valid.
+In OpenIDEA the project's build system builds it (Maven, Gradle, Cargo, Go or TypeScript); with `filesToRebuild`, the \
+modules containing those files. Asks the user first for every call. Problems have the project-relative \
+`file` and 1-based `line` / `column`; at most 300 problems are listed, and `isSuccess` is false whenever one of them \
+is an ERROR. On timeout (at most 1 hour; 0 times out at once) the build is stopped.",
+        |call| async move {
+            let files: Vec<String> =
+                call.str_list("filesToRebuild")?.into_iter().filter(|f| !f.trim().is_empty()).collect();
+            let rebuild = call.flag("rebuild", false)? && files.is_empty();
+            let kind = if rebuild { BuildKind::Rebuild } else { BuildKind::Build };
+            let limit = timeout(&call, DEFAULT_TIMEOUT_MS, MAX_TIMEOUT_MS)?;
+            let mut targets: Vec<Option<PathBuf>> = Vec::new();
+            let mut dirs: Vec<PathBuf> = Vec::new();
+            for f in &files {
+                let path = call.resolve_inside(f)?;
+                if !path.exists() {
+                    return Err(IdeError::not_found(format!("File not found: {f}")));
+                }
+                let dir = if path.is_dir() { path.clone() } else { path.parent().unwrap_or(&path).to_path_buf() };
+                if !dirs.contains(&dir) {
+                    dirs.push(dir);
+                    targets.push(Some(path));
+                }
+            }
+            if targets.is_empty() {
+                targets.push(None);
+            }
+            let subject = if rebuild { "Rebuild project" } else { "Build project" };
+            let detail = targets.iter().flatten().map(|p| call.display(p)).collect::<Vec<_>>().join(", ");
+            call.confirm(subject, (!detail.is_empty()).then(|| format!("modules of {detail}"))).await?;
+
+            if limit.is_zero() {
+                // JetBrains' `withTimeoutOrNull(0)`: nothing is built.
+                return Output::json(json!({ "isSuccess": false, "problems": [], "timedOut": true }));
+            }
+            let console = Arc::new(Mutex::new(String::new()));
+            let deadline = Instant::now() + limit;
+            let mut results: Vec<BuildResult> = Vec::new();
+            let mut timed_out = false;
+            for target in targets {
+                match build_once(&call, kind, target, deadline, &console).await? {
+                    Some(r) => {
+                        let failed = !r.success;
+                        results.push(r);
+                        if failed {
+                            break;
+                        }
+                    }
+                    None => {
+                        timed_out = true;
+                        break;
+                    }
+                }
+            }
+            let messages: Vec<&BuildMessage> = results
+                .iter()
+                .flat_map(|r| r.messages.iter())
+                .filter(|m| matches!(m.severity, Severity::Error | Severity::Warning))
+                .collect();
+            let mut problems: Vec<Value> = messages.iter().take(MAX_PROBLEMS).map(|m| problem(&call, m)).collect();
+            let has_errors = messages.iter().any(|m| m.severity == Severity::Error);
+            let failed = results.iter().any(|r| !r.success);
+            if failed && !has_errors {
+                let tail = truncate_tail(
+                    console.lock().trim_end(),
+                    CONSOLE_LINES,
+                    MAX_TEXT_LENGTH,
+                    TRUNCATED_MARKER,
+                );
+                problems.push(json!({
+                    "message": "Build reported errors, but detailed error messages were not captured through build events.",
+                    "kind": "ERROR",
+                    "description": tail,
+                }));
+            }
+            let mut result = Map::new();
+            result.insert("isSuccess".into(), is_success(timed_out, &results).into());
+            result.insert("problems".into(), problems.into());
+            if timed_out {
+                result.insert("timedOut".into(), true.into());
+            }
+            Output::json(Value::Object(result))
+        },
+    )
+    .write()
+    .param(Param::optional(
+        "rebuild",
+        ParamType::Boolean,
+        "Whether to perform full rebuild the project. Defaults to false. Effective only when `filesToRebuild` is not \
+specified.",
+    ))
+    .param(Param::optional(
+        "filesToRebuild",
+        ParamType::StringList,
+        "If specified, only compile files with the specified paths. Paths are relative to the project root.",
+    ))
+    .param(Param::optional("timeout", ParamType::Integer, "Timeout in milliseconds"))
+}
+
+/// JetBrains' `isSuccess`: finished in time, every build succeeded and no ERROR was reported
+/// (a build tool may exit 0 after printing errors).
+fn is_success(timed_out: bool, results: &[BuildResult]) -> bool {
+    !timed_out && results.iter().all(|r| r.success && r.messages.iter().all(|m| m.severity != Severity::Error))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn result(success: bool, severities: &[Severity]) -> BuildResult {
+        BuildResult {
+            system: ide_build::compile::BuildSystem::Cargo,
+            title: "build".into(),
+            success,
+            errors: 0,
+            warnings: 0,
+            duration_ms: 0.0,
+            messages: severities
+                .iter()
+                .map(|s| BuildMessage { severity: *s, text: "m".into(), path: None, range: None, code: None })
+                .collect(),
+        }
+    }
+
+    #[test]
+    fn an_error_problem_fails_the_build() {
+        assert!(is_success(false, &[result(true, &[Severity::Warning])]));
+        assert!(!is_success(false, &[result(true, &[Severity::Warning, Severity::Error])]));
+        assert!(!is_success(false, &[result(false, &[])]));
+        assert!(!is_success(true, &[result(true, &[])]));
+    }
+}
@@ -0,0 +1,709 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (mcpserver.toolsets/src/general/ExecutionToolset.kt,
+// mcpserver.toolsets/src/util/execution.util.kt, mcpserver.toolsets/src/util/RunConfigurationBuildErrors.kt), Apache-2.0.
+//! `get_run_configurations` and `execute_run_configuration`.
+
+use super::build::build_once;
+use super::output::OutputCollector;
+use super::process::{quote, split_words};
+use super::targets;
+use crate::Project;
+use crate::mcp::run::timeout;
+use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
+use ide_build::compile::BuildKind;
+use ide_core::{IdeError, IdeResult, RunId, Severity};
+use ide_run::{OutputChunk, RunConfig};
+use parking_lot::Mutex;
+use serde_json::{Map, Value, json};
+use std::path::Path;
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+const DEFAULT_TIMEOUT_MS: usize = 10_000;
+/// No limit in JetBrains; the process keeps running after the timeout anyway.
+const MAX_TIMEOUT_MS: usize = 1_800_000;
+/// Output of a failed before-launch process kept for the error message.
+const MAX_PROCESS_OUTPUT_LENGTH: usize = 20_000;
+/// A before-launch build gets this long.
+const BEFORE_LAUNCH_BUILD_TIMEOUT: Duration = Duration::from_secs(3600);
+
+async fn load_configs(call: &Call) -> IdeResult<Vec<RunConfig>> {
+    let host = call.host();
+    let window = call.window().to_owned();
+    let h = host.clone();
+    host.blocking(move || crate::ops::run::configs(&h, &window)).await
+}
+
+fn supports_overrides(config: &RunConfig) -> bool {
+    config.extras.compound.is_empty() && !config.command.trim().is_empty()
+}
+
+fn command_line(config: &RunConfig) -> String {
+    std::iter::once(config.command.clone()).chain(config.args.iter().map(|a| quote(a))).collect::<Vec<_>>().join(" ")
+}
+
+fn describe_config(call: &Call, c: &RunConfig) -> Value {
+    let mut v = json!({
+        "name": c.name,
+        "description": c.kind,
+        "supportsDynamicLaunchOverrides": supports_overrides(c),
+    });
+    if supports_overrides(c) {
+        v["commandLine"] = command_line(c).into();
+        if let Some(cwd) = c.cwd.as_deref() {
+            v["workingDirectory"] = call.display(&call.root().join(cwd)).into();
+        }
+        if !c.env.is_empty() {
+            v["environment"] = json!(c.env);
+        }
+    }
+    v
+}
+
+/// A file of the project to look for run points in: its `/`-separated project-relative path
+/// and current text (unsaved edits included).
+fn read_file(project: &Project, path: &Path, file: &str) -> IdeResult<(String, String)> {
+    let meta = std::fs::metadata(path).map_err(|_| IdeError::not_found(format!("File not found: {file}")))?;
+    if !meta.is_file() {
+        return Err(IdeError::invalid(format!("Not a file: {file}")));
+    }
+    let rel = path.strip_prefix(&project.root).unwrap_or(path).to_string_lossy().replace('\\', "/");
+    let text = match project.documents.text_of(path) {
+        Some(text) => text,
+        None => std::fs::read_to_string(path).map_err(|e| IdeError::invalid(format!("Cannot read {file}: {e}")))?,
+    };
+    Ok((rel, text))
+}
+
+/// Reads `file` and runs `scan` (root, relative path, text) over it off the async threads:
+/// the run point patterns go over up to 400 KB of text.
+async fn scan_file<T: Send + 'static>(
+    call: &Call,
+    file: &str,
+    scan: impl FnOnce(&Path, &str, &str) -> IdeResult<T> + Send + 'static,
+) -> IdeResult<T> {
+    let path = call.resolve_inside(file)?;
+    let project = call.project().clone();
+    let file = file.to_owned();
+    call.host()
+        .blocking(move || {
+            let (rel, text) = read_file(&project, &path, &file)?;
+            scan(&project.root, &rel, &text)
+        })
+        .await
+}
+
+pub fn get_run_configurations() -> Tool {
+    Tool::new(
+        "get_run_configurations",
+        "Returns either project run configurations or executable code locations, depending on the input.
+
+Without `filePath`, this tool lists the project's existing run configurations. The result includes configuration
+names and, when available, launch details such as program arguments, working directory, environment variables,
+and `supportsDynamicLaunchOverrides`.
+
+`supportsDynamicLaunchOverrides` is the source-of-truth capability flag for one-time launch overrides
+(`programArguments`, `workingDirectory`, `envs`) in `execute_run_configuration` and `xdebug_start_debugger_session`.
+Only pass those override parameters when this flag is `true` for the selected configuration.
+
+With `filePath`, this tool discovers executable entry points (run points) in that file, such as test methods,
+main methods, or other executable entry points where the IDE shows a Run gutter icon. The result contains `filePath` and
+`runPoints`; use the returned line numbers with `execute_run_configuration` to run from code.
+In OpenIDEA the configurations are the saved ones and those detected from the build files (package.json scripts, \
+Cargo targets, Gradle/Maven tasks, Go, Python, Makefile…); `description` is the configuration type and `commandLine` \
+the whole command. Run points are found in Rust, JavaScript/TypeScript, Python and Go files.",
+        |call| async move {
+            let configs = load_configs(&call).await?;
+            if let Some(file) = call.opt_str("filePath")? {
+                let points = scan_file(&call, &file, move |root, rel, text| {
+                    let mut points: Vec<Value> = Vec::new();
+                    let mut lines = std::collections::HashSet::new();
+                    for t in targets::detect(text, rel) {
+                        if lines.contains(&t.line) {
+                            continue;
+                        }
+                        if let Some(config) = targets::target_config(root, &t, rel, &configs, text) {
+                            lines.insert(t.line);
+                            points.push(json!({
+                                "line": t.line + 1,
+                                "description": format!("Run '{}'", config.name),
+                                "elementText": t.name,
+                            }));
+                        }
+                    }
+                    Ok(points)
+                })
+                .await?;
+                return Output::json(json!({ "filePath": file, "runPoints": points }));
+            }
+            let list: Vec<Value> = configs.iter().map(|c| describe_config(&call, c)).collect();
+            Output::json(json!({ "configurations": list }))
+        },
+    )
+    .write()
+    .param(Param::optional(
+        "filePath",
+        ParamType::String,
+        "Optional file path relative to the project root. When provided, returns run points (executable entry points) \
+in the file instead of project-wide run configurations.",
+    ))
+}
+
+/// What `execute_run_configuration` runs.
+enum ExecutionTarget {
+    ByName(String),
+    ByContext(String, i64),
+}
+
+fn execution_target(name: Option<String>, file: Option<String>, line: Option<i64>) -> IdeResult<ExecutionTarget> {
+    let name = name.filter(|n| !n.trim().is_empty());
+    let file = file.filter(|f| !f.trim().is_empty());
+    match (name, file, line) {
+        (Some(_), f, l) if f.is_some() || l.is_some() => {
+            Err(IdeError::invalid("Pass either configurationName or filePath + line, but not both."))
+        }
+        (Some(name), _, _) => Ok(ExecutionTarget::ByName(name)),
+        (None, Some(file), Some(line)) => Ok(ExecutionTarget::ByContext(file, line)),
+        (None, Some(_), None) | (None, None, Some(_)) => {
+            Err(IdeError::invalid("Pass both filePath and line together, or use configurationName."))
+        }
+        (None, None, None) => Err(IdeError::invalid("Pass either configurationName or filePath + line.")),
+    }
+}
+
+/// The temporary configuration of the run point at `file:line` (1-based): the innermost target
+/// enclosing that line (as JetBrains walks up to the enclosing test), else the whole file's
+/// (its tests, its main function).
+async fn config_from_code_location(
+    call: &Call,
+    configs: Vec<RunConfig>,
+    file: &str,
+    line: i64,
+) -> IdeResult<RunConfig> {
+    let file_name = file.to_owned();
+    scan_file(call, file, move |root, rel, text| {
+        if line < 1 {
+            return Err(IdeError::invalid(format!("Line number must be >= 1, got: {line}")));
+        }
+        let count = text.split('\n').count();
+        if line as usize > count {
+            return Err(IdeError::invalid(format!("Line {line} is out of range (file has {count} lines)")));
+        }
+        targets::enclosing(text, rel, line as usize - 1)
+            .iter()
+            .find_map(|t| targets::target_config(root, t, rel, &configs, text))
+            .or_else(|| targets::context_config(root, rel, &configs, text))
+            .ok_or_else(|| {
+                IdeError::not_found(format!(
+                    "No run configuration could be created from {file_name}:{line}. Use get_run_configurations with \
+filePath to find valid run locations."
+                ))
+            })
+    })
+    .await
+}
+
+/// Applies the one-off overrides (JetBrains' `prepareRunConfigurationForExecution`): a missing or
+/// empty string keeps the value, a whitespace-only one clears it; `envs` merge over the configuration's.
+fn apply_overrides(
+    config: &mut RunConfig,
+    root: &Path,
+    args: Option<String>,
+    cwd: Option<String>,
+    envs: Option<Vec<(String, String)>>,
+) -> IdeResult<()> {
+    let args = args.filter(|a| !a.is_empty());
+    let cwd = cwd.filter(|d| !d.is_empty());
+    if args.is_none() && cwd.is_none() && envs.is_none() {
+        return Ok(());
+    }
+    if !supports_overrides(config) {
+        return Err(IdeError::invalid(format!(
+            "Run configuration '{}' of type '{}' doesn't support dynamic launch overrides (programArguments, \
+workingDirectory, envs).",
+            config.name,
+            if config.extras.compound.is_empty() { config.kind.as_str() } else { "Compound" }
+        )));
+    }
+    if let Some(args) = args {
+        let words = split_words(&args)?;
+        // A configuration that is one shell line (`npm run dev`, no separate arguments)
+        // keeps its command and gets the new line's arguments appended.
+        let shell_line = config.args.is_empty() && config.command.trim().contains(char::is_whitespace);
+        if shell_line {
+            if !words.is_empty() {
+                config.command = format!("{} {}", config.command.trim(), args.trim());
+            }
+        } else {
+            config.args = words;
+        }
+    }
+    if let Some(dir) = cwd {
+        if dir.trim().is_empty() {
+            config.cwd = None;
+        } else {
+            let path = crate::mcp::tool::resolve_inside(root, &dir)?;
+            if !path.is_dir() {
+                return Err(IdeError::not_found(format!("workingDirectory {} is not a directory", path.display())));
+            }
+            config.cwd = Some(path.into());
+        }
+    }
+    config.env.extend(envs.into_iter().flatten());
+    Ok(())
+}
+
+/// Polls how run `id` ended: `None` while running, else its exit code (if known).
+fn run_exit(host: &crate::Host, id: RunId) -> Option<Option<i32>> {
+    match host.processes.exit_code(id) {
+        Ok(exit) => exit,
+        // Remote (SSH) runs, or a finished run already forgotten: the run list knows whether it runs.
+        Err(_) => match crate::ops::run::list(host).into_iter().find(|r| r.id == id) {
+            Some(r) if r.running => None,
+            _ => Some(None),
+        },
+    }
+}
+
+/// Waits for run `id` to exit, until `deadline`: `None` when it is still running. Cancelling
+/// the call stops the run.
+async fn wait_exit(call: &Call, id: RunId, deadline: Option<Instant>) -> IdeResult<Option<Option<i32>>> {
+    let host = call.host();
+    loop {
+        if let Some(exit) = run_exit(&host, id) {
+            return Ok(Some(exit));
+        }
+        if deadline.is_some_and(|d| Instant::now() >= d) {
+            return Ok(None);
+        }
+        tokio::select! {
+            _ = tokio::time::sleep(Duration::from_millis(50)) => {}
+            _ = call.cancel.cancelled() => {
+                let _ = crate::ops::run::stop(&host, call.window(), id);
+                return Err(IdeError::cancelled());
+            }
+        }
+    }
+}
+
+/// An output callback that skips the IDE's own lines (`Process finished…`), as JetBrains
+/// skips `ProcessOutputType.SYSTEM`.
+fn process_output(mut f: impl FnMut(&str) + Send + 'static) -> crate::ops::Emit<OutputChunk> {
+    let f = Mutex::new(move |t: &str| f(t));
+    Arc::new(move |chunk: OutputChunk| match &chunk {
+        OutputChunk::Stdout { text } | OutputChunk::Stderr { text } => (f.lock())(text),
+        OutputChunk::System { .. } => {}
+    })
+}
+
+/// What failed before launch (JetBrains' `RunConfigurationBuildErrors`): build errors as
+/// `path:line: message`, else the output of before-launch processes that failed.
+#[derive(Default)]
+struct BuildErrors {
+    errors: Vec<String>,
+    process_outputs: Vec<String>,
+}
+
+impl BuildErrors {
+    fn text(&self) -> Option<String> {
+        let mut seen = std::collections::HashSet::new();
+        let errors: Vec<&String> = self.errors.iter().filter(|e| seen.insert(*e)).collect();
+        if !errors.is_empty() {
+            return Some(errors.iter().map(|e| e.as_str()).collect::<Vec<_>>().join("\n"));
+        }
+        let outputs: Vec<&str> = self.process_outputs.iter().map(|o| o.trim()).filter(|o| !o.is_empty()).collect();
+        (!outputs.is_empty()).then(|| outputs.join("\n"))
+    }
+}
+
+/// Runs `config` to its end; `Ok(false)` (with its output recorded) when it failed.
+async fn run_to_end(call: &Call, config: RunConfig, errors: &mut BuildErrors) -> IdeResult<bool> {
+    let tail = Arc::new(Mutex::new(String::new()));
+    let sink = tail.clone();
+    let emit = process_output(move |text| {
+        let mut t = sink.lock();
+        t.push_str(text);
+        if t.len() > 2 * MAX_PROCESS_OUTPUT_LENGTH {
+            let mut cut = t.len() - MAX_PROCESS_OUTPUT_LENGTH;
+            while !t.is_char_boundary(cut) {
+                cut += 1;
+            }
+            t.drain(..cut);
+        }
+    });
+    let info = crate::ops::run::start(&call.host(), call.window(), config, emit).await?;
+    let exit = wait_exit(call, info.id, None).await?.flatten();
+    if exit == Some(0) {
+        return Ok(true);
+    }
+    let t = tail.lock();
+    let start = t.char_indices().rev().nth(MAX_PROCESS_OUTPUT_LENGTH - 1).map_or(0, |(i, _)| i);
+    errors.process_outputs.push(t[start..].to_owned());
+    Ok(false)
+}
+
+/// The configuration's before-launch tasks, as the Run tool window runs them; returns why
+/// the launch is aborted, if it is. Tool windows are not activated.
+async fn before_launch(
+    call: &Call,
+    config: &RunConfig,
+    configs: &[RunConfig],
+    chain: &mut Vec<String>,
+    errors: &mut BuildErrors,
+) -> IdeResult<Option<String>> {
+    chain.push(config.id.clone());
+    for task in &config.extras.before_launch {
+        let target = task.target.as_str();
+        let (label, failure) = match task.kind.as_str() {
+            "build" => {
+                let console = Arc::new(Mutex::new(String::new()));
+                let deadline = Instant::now() + BEFORE_LAUNCH_BUILD_TIMEOUT;
+                let failure = match build_once(call, BuildKind::Build, None, deadline, &console).await {
+                    Ok(Some(r)) => {
+                        for m in r.messages.iter().filter(|m| m.severity == Severity::Error) {
+                            errors.errors.push(match (&m.path, m.range) {
+                                (Some(p), Some(r)) => format!("{}:{}: {}", p.display(), r.start.line + 1, m.text),
+                                _ => m.text.clone(),
+                            });
+                        }
+                        (!r.success).then(|| "Build failed".to_owned())
+                    }
+                    Ok(None) => Some("The build timed out".to_owned()),
+                    Err(e) => Some(e.message),
+                };
+                ("Build Project".to_owned(), failure)
+            }
+            "run" => {
+                let other = configs.iter().find(|c| c.id == target);
+                let label = format!("Run '{}'", other.map_or(target, |c| c.name.as_str()));
+                let failure = if chain.iter().any(|c| c == target) {
+                    Some("The before launch tasks run in a cycle".to_owned())
+                } else if let Some(other) = other {
+                    let ok = Box::pin(before_launch(call, other, configs, chain, errors)).await?.is_none()
+                        && run_to_end(call, other.clone(), errors).await?;
+                    (!ok).then(|| format!("'{}' failed", other.name))
+                } else {
+                    Some(format!("Configuration '{target}' no longer exists"))
+                };
+                (label, failure)
+            }
+            "command" => {
+                let failure = if target.trim().is_empty() {
+                    Some("No command".to_owned())
+                } else {
+                    let run = RunConfig {
+                        id: format!("before-launch:{}:{target}", config.id),
+                        name: target.to_owned(),
+                        kind: "shell".into(),
+                        command: target.to_owned(),
+                        args: Vec::new(),
+                        cwd: config.cwd.clone(),
+                        env: Default::default(),
+                        detected: true,
+                        is_test: false,
+                        debug_adapter: None,
+                        allow_parallel: false,
+                        extras: Default::default(),
+                    };
+                    (!run_to_end(call, run, errors).await?).then(|| format!("'{target}' failed"))
+                };
+                (format!("Run '{target}'"), failure)
+            }
+            "toolWindow" => continue,
+            "tool" => (format!("External tool '{target}'"), Some("External tools cannot run through MCP".to_owned())),
+            other => (other.to_owned(), Some(format!("Unknown before launch task '{other}'"))),
+        };
+        if let Some(failure) = failure {
+            chain.pop();
+            return Ok(Some(format!("Before launch: {label}: {failure}")));
+        }
+    }
+    chain.pop();
+    Ok(None)
+}
+
+/// The before-launch tasks of `config` as the confirmation lists them, nested ones indented.
+fn describe_before_launch(
+    config: &RunConfig,
+    configs: &[RunConfig],
+    depth: usize,
+    chain: &mut Vec<String>,
+    out: &mut String,
+) {
+    chain.push(config.id.clone());
+    let indent = "  ".repeat(depth + 1);
+    for task in &config.extras.before_launch {
+        let target = task.target.as_str();
+        match task.kind.as_str() {
+            "build" => out.push_str(&format!("\n{indent}Build Project")),
+            "command" => out.push_str(&format!("\n{indent}Run command: {target}")),
+            "run" => match configs.iter().find(|c| c.id == target) {
+                Some(other) => {
+                    let line = if other.extras.compound.is_empty() { command_line(other) } else { "compound".into() };
+                    out.push_str(&format!("\n{indent}Run '{}': {line}", other.name));
+                    if !chain.contains(&other.id) {
+                        describe_before_launch(other, configs, depth + 1, chain, out);
+                    }
+                }
+                None => out.push_str(&format!("\n{indent}Run '{target}' (missing)")),
+            },
+            "toolWindow" => {}
+            "tool" => out.push_str(&format!("\n{indent}External tool '{target}'")),
+            other => out.push_str(&format!("\n{indent}{other} '{target}'")),
+        }
+    }
+    chain.pop();
+}
+
+/// What the user approves for `config` besides its command line: everything else that runs
+/// or applies — before-launch tasks, the stored environment (for a configuration made from
+/// code, the one of the configuration it derives from), `.env` files, the `envs` overrides
+/// (`NODE_OPTIONS`, `PATH`, ...), the stop command and a remote run target.
+fn confirmation_detail(
+    config: &RunConfig,
+    cwd: &str,
+    stored_env: &std::collections::BTreeMap<String, String>,
+    overrides: &[(String, String)],
+    configs: &[RunConfig],
+) -> String {
+    let mut detail = command_line(config);
+    if !cwd.is_empty() {
+        detail.push_str(&format!("\nin {cwd}"));
+    }
+    if let Some(target) = config.extras.target.as_deref().filter(|t| !t.is_empty()) {
+        detail.push_str(&format!("\non run target {target}"));
+    }
+    let mut tasks = String::new();
+    describe_before_launch(config, configs, 0, &mut Vec::new(), &mut tasks);
+    if !tasks.is_empty() {
+        detail.push_str(&format!("\nbefore launch:{tasks}"));
+    }
+    if !config.extras.env_files.is_empty() {
+        detail.push_str(&format!("\nenv files: {}", config.extras.env_files.join(", ")));
+    }
+    if !config.extras.include_system_env {
+        detail.push_str("\nwithout the system environment");
+    }
+    if !stored_env.is_empty() {
+        detail.push_str("\nenvironment:");
+        for (k, v) in stored_env {
+            detail.push_str(&format!("\n  {k}={v}"));
+        }
+    }
+    if !overrides.is_empty() {
+        detail.push_str("\nenvironment overrides:");
+        for (k, v) in overrides {
+            detail.push_str(&format!("\n  {k}={v}"));
+        }
+    }
+    if let Some(stop) = config.extras.stop_command.as_deref().filter(|s| !s.trim().is_empty()) {
+        detail.push_str(&format!("\non stop: {stop}"));
+    }
+    detail
+}
+
+fn execution_failed(details: &[Option<String>]) -> IdeError {
+    let details: Vec<&str> = details.iter().flatten().map(String::as_str).collect();
+    IdeError::invalid(format!("Execution failed: {}", details.join("\n")))
+}
+
+pub fn execute_run_configuration() -> Tool {
+    Tool::new(
+        "execute_run_configuration",
+        "Run either an existing run configuration by name or a temporary run configuration created from a code location \
+(`filePath` + `line`) in the current project, then wait up to specified timeout for it to finish.
+
+Use this tool with either a configuration name returned by `get_run_configurations`, or with a run point
+(`filePath` + `line`) returned by `get_run_configurations(filePath = ...)`.
+
+Optional launch overrides (`programArguments`, `workingDirectory`, `envs`) are applied only for this run and are not persisted.
+Do not pass these override parameters unless you explicitly need to change the configured launch values for this run.
+Missing/null override parameters keep existing run configuration values unchanged.
+For string overrides (`programArguments`, `workingDirectory`), missing/null or empty string (`\"\"`) keeps the existing value unchanged.
+Pass a whitespace-only string such as `\" \"` to clear an existing value for this launch.
+
+Pass either `configurationName`, or `filePath` together with `line`. These modes are mutually exclusive.
+
+Behavior:
+- When `waitForExit=true`, waits up to `timeout` milliseconds for process termination. If the timeout expires,
+  the process keeps running in the background and `exitCode` is omitted from the result.
+- When `waitForExit=false`, waits only for the process to start, then returns immediately without applying `timeout`.
+- `fullOutputPath` points to a temp file with the full raw output and may continue growing while the process is alive.
+
+Returns the execution result including current output snapshot, optional exit code, and optional `fullOutputPath`.
+In OpenIDEA the user is asked first for every call; `programArguments` replace the configuration's \
+arguments (appended to a command that is one shell line, such as `npm run dev`); the run does not appear in the Run \
+tool window; output files are private and deleted after a day.",
+        |call| async move {
+            let target = execution_target(
+                call.opt_str("configurationName")?,
+                call.opt_str("filePath")?,
+                call.opt_i64("line")?,
+            )?;
+            let wait = call.flag("waitForExit", true)?;
+            // As JetBrains: `timeout` is ignored without waiting, and 0 returns without waiting.
+            let limit = if wait { Some(timeout(&call, DEFAULT_TIMEOUT_MS, MAX_TIMEOUT_MS)?) } else { None };
+            let envs = call.args.get("envs").filter(|v| !v.is_null()).map(|_| call.str_map("envs")).transpose()?;
+            let configs = load_configs(&call).await?;
+            let mut config = match &target {
+                ExecutionTarget::ByName(name) => configs
+                    .iter()
+                    .find(|c| c.name == *name)
+                    .cloned()
+                    .ok_or_else(|| IdeError::not_found(format!("Run configuration with name '{name}' not found.")))?,
+                ExecutionTarget::ByContext(file, line) => {
+                    config_from_code_location(&call, configs.clone(), file, *line).await?
+                }
+            };
+            let stored_env = config.env.clone();
+            let overrides: Vec<(String, String)> = envs.clone().unwrap_or_default();
+            apply_overrides(
+                &mut config,
+                call.root(),
+                call.opt_str("programArguments")?,
+                call.opt_str("workingDirectory")?,
+                envs,
+            )?;
+            if !config.extras.compound.is_empty() {
+                return Err(IdeError::invalid(format!(
+                    "`{}` is a compound configuration, which cannot run through MCP; run its configurations ({}) \
+one by one",
+                    config.name,
+                    config.extras.compound.join(", ")
+                )));
+            }
+            let cwd = match config.cwd.as_deref() {
+                Some(p) => call.root().join(p),
+                None => call.root().to_path_buf(),
+            };
+            let detail = confirmation_detail(&config, &call.display(&cwd), &stored_env, &overrides, &configs);
+            call.confirm(&config.name, Some(detail)).await?;
+
+            let mut errors = BuildErrors::default();
+            if let Some(reason) = before_launch(&call, &config, &configs, &mut Vec::new(), &mut errors).await? {
+                return Err(execution_failed(&[errors.text(), Some(reason)]));
+            }
+            let collector = Arc::new(Mutex::new(OutputCollector::create(&config.name)?));
+            let output_path = collector.lock().path.clone();
+            let sink = collector.clone();
+            let emit = process_output(move |text| sink.lock().append(text));
+            let info = match crate::ops::run::start(&call.host(), call.window(), config, emit).await {
+                Ok(info) => info,
+                Err(e) => {
+                    let _ = std::fs::remove_file(&output_path);
+                    return Err(execution_failed(&[errors.text(), Some(e.message)]));
+                }
+            };
+
+            let exit = match limit {
+                Some(limit) if !limit.is_zero() => wait_exit(&call, info.id, Some(Instant::now() + limit)).await?,
+                _ => None,
+            };
+            let c = collector.lock();
+            let mut result = Map::new();
+            if let Some(Some(code)) = exit {
+                result.insert("exitCode".into(), code.into());
+            }
+            result.insert("output".into(), c.preview().into());
+            // An exited run whose whole output is in `output` needs no file.
+            if exit.is_none() || c.truncated {
+                result.insert("fullOutputPath".into(), c.path.to_string_lossy().into_owned().into());
+            } else {
+                let _ = std::fs::remove_file(&c.path);
+            }
+            Output::json(Value::Object(result))
+        },
+    )
+    .write()
+    .param(Param::optional("configurationName", ParamType::String, "Name of the existing run configuration to execute"))
+    .param(Param::optional(
+        "filePath",
+        ParamType::String,
+        "File path relative to the project root. Provide together with `line` to create and execute a temporary run \
+configuration from code context.",
+    ))
+    .param(Param::optional(
+        "line",
+        ParamType::Integer,
+        "1-based line number for `filePath`. Provide together with `filePath` and do not combine with \
+`configurationName`.",
+    ))
+    .param(Param::optional("timeout", ParamType::Integer, "Timeout in milliseconds"))
+    .param(Param::optional(
+        "waitForExit",
+        ParamType::Boolean,
+        "Whether to wait for process termination. If false, the tool returns immediately after the process starts and \
+ignores `timeout`.",
+    ))
+    .param(Param::optional(
+        "programArguments",
+        ParamType::String,
+        "Optional program arguments override for this launch only. Missing/null or empty string keeps the existing \
+value; whitespace-only string clears it.",
+    ))
+    .param(Param::optional(
+        "workingDirectory",
+        ParamType::String,
+        "Optional working directory override for this launch only. Missing/null or empty string keeps the existing \
+value; whitespace-only string clears it.",
+    ))
+    .param(Param::optional(
+        "envs",
+        ParamType::StringMap,
+        "Optional environment variable overrides for this launch only. Missing/null keeps existing env unchanged; when \
+provided, values are merged over existing env.",
+    ))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn config() -> RunConfig {
+        RunConfig {
+            id: "user:x".into(),
+            name: "x".into(),
+            kind: "shell".into(),
+            command: "prog".into(),
+            args: vec!["a".into()],
+            cwd: Some(std::path::PathBuf::from("sub").into()),
+            env: [("A".to_owned(), "1".to_owned())].into(),
+            detected: false,
+            is_test: false,
+            debug_adapter: None,
+            allow_parallel: false,
+            extras: Default::default(),
+        }
+    }
+
+    #[test]
+    fn empty_overrides_keep_and_blank_ones_clear() {
+        let root = Path::new("/");
+        let mut c = config();
+        apply_overrides(&mut c, root, Some(String::new()), Some(String::new()), None).unwrap();
+        assert_eq!(c, config());
+        apply_overrides(&mut c, root, Some(" ".into()), Some(" ".into()), Some(vec![("C".into(), "3".into())]))
+            .unwrap();
+        assert!(c.args.is_empty());
+        assert!(c.cwd.is_none());
+        assert_eq!(c.env.keys().collect::<Vec<_>>(), ["A", "C"]);
+        apply_overrides(&mut c, root, Some("x 'y z'".into()), None, None).unwrap();
+        assert_eq!(c.args, ["x", "y z"]);
+    }
+
+    #[test]
+    fn execution_targets_are_exclusive() {
+        let err = |n: Option<&str>, f: Option<&str>, l| {
+            execution_target(n.map(Into::into), f.map(Into::into), l).err().map(|e| e.message)
+        };
+        assert_eq!(
+            err(Some("a"), Some("f"), Some(1)).as_deref(),
+            Some("Pass either configurationName or filePath + line, but not both.")
+        );
+        assert_eq!(
+            err(None, Some("f"), None).as_deref(),
+            Some("Pass both filePath and line together, or use configurationName.")
+        );
+        assert_eq!(err(None, None, None).as_deref(), Some("Pass either configurationName or filePath + line."));
+        assert!(err(Some("a"), None, None).is_none());
+    }
+}
@@ -0,0 +1,25 @@
+//! Run configurations and builds; every call asks the user first.
+
+mod build;
+mod configs;
+mod output;
+mod process;
+mod targets;
+
+use crate::mcp::tool::{Call, Tool};
+use ide_core::IdeResult;
+use std::time::Duration;
+
+pub fn tools() -> Vec<Tool> {
+    vec![configs::get_run_configurations(), configs::execute_run_configuration(), build::build_project()]
+}
+
+/// The `timeout` argument: `default` when absent, at most `max` milliseconds. As in JetBrains
+/// (`withTimeoutOrNull`), zero or a negative value times out at once.
+fn timeout(call: &Call, default: usize, max: usize) -> IdeResult<Duration> {
+    Ok(match call.opt_i64("timeout")? {
+        None => Duration::from_millis(default as u64),
+        Some(n) if n <= 0 => Duration::ZERO,
+        Some(n) => Duration::from_millis((n as u64).min(max as u64)),
+    })
+}
@@ -0,0 +1,188 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (src/com/intellij/mcpserver/util/text.util.kt,
+// mcpserver.toolsets/src/util/OutputCollector.kt), Apache-2.0.
+//! Output of commands and runs: truncation, the run output collector and the private
+//! directory of full output files.
+
+use ide_core::IdeResult;
+use std::io::Write as _;
+use std::path::{Path, PathBuf};
+
+/// Marker of text cut by [`truncate_tail`].
+pub const TRUNCATED_MARKER: &str = "<<<...content truncated...>>>";
+/// Longest text [`truncate_tail`] returns (before its marker).
+pub const MAX_TEXT_LENGTH: usize = 64 * 1024;
+/// Characters of a run's output returned inline.
+pub const RUN_PREVIEW_MAX_LENGTH: usize = 10_000;
+pub const RUN_PREVIEW_TRUNCATED_MARKER: &str = "<truncated>";
+
+/// Console tail bounded by line count and character count.
+pub fn truncate_tail(text: &str, max_lines: usize, max_length: usize, marker: &str) -> String {
+    let lines: Vec<&str> = text.split('\n').collect();
+    let text = if lines.len() > max_lines {
+        [vec![marker], lines[lines.len() - (max_lines - 1)..].to_vec()].concat().join("\n")
+    } else {
+        text.to_owned()
+    };
+    if text.chars().count() <= max_length {
+        return text;
+    }
+    let start = text.char_indices().rev().nth(max_length - 1).map_or(0, |(i, _)| i);
+    format!("{marker}{}", &text[start..])
+}
+
+/// A run's output: all of it to a file, its first [`RUN_PREVIEW_MAX_LENGTH`] characters
+/// in memory (then [`RUN_PREVIEW_TRUNCATED_MARKER`]).
+pub struct OutputCollector {
+    pub path: PathBuf,
+    preview: String,
+    preview_chars: usize,
+    pub truncated: bool,
+    file: Option<std::fs::File>,
+}
+
+impl OutputCollector {
+    pub fn create(name: &str) -> IdeResult<Self> {
+        let (path, file) = temp_output_file(&format!("run-{name}"))?;
+        Ok(Self { path, preview: String::new(), preview_chars: 0, truncated: false, file: Some(file) })
+    }
+
+    pub fn append(&mut self, text: &str) {
+        // A failed write keeps the preview going; the file is then incomplete.
+        if let Some(f) = &mut self.file
+            && f.write_all(text.as_bytes()).is_err()
+        {
+            self.file = None;
+        }
+        if self.truncated {
+            return;
+        }
+        // As JetBrains: reaching the limit marks the preview truncated, even without more output.
+        let room = RUN_PREVIEW_MAX_LENGTH - self.preview_chars;
+        let chars = text.chars().count();
+        if chars < room {
+            self.preview_chars += chars;
+            self.preview.push_str(text);
+        } else {
+            let cut = text.char_indices().nth(room).map_or(text.len(), |(i, _)| i);
+            self.preview.push_str(&text[..cut]);
+            self.preview.push_str(RUN_PREVIEW_TRUNCATED_MARKER);
+            self.preview_chars = RUN_PREVIEW_MAX_LENGTH;
+            self.truncated = true;
+        }
+    }
+
+    pub fn preview(&self) -> &str {
+        &self.preview
+    }
+}
+
+/// Output files older than this are removed when a new one is created.
+const OUTPUT_MAX_AGE: std::time::Duration = std::time::Duration::from_secs(24 * 60 * 60);
+
+pub fn temp_output_file(prefix: &str) -> IdeResult<(PathBuf, std::fs::File)> {
+    let dir = output_dir()?;
+    remove_old_logs(&dir, OUTPUT_MAX_AGE);
+    let safe: String =
+        prefix.chars().map(|c| if c.is_ascii_alphanumeric() || c == '-' { c } else { '_' }).take(40).collect();
+    let path = dir.join(format!("{safe}-{}.log", uuid::Uuid::new_v4().simple()));
+    let mut options = std::fs::OpenOptions::new();
+    options.write(true).create_new(true);
+    #[cfg(unix)]
+    std::os::unix::fs::OpenOptionsExt::mode(&mut options, 0o600);
+    let file = options.open(&path)?;
+    Ok((path, file))
+}
+
+/// Best effort: removes `*.log` files in `dir` last modified more than `max_age` ago.
+fn remove_old_logs(dir: &Path, max_age: std::time::Duration) {
+    let Ok(entries) = std::fs::read_dir(dir) else { return };
+    let now = std::time::SystemTime::now();
+    for entry in entries.flatten() {
+        let path = entry.path();
+        if path.extension().is_none_or(|e| e != "log") {
+            continue;
+        }
+        let old = entry
+            .metadata()
+            .ok()
+            .filter(std::fs::Metadata::is_file)
+            .and_then(|m| m.modified().ok())
+            .and_then(|modified| now.duration_since(modified).ok())
+            .is_some_and(|age| age > max_age);
+        if old {
+            let _ = std::fs::remove_file(&path);
+        }
+    }
+}
+
+/// A directory only this user can read: output may hold secrets, and `/tmp` is shared on Linux.
+fn output_dir() -> IdeResult<PathBuf> {
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::{DirBuilderExt, MetadataExt};
+        let uid = rustix::process::getuid().as_raw();
+        let dir = std::env::temp_dir().join(format!("openidea-mcp-{uid}"));
+        match std::fs::DirBuilder::new().mode(0o700).create(&dir) {
+            Ok(()) => {}
+            Err(e) if e.kind() == std::io::ErrorKind::AlreadyExists => {}
+            Err(e) => return Err(e.into()),
+        }
+        let meta = std::fs::symlink_metadata(&dir)?;
+        if !meta.is_dir() || meta.uid() != uid || meta.mode() & 0o077 != 0 {
+            return Err(ide_core::IdeError::new(
+                ide_core::error::ErrorKind::PermissionDenied,
+                format!("{} is not a private directory of this user", dir.display()),
+            ));
+        }
+        Ok(dir)
+    }
+    #[cfg(not(unix))]
+    {
+        let dir = std::env::temp_dir().join("openidea-mcp");
+        std::fs::create_dir_all(&dir)?;
+        Ok(dir)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::time::Duration;
+
+    #[test]
+    fn preview_line_keeps_a_fixed_length() {
+        // JetBrains' `truncateRunConfigurationPreviewLine`: 1000 characters including the marker.
+        let line = "a".repeat(2000);
+        let cut = truncate_tail(&line, 3, 1000 - RUN_PREVIEW_TRUNCATED_MARKER.len(), RUN_PREVIEW_TRUNCATED_MARKER);
+        assert!(cut.starts_with("<truncated>"));
+        assert_eq!(cut.len(), 1000);
+    }
+
+    #[test]
+    fn collector_limits_the_preview_and_keeps_everything_in_the_file() {
+        let mut c = OutputCollector::create("test").unwrap();
+        let output = "a".repeat(RUN_PREVIEW_MAX_LENGTH + 1);
+        c.append(&output[..10]);
+        c.append(&output[10..]);
+        assert_eq!(c.preview(), format!("{}{RUN_PREVIEW_TRUNCATED_MARKER}", &output[..RUN_PREVIEW_MAX_LENGTH]));
+        assert!(c.truncated);
+        assert_eq!(std::fs::read_to_string(&c.path).unwrap(), output);
+        let _ = std::fs::remove_file(&c.path);
+    }
+
+    #[test]
+    fn removes_day_old_logs() {
+        let dir = tempfile::tempdir().unwrap();
+        let old = std::time::SystemTime::now() - Duration::from_secs(25 * 60 * 60);
+        for name in ["old.log", "new.log", "old.txt"] {
+            let file = std::fs::File::create(dir.path().join(name)).unwrap();
+            if name.starts_with("old") {
+                file.set_modified(old).unwrap();
+            }
+        }
+        remove_old_logs(dir.path(), OUTPUT_MAX_AGE);
+        assert!(!dir.path().join("old.log").exists());
+        assert!(dir.path().join("new.log").exists());
+        assert!(dir.path().join("old.txt").exists(), "only logs are removed");
+    }
+}
@@ -0,0 +1,65 @@
+use ide_core::{IdeError, IdeResult};
+/// POSIX-like word splitting: whitespace separates, quotes group, `\` escapes (not inside `'…'`).
+pub fn split_words(line: &str) -> IdeResult<Vec<String>> {
+    let mut words = Vec::new();
+    let mut word = String::new();
+    let mut in_word = false;
+    let mut chars = line.chars();
+    while let Some(c) = chars.next() {
+        match c {
+            '\'' => {
+                in_word = true;
+                loop {
+                    match chars.next() {
+                        Some('\'') => break,
+                        Some(c) => word.push(c),
+                        None => return Err(IdeError::invalid("unterminated ' quote")),
+                    }
+                }
+            }
+            '"' => {
+                in_word = true;
+                loop {
+                    match chars.next() {
+                        Some('"') => break,
+                        Some('\\') => match chars.next() {
+                            Some(c @ ('"' | '\\' | '$' | '`')) => word.push(c),
+                            Some(c) => {
+                                word.push('\\');
+                                word.push(c);
+                            }
+                            None => return Err(IdeError::invalid("unterminated \" quote")),
+                        },
+                        Some(c) => word.push(c),
+                        None => return Err(IdeError::invalid("unterminated \" quote")),
+                    }
+                }
+            }
+            '\\' if !cfg!(windows) => {
+                in_word = true;
+                if let Some(c) = chars.next() {
+                    word.push(c);
+                }
+            }
+            c if c.is_whitespace() => {
+                if in_word {
+                    words.push(std::mem::take(&mut word));
+                    in_word = false;
+                }
+            }
+            c => {
+                in_word = true;
+                word.push(c);
+            }
+        }
+    }
+    if in_word {
+        words.push(word);
+    }
+    Ok(words)
+}
+
+pub fn quote(arg: &str) -> String {
+    let plain = !arg.is_empty() && arg.chars().all(|c| c.is_ascii_alphanumeric() || "-_./=:@%+,".contains(c));
+    if plain { arg.to_owned() } else { format!("'{}'", arg.replace('\'', "'\\''")) }
+}
@@ -0,0 +1,975 @@
+//! Run points inside a file (the editor's gutter ▶ icons) and the run configuration of
+//! one: a port of the frontend's `features/run/targets.ts` and `context.ts` for Rust,
+//! JavaScript/TypeScript, Python and Go. JVM files are not covered (the editor scans
+//! them with a parser of its own).
+
+use ide_run::RunConfig;
+use regex_lite::Regex;
+use std::path::Path;
+use std::sync::LazyLock;
+
+/// Above this size files are not scanned (generated / minified files).
+const MAX_SCAN: usize = 400_000;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Kind {
+    Main,
+    Test,
+    Suite,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Target {
+    /// 0-based line of the declaration.
+    pub line: usize,
+    pub kind: Kind,
+    /// Display name (`adds_numbers`, `math > adds`).
+    pub name: String,
+    /// Rust module path, describe chain, Python class chain…
+    pub path: Vec<String>,
+}
+
+macro_rules! re {
+    ($name:ident, $re:expr) => {
+        static $name: LazyLock<Regex> = LazyLock::new(|| Regex::new($re).expect("valid regex"));
+    };
+}
+
+fn indent_of(s: &str) -> usize {
+    s.chars().take_while(|c| c.is_whitespace()).map(|c| if c == '\t' { 4 } else { 1 }).sum()
+}
+
+// ---------------------------------------------------------------- Rust
+
+re!(LINE_COMMENT, r"//.*$");
+re!(STRING, r#""(?:[^"\\]|\\.)*""#);
+re!(CHAR, r"'(?:[^'\\]|\\.)'");
+
+/// Strips string literals and line comments (rough) so braces inside them don't count.
+fn code_only(line: &str) -> String {
+    let line = LINE_COMMENT.replace(line, "");
+    let line = STRING.replace_all(&line, "\"\"");
+    CHAR.replace_all(&line, "''").into_owned()
+}
+
+re!(RUST_SRC, r"(?:^|/)src/(.+)\.rs$");
+
+fn rust_module_prefix(rel: &str) -> Vec<String> {
+    let Some(m) = RUST_SRC.captures(rel) else { return Vec::new() };
+    let mut parts: Vec<String> = m[1].split('/').map(str::to_owned).collect();
+    let last = parts.last().cloned().unwrap_or_default();
+    if parts.len() == 1 && (last == "lib" || last == "main") || parts[0] == "bin" {
+        return Vec::new();
+    }
+    if last == "mod" {
+        parts.pop();
+    }
+    parts
+}
+
+re!(RUST_TEST_ATTR, r"^#\[(?:[\w:]+::)?test\b|^#\[(?:tokio|async_std|actix_rt|rstest|test_case)(?:::\w+)?\b");
+re!(RUST_CFG_TEST, r"^#\[cfg\(test\)\]");
+re!(RUST_FN, r"^(?:pub(?:\([^)]*\))?\s+)?(?:async\s+)?(?:unsafe\s+)?fn\s+(\w+)");
+re!(RUST_MOD, r"^(?:pub(?:\([^)]*\))?\s+)?mod\s+(\w+)\s*\{");
+re!(RUST_MAIN_FILE, r"(?:^|/)(?:src/main|src/bin/[^/]+|examples/[^/]+)\.rs$");
+
+fn rust_targets(lines: &[&str], rel: &str) -> Vec<Target> {
+    let mut out: Vec<Target> = Vec::new();
+    let prefix = rust_module_prefix(rel);
+    let mut mods: Vec<(String, i64)> = Vec::new();
+    let mut depth: i64 = 0;
+    let mut pending_test = false;
+    let mut pending_cfg_test = false;
+    for (i, raw) in lines.iter().enumerate() {
+        let line = code_only(raw);
+        let trimmed = line.trim();
+        if RUST_TEST_ATTR.is_match(trimmed) {
+            pending_test = true;
+        }
+        if RUST_CFG_TEST.is_match(trimmed) {
+            pending_cfg_test = true;
+        }
+        let mod_path = || prefix.iter().cloned().chain(mods.iter().map(|m| m.0.clone())).collect::<Vec<_>>();
+        if let Some(f) = RUST_FN.captures(trimmed) {
+            let name = f[1].to_owned();
+            if pending_test {
+                let mut path = mod_path();
+                path.push(name.clone());
+                out.push(Target { line: i, kind: Kind::Test, name, path });
+            } else if name == "main" && depth == 0 && RUST_MAIN_FILE.is_match(rel) {
+                out.push(Target { line: i, kind: Kind::Main, name, path: Vec::new() });
+            }
+            pending_test = false;
+            pending_cfg_test = false;
+        } else if let Some(m) = RUST_MOD.captures(trimmed) {
+            let name = m[1].to_owned();
+            let mut path = mod_path();
+            path.push(name.clone());
+            if pending_cfg_test || name == "tests" {
+                out.push(Target { line: i, kind: Kind::Suite, name: name.clone(), path });
+            }
+            mods.push((name, depth));
+            pending_test = false;
+            pending_cfg_test = false;
+        } else if !trimmed.is_empty() && !trimmed.starts_with("#[") && !trimmed.starts_with("//") {
+            pending_test = false;
+            if !trimmed.starts_with('#') {
+                pending_cfg_test = false;
+            }
+        }
+        for ch in line.chars() {
+            if ch == '{' {
+                depth += 1;
+            } else if ch == '}' {
+                depth -= 1;
+                while mods.last().is_some_and(|m| m.1 >= depth) {
+                    mods.pop();
+                }
+            }
+        }
+    }
+    // A suite that contains no tests is noise.
+    let tests: Vec<Vec<String>> = out.iter().filter(|t| t.kind == Kind::Test).map(|t| t.path.clone()).collect();
+    out.retain(|t| t.kind != Kind::Suite || tests.iter().any(|p| p.len() > t.path.len() && p.starts_with(&t.path)));
+    out
+}
+
+// ---------------------------------------------------------------- JavaScript / TypeScript
+
+re!(
+    JS_CALL,
+    r"^(\s*)(describe|suite|context|test|it)\b(?:\.(?:only|skip|todo|concurrent|failing|sequential))*(\.each\s*(?:\(.*?\)|`[^`]*`))?\s*\(\s*"
+);
+
+/// The string literal at the start of `s` (quote, then text up to the same unescaped quote).
+fn js_string(s: &str) -> Option<(char, String)> {
+    let mut chars = s.chars();
+    let quote = chars.next().filter(|q| matches!(q, '\'' | '"' | '`'))?;
+    let mut raw = String::new();
+    while let Some(c) = chars.next() {
+        if c == quote {
+            return Some((quote, raw));
+        }
+        raw.push(c);
+        if c == '\\' {
+            raw.push(chars.next()?);
+        }
+    }
+    None
+}
+
+re!(JS_ESCAPE, r"\\(.)");
+
+fn js_targets(lines: &[&str]) -> Vec<Target> {
+    let mut out = Vec::new();
+    let mut stack: Vec<(usize, String)> = Vec::new();
+    for (i, line) in lines.iter().enumerate() {
+        let Some(m) = JS_CALL.captures(line) else { continue };
+        let Some((_quote, raw)) = js_string(&line[m.get(0).map_or(0, |g| g.end())..]) else { continue };
+        let indent = indent_of(&m[1]);
+        while stack.last().is_some_and(|s| s.0 >= indent) {
+            stack.pop();
+        }
+        let name = JS_ESCAPE.replace_all(&raw, "$1").into_owned();
+        let mut path: Vec<String> = stack.iter().map(|s| s.1.clone()).collect();
+        path.push(name.clone());
+        let suite = matches!(&m[2], "describe" | "suite" | "context");
+        out.push(Target { line: i, kind: if suite { Kind::Suite } else { Kind::Test }, name: path.join(" > "), path });
+        if suite {
+            stack.push((indent, name));
+        }
+    }
+    out
+}
+
+fn escape_regexp(s: &str) -> String {
+    let mut out = String::with_capacity(s.len());
+    for c in s.chars() {
+        if ".*+?^${}()|[]\\".contains(c) {
+            out.push('\\');
+        }
+        out.push(c);
+    }
+    out
+}
+
+re!(JS_PATTERN_PLACEHOLDER, r"%[sdifjo#p]|\\\$\\\{[^}]*\\\}|\$\w+");
+
+/// Jest / Vitest `-t` pattern for a test (full name = describe chain + name, space separated).
+fn js_name_pattern(target: &Target) -> String {
+    let pattern = escape_regexp(&target.path.join(" "));
+    // `test.each` placeholders (%s, $name, ${…}) match anything.
+    let pattern = JS_PATTERN_PLACEHOLDER.replace_all(&pattern, ".*");
+    if target.kind == Kind::Suite { format!("^{pattern}") } else { format!("^{pattern}$") }
+}
+
+// ---------------------------------------------------------------- Python
+
+re!(PY_COMMENT, r"^\s*#");
+re!(PY_CLASS, r"^\s*class\s+(\w+)");
+re!(PY_TEST_DEF, r"^\s*(?:async\s+)?def\s+(test\w*)\s*\(");
+re!(PY_MAIN, r#"^if\s+__name__\s*==\s*['"]__main__['"]\s*:"#);
+
+fn python_targets(lines: &[&str]) -> Vec<Target> {
+    let mut out = Vec::new();
+    let mut classes: Vec<(usize, String, bool)> = Vec::new();
+    for (i, line) in lines.iter().enumerate() {
+        if line.trim().is_empty() || PY_COMMENT.is_match(line) {
+            continue;
+        }
+        let indent = indent_of(line);
+        while classes.last().is_some_and(|c| c.0 >= indent) {
+            classes.pop();
+        }
+        if let Some(c) = PY_CLASS.captures(line) {
+            let test = c[1].starts_with("Test") && classes.iter().all(|c| c.2);
+            classes.push((indent, c[1].to_owned(), test));
+            if test {
+                let path: Vec<String> = classes.iter().map(|c| c.1.clone()).collect();
+                out.push(Target { line: i, kind: Kind::Suite, name: c[1].to_owned(), path });
+            }
+            continue;
+        }
+        if let Some(d) = PY_TEST_DEF.captures(line)
+            && classes.iter().all(|c| c.2)
+        {
+            let mut path: Vec<String> = classes.iter().map(|c| c.1.clone()).collect();
+            path.push(d[1].to_owned());
+            out.push(Target { line: i, kind: Kind::Test, name: path.join("."), path });
+            continue;
+        }
+        if indent == 0 && PY_MAIN.is_match(line) {
+            out.push(Target { line: i, kind: Kind::Main, name: "main".into(), path: Vec::new() });
+        }
+    }
+    out
+}
+
+// ---------------------------------------------------------------- Go
+
+re!(GO_PACKAGE_MAIN, r"^package\s+main\b");
+re!(GO_TEST, r"^func\s+(Test\w*|Benchmark\w*|Example\w*|Fuzz\w*)\s*\(\s*(?:\w+\s+\*testing\.[TFB])?\s*\)?");
+re!(GO_TESTING_ARG, r"\*testing\.[TFB]");
+re!(GO_TESTING_TB, r"\*testing\.[TB]\b");
+re!(GO_MAIN, r"^func\s+main\s*\(\s*\)");
+re!(GO_ONE_LINE, r"\}\s*(?://.*)?$");
+re!(GO_RUN_LITERAL, r#"\b\w+\.Run\(\s*"((?:[^"\\]|\\.)*)"\s*,"#);
+re!(GO_RUN_FIELD, r"\b\w+\.Run\(\s*\w+\.(\w+)\s*,");
+re!(GO_RUN_KEY, r"\b\w+\.Run\(\s*(\w+)\s*,");
+re!(GO_MAP_KEY, r#"^\s*"((?:[^"\\]|\\.)*)"\s*:\s*\{"#);
+re!(WHITESPACE, r"\s");
+
+fn go_targets(lines: &[&str]) -> Vec<Target> {
+    let mut out = Vec::new();
+    let is_main = lines.iter().any(|l| GO_PACKAGE_MAIN.is_match(l));
+    for (i, line) in lines.iter().enumerate() {
+        if let Some(t) = GO_TEST.captures(line) {
+            let name = t[1].to_owned();
+            if name.starts_with("Example") || GO_TESTING_ARG.is_match(line) {
+                out.push(Target { line: i, kind: Kind::Test, name: name.clone(), path: vec![name.clone()] });
+                if GO_TESTING_TB.is_match(line) {
+                    out.extend(go_subtests(lines, i, &name));
+                }
+                continue;
+            }
+        }
+        if is_main && GO_MAIN.is_match(line) {
+            out.push(Target { line: i, kind: Kind::Main, name: "main".into(), path: Vec::new() });
+        }
+    }
+    out
+}
+
+/// Subtests of the test function at `start`: `t.Run("name", …)`, and table entries run with
+/// `t.Run(tt.name, …)` (`{name: "…", …}`) or keyed by name (`"…": {…}`).
+fn go_subtests(lines: &[&str], start: usize, test: &str) -> Vec<Target> {
+    if GO_ONE_LINE.is_match(lines[start]) {
+        return Vec::new();
+    }
+    let mut end = start;
+    while end + 1 < lines.len() && !lines[end].starts_with('}') {
+        end += 1;
+    }
+    let body = &lines[start + 1..end.max(start + 1)];
+    let mut out: Vec<Target> = Vec::new();
+    let mut add = |offset: usize, name: &str| {
+        let sub = WHITESPACE.replace_all(&JS_ESCAPE.replace_all(name, "$1"), "_").into_owned();
+        if !out.iter().any(|t| t.path[1] == sub) {
+            out.push(Target {
+                line: start + 1 + offset,
+                kind: Kind::Test,
+                name: format!("{test}/{sub}"),
+                path: vec![test.to_owned(), sub],
+            });
+        }
+    };
+    let mut fields: Vec<String> = Vec::new();
+    let mut keys: Vec<String> = Vec::new();
+    for (i, l) in body.iter().enumerate() {
+        if let Some(m) = GO_RUN_LITERAL.captures(l) {
+            add(i, &m[1]);
+        }
+        if let Some(m) = GO_RUN_FIELD.captures(l) {
+            fields.push(m[1].to_owned());
+        }
+        if let Some(m) = GO_RUN_KEY.captures(l) {
+            let range = Regex::new(&format!(r"\bfor\s+{}\s*,\s*\w+\s*:=\s*range\b", &m[1])).expect("valid regex");
+            if body[..i].iter().any(|b| range.is_match(b)) {
+                keys.push(m[1].to_owned());
+            }
+        }
+    }
+    if !fields.is_empty() || !keys.is_empty() {
+        let field_res: Vec<Regex> = fields
+            .iter()
+            .map(|f| Regex::new(&format!(r#"\b{f}\s*:\s*"((?:[^"\\]|\\.)*)""#)).expect("valid regex"))
+            .collect();
+        for (i, l) in body.iter().enumerate() {
+            for re in &field_res {
+                if let Some(m) = re.captures(l) {
+                    add(i, &m[1]);
+                }
+            }
+            if !keys.is_empty()
+                && let Some(m) = GO_MAP_KEY.captures(l)
+            {
+                add(i, &m[1]);
+            }
+        }
+    }
+    out.sort_by_key(|t| t.line);
+    out
+}
+
+// ---------------------------------------------------------------- detection
+
+re!(JS_FILE, r"\.[cm]?[jt]sx?$");
+re!(JS_TEST_FILE, r"\.(test|spec)\.[cm]?[jt]sx?$|(^|/)__tests__/");
+re!(PY_TEST_FILE, r"(^|/)(test_[^/]*|[^/]*_test)\.py$|(^|/)tests?/");
+
+/// Run targets of a file (`rel`: project-relative with `/`, picks the language).
+pub fn detect(text: &str, rel: &str) -> Vec<Target> {
+    if text.len() > MAX_SCAN {
+        return Vec::new();
+    }
+    let lines: Vec<&str> = text.split('\n').map(|l| l.strip_suffix('\r').unwrap_or(l)).collect();
+    if rel.ends_with(".rs") {
+        rust_targets(&lines, rel)
+    } else if JS_FILE.is_match(rel) {
+        if JS_TEST_FILE.is_match(rel) { js_targets(&lines) } else { Vec::new() }
+    } else if rel.ends_with(".py") {
+        let test_file = PY_TEST_FILE.is_match(rel);
+        python_targets(&lines).into_iter().filter(|t| t.kind == Kind::Main || test_file).collect()
+    } else if rel.ends_with(".go") {
+        let test_file = rel.ends_with("_test.go");
+        go_targets(&lines).into_iter().filter(|t| t.kind == Kind::Main || test_file).collect()
+    } else {
+        Vec::new()
+    }
+}
+
+/// The last line (0-based) of the block declared at `start`: by indentation in Python, else
+/// where the braces opened on (or, for a Rust signature, after) the declaration close again.
+fn block_end(lines: &[&str], start: usize, rel: &str) -> usize {
+    if rel.ends_with(".py") {
+        let indent = indent_of(lines[start]);
+        let mut end = start;
+        for (i, line) in lines.iter().enumerate().skip(start + 1) {
+            if line.trim().is_empty() || PY_COMMENT.is_match(line) {
+                continue;
+            }
+            if indent_of(line) <= indent {
+                break;
+            }
+            end = i;
+        }
+        return end;
+    }
+    let rust = rel.ends_with(".rs");
+    let mut depth: i64 = 0;
+    let mut opened = false;
+    for (i, raw) in lines.iter().enumerate().skip(start) {
+        let line = code_only(raw);
+        for ch in line.chars() {
+            match ch {
+                '{' => {
+                    depth += 1;
+                    opened = true;
+                }
+                '}' => depth -= 1,
+                // A Rust declaration without a body (`fn f();`).
+                ';' if rust && !opened => return i,
+                _ => {}
+            }
+            if opened && depth <= 0 {
+                return i;
+            }
+        }
+        // Only a Rust signature continues on the next lines; a call without a block ends here.
+        if !opened && !rust {
+            return i;
+        }
+    }
+    lines.len().saturating_sub(1)
+}
+
+/// The run targets whose declaration or body contains `line` (0-based), innermost first.
+pub fn enclosing(text: &str, rel: &str, line: usize) -> Vec<Target> {
+    let lines: Vec<&str> = text.split('\n').map(|l| l.strip_suffix('\r').unwrap_or(l)).collect();
+    let mut out: Vec<Target> =
+        detect(text, rel).into_iter().filter(|t| t.line <= line && line <= block_end(&lines, t.line, rel)).collect();
+    out.sort_by_key(|t| std::cmp::Reverse(t.line));
+    out
+}
+
+// ---------------------------------------------------------------- configurations
+
+/// A configuration's working directory relative to the project root, with `/` (Go: its module).
+fn cwd_of(root: &Path, c: &RunConfig) -> String {
+    let module = (c.kind == "go").then(|| c.extras.params.get("module").cloned()).flatten();
+    let cwd = module
+        .or_else(|| c.cwd.as_deref().map(|p| p.strip_prefix(root).unwrap_or(p).to_string_lossy().replace('\\', "/")));
+    let cwd = cwd.unwrap_or_default();
+    let cwd = cwd.strip_prefix("./").or_else(|| cwd.strip_prefix('.')).unwrap_or(&cwd);
+    cwd.trim_end_matches('/').to_owned()
+}
+
+/// Configs whose working directory most specifically contains `rel` (ties in their original order).
+fn all_closest<'a>(root: &Path, configs: &[&'a RunConfig], rel: &str) -> Vec<&'a RunConfig> {
+    let score = |c: &RunConfig| -> Option<usize> {
+        let cwd = cwd_of(root, c);
+        if cwd.is_empty() { Some(0) } else { (rel == cwd || rel.starts_with(&format!("{cwd}/"))).then_some(cwd.len()) }
+    };
+    let scored: Vec<(&RunConfig, usize)> = configs.iter().filter_map(|c| score(c).map(|s| (*c, s))).collect();
+    let best = scored.iter().map(|s| s.1).max();
+    scored.into_iter().filter(|s| Some(s.1) == best).map(|s| s.0).collect()
+}
+
+fn closest<'a>(root: &Path, configs: &[&'a RunConfig], rel: &str) -> Option<&'a RunConfig> {
+    all_closest(root, configs, rel).into_iter().next()
+}
+
+fn rel_to_cwd(root: &Path, rel: &str, c: &RunConfig) -> String {
+    let cwd = cwd_of(root, c);
+    match rel.strip_prefix(&format!("{cwd}/")) {
+        Some(inner) if !cwd.is_empty() => inner.to_owned(),
+        _ => rel.to_owned(),
+    }
+}
+
+fn file_name(rel: &str) -> &str {
+    rel.rsplit('/').next().unwrap_or(rel)
+}
+
+fn dir_of(p: &str) -> &str {
+    p.rfind('/').map_or("", |i| &p[..i])
+}
+
+fn derived(base: &RunConfig, rel: &str, args: Vec<String>) -> RunConfig {
+    RunConfig {
+        id: format!("context:{}:{rel}", base.id),
+        name: file_name(rel).to_owned(),
+        args,
+        detected: true,
+        ..base.clone()
+    }
+}
+
+/// Kinds whose test configs can run a file of this extension.
+fn test_kinds(rel: &str) -> &'static [&'static str] {
+    if JS_FILE.is_match(rel) {
+        &["npm", "deno", "bun"]
+    } else if rel.ends_with(".py") {
+        &["pytest", "python"]
+    } else if rel.ends_with(".go") {
+        &["go"]
+    } else if rel.ends_with(".rs") {
+        &["cargo"]
+    } else {
+        &[]
+    }
+}
+
+/// The project's Python interpreter as `(command, leading args)`, from detected configs.
+fn project_python(configs: &[RunConfig]) -> Option<(String, Vec<String>)> {
+    if let Some(py) = configs.iter().find(|c| c.kind == "python") {
+        let prefix = match py.args.iter().position(|a| a == "-m") {
+            Some(m) => py.args[..m].to_vec(),
+            None => py.args.iter().filter(|a| !a.ends_with(".py")).cloned().collect(),
+        };
+        return Some((py.command.clone(), prefix));
+    }
+    let pytest = configs.iter().find(|c| c.kind == "pytest")?;
+    static VENV: LazyLock<Regex> =
+        LazyLock::new(|| Regex::new(r"^(.*[/\\](?:bin|Scripts)[/\\])pytest(\.exe)?$").expect("valid regex"));
+    if let Some(m) = VENV.captures(&pytest.command) {
+        return Some((format!("{}python{}", &m[1], m.get(2).map_or("", |g| g.as_str())), Vec::new()));
+    }
+    if let Some(m) = pytest.args.iter().position(|a| a == "-m")
+        && pytest.args.get(m + 1).is_some_and(|a| a == "pytest")
+    {
+        return Some((pytest.command.clone(), pytest.args[..m].to_vec()));
+    }
+    if pytest.args.first().is_some_and(|a| a == "run") && pytest.args.get(1).is_some_and(|a| a == "pytest") {
+        return Some((pytest.command.clone(), vec!["run".into(), "python".into()]));
+    }
+    None
+}
+
+fn blank(id: String, name: &str, kind: &str, command: String, args: Vec<String>) -> RunConfig {
+    RunConfig {
+        id,
+        name: name.to_owned(),
+        kind: kind.to_owned(),
+        command,
+        args,
+        cwd: None,
+        env: Default::default(),
+        detected: true,
+        is_test: false,
+        debug_adapter: None,
+        allow_parallel: false,
+        extras: Default::default(),
+    }
+}
+
+/// PyCharm runs pytest for a test file even when the project declares no test setup.
+fn implicit_pytest(rel: &str, configs: &[RunConfig]) -> Option<RunConfig> {
+    if !rel.ends_with(".py") {
+        return None;
+    }
+    let (command, mut args) = project_python(configs).unwrap_or_else(|| ("python3".into(), Vec::new()));
+    args.extend(["-m".to_owned(), "pytest".to_owned()]);
+    let mut c = blank("pytest:implicit".into(), "pytest", "pytest", command, args);
+    c.is_test = true;
+    c.debug_adapter = Some("debugpy".into());
+    Some(c)
+}
+
+fn test_base_for(root: &Path, rel: &str, configs: &[RunConfig]) -> Option<RunConfig> {
+    let kinds = test_kinds(rel);
+    // Configurations produced from a test or file are results of narrowing, never bases for it.
+    let candidates: Vec<&RunConfig> = configs
+        .iter()
+        .filter(|c| c.is_test && kinds.contains(&c.kind.as_str()) && !c.id.starts_with("context:"))
+        .collect();
+    closest(root, &candidates, rel).or(candidates.first().copied()).cloned().or_else(|| implicit_pytest(rel, configs))
+}
+
+/// Go test flags may come before or after package targets; binary arguments start at `-args`.
+fn go_test_parts(args: &[String]) -> (Vec<String>, Vec<String>, Vec<String>) {
+    const BOOLEAN_FLAGS: &[&str] = &[
+        "-a",
+        "-n",
+        "-race",
+        "-msan",
+        "-asan",
+        "-cover",
+        "-linkshared",
+        "-modcacherw",
+        "-trimpath",
+        "-v",
+        "-work",
+        "-x",
+        "-json",
+        "-c",
+        "-i",
+        "-short",
+        "-failfast",
+        "-benchmem",
+        "-fullpath",
+        "-buildvcs",
+    ];
+    let (mut flags, mut targets, mut program) = (Vec::new(), Vec::new(), Vec::new());
+    let mut i = 1;
+    while i < args.len() {
+        let arg = &args[i];
+        if arg == "-args" || arg == "--" {
+            program = args[i..].to_vec();
+            break;
+        }
+        if arg.starts_with('-') {
+            flags.push(arg.clone());
+            if !arg.contains('=') && !BOOLEAN_FLAGS.contains(&arg.as_str()) && i + 1 < args.len() {
+                i += 1;
+                flags.push(args[i].clone());
+            }
+        } else {
+            targets.push(arg.clone());
+        }
+        i += 1;
+    }
+    (flags, targets, program)
+}
+
+fn without_go_selection(flags: &[String]) -> Vec<String> {
+    let mut out = Vec::new();
+    let mut i = 0;
+    while i < flags.len() {
+        let f = flags[i].as_str();
+        if matches!(f, "-run" | "-skip" | "-bench" | "-fuzz") {
+            i += 2;
+            continue;
+        }
+        if ["-run=", "-skip=", "-bench=", "-fuzz="].iter().any(|p| f.starts_with(p)) {
+            i += 1;
+            continue;
+        }
+        out.push(flags[i].clone());
+        i += 1;
+    }
+    out
+}
+
+/// File-level test configuration for `rel` (the closest matching test config narrowed to the file).
+fn test_config_for(root: &Path, rel: &str, configs: &[RunConfig]) -> Option<RunConfig> {
+    let base = test_base_for(root, rel, configs)?;
+    let file = rel_to_cwd(root, rel, &base);
+    let with = |extra: &[String]| [base.args.clone(), extra.to_vec()].concat();
+    Some(match base.kind.as_str() {
+        // `npm run test -- file` works for npm, pnpm, yarn and bun.
+        "npm" | "bun" if base.args.iter().any(|a| a == "--") => derived(&base, rel, with(&[file])),
+        "npm" | "bun" => derived(&base, rel, with(&["--".into(), file])),
+        "deno" | "pytest" | "python" => derived(&base, rel, with(&[file])),
+        "go" => {
+            let dir = dir_of(&file);
+            let target = if dir.is_empty() { ".".to_owned() } else { format!("./{dir}") };
+            let (flags, _, program) = go_test_parts(&base.args);
+            let args = [vec!["test".to_owned()], flags, vec![target.clone()], program].concat();
+            let mut c = derived(&base, rel, args);
+            c.name = format!("go test {target}");
+            if c.extras.params.contains_key("goKind") {
+                c.extras.params.insert("scope".into(), "directory".into());
+                c.extras.params.insert("target".into(), target);
+            }
+            c
+        }
+        "cargo" => {
+            static TESTS: LazyLock<Regex> =
+                LazyLock::new(|| Regex::new(r"(?:^|/)tests/([^/]+)\.rs$").expect("valid regex"));
+            match TESTS.captures(rel) {
+                Some(m) => {
+                    // Cargo's own options go before the test binary's `--`.
+                    let at = base.args.iter().position(|a| a == "--").unwrap_or(base.args.len());
+                    let mut args = base.args.clone();
+                    args.splice(at..at, ["--test".to_owned(), m[1].to_owned()]);
+                    derived(&base, rel, args)
+                }
+                None => base,
+            }
+        }
+        _ => base,
+    })
+}
+
+fn main_config_for(root: &Path, rel: &str, configs: &[RunConfig]) -> Option<RunConfig> {
+    if rel.ends_with(".rs") {
+        static BIN: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"src/bin/([^/]+)\.rs$").expect("valid regex"));
+        let bin = BIN.captures(rel).map(|m| m[1].to_owned());
+        let runs: Vec<&RunConfig> =
+            configs.iter().filter(|c| c.kind == "cargo" && c.id.starts_with("cargo:run")).collect();
+        let by_bin =
+            bin.and_then(|b| runs.iter().find(|c| c.id == format!("cargo:run:{b}") || c.args.contains(&b)).copied());
+        return by_bin.or_else(|| closest(root, &runs, rel)).or(runs.first().copied()).cloned();
+    }
+    if rel.ends_with(".go") {
+        let gos: Vec<&RunConfig> = configs.iter().filter(|c| c.kind == "go").collect();
+        let runs: Vec<&RunConfig> =
+            gos.iter().filter(|c| c.args.first().is_some_and(|a| a == "run")).copied().collect();
+        // The module containing the file (nested modules run from their own directory).
+        let base = closest(root, &runs, rel)
+            .or_else(|| closest(root, &gos, rel))
+            .or(runs.first().copied())
+            .or(gos.first().copied())?;
+        let dir = rel_to_cwd(root, rel, base);
+        let dir = dir_of(&dir);
+        let target = if dir.is_empty() { ".".to_owned() } else { format!("./{dir}") };
+        if let Some(hit) = runs.iter().find(|c| c.cwd == base.cwd && c.args.get(1) == Some(&target)) {
+            return Some((*hit).clone());
+        }
+        let mut c = derived(base, rel, vec!["run".into(), target.clone()]);
+        c.name = format!("go run {target}");
+        c.is_test = false;
+        return Some(c);
+    }
+    None
+}
+
+fn script_config_for(rel: &str, configs: &[RunConfig]) -> Option<RunConfig> {
+    let id = format!("context:file:{rel}");
+    let name = file_name(rel);
+    let script = |command: &str, args: Vec<String>| blank(id.clone(), name, "shell", command.to_owned(), args);
+    if rel.ends_with(".py") {
+        // Reuse the project's interpreter (venv / uv / poetry) when detected.
+        let (command, mut args) = project_python(configs).unwrap_or_else(|| ("python3".into(), Vec::new()));
+        args.push(rel.to_owned());
+        let mut c = blank(id, name, "python", command, args);
+        c.debug_adapter = Some("debugpy".into());
+        return Some(c);
+    }
+    static JS: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"\.[cm]?js$").expect("valid regex"));
+    if JS.is_match(rel) {
+        return Some(script("node", vec![rel.to_owned()]));
+    }
+    if rel.ends_with(".ts") {
+        return Some(script("npx", vec!["tsx".into(), rel.to_owned()]));
+    }
+    for (ext, shell) in [(".zsh", "zsh"), (".bash", "bash"), (".sh", "sh")] {
+        if rel.ends_with(ext) {
+            return Some(script(shell, vec![rel.to_owned()]));
+        }
+    }
+    None
+}
+
+re!(TEST_FILE, r"\.(test|spec)\.[cm]?[jt]sx?$|(^|/)__tests__/|(^|/)(test_[^/]*\.py|[^/]*_test\.py|[^/]*_test\.go)$");
+re!(RUST_TESTS_FILE, r"(^|/)tests/[^/]+\.rs$");
+re!(RUST_MAIN_ROLE, r"(^|/)src/main\.rs$|(^|/)src/bin/[^/]+\.rs$");
+re!(GO_PACKAGE_MAIN_MULTILINE, r"(?m)^\s*package\s+main\b");
+re!(SCRIPT_FILE, r"\.(py|sh|bash|zsh|[cm]?js|ts)$");
+
+/// "Run Context Configuration" for the whole file: its tests, its main target or the script.
+pub fn context_config(root: &Path, rel: &str, configs: &[RunConfig], content: &str) -> Option<RunConfig> {
+    let name = file_name(rel);
+    if TEST_FILE.is_match(rel) || (RUST_TESTS_FILE.is_match(rel) && name != "mod.rs") {
+        return test_config_for(root, rel, configs);
+    }
+    if RUST_MAIN_ROLE.is_match(rel) || (rel.ends_with(".go") && GO_PACKAGE_MAIN_MULTILINE.is_match(content)) {
+        return main_config_for(root, rel, configs).or_else(|| script_config_for(rel, configs));
+    }
+    if SCRIPT_FILE.is_match(name) {
+        return script_config_for(rel, configs);
+    }
+    None
+}
+
+fn replace_last(mut args: Vec<String>, f: impl FnOnce(&str) -> String) -> Vec<String> {
+    if let Some(last) = args.last_mut() {
+        *last = f(last);
+    }
+    args
+}
+
+/// The run configuration of one target, or `None` when the project has no matching runner.
+pub fn target_config(
+    root: &Path,
+    target: &Target,
+    rel: &str,
+    configs: &[RunConfig],
+    content: &str,
+) -> Option<RunConfig> {
+    if target.kind == Kind::Main {
+        return context_config(root, rel, configs, content);
+    }
+    let file = test_config_for(root, rel, configs)?;
+    let short =
+        if target.kind == Kind::Suite { target.path.last().cloned().unwrap_or_default() } else { target.name.clone() };
+    let named = |args: Vec<String>| RunConfig {
+        id: format!("context:target:{}:{rel}:{}", file.id, target.path.join("/")),
+        name: short.clone(),
+        args,
+        detected: true,
+        ..file.clone()
+    };
+    let with = |extra: Vec<String>| [file.args.clone(), extra].concat();
+    match file.kind.as_str() {
+        "npm" | "bun" | "deno" => Some(named(with(vec!["-t".into(), js_name_pattern(target)]))),
+        "pytest" | "python" => {
+            Some(named(replace_last(file.args.clone(), |f| format!("{f}::{}", target.path.join("::")))))
+        }
+        "go" => {
+            let pattern = format!("^{}$", target.path.iter().map(|p| escape_regexp(p)).collect::<Vec<_>>().join("$/^"));
+            let benchmark = target.path.first().is_some_and(|p| p.starts_with("Benchmark"));
+            let (flags, targets, program) = go_test_parts(&file.args);
+            let selection: Vec<String> = if benchmark {
+                vec!["-run".into(), "^$".into(), "-bench".into(), pattern.clone()]
+            } else {
+                vec!["-run".into(), pattern.clone()]
+            };
+            let flags = without_go_selection(&flags);
+            let mut c = named([vec!["test".to_owned()], flags.clone(), targets, selection, program].concat());
+            if c.extras.params.contains_key("goKind") {
+                let mut tool_args: Vec<String> = flags;
+                if benchmark {
+                    tool_args.extend(["-bench".to_owned(), pattern.clone()]);
+                }
+                c.extras.params.insert("pattern".into(), if benchmark { "^$".into() } else { pattern });
+                c.extras.params.insert(
+                    "toolArgs".into(),
+                    tool_args.iter().map(|a| super::process::quote(a)).collect::<Vec<_>>().join(" "),
+                );
+            }
+            Some(c)
+        }
+        "cargo" => {
+            let path = target.path.join("::");
+            // Test-binary arguments follow the one `--` (`cargo test -- --nocapture` has it already).
+            let separator: Vec<String> =
+                if file.args.iter().any(|a| a == "--") { Vec::new() } else { vec!["--".into()] };
+            Some(named(if target.kind == Kind::Suite {
+                with([separator, vec![format!("{path}::")]].concat())
+            } else {
+                with([separator, vec![path, "--exact".into()]].concat())
+            }))
+        }
+        _ => None,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn pick(ts: &[Target]) -> Vec<(usize, Kind, String)> {
+        ts.iter().map(|t| (t.line, t.kind, t.path.join("/"))).collect()
+    }
+
+    #[test]
+    fn rust_main_tests_and_test_modules() {
+        let src = [
+            "fn main() {}",
+            "#[cfg(test)]",
+            "mod tests {",
+            "    use super::*;",
+            "    #[test]",
+            "    fn adds() { let s = \"}\"; }",
+            "    #[tokio::test]",
+            "    #[ignore]",
+            "    async fn async_one() {}",
+            "    fn helper() {}",
+            "}",
+            "fn after() {}",
+        ]
+        .join("\n");
+        assert_eq!(
+            pick(&detect(&src, "src/main.rs")),
+            [
+                (0, Kind::Main, String::new()),
+                (2, Kind::Suite, "tests".into()),
+                (5, Kind::Test, "tests/adds".into()),
+                (8, Kind::Test, "tests/async_one".into()),
+            ]
+        );
+        assert_eq!(
+            pick(&detect("#[test]\nfn x() {}", "crates/a/src/foo/bar.rs")),
+            [(1, Kind::Test, "foo/bar/x".into())]
+        );
+        assert!(detect("fn main() {}", "src/lib.rs").is_empty());
+    }
+
+    #[test]
+    fn js_describe_chains() {
+        let src = [
+            "describe('math', () => {",
+            "  it('adds', () => {});",
+            "  describe(\"nested\", () => {",
+            "    test.each([[1]])('n=%i', () => {});",
+            "  });",
+            "  test.skip(`subs`, () => {});",
+            "});",
+            "const item = items.find((x) => x);",
+            "test('top', () => {});",
+        ]
+        .join("\n");
+        let ts = detect(&src, "src/math.test.ts");
+        assert_eq!(
+            pick(&ts),
+            [
+                (0, Kind::Suite, "math".into()),
+                (1, Kind::Test, "math/adds".into()),
+                (2, Kind::Suite, "math/nested".into()),
+                (3, Kind::Test, "math/nested/n=%i".into()),
+                (5, Kind::Test, "math/subs".into()),
+                (8, Kind::Test, "top".into()),
+            ]
+        );
+        assert_eq!(js_name_pattern(&ts[1]), "^math adds$");
+        assert_eq!(js_name_pattern(&ts[3]), "^math nested n=.*$");
+        assert_eq!(js_name_pattern(&ts[0]), "^math");
+        assert!(detect("test('x', () => {})", "src/math.ts").is_empty());
+    }
+
+    #[test]
+    fn python_and_go() {
+        let src = "class TestCalc:\n    def test_add(self):\n        pass\ndef test_top():\n    pass\nclass Helper:\n    def test_no(self):\n        pass\nif __name__ == '__main__':\n    main()\n";
+        assert_eq!(
+            pick(&detect(src, "tests/test_calc.py")),
+            [
+                (0, Kind::Suite, "TestCalc".into()),
+                (1, Kind::Test, "TestCalc/test_add".into()),
+                (3, Kind::Test, "test_top".into()),
+                (8, Kind::Main, String::new()),
+            ]
+        );
+        let go = "package calc\n\nfunc TestAdd(t *testing.T) {\n\tt.Run(\"zero case\", func(t *testing.T) {})\n}\n";
+        assert_eq!(
+            pick(&detect(go, "calc_test.go")),
+            [(2, Kind::Test, "TestAdd".into()), (3, Kind::Test, "TestAdd/zero_case".into())]
+        );
+    }
+
+    #[test]
+    fn narrows_cargo_test_configs() {
+        let root = Path::new("/p");
+        let mut test = blank("cargo:test".into(), "test", "cargo", "cargo".into(), vec!["test".into()]);
+        test.is_test = true;
+        let configs = vec![test];
+        let src = "#[cfg(test)]\nmod tests {\n    #[test]\n    fn adds() {}\n}\n";
+        let ts = detect(src, "src/math.rs");
+        let c = target_config(root, &ts[1], "src/math.rs", &configs, src).unwrap();
+        assert_eq!(c.args, ["test", "--", "math::tests::adds", "--exact"]);
+        let c = target_config(root, &ts[0], "src/math.rs", &configs, src).unwrap();
+        assert_eq!(c.args, ["test", "--", "math::tests::"]);
+    }
+
+    #[test]
+    fn cargo_test_args_get_one_separator() {
+        let root = Path::new("/p");
+        let mut test =
+            blank("cargo:test".into(), "test", "cargo", "cargo".into(), vec!["test".into(), "--".into(), "-q".into()]);
+        test.is_test = true;
+        let configs = vec![test];
+        let src = "#[test]\nfn adds() {}\n";
+        let ts = detect(src, "tests/math.rs");
+        let c = target_config(root, &ts[0], "tests/math.rs", &configs, src).unwrap();
+        assert_eq!(c.args, ["test", "--test", "math", "--", "-q", "adds", "--exact"]);
+    }
+
+    #[test]
+    fn a_line_in_a_body_picks_the_enclosing_target() {
+        let names = |src: &str, rel: &str, line: usize| -> Vec<String> {
+            enclosing(src, rel, line).iter().map(|t| t.path.join("/")).collect()
+        };
+        let rust = [
+            "#[cfg(test)]",
+            "mod tests {",
+            "    #[test]",
+            "    fn adds(",
+            "        x: u8,",
+            "    ) {",
+            "        let s = \"}\";",
+            "        assert!(true);",
+            "    }",
+            "",
+            "    fn helper() {}",
+            "}",
+        ]
+        .join("\n");
+        assert_eq!(names(&rust, "src/math.rs", 7), ["math/tests/adds", "math/tests"]);
+        assert_eq!(names(&rust, "src/math.rs", 4), ["math/tests/adds", "math/tests"]);
+        assert_eq!(names(&rust, "src/math.rs", 10), ["math/tests"]);
+
+        let js = "describe('math', () => {\n  it('adds', () => {\n    expect(1).toBe(1);\n  });\n  it('one', fn);\n  const x = 1;\n});\n";
+        assert_eq!(names(js, "src/math.test.ts", 2), ["math/adds", "math"]);
+        assert_eq!(names(js, "src/math.test.ts", 5), ["math"]);
+
+        let py = "class TestCalc:\n    def test_add(self):\n        x = 1\n\n        assert x\n    def helper(self):\n        pass\n";
+        assert_eq!(names(py, "tests/test_calc.py", 4), ["TestCalc/test_add", "TestCalc"]);
+        assert_eq!(names(py, "tests/test_calc.py", 6), ["TestCalc"]);
+
+        let go = "package calc\n\nfunc TestAdd(t *testing.T) {\n\tt.Run(\"zero\", func(t *testing.T) {\n\t\tx := 0\n\t})\n\ty := 1\n}\n";
+        assert_eq!(names(go, "calc_test.go", 4), ["TestAdd/zero", "TestAdd"]);
+        assert_eq!(names(go, "calc_test.go", 6), ["TestAdd"]);
+        assert!(names(go, "calc_test.go", 0).is_empty());
+    }
+}
@@ -0,0 +1,901 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (mcpserver.toolsets/src/general/SearchToolset.kt,
+// SearchSymbolSupport.kt), Apache-2.0.
+//! Text, regex, file and symbol search.
+//!
+//! Coordinates are 1-based, end exclusive; columns count UTF-16 code units like
+//! the editor (one per character except emoji and other astral characters).
+
+use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
+use crate::mcp::util::{INDEXING_PARTIAL_RESULT_REASON, MEDIUM_TIMEOUT};
+use crate::ops::search::SearchEvent;
+use globset::{GlobBuilder, GlobSet, GlobSetBuilder};
+use ide_core::{CancellationToken, IdeError, IdeResult, Location, Range};
+use ide_search::{FileMask, FileMatches, SearchQuery, SearchScope, SearchSummary};
+use ide_vfs::EntryKind;
+use parking_lot::Mutex;
+use serde::Serialize;
+use serde_json::{Value, json};
+use std::cell::Cell;
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+pub const MAX_RESULTS_UPPER_BOUND: usize = 5000;
+const DEFAULT_LIMIT: i64 = 1000;
+pub const SYMBOL_SEARCH_DEFAULT_LIMIT: i64 = 50;
+pub const SEARCH_TIMEOUT_PARTIAL_RESULT_REASON: &str =
+    "The search timed out after 10 s. Narrow the query or pass paths.";
+/// Symbols requested from the index per result when `paths` filters them afterwards.
+const SYMBOL_POOL_FACTOR: usize = 20;
+const MAX_SYMBOL_POOL: usize = 20_000;
+/// Matches Find in Files may report, per result asked for, when `paths` are filtered afterwards.
+const UNMASKED_MATCH_FACTOR: usize = 20;
+const MIN_UNMASKED_MATCHES: usize = 10_000;
+/// UTF-16 units of a line Find in Files reports (`ide_search`'s line window); matches
+/// outside the window of a longer line are left out.
+const LINE_WINDOW: usize = 500;
+
+const PATHS_DESCRIPTION: &str = "Optional list of project-relative glob patterns to filter results. Supports '!' \
+excludes. Trailing '/' expands to '**'. Patterns without '/' are treated as '**/pattern'. Empty strings are ignored.";
+const LIMIT_DESCRIPTION: &str = "Maximum number of results to return";
+
+pub fn tools() -> Vec<Tool> {
+    vec![search_text(), search_regex(), search_symbol(), search_file()]
+}
+
+fn search_text() -> Tool {
+    Tool::new(
+        "search_text",
+        "Searches for a text substring within project files.
+Use this tool for fast text search with match coordinates.
+Results include match coordinates when available (1-based line/column, end exclusive).
+
+Paths are glob patterns relative to the project root.
+Examples: [\"src/**\", \"!**/test/**\"], [\"**/*.kt\"], [\"foo/\"].",
+        |call| async move { text_search(call, false).await },
+    )
+    .param(Param::required("q", ParamType::String, "Text to search for"))
+    .param(Param::optional("paths", ParamType::StringList, PATHS_DESCRIPTION))
+    .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .output(result_schema())
+}
+
+fn search_regex() -> Tool {
+    Tool::new(
+        "search_regex",
+        "Searches for regex matches within project files.
+Use this tool when you need regex search with match coordinates.
+Results include match coordinates when available (1-based line/column, end exclusive).
+The pattern uses Rust regex syntax and is case-sensitive; prefix `(?i)` to ignore case.
+
+Paths are glob patterns relative to the project root.
+Examples: [\"src/**\", \"!**/test/**\"], [\"**/*.kt\"], [\"foo/\"].",
+        |call| async move { text_search(call, true).await },
+    )
+    .param(Param::required("q", ParamType::String, "Regex pattern to search for"))
+    .param(Param::optional("paths", ParamType::StringList, PATHS_DESCRIPTION))
+    .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .output(result_schema())
+}
+
+fn search_symbol() -> Tool {
+    Tool::new(
+        "search_symbol",
+        "Searches for symbols (classes, methods, fields).
+Use this tool for semantic lookup by identifier fragments.
+Results include match coordinates when available (1-based line/column, end exclusive).
+
+Paths are glob patterns relative to the project root.
+By default this searches project symbols only.
+If you don't find a suitable result, try again with include_external=true to search SDK and library symbols too.",
+        |call| async move { symbol_search(call).await },
+    )
+    .param(Param::required("q", ParamType::String, "Symbol query text"))
+    .param(Param::optional("paths", ParamType::StringList, PATHS_DESCRIPTION))
+    .param(Param::optional(
+        "include_external",
+        ParamType::Boolean,
+        "Whether to include SDK and library symbols. Disabled by default; if nothing suitable is found, try again \
+with include_external=true.",
+    ))
+    .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .output(result_schema())
+}
+
+fn search_file() -> Tool {
+    Tool::new(
+        "search_file",
+        "Searches for files by glob pattern within the project.
+Use this tool when you need to match file paths using glob syntax.
+
+Glob patterns are relative to the project root.
+Examples: \"**/*.kt\", \"src/**/Foo*.java\", \"build.gradle.kts\".
+Patterns without '/' are treated as \"**/pattern\".
+Paths are optional additional glob filters relative to the project root.",
+        |call| async move { file_search(call).await },
+    )
+    .param(Param::required("q", ParamType::String, "Glob pattern to search for"))
+    .param(Param::optional("paths", ParamType::StringList, PATHS_DESCRIPTION))
+    .param(Param::optional(
+        "includeExcluded",
+        ParamType::Boolean,
+        "Whether to include excluded/ignored files in results",
+    ))
+    .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .output(result_schema())
+}
+
+// --- results -------------------------------------------------------------------
+
+/// One hit. Every search tool returns these, so they share one schema: `search_file`
+/// fills only `filePath`, only `search_symbol` fills `name` and `container`.
+#[derive(Serialize, Debug, Default, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+struct SearchItem {
+    file_path: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    start_line: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    start_column: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    end_line: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    end_column: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    name: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    container: Option<String>,
+}
+
+impl SearchItem {
+    fn at(file_path: String, r: Range) -> Self {
+        Self {
+            file_path,
+            start_line: Some(r.start.line + 1),
+            start_column: Some(r.start.col + 1),
+            end_line: Some(r.end.line + 1),
+            end_column: Some(r.end.col + 1),
+            ..Default::default()
+        }
+    }
+}
+
+/// Empty fields are left out, so a search without hits is `{}`.
+#[derive(Serialize, Default)]
+#[serde(rename_all = "camelCase")]
+struct SearchResult {
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    items: Vec<SearchItem>,
+    #[serde(skip_serializing_if = "std::ops::Not::not")]
+    more: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    partial_result_reason: Option<&'static str>,
+}
+
+fn result_schema() -> Value {
+    let int = json!({ "type": "integer" });
+    let string = json!({ "type": "string" });
+    json!({
+        "type": "object",
+        "properties": {
+            "items": { "type": "array", "items": {
+                "type": "object",
+                "properties": {
+                    "filePath": string, "startLine": int, "startColumn": int, "endLine": int, "endColumn": int,
+                    "name": string, "container": string,
+                },
+                "required": ["filePath"],
+            } },
+            "more": { "type": "boolean" },
+            "partialResultReason": string,
+        },
+    })
+}
+
+fn limit(call: &Call, default: i64) -> IdeResult<usize> {
+    match call.opt_i64("limit")?.unwrap_or(default) {
+        n if n <= 0 => Err(IdeError::invalid("limit must be > 0")),
+        n => Ok((n as usize).min(MAX_RESULTS_UPPER_BOUND)),
+    }
+}
+
+fn query(call: &Call, empty: &str) -> IdeResult<String> {
+    let q = call.str("q")?;
+    if q.trim().is_empty() {
+        return Err(IdeError::invalid(empty));
+    }
+    Ok(q)
+}
+
+// --- path globs ----------------------------------------------------------------
+
+/// The `paths` argument: project-relative globs, `!` excludes.
+struct PathScope {
+    /// `None` when only excludes were given (everything is included).
+    include: Option<GlobSet>,
+    exclude: GlobSet,
+    /// The globs as `FileMask` masks for Find in Files (`{a,b}` expanded, as masks
+    /// split on commas), `None` when they cannot be expressed.
+    masks: Option<(Vec<String>, Vec<String>)>,
+}
+
+impl PathScope {
+    fn new(root: &Path, patterns: &[String]) -> IdeResult<Self> {
+        let (mut include, mut exclude) = (GlobSetBuilder::new(), GlobSetBuilder::new());
+        let (mut include_masks, mut exclude_masks) = (Vec::new(), Vec::new());
+        let mut has_include = false;
+        let mut maskable = true;
+        for raw in patterns {
+            let raw = raw.trim();
+            if raw.is_empty() {
+                continue;
+            }
+            let (negated, pattern) = match raw.strip_prefix('!') {
+                Some(rest) if rest.trim().is_empty() => return Err(IdeError::invalid("Exclude pattern is empty")),
+                Some(rest) => (true, rest.trim()),
+                None => (false, raw),
+            };
+            let mut glob = normalize_glob(pattern, root)?;
+            // A path naming an existing directory covers the files below it.
+            if index_of_glob_char(&glob).is_none() && root.join(&glob).is_dir() {
+                glob.push_str("/**");
+            }
+            let alternatives = expand_braces(&glob);
+            maskable &= alternatives.is_some();
+            let (set, masks) =
+                if negated { (&mut exclude, &mut exclude_masks) } else { (&mut include, &mut include_masks) };
+            set.add(build_glob(&glob)?);
+            masks.extend(alternatives.into_iter().flatten());
+            has_include |= !negated;
+        }
+        let build = |b: GlobSetBuilder| b.build().map_err(|e| IdeError::invalid(format!("Invalid glob pattern: {e}")));
+        Ok(Self {
+            include: if has_include { Some(build(include)?) } else { None },
+            exclude: build(exclude)?,
+            masks: maskable.then_some((include_masks, exclude_masks)),
+        })
+    }
+
+    fn is_all(&self) -> bool {
+        self.include.is_none() && self.exclude.is_empty()
+    }
+
+    /// `path` is project-relative with `/` (absolute outside the project).
+    fn matches(&self, path: &str) -> bool {
+        self.include.as_ref().is_none_or(|s| s.is_match(path)) && !self.exclude.is_match(path)
+    }
+}
+
+/// A glob as a project-relative pattern: `\` → `/`, leading `./` dropped, `dir/` → `dir/**`,
+/// `name` → `**/name`, and its leading directories (`..`, absolute paths) resolved against
+/// `root`. Errors when that points outside the project.
+fn normalize_glob(raw: &str, root: &Path) -> IdeResult<String> {
+    let mut value = raw.trim().replace('\\', "/");
+    if value.is_empty() {
+        return Err(IdeError::invalid("Glob pattern is empty"));
+    }
+    while let Some(rest) = value.strip_prefix("./") {
+        value = rest.to_owned();
+    }
+    if value.ends_with('/') {
+        let dir = value.trim_end_matches('/');
+        value = if dir.is_empty() { "**".into() } else { format!("{dir}/**") };
+    }
+    if !value.contains('/') {
+        value = format!("**/{value}");
+    }
+    let value = normalize_path_pattern(&value, root)?;
+    if value.is_empty() {
+        return Err(IdeError::invalid(format!("Invalid glob pattern: {raw}")));
+    }
+    Ok(value)
+}
+
+/// Resolves the whole directory segments before the first glob character against `root`.
+/// (JetBrains resolves up to the glob character itself, turning `src/Foo*.java` into
+/// `src/Foo/*.java`; only whole segments are resolved here.)
+fn normalize_path_pattern(pattern: &str, root: &Path) -> IdeResult<String> {
+    let outside = || {
+        IdeError::invalid(format!("Specified path '{pattern}' points to the location outside of the project directory"))
+    };
+    let prefix_len = match index_of_glob_char(pattern) {
+        None => pattern.len(),
+        Some(i) => pattern[..i].rfind('/').map_or(0, |slash| slash + 1),
+    };
+    let prefix = pattern[..prefix_len].trim_end_matches('/');
+    if prefix.is_empty() {
+        if is_absolute_pattern(pattern) {
+            return Err(outside());
+        }
+        return Ok(pattern.to_owned());
+    }
+    let prefix_path = Path::new(prefix);
+    let absolute = crate::mcp::tool::normalize(&if prefix_path.is_absolute() {
+        prefix_path.to_path_buf()
+    } else {
+        root.join(prefix_path)
+    });
+    let relative = relative_to_root(root, &absolute).ok_or_else(outside)?;
+    let suffix = pattern[prefix_len..].trim_start_matches('/');
+    Ok(match (relative.is_empty(), suffix.is_empty()) {
+        (true, _) => suffix.to_owned(),
+        (false, true) => relative,
+        (false, false) => format!("{relative}/{suffix}"),
+    })
+}
+
+/// `path` relative to `root` with `/`, also when one of them is spelled through a symlink
+/// (`/var` and `/private/var`); `None` outside `root`.
+fn relative_to_root(root: &Path, path: &Path) -> Option<String> {
+    let rel = match path.strip_prefix(root) {
+        Ok(rel) => rel.to_path_buf(),
+        Err(_) => {
+            let canon_root = dunce::canonicalize(root).ok()?;
+            let existing = path.ancestors().find(|a| a.exists())?;
+            let real = dunce::canonicalize(existing).ok()?.join(path.strip_prefix(existing).ok()?);
+            real.strip_prefix(&canon_root).ok()?.to_path_buf()
+        }
+    };
+    Some(rel.to_string_lossy().replace('\\', "/"))
+}
+
+fn is_absolute_pattern(pattern: &str) -> bool {
+    let b = pattern.as_bytes();
+    pattern.starts_with('/') || (b.len() >= 3 && b[1] == b':' && b[2] == b'/')
+}
+
+fn index_of_glob_char(pattern: &str) -> Option<usize> {
+    pattern.find(['*', '?', '[', ']', '{', '}'])
+}
+
+/// At most this many masks per glob from expanding its `{a,b}` groups.
+const MAX_BRACE_ALTERNATIVES: usize = 64;
+
+/// `glob` with its `{a,b}` groups expanded into separate globs without commas, for
+/// `FileMask` (which splits on them). `None` for nested groups, braces or commas in a
+/// character class, a comma outside a group, an unbalanced brace, or too many results.
+fn expand_braces(glob: &str) -> Option<Vec<String>> {
+    let mut out = vec![String::new()];
+    let mut chars = glob.chars();
+    let mut in_class = false;
+    while let Some(c) = chars.next() {
+        match c {
+            '{' | '}' | ',' if in_class => return None,
+            '[' => {
+                in_class = true;
+                out.iter_mut().for_each(|o| o.push(c));
+            }
+            ']' => {
+                in_class = false;
+                out.iter_mut().for_each(|o| o.push(c));
+            }
+            '{' => {
+                let mut group = String::new();
+                loop {
+                    match chars.next()? {
+                        '}' => break,
+                        '{' | '[' | ']' => return None,
+                        g => group.push(g),
+                    }
+                }
+                let options: Vec<&str> = group.split(',').collect();
+                if out.len() * options.len() > MAX_BRACE_ALTERNATIVES {
+                    return None;
+                }
+                out = out.iter().flat_map(|o| options.iter().map(move |a| format!("{o}{a}"))).collect();
+            }
+            '}' | ',' => return None,
+            _ => out.iter_mut().for_each(|o| o.push(c)),
+        }
+    }
+    (!in_class).then_some(out)
+}
+
+/// `**/` matches zero or more directories; case follows the file system (insensitive on
+/// macOS and Windows, like Find in Files' masks).
+fn build_glob(glob: &str) -> IdeResult<globset::Glob> {
+    GlobBuilder::new(glob)
+        .literal_separator(true)
+        .backslash_escape(false)
+        .case_insensitive(cfg!(any(target_os = "macos", target_os = "windows")))
+        .build()
+        .map_err(|_| IdeError::invalid(format!("Invalid glob pattern: {glob}")))
+}
+
+// --- text / regex --------------------------------------------------------------
+
+/// A match before it becomes a [`SearchItem`]; 1-based, end exclusive.
+struct TextHit {
+    file_path: String,
+    line: u32,
+    column: u32,
+    end_line: u32,
+    end_column: u32,
+}
+
+async fn text_search(call: Call, is_regex: bool) -> IdeResult<Output> {
+    let pattern = query(&call, if is_regex { "Regex pattern is empty" } else { "Search text is empty" })?;
+    let limit = limit(&call, DEFAULT_LIMIT)?;
+    let scope = PathScope::new(call.root(), &call.str_list("paths")?)?;
+    // Globs Find in Files cannot take are applied afterwards, so the engine must not
+    // stop at `limit` matches the filter may drop.
+    let (masks, max_matches) = match scope.masks.clone() {
+        // One more than asked tells whether there are more.
+        Some(masks) => (masks, (limit + 1) as u32),
+        // Bounded all the same (as the symbol pool): past it the result reports `more`.
+        None => {
+            let budget = ((limit + 1) * UNMASKED_MATCH_FACTOR).max(MIN_UNMASKED_MATCHES);
+            (Default::default(), u32::try_from(budget).unwrap_or(u32::MAX))
+        }
+    };
+    let (include, exclude) = masks;
+    let query = SearchQuery {
+        pattern: pattern.clone(),
+        is_regex,
+        case_sensitive: true,
+        whole_word: false,
+        include,
+        exclude,
+        scope: SearchScope::Project,
+        max_matches,
+        context: Default::default(),
+    };
+    if is_regex && let Err(e) = ide_search::match_ranges("", &query) {
+        return Err(IdeError::invalid(format!("Invalid regex pattern: {pattern} ({})", e.message)));
+    }
+    let (files, summary, timed_out) = run_search(&call, query.clone()).await?;
+    // Content roots outside the project are reported by absolute path.
+    let mut files: Vec<(String, FileMatches)> =
+        files.into_iter().map(|f| (call.display(&f.path.0), f)).filter(|(path, _)| scope.matches(path)).collect();
+    files.sort_by(|a, b| a.0.cmp(&b.0));
+    // Only these can match a line break.
+    let may_span = is_regex || pattern.contains('\n');
+    let mut hits = Vec::new();
+    let mut spanning = Vec::new();
+    let host = call.host();
+    for (path, file) in &files {
+        if hits.len() > limit {
+            break;
+        }
+        // Find in Files keeps a window of very long lines and drops the matches outside it:
+        // such lines are matched again in the file's whole text.
+        let long = |m: &ide_search::LineMatch| m.text_offset > 0 || m.text.encode_utf16().count() + 1 >= LINE_WINDOW;
+        let whole = if file.matches.iter().any(long) {
+            crate::ops::fs::read_text(&host, call.window(), file.path.0.clone())
+                .await
+                .ok()
+                .and_then(|text| Some((ide_search::match_ranges(&text, &query).ok()?, text)))
+        } else {
+            None
+        };
+        for m in &file.matches {
+            if let Some((ranges, text)) = &whole
+                && long(m)
+            {
+                hits.extend(line_hits(path, text, ranges, m.line));
+                continue;
+            }
+            let line_end = m.text_offset + m.text.encode_utf16().count() as u32;
+            for &(a, b) in &m.ranges {
+                let (a, b) = (m.text_offset + a, m.text_offset + b);
+                if may_span && b == line_end && hits.len() < limit {
+                    spanning.push((hits.len(), file.path.0.clone()));
+                }
+                hits.push(TextHit {
+                    file_path: path.clone(),
+                    line: m.line + 1,
+                    column: a + 1,
+                    end_line: m.line + 1,
+                    end_column: b + 1,
+                });
+            }
+        }
+    }
+    let more = hits.len() > limit || summary.limit_hit || timed_out;
+    hits.truncate(limit);
+    extend_spanning(&call, &query, &mut hits, spanning).await;
+    let items = hits
+        .into_iter()
+        .map(|h| SearchItem {
+            file_path: h.file_path,
+            start_line: Some(h.line),
+            start_column: Some(h.column),
+            end_line: Some(h.end_line),
+            end_column: Some(h.end_column),
+            ..Default::default()
+        })
+        .collect();
+    let partial_result_reason = timed_out.then_some(SEARCH_TIMEOUT_PARTIAL_RESULT_REASON);
+    Output::json(SearchResult { items, more, partial_result_reason })
+}
+
+/// The matches of `ranges` (byte ranges in `text`) that start on 0-based `line`, with their
+/// real end (on a later line for a match spanning lines).
+fn line_hits(path: &str, text: &str, ranges: &[(usize, usize)], line: u32) -> Vec<TextHit> {
+    let starts: Vec<usize> = std::iter::once(0).chain(text.match_indices('\n').map(|(i, _)| i + 1)).collect();
+    let Some(&line_start) = starts.get(line as usize) else { return Vec::new() };
+    let line_end = starts.get(line as usize + 1).map_or(text.len(), |s| s - 1);
+    let column = |at: usize| -> (u32, u32) {
+        let l = starts.partition_point(|&s| s <= at) - 1;
+        (l as u32 + 1, text[starts[l]..at].encode_utf16().count() as u32 + 1)
+    };
+    let first = ranges.partition_point(|r| r.0 < line_start);
+    ranges[first..]
+        .iter()
+        .take_while(|r| r.0 <= line_end)
+        .map(|&(a, b)| {
+            let (end_line, end_column) = column(b);
+            TextHit { file_path: path.to_owned(), line: line + 1, column: column(a).1, end_line, end_column }
+        })
+        .collect()
+}
+
+/// A file's path, text, line start offsets and match byte ranges.
+type FileText = (PathBuf, String, Vec<usize>, Vec<(usize, usize)>);
+
+/// Find in Files reports only the first line of a match that spans lines: matches
+/// ending at a line end get their real end from matching the file's text again.
+async fn extend_spanning(call: &Call, query: &SearchQuery, hits: &mut [TextHit], spanning: Vec<(usize, PathBuf)>) {
+    let host = call.host();
+    let mut current: Option<FileText> = None;
+    for (i, path) in spanning {
+        if current.as_ref().is_none_or(|(p, ..)| p != &path) {
+            let Ok(text) = crate::ops::fs::read_text(&host, call.window(), path.clone()).await else { continue };
+            let Ok(ranges) = ide_search::match_ranges(&text, query) else { continue };
+            let starts = std::iter::once(0).chain(text.match_indices('\n').map(|(i, _)| i + 1)).collect();
+            current = Some((path, text, starts, ranges));
+        }
+        let Some((_, text, starts, ranges)) = &current else { continue };
+        let h = &mut hits[i];
+        let Some(&line_start) = starts.get(h.line as usize - 1) else { continue };
+        let Some(start) = byte_at(&text[line_start..], h.column - 1).map(|b| line_start + b) else { continue };
+        let Ok(found) = ranges.binary_search_by_key(&start, |r| r.0) else { continue };
+        let end = ranges[found].1;
+        let end_line = starts.partition_point(|&s| s <= end) - 1;
+        h.end_line = end_line as u32 + 1;
+        h.end_column = text[starts[end_line]..end].encode_utf16().count() as u32 + 1;
+    }
+}
+
+/// The byte offset of UTF-16 column `col` in `line`.
+fn byte_at(line: &str, col: u32) -> Option<usize> {
+    let mut units = 0;
+    for (i, c) in line.char_indices() {
+        if units == col {
+            return Some(i);
+        }
+        units += c.len_utf16() as u32;
+    }
+    (units == col).then_some(line.len())
+}
+
+/// Runs Find in Files for at most [`MEDIUM_TIMEOUT`], cancelling it when the call is
+/// cancelled. Returns what was found and whether the time ran out.
+async fn run_search(call: &Call, query: SearchQuery) -> IdeResult<(Vec<FileMatches>, SearchSummary, bool)> {
+    let host = call.host();
+    let request = crate::mcp::tool::request_id();
+    let files = Arc::new(Mutex::new(Vec::new()));
+    let done = Arc::new(Mutex::new(None));
+    let emit: crate::ops::Emit<SearchEvent> = {
+        let (files, done) = (files.clone(), done.clone());
+        Arc::new(move |event| match event {
+            SearchEvent::File { file } => files.lock().push(file),
+            SearchEvent::Done { summary } => *done.lock() = Some(summary),
+        })
+    };
+    let search = crate::ops::search::start(&host, call.window(), request, query, emit);
+    tokio::pin!(search);
+    let mut timed_out = false;
+    tokio::select! {
+        r = &mut search => r?,
+        _ = call.cancel.cancelled() => {
+            host.cancel_request(request);
+            let _ = search.await;
+            return Err(IdeError::cancelled());
+        }
+        _ = tokio::time::sleep(MEDIUM_TIMEOUT) => {
+            host.cancel_request(request);
+            let _ = search.await;
+            timed_out = true;
+        }
+    }
+    let summary = done.lock().take().unwrap_or_default();
+    if summary.cancelled && !timed_out {
+        return Err(IdeError::cancelled());
+    }
+    let files = std::mem::take(&mut *files.lock());
+    Ok((files, summary, timed_out))
+}
+
+// --- files ---------------------------------------------------------------------
+
+async fn file_search(call: Call) -> IdeResult<Output> {
+    let q = query(&call, "Glob pattern is empty")?;
+    let limit = limit(&call, DEFAULT_LIMIT)?;
+    let scope = PathScope::new(call.root(), &call.str_list("paths")?)?;
+    let include_excluded = call.flag("includeExcluded", false)?;
+    let glob = GlobSetBuilder::new()
+        .add(build_glob(&normalize_glob(&q, call.root())?)?)
+        .build()
+        .map_err(|_| IdeError::invalid(format!("Invalid glob pattern: {q}")))?;
+    // Ignored names and "Exclude files" patterns, which `read_dir` does not flag.
+    let excludes = if include_excluded { None } else { Some(FileMask::new(&[], &call.project().search_excludes())?) };
+    let root = call.root().to_path_buf();
+    // The project folder and the content roots outside it.
+    let roots: Vec<PathBuf> = std::iter::once(root.clone())
+        .chain(call.project().content_roots().into_iter().filter(|r| relative_to_root(&root, r).is_none()))
+        .collect();
+    let host = call.host();
+    let walk = Walk {
+        host: host.clone(),
+        window: call.window().to_owned(),
+        root,
+        include_excluded,
+        excludes,
+        glob,
+        scope,
+        limit,
+        cancel: call.cancel.clone(),
+        deadline: Instant::now() + MEDIUM_TIMEOUT,
+        timed_out: Cell::new(false),
+    };
+    let (paths, more, timed_out) = host
+        .blocking(move || {
+            let mut found = Vec::new();
+            let more = roots.iter().any(|base| walk.dir(base, base, &mut found));
+            if walk.cancel.is_cancelled() {
+                return Err(IdeError::cancelled());
+            }
+            Ok((found, more, walk.timed_out.get()))
+        })
+        .await?;
+    let items = paths.into_iter().map(|file_path| SearchItem { file_path, ..Default::default() }).collect();
+    let partial_result_reason = timed_out.then_some(SEARCH_TIMEOUT_PARTIAL_RESULT_REASON);
+    Output::json(SearchResult { items, more, partial_result_reason })
+}
+
+struct Walk {
+    host: Arc<crate::Host>,
+    window: String,
+    root: PathBuf,
+    include_excluded: bool,
+    excludes: Option<FileMask>,
+    glob: GlobSet,
+    scope: PathScope,
+    limit: usize,
+    cancel: CancellationToken,
+    deadline: Instant,
+    timed_out: Cell<bool>,
+}
+
+impl Walk {
+    /// Collects matching files under `dir` (inside the walked root `base`) depth first in
+    /// name order; true when it stopped early: more than `limit` match or the time ran out.
+    fn dir(&self, dir: &Path, base: &Path, found: &mut Vec<String>) -> bool {
+        let Ok(mut entries) = tokio::runtime::Handle::current().block_on(crate::ops::fs::read_dir(
+            &self.host,
+            &self.window,
+            dir.to_path_buf(),
+        )) else {
+            return false;
+        };
+        entries.sort_by(|a, b| a.name.cmp(&b.name));
+        for entry in entries {
+            if self.cancel.is_cancelled() {
+                return false;
+            }
+            if Instant::now() >= self.deadline {
+                self.timed_out.set(true);
+                return true;
+            }
+            if entry.name == ".git" || (!self.include_excluded && (entry.ignored || entry.excluded)) {
+                continue;
+            }
+            let Ok(in_base) = entry.path.strip_prefix(base) else { continue };
+            if self.excludes.as_ref().is_some_and(|m| !m.matches(&in_base.to_string_lossy().replace('\\', "/"))) {
+                continue;
+            }
+            match entry.kind {
+                // Symlinked directories are not followed (they may loop).
+                EntryKind::Dir => {
+                    if self.dir(&entry.path, base, found) {
+                        return true;
+                    }
+                }
+                EntryKind::File => {
+                    // Files of content roots outside the project go by absolute path.
+                    let path = relative_to_root(&self.root, &entry.path)
+                        .unwrap_or_else(|| entry.path.to_string_lossy().into_owned());
+                    if self.glob.is_match(&path) && self.scope.matches(&path) {
+                        if found.len() == self.limit {
+                            return true;
+                        }
+                        found.push(path);
+                    }
+                }
+                _ => {}
+            }
+        }
+        false
+    }
+}
+
+// --- symbols -------------------------------------------------------------------
+
+async fn symbol_search(call: Call) -> IdeResult<Output> {
+    let started = Instant::now();
+    let q = query(&call, "Search query is empty")?;
+    let limit = limit(&call, SYMBOL_SEARCH_DEFAULT_LIMIT)?;
+    let scope = PathScope::new(call.root(), &call.str_list("paths")?)?;
+    let external = call.flag("include_external", false)?;
+    let host = call.host();
+    let project = call.project().clone();
+    let indexing_before = project.index.status().indexing;
+    let pool = if scope.is_all() { limit + 1 } else { ((limit + 1) * SYMBOL_POOL_FACTOR).min(MAX_SYMBOL_POOL) };
+    let found = {
+        let (project, q) = (project.clone(), q.clone());
+        host.blocking(move || Ok(project.index.find_symbols(&q, ide_index::SymbolFilter::All, pool))).await?
+    };
+    let mut items: Vec<SearchItem> = found
+        .into_iter()
+        .filter(|s| scope.matches(&s.rel_path))
+        .map(|s| SearchItem {
+            name: Some(s.name),
+            container: s.container.filter(|c| !c.is_empty()),
+            ..SearchItem::at(s.rel_path, s.range)
+        })
+        .collect();
+    let mut timed_out = false;
+    if external && items.len() <= limit {
+        let budget = MEDIUM_TIMEOUT.saturating_sub(started.elapsed());
+        let (symbols, out_of_time) = workspace_symbols(&call, &q, budget).await;
+        timed_out = out_of_time;
+        for (name, container, location) in symbols {
+            let path = location.uri.clone().unwrap_or_else(|| call.display(&location.path));
+            // Project files obey `paths`; library symbols are what was asked for.
+            let inside = location.uri.is_none() && !Path::new(&path).is_absolute();
+            if inside && !scope.matches(&path) {
+                continue;
+            }
+            let item = SearchItem {
+                name: Some(name),
+                container: container.filter(|c| !c.is_empty()),
+                ..SearchItem::at(path, location.range)
+            };
+            if !items
+                .iter()
+                .any(|e| e.name == item.name && e.file_path == item.file_path && e.start_line == item.start_line)
+            {
+                items.push(item);
+            }
+            if items.len() > limit {
+                break;
+            }
+        }
+    }
+    let more = items.len() > limit || timed_out;
+    items.truncate(limit);
+    let indexing = indexing_before || project.index.status().indexing;
+    let partial_result_reason = if indexing {
+        Some(INDEXING_PARTIAL_RESULT_REASON)
+    } else {
+        timed_out.then_some(SEARCH_TIMEOUT_PARTIAL_RESULT_REASON)
+    };
+    Output::json(SearchResult { items, more, partial_result_reason })
+}
+
+/// The language servers' workspace symbols, and whether `budget` ran out first; empty
+/// when none runs or they fail.
+async fn workspace_symbols(call: &Call, q: &str, budget: Duration) -> (Vec<(String, Option<String>, Location)>, bool) {
+    let host = call.host();
+    let request = crate::mcp::tool::request_id();
+    let symbols = crate::ops::lsp::lsp_workspace_symbols(&host, call.window(), request, q.to_owned());
+    tokio::pin!(symbols);
+    let result = tokio::select! {
+        r = tokio::time::timeout(budget, &mut symbols) => r.ok(),
+        _ = call.cancel.cancelled() => None,
+    };
+    match result {
+        Some(Ok(symbols)) => (symbols.into_iter().map(|s| (s.name, s.container, s.location)).collect(), false),
+        Some(Err(e)) => {
+            tracing::debug!("MCP search_symbol: workspace symbols: {e}");
+            (Vec::new(), false)
+        }
+        None => {
+            host.cancel_request(request);
+            let _ = symbols.await;
+            (Vec::new(), !call.cancel.is_cancelled())
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn root() -> (tempfile::TempDir, PathBuf) {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(dir.path()).unwrap().join("project");
+        std::fs::create_dir_all(root.join("subdir1/nested")).unwrap();
+        (dir, root)
+    }
+
+    fn scope(root: &Path, p: &[&str]) -> PathScope {
+        PathScope::new(root, &p.iter().map(|s| s.to_string()).collect::<Vec<_>>()).unwrap()
+    }
+
+    #[test]
+    fn normalizes_globs() {
+        let (_dir, root) = root();
+        let n = |p: &str| normalize_glob(p, &root);
+        assert_eq!(n("*.rs").unwrap(), "**/*.rs");
+        assert_eq!(n("./foo/bar.txt").unwrap(), "foo/bar.txt");
+        assert_eq!(n("foo/").unwrap(), "foo/**");
+        assert_eq!(n("/").unwrap(), "**/**");
+        assert_eq!(n("./src/**/*.ts").unwrap(), "src/**/*.ts");
+        assert_eq!(n("src\\gen\\*.rs").unwrap(), "src/gen/*.rs");
+        assert_eq!(n("src/a/../Foo*.java").unwrap(), "src/Foo*.java");
+        assert_eq!(n(&root.join("sub/Foo.kt").to_string_lossy()).unwrap(), "sub/Foo.kt");
+        assert_eq!(n(&format!("{}/**/*.kt", root.display())).unwrap(), "**/*.kt");
+        for outside in ["../outside/**", "/elsewhere/*.rs", "/**"] {
+            let err = n(outside).unwrap_err().message;
+            assert!(err.contains("outside of the project directory"), "{outside}: {err}");
+        }
+        assert!(n("  ").unwrap_err().message.contains("Glob pattern is empty"));
+    }
+
+    #[test]
+    fn expands_brace_groups() {
+        let e = |g: &str| expand_braces(g);
+        assert_eq!(e("src/**/*.rs"), Some(vec!["src/**/*.rs".to_owned()]));
+        assert_eq!(e("src/**/*.{ts,tsx}"), Some(vec!["src/**/*.ts".to_owned(), "src/**/*.tsx".to_owned()]));
+        assert_eq!(e("{a,b}/*.{x,y}"), Some(["a/*.x", "a/*.y", "b/*.x", "b/*.y"].map(String::from).to_vec()));
+        assert_eq!(e("a{,.bak}"), Some(vec!["a".to_owned(), "a.bak".to_owned()]));
+        assert_eq!(e("[{]x"), None);
+        assert_eq!(e("{a,{b,c}}"), None);
+        assert_eq!(e("a,b"), None);
+        assert_eq!(e("{a,b"), None);
+        assert_eq!(e("a}"), None);
+        assert_eq!(e(&"{a,b}".repeat(7)), None);
+        assert_eq!(e(&"{a,b}".repeat(6)).map(|v| v.len()), Some(64));
+    }
+
+    #[test]
+    fn utf16_columns_to_bytes() {
+        assert_eq!(byte_at("a😀b", 0), Some(0));
+        assert_eq!(byte_at("a😀b", 3), Some(5));
+        assert_eq!(byte_at("a😀b", 4), Some(6));
+        assert_eq!(byte_at("a😀b", 2), None);
+        assert_eq!(byte_at("ab", 5), None);
+    }
+
+    #[test]
+    fn path_scopes() {
+        let (_dir, root) = root();
+        let root = root.as_path();
+        assert!(scope(root, &[]).is_all());
+        assert!(scope(root, &["", " "]).is_all());
+        let s = scope(root, &["subdir1/**", "!**/*.java"]);
+        assert!(s.matches("subdir1/foo.txt"));
+        assert!(!s.matches("subdir1/foo.java"));
+        assert!(!s.matches("subdir2/foo.txt"));
+        let s = scope(root, &["subdir1/**", "!subdir1/excluded/**"]);
+        assert!(s.matches("subdir1/foo.txt") && !s.matches("subdir1/excluded/foo.txt"));
+        // An existing directory covers the files below it; other names match files only.
+        let s = scope(root, &["subdir1/nested"]);
+        assert!(s.matches("subdir1/nested/foo.txt") && !s.matches("subdir1/other/foo.txt"));
+        let s = scope(root, &["!gen"]);
+        assert!(s.matches("src/gen/a.rs") && !s.matches("src/gen"));
+        let s = scope(root, &["*.rs"]);
+        assert!(s.matches("a.rs") && s.matches("x/y/a.rs") && !s.matches("a.ts"));
+        assert!(s.matches("/abs/content/root/a.rs"));
+        let s = scope(root, &["!*.md"]);
+        assert!(s.matches("a.rs") && !s.matches("docs/a.md"));
+        assert!(scope(root, &["*.{rs,ts}"]).masks.is_some());
+        assert!(scope(root, &["*.{rs,{ts,js}}"]).masks.is_none());
+        let err = |p: &str| PathScope::new(root, &[p.to_owned()]).err().unwrap().message;
+        assert!(err("a[").contains("Invalid glob pattern"));
+        assert!(err("!").contains("Exclude pattern is empty"));
+        assert!(err("../x/**").contains("outside of the project directory"));
+    }
+}
@@ -0,0 +1,264 @@
+//! Quick Documentation through the project's language services.
+use super::tool::{Call, Output, Param, ParamType, Tool};
+use ide_core::{IdeError, IdeResult, Pos, Range};
+use ide_lsp::types::GotoKind;
+use serde::Serialize;
+use serde_json::json;
+use std::path::Path;
+
+pub fn get_symbol_info() -> Tool {
+    Tool::new("get_symbol_info", "Retrieves information about the symbol at the specified position in the specified file.
+Provides the same information as the Quick Documentation feature of the IDE does (the language server's hover).
+
+This tool is useful for getting information about the symbol at the specified position in the specified file.
+The information may include the symbol's name, signature, type, documentation, etc. It depends on a particular language.
+
+If the position has a reference to a symbol the tool will return a piece of code with the declaration of the symbol if possible.
+
+Use this tool to understand symbols declaration, semantics, where it's declared, etc.", get_info)
+    .param(Param::required("filePath", ParamType::String, "Path relative to the project root"))
+    .param(Param::required("line", ParamType::Integer, "1-based line number"))
+    .param(Param::required("column", ParamType::Integer, "1-based UTF-16 column number"))
+}
+
+async fn get_info(call: Call) -> IdeResult<Output> {
+    let path = call.resolve_readable(&call.str("filePath")?).await?;
+    let line = call.opt_i64("line")?.ok_or_else(|| IdeError::invalid("missing line"))?;
+    let col = call.opt_i64("column")?.ok_or_else(|| IdeError::invalid("missing column"))?;
+    let project = call.project.clone();
+    let p = path.clone();
+    struct Document(std::sync::Arc<crate::Project>, ide_core::DocId);
+    impl Drop for Document {
+        fn drop(&mut self) {
+            self.0.documents.close(self.1);
+        }
+    }
+    let (text, document) = call
+        .host
+        .blocking(move || {
+            let text = project.text_of(&p)?;
+            let doc = project.documents.open(&p)?;
+            Ok((text, Document(project, doc.id)))
+        })
+        .await?;
+    let doc = document.1;
+    if line < 1 || line > u32::MAX as i64 {
+        return Err(IdeError::invalid("line is out of bounds"));
+    }
+    let line_text = usize::try_from(line.saturating_sub(1))
+        .ok()
+        .and_then(|l| text.split('\n').nth(l))
+        .ok_or_else(|| IdeError::invalid("Line number is out of bounds of the document"))?;
+    if col < 1 || col as usize > line_text.encode_utf16().count() + 1 {
+        return Err(IdeError::invalid("Column number is out of bounds of the document"));
+    }
+    let pos = Pos::new((line - 1) as u32, (col - 1) as u32);
+    let word = word_at(line_text, char_column(line_text, col as u32));
+    let mut output = json!({"documentation":""});
+    let work = async {
+        let hover = call.project.lsp.hover(doc, pos, call.cancel.clone()).await;
+        let definitions = call.project.lsp.goto(doc, pos, GotoKind::Definition).await;
+        Ok::<_, IdeError>((hover, definitions))
+    };
+    let result = tokio::select! {
+        result = tokio::time::timeout(std::time::Duration::from_secs(20), work) => result,
+        _ = call.cancel.cancelled() => return Err(IdeError::cancelled()),
+    };
+    match result {
+        Ok(Ok((hover, definitions))) => {
+            if let Ok(Some(hover)) = hover {
+                output["documentation"] = hover.contents.value.into();
+            }
+            if let Ok(definitions) = definitions
+                && let Some(location) = definitions.iter().find(|l| l.uri.is_none())
+                && let Some(info) = symbol_info(&call, &location.path, word.clone(), location.range, 1)
+            {
+                output["symbolInfo"] = serde_json::to_value(info).map_err(|e| IdeError::internal(e.to_string()))?;
+            }
+        }
+        Ok(Err(e)) => {
+            output["partialResultReason"] = e.message.into();
+        }
+        Err(_) => {
+            output["partialResultReason"] = "The language server did not answer in time; retry later.".into();
+        }
+    }
+    if output.get("symbolInfo").is_none()
+        && let Some(word) = word
+    {
+        let project = call.project.clone();
+        let path = path.clone();
+        let found = call
+            .host
+            .blocking(move || {
+                let mut symbols = project.index.symbols_named(&word, None, 50);
+                symbols.sort_by_key(|s| s.path != path);
+                Ok(symbols.into_iter().next())
+            })
+            .await?;
+        if let Some(symbol) = found
+            && let Some(info) = symbol_info(&call, &symbol.path, Some(symbol.name), symbol.range, 1)
+        {
+            output["symbolInfo"] = serde_json::to_value(info).map_err(|e| IdeError::internal(e.to_string()))?;
+        }
+    }
+    if call.project.index.status().indexing {
+        output["partialResultReason"] = super::util::INDEXING_PARTIAL_RESULT_REASON.into();
+    }
+    Ok(Output::text(output.to_string()))
+}
+
+/// The 1-based character index of 1-based UTF-16 `column` in `line`.
+fn char_column(line: &str, column: u32) -> u32 {
+    let mut units = 0u32;
+    let mut chars = 0u32;
+    for c in line.chars() {
+        if units + 1 >= column {
+            break;
+        }
+        units += c.len_utf16() as u32;
+        chars += 1;
+    }
+    chars + 1
+}
+
+fn is_word(c: char) -> bool {
+    c.is_alphanumeric() || c == '_' || c == '$'
+}
+
+/// The identifier at (or just before) 1-based character `column` of `line`.
+fn word_at(line: &str, column: u32) -> Option<String> {
+    let chars: Vec<char> = line.chars().collect();
+    let mut at = (column as usize).saturating_sub(1).min(chars.len());
+    if !chars.get(at).is_some_and(|c| is_word(*c)) {
+        if at > 0 && is_word(chars[at - 1]) {
+            at -= 1;
+        } else {
+            return None;
+        }
+    }
+    let start = (0..=at).rev().take_while(|i| is_word(chars[*i])).last()?;
+    let end = (at..chars.len()).take_while(|i| is_word(chars[*i])).last()? + 1;
+    Some(chars[start..end].iter().collect())
+}
+
+/// Lines of comments and annotations above a declaration that count as part of it.
+const MAX_LEADING_LINES: usize = 30;
+
+/// JetBrains' `SymbolInfo`.
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+struct SymbolInfo {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    name: Option<String>,
+    declaration_text: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    declaration_file: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    declaration_line: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    language: Option<String>,
+}
+
+/// JetBrains' `getElementSymbolInfo` over a declaration's name range: from the comments and
+/// annotations right above it to the line where the name ends, plus `extra_lines`.
+fn symbol_info(
+    call: &Call,
+    path: &Path,
+    name: Option<String>,
+    name_range: Range,
+    extra_lines: u32,
+) -> Option<SymbolInfo> {
+    let project = call.project();
+    let text = project.text_of(path).ok()?;
+    let text = text.replace("\r\n", "\n");
+    let lines: Vec<&str> = text.split('\n').collect();
+    let name_line = name_range.start.line as usize;
+    if name_line >= lines.len() {
+        return None;
+    }
+    let language = project.languages.detect(path, lines.first().copied());
+    let config = project.languages.get(&language);
+    let line_comment = config.as_ref().and_then(|c| c.line_comment.clone());
+    let mut start = name_line;
+    while start > 0
+        && name_line - start < MAX_LEADING_LINES
+        && leads_declaration(lines[start - 1], line_comment.as_deref())
+    {
+        start -= 1;
+    }
+    let end = (name_range.end.line.max(name_range.start.line) as usize + extra_lines as usize).min(lines.len() - 1);
+    Some(SymbolInfo {
+        name,
+        declaration_text: format!("<…>\n{}\n<…>", lines[start..=end].join("\n")),
+        declaration_file: Some(call.display(path)),
+        declaration_line: Some(name_line as u32 + 1),
+        language: config.map(|c| c.name),
+    })
+}
+
+/// Doc comments, comments and annotations / attributes / decorators belong to the declaration below.
+fn leads_declaration(line: &str, line_comment: Option<&str>) -> bool {
+    let t = line.trim_start();
+    if t.is_empty() {
+        return false;
+    }
+    ["//", "/*", "*", "#[", "#![", "@"].iter().any(|p| t.starts_with(p))
+        || line_comment.is_some_and(|c| !c.is_empty() && t.starts_with(c))
+}
+
+pub fn find_references() -> Tool {
+    Tool::new("find_references", "Find references using the language service and the IDE's project index. Positions are 1-based UTF-16. Reports incomplete results when analysis is still running.", |call| async move {
+        let path = call.resolve_readable(&call.str("filePath")?).await?;
+        let line = call.opt_i64("line")?.ok_or_else(|| IdeError::invalid("missing line"))?;
+        let column = call.opt_i64("column")?.ok_or_else(|| IdeError::invalid("missing column"))?;
+        let project = call.project.clone();
+        let (doc, text) = call.host.blocking(move || {
+            let text = project.text_of(&path)?;
+            let doc = project.documents.open(&path)?;
+            Ok((doc.id, text))
+        }).await?;
+        struct Close(std::sync::Arc<crate::Project>, ide_core::DocId);
+        impl Drop for Close { fn drop(&mut self) { self.0.documents.close(self.1); } }
+        let _close = Close(call.project.clone(), doc);
+        let pos = mcp_position(&text, line, column)?;
+        let request = super::tool::request_id();
+        let work = crate::ops::lsp::lsp_references(&call.host, &call.window, request, doc, pos, call.flag("includeDeclaration", true)?, true, false, crate::ops::Channel::new(|_| {}));
+        tokio::pin!(work);
+        let result = tokio::select! {
+            result = &mut work => result?,
+            _ = call.cancel.cancelled() => { call.host.cancel_request(request); let _ = work.await; return Err(IdeError::cancelled()); }
+            _ = tokio::time::sleep(std::time::Duration::from_secs(60)) => { call.host.cancel_request(request); let _ = work.await; return Err(IdeError::unavailable("references timed out; retry when analysis finishes")); }
+        };
+        let mut value = serde_json::to_value(&result).map_err(|e| IdeError::internal(e.to_string()))?;
+        // Convert every Location range at this boundary, including declarations.
+        fn positions(value: &mut serde_json::Value) {
+            match value {
+                serde_json::Value::Object(map) => {
+                    if let (Some(line), Some(col)) = (map.get("line").and_then(|v| v.as_u64()), map.get("col").and_then(|v| v.as_u64())) {
+                        map.insert("line".into(), (line + 1).into()); map.insert("col".into(), (col + 1).into());
+                    } else { for v in map.values_mut() { positions(v); } }
+                }
+                serde_json::Value::Array(items) => { for v in items { positions(v); } }
+                _ => {}
+            }
+        }
+        positions(&mut value);
+        Output::json(value)
+    })
+    .param(Param::required("filePath", ParamType::String, "Path relative to the project root"))
+    .param(Param::required("line", ParamType::Integer, "1-based line"))
+    .param(Param::required("column", ParamType::Integer, "1-based UTF-16 column"))
+    .param(Param::optional("includeDeclaration", ParamType::Boolean, "Include declarations (default true)"))
+}
+
+fn mcp_position(text: &str, line: i64, column: i64) -> IdeResult<Pos> {
+    if line < 1 || line > u32::MAX as i64 || column < 1 || column > u32::MAX as i64 {
+        return Err(IdeError::invalid("line and column must be positive 1-based positions"));
+    }
+    let row = text.split('\n').nth((line - 1) as usize).ok_or_else(|| IdeError::invalid("line is out of bounds"))?;
+    if column as usize > row.encode_utf16().count() + 1 {
+        return Err(IdeError::invalid("column is out of bounds"));
+    }
+    Ok(Pos::new((line - 1) as u32, (column - 1) as u32))
+}
@@ -0,0 +1,297 @@
+use crate::{Host, Project};
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use serde::Serialize;
+use serde_json::{Value, json};
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+pub struct Call {
+    pub client: String,
+    pub tool: String,
+    pub host: Arc<Host>,
+    pub project: Arc<Project>,
+    pub window: String,
+    pub args: Value,
+    pub cancel: CancellationToken,
+}
+
+impl Call {
+    pub fn opt_str(&self, name: &str) -> IdeResult<Option<String>> {
+        self.args
+            .get(name)
+            .filter(|v| !v.is_null())
+            .map(|v| v.as_str().map(str::to_owned).ok_or_else(|| IdeError::invalid(format!("{name} must be a string"))))
+            .transpose()
+    }
+    pub fn str_map(&self, name: &str) -> IdeResult<Vec<(String, String)>> {
+        self.args
+            .get(name)
+            .and_then(Value::as_object)
+            .ok_or_else(|| IdeError::invalid(format!("{name} must be an object")))?
+            .iter()
+            .map(|(k, v)| {
+                v.as_str()
+                    .map(|v| (k.clone(), v.to_owned()))
+                    .ok_or_else(|| IdeError::invalid(format!("{name} must contain strings")))
+            })
+            .collect()
+    }
+    pub fn resolve_inside(&self, path: &str) -> IdeResult<PathBuf> {
+        resolve_inside(self.root(), path)
+    }
+    pub async fn resolve_writable(&self, path: &str) -> IdeResult<PathBuf> {
+        let path = self.resolve_inside(path)?;
+        self.check_writable(&path).await?;
+        Ok(path)
+    }
+    pub async fn check_writable(&self, path: &Path) -> IdeResult<()> {
+        self.project.require_trust()?;
+        ensure_inside(self.root(), path)
+    }
+    pub async fn ask(&self, request: ide_core::event::McpUiRequest) -> IdeResult<()> {
+        self.host.mcp_requests.ask(self, request).await
+    }
+    pub async fn confirm(&self, subject: &str, detail: Option<String>) -> IdeResult<()> {
+        self.ask(ide_core::event::McpUiRequest::Confirm {
+            client: self.client.clone(),
+            tool: self.tool.clone(),
+            subject: subject.into(),
+            project: self.root().to_string_lossy().into_owned(),
+            detail,
+        })
+        .await?;
+        self.project.require_trust()
+    }
+    pub fn host(&self) -> Arc<Host> {
+        self.host.clone()
+    }
+    pub fn project(&self) -> &Arc<Project> {
+        &self.project
+    }
+    pub fn root(&self) -> &Path {
+        &self.project.root
+    }
+    pub fn window(&self) -> &str {
+        &self.window
+    }
+    pub fn str(&self, name: &str) -> IdeResult<String> {
+        self.args
+            .get(name)
+            .and_then(Value::as_str)
+            .map(str::to_owned)
+            .ok_or_else(|| IdeError::invalid(format!("missing or invalid argument `{name}`")))
+    }
+    pub fn opt_i64(&self, name: &str) -> IdeResult<Option<i64>> {
+        self.args
+            .get(name)
+            .map(|v| v.as_i64().ok_or_else(|| IdeError::invalid(format!("{name} must be an integer"))))
+            .transpose()
+    }
+    pub fn flag(&self, name: &str, default: bool) -> IdeResult<bool> {
+        self.args
+            .get(name)
+            .map(|v| v.as_bool().ok_or_else(|| IdeError::invalid(format!("{name} must be a boolean"))))
+            .unwrap_or(Ok(default))
+    }
+    pub fn str_list(&self, name: &str) -> IdeResult<Vec<String>> {
+        match self.args.get(name) {
+            None => Ok(Vec::new()),
+            Some(Value::Array(values)) => values
+                .iter()
+                .map(|v| {
+                    v.as_str()
+                        .map(str::to_owned)
+                        .ok_or_else(|| IdeError::invalid(format!("{name} must contain strings")))
+                })
+                .collect(),
+            _ => Err(IdeError::invalid(format!("{name} must be an array"))),
+        }
+    }
+    pub fn display(&self, path: &Path) -> String {
+        path.strip_prefix(self.root()).unwrap_or(path).to_string_lossy().replace('\\', "/")
+    }
+    pub async fn resolve_readable(&self, path: &str) -> IdeResult<PathBuf> {
+        let root = self.root().to_path_buf();
+        let mut roots = self.project.content_roots();
+        roots.extend(self.host.mcp_reports.libraries(&self.host.mcp_windows(self.root())));
+        roots.extend(
+            self.project
+                .settings
+                .effective()
+                .project_structure
+                .libraries
+                .iter()
+                .flat_map(|l| l.sources.iter().chain(&l.classes).chain(&l.javadocs))
+                .map(|p| self.root().join(p)),
+        );
+        let path = path.to_owned();
+        self.host
+            .blocking(move || {
+                let path = if path.starts_with("file://") {
+                    ide_lsp::uri_to_path(&path).ok_or_else(|| IdeError::invalid("invalid file URL"))?
+                } else {
+                    PathBuf::from(path)
+                };
+                let path = if path.is_absolute() { path } else { root.join(path) };
+                let (local, entry) =
+                    ide_vfs::split_archive_path(&path).map_or((path.clone(), None), |(p, e)| (p, Some(e)));
+                let real = if let Ok(real) = dunce::canonicalize(&local) {
+                    real
+                } else {
+                    let parent =
+                        local.ancestors().find(|p| p.exists()).ok_or_else(|| IdeError::not_found("path not found"))?;
+                    normalize(
+                        &dunce::canonicalize(parent)?
+                            .join(local.strip_prefix(parent).map_err(|e| IdeError::invalid(e.to_string()))?),
+                    )
+                };
+                if !std::iter::once(root).chain(roots).any(|r| {
+                    let r = ide_vfs::split_archive_path(&r).map_or(r.clone(), |(archive, _)| archive);
+                    dunce::canonicalize(r).is_ok_and(|r| real.starts_with(r))
+                }) {
+                    return Err(IdeError::invalid("path is outside the project's content roots"));
+                }
+                Ok(entry.map_or_else(|| real.clone(), |entry| PathBuf::from(format!("{}!/{entry}", real.display()))))
+            })
+            .await
+    }
+}
+
+pub struct Output(pub String);
+impl Output {
+    pub fn text(text: impl Into<String>) -> Self {
+        Self(text.into())
+    }
+    pub fn json(value: impl Serialize) -> IdeResult<Self> {
+        serde_json::to_string(&value).map(Self).map_err(|e| IdeError::internal(e.to_string()))
+    }
+}
+
+#[derive(Clone, Copy)]
+pub enum ParamType {
+    String,
+    Integer,
+    Boolean,
+    StringList,
+    StringMap,
+}
+pub struct Param {
+    name: &'static str,
+    kind: ParamType,
+    description: &'static str,
+    required: bool,
+}
+impl Param {
+    pub fn required(name: &'static str, kind: ParamType, description: &'static str) -> Self {
+        Self { name, kind, description, required: true }
+    }
+    pub fn optional(name: &'static str, kind: ParamType, description: &'static str) -> Self {
+        Self { name, kind, description, required: false }
+    }
+}
+
+type Handler = Arc<dyn Fn(Call) -> futures::future::BoxFuture<'static, IdeResult<Output>> + Send + Sync>;
+pub struct Tool {
+    pub metadata: ide_mcp::Tool,
+    pub handler: Handler,
+}
+impl Tool {
+    pub fn new<F, Fut>(name: &str, description: &str, handler: F) -> Self
+    where
+        F: Fn(Call) -> Fut + Send + Sync + 'static,
+        Fut: Future<Output = IdeResult<Output>> + Send + 'static,
+    {
+        Self {
+            metadata: ide_mcp::Tool {
+                name: name.into(),
+                description: description.into(),
+                read_only: true,
+                destructive: false,
+                output_schema: None,
+                input_schema: json!({ "type": "object", "properties": {
+                    "projectPath": { "type": "string", "description": "Any directory inside an open project. Optional when only one project is open." }
+                }, "required": [] }),
+            },
+            handler: Arc::new(move |call| Box::pin(handler(call))),
+        }
+    }
+    pub fn write(mut self) -> Self {
+        self.metadata.read_only = false;
+        self
+    }
+    pub fn param(mut self, param: Param) -> Self {
+        let mut schema = match param.kind {
+            ParamType::String => json!({"type":"string"}),
+            ParamType::Integer => json!({"type":"integer"}),
+            ParamType::Boolean => json!({"type":"boolean"}),
+            ParamType::StringMap => json!({"type":"object","additionalProperties":{"type":"string"}}),
+            ParamType::StringList => json!({"type":"array","items":{"type":"string"}}),
+        };
+        schema["description"] = param.description.into();
+        self.metadata.input_schema["properties"][param.name] = schema;
+        if param.required {
+            self.metadata.input_schema["required"].as_array_mut().unwrap().push(param.name.into());
+        }
+        self
+    }
+    pub fn output(mut self, schema: Value) -> Self {
+        self.metadata.output_schema = Some(schema);
+        self
+    }
+}
+
+pub fn normalize(path: &Path) -> PathBuf {
+    let mut out = PathBuf::new();
+    for part in path.components() {
+        match part {
+            std::path::Component::CurDir => {}
+            std::path::Component::ParentDir => {
+                out.pop();
+            }
+            p => out.push(p.as_os_str()),
+        }
+    }
+    out
+}
+
+pub fn request_id() -> ide_core::RequestId {
+    static NEXT: std::sync::atomic::AtomicU32 = std::sync::atomic::AtomicU32::new(0x8000_0000);
+    ide_core::RequestId(NEXT.fetch_add(1, std::sync::atomic::Ordering::Relaxed))
+}
+
+/// Resolve existing ancestors too, so symlinks cannot escape the project.
+pub fn resolve_inside(root: &Path, raw: &str) -> IdeResult<PathBuf> {
+    let path = if raw.starts_with("file://") {
+        ide_lsp::uri_to_path(raw).ok_or_else(|| IdeError::invalid("invalid file URL"))?
+    } else {
+        PathBuf::from(raw)
+    };
+    let path = if path.is_absolute() { path } else { root.join(path) };
+    if path.components().any(|c| c.as_os_str().to_string_lossy().eq_ignore_ascii_case(".git")) {
+        return Err(IdeError::invalid("VCS metadata cannot be changed"));
+    }
+    let path = normalize(&path);
+    let ancestor =
+        path.ancestors().find(|p| p.exists()).ok_or_else(|| IdeError::invalid("path has no existing parent"))?;
+    let mut real = dunce::canonicalize(ancestor)?;
+    let suffix = path.strip_prefix(ancestor).map_err(|e| IdeError::invalid(e.to_string()))?;
+    if !suffix.as_os_str().is_empty() {
+        real.push(suffix);
+    }
+    let root = dunce::canonicalize(root)?;
+    if !real.starts_with(&root) {
+        return Err(IdeError::invalid("path is outside the project"));
+    }
+    if real
+        .strip_prefix(&root)
+        .unwrap()
+        .components()
+        .any(|c| c.as_os_str().to_string_lossy().eq_ignore_ascii_case(".git"))
+    {
+        return Err(IdeError::invalid("VCS metadata cannot be changed"));
+    }
+    Ok(real)
+}
+pub fn ensure_inside(root: &Path, path: &Path) -> IdeResult<()> {
+    resolve_inside(root, &path.to_string_lossy()).map(|_| ())
+}
@@ -0,0 +1,69 @@
+// Ported from JetBrains intellij-community plugins/mcp-server (src/com/intellij/mcpserver/util/fs.util.kt,
+// util/text.util.kt, toolsets/Constants.kt), Apache-2.0.
+//! Helpers shared by the tools: the strings and timeouts of JetBrains' `Constants`,
+//! resolving the paths `read_file` accepts, and text truncation.
+
+use crate::mcp::tool::Call;
+use ide_core::{IdeError, IdeResult};
+use std::path::PathBuf;
+use std::time::Duration;
+
+pub const RELATIVE_PATH_IN_PROJECT_DESCRIPTION: &str = "Path relative to the project root";
+pub const FILE_PATH_DESCRIPTION: &str = "Path to the file. Supports project-relative paths, paths with '..', \
+absolute paths, archive entries like '/path/lib.jar!/pkg/Foo.java', and URLs such as 'file://' and 'jar://'. \
+Any path returned from the other tools can be passed as is (e.g. paths from 'search_*' tools).";
+pub const TIMEOUT_MILLISECONDS_DESCRIPTION: &str = "Timeout in milliseconds";
+pub const TIMED_OUT_DESCRIPTION: &str = "Indicates whether the operation was timed out. 'true' value may mean that \
+the results may be incomplete or partial. 'false', 'null' or missing value means that the operation has not been \
+timed out.";
+pub const MEDIUM_TIMEOUT: Duration = Duration::from_secs(10);
+pub const INDEXING_PARTIAL_RESULT_REASON: &str =
+    "Project indexing was in progress; results may be incomplete — retry once indexing completes.";
+
+/// Whether `path` starts with a URL scheme (`file://`, `jar://`, `jrt://` …).
+pub fn looks_like_vfs_url(path: &str) -> bool {
+    path.find("://")
+        .is_some_and(|i| i > 0 && path[..i].chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '+' | '-' | '.')))
+}
+
+/// Resolves `read_file`'s `file_path`: project-relative or absolute paths, archive entries
+/// (`/lib.jar!/pkg/Foo.java`) and `file://` / `jar://` URLs, within known content or library roots.
+pub async fn resolve_read_file(call: &Call, file_path: &str) -> IdeResult<PathBuf> {
+    let normalized = file_path.trim().replace('\\', "/");
+    if normalized.is_empty() {
+        return Err(IdeError::invalid("file_path is empty"));
+    }
+    let missing = || IdeError::not_found(format!("File {file_path} doesn't exist or can't be opened"));
+    let local = if looks_like_vfs_url(&normalized) {
+        let (scheme, rest) = normalized.split_once("://").unwrap_or_default();
+        match scheme.to_ascii_lowercase().as_str() {
+            // `file://` URLs are percent-decoded by `resolve`.
+            "file" => normalized.clone(),
+            "jar" => rest.to_owned(),
+            "jrt" => {
+                return Err(IdeError::invalid(format!(
+                    "File {file_path} can't be opened: OpenIDEA does not read jrt:// (Java runtime image) entries"
+                )));
+            }
+            _ => return Err(missing()),
+        }
+    } else {
+        normalized
+    };
+    let path = call.resolve_readable(&local).await?;
+    match ide_vfs::split_archive_path(&path) {
+        Some((archive, entry)) => {
+            if !archive.is_file() {
+                return Err(missing());
+            }
+            if entry.is_empty() || ide_vfs::read_archive_dir(&archive, &entry).is_ok() {
+                return Err(IdeError::invalid(format!("File {file_path} is a directory")));
+            }
+            ide_vfs::probe(&path).map_err(|_| missing())?;
+        }
+        None if path.is_dir() => return Err(IdeError::invalid(format!("File {file_path} is a directory"))),
+        None if !path.is_file() && call.project().documents.by_path(&path).is_none() => return Err(missing()),
+        None => {}
+    }
+    Ok(path)
+}
@@ -0,0 +1,362 @@
+// Ported from JetBrains intellij-community plugins/mcp-server
+// (mcpserver.vcs/src/com/intellij/mcpserver/toolsets/vcs/VcsToolset.kt), Apache-2.0.
+//! Version control: repositories and git status.
+
+use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
+use ide_core::{IdeError, IdeResult};
+use serde_json::{Value, json};
+use std::path::{Path, PathBuf};
+
+const STATUS_DEFAULT_LIMIT: i64 = 1000;
+
+pub fn tools() -> Vec<Tool> {
+    vec![get_repositories(), git_status(), git_diff()]
+}
+
+/// `path` with symbolic links resolved (macOS `/var` is `/private/var`), as given when it
+/// does not exist.
+fn canonical(path: &Path) -> PathBuf {
+    dunce::canonicalize(path).unwrap_or_else(|_| path.to_path_buf())
+}
+
+/// A path relative to the project root with `/`; empty for the root itself. Either may
+/// name the other through a symbolic link.
+fn relative_to(root: &Path, path: &Path) -> String {
+    let rel = match path.strip_prefix(root) {
+        Ok(rel) => Some(rel.to_path_buf()),
+        Err(_) => canonical(path).strip_prefix(canonical(root)).ok().map(Path::to_path_buf),
+    };
+    match rel {
+        Some(rel) => rel.to_string_lossy().replace('\\', "/"),
+        None => path.to_string_lossy().into_owned(),
+    }
+}
+
+fn relative_to_project(call: &Call, path: &Path) -> String {
+    relative_to(call.root(), path)
+}
+
+/// The repository whose roots contain `path` most specifically (paths compared canonically).
+fn innermost_repo<T>(repos: Vec<(PathBuf, T)>, path: &Path) -> Option<(PathBuf, T)> {
+    let path = canonical(path);
+    repos.into_iter().filter(|r| path.starts_with(canonical(&r.0))).max_by_key(|r| canonical(&r.0).components().count())
+}
+
+// Read tools must never invoke repository-configured executables, including in Restricted Mode.
+fn read_command(git: &str, root: &Path) -> std::process::Command {
+    let mut command = std::process::Command::new(git);
+    command
+        .current_dir(root)
+        .args([
+            "-c",
+            "core.fsmonitor=false",
+            "-c",
+            "core.hooksPath=",
+            "-c",
+            "diff.external=",
+            "-c",
+            "core.attributesFile=",
+            "-c",
+            "submodule.recurse=false",
+            "-c",
+            "color.ui=false",
+        ])
+        .env("GIT_NO_LAZY_FETCH", "1")
+        .env("GIT_TERMINAL_PROMPT", "0")
+        .env("GIT_OPTIONAL_LOCKS", "0")
+        .env_remove("GIT_EXTERNAL_DIFF")
+        .env_remove("GIT_DIR")
+        .env_remove("GIT_WORK_TREE")
+        .env_remove("GIT_INDEX_FILE");
+    ide_core::process::prepare(&mut command);
+    command
+}
+
+/// The branch HEAD is on (unborn too); `None` when HEAD is detached or git fails.
+fn read_branch(git: &str, root: &Path) -> Option<String> {
+    let mut cmd = read_command(git, root);
+    cmd.args(["symbolic-ref", "--short", "-q", "HEAD"]);
+    ide_core::process::prepare(&mut cmd);
+    let out = cmd.output().ok().filter(|o| o.status.success())?;
+    Some(String::from_utf8_lossy(&out.stdout).trim().to_owned()).filter(|b| !b.is_empty())
+}
+
+fn get_repositories() -> Tool {
+    Tool::new(
+        "get_repositories",
+        "Retrieves the list of VCS roots in the project.
+This is useful to detect all repositories in a multi-repository project.
+In OpenIDEA each root also tells its current `branch` (absent when HEAD is detached), `headCommit` and a merge, \
+rebase or cherry-pick in progress (`operationInProgress`).",
+        |call| async move {
+            let host = call.host();
+            let window = call.window.clone();
+            let roots = call.host.blocking(move || crate::ops::vcs::vcs_roots(&host, &window)).await?;
+            let list: Vec<Value> = roots
+                .into_iter()
+                .map(|r| {
+                    let mut v =
+                        json!({ "pathRelativeToProject": relative_to_project(&call, &r.root), "vcsName": "Git" });
+                    if let Some(head) = r.head {
+                        v["branch"] = head.into();
+                    }
+                    if let Some(commit) = r.head_commit {
+                        v["headCommit"] = commit.into();
+                    }
+                    if let Some(op) = r.operation {
+                        v["operationInProgress"] = op.into();
+                    }
+                    v
+                })
+                .collect();
+            Output::json(json!({ "roots": list }))
+        },
+    )
+}
+
+/// One entry of `git status --porcelain -z`.
+#[derive(Debug, PartialEq)]
+struct StatusEntry {
+    index: char,
+    work_tree: char,
+    path: String,
+    orig_path: Option<String>,
+}
+
+impl StatusEntry {
+    fn untracked(&self) -> bool {
+        self.index == '?'
+    }
+    fn ignored(&self) -> bool {
+        self.index == '!'
+    }
+    fn conflicted(&self) -> bool {
+        matches!((self.index, self.work_tree), ('D', 'D') | ('A', 'U') | ('U', _) | ('A', 'A') | ('D', 'U'))
+    }
+    fn staged(&self) -> bool {
+        !self.conflicted() && !matches!(self.index, ' ' | '?' | '!')
+    }
+    fn unstaged(&self) -> bool {
+        !self.conflicted() && !matches!(self.work_tree, ' ' | '?' | '!')
+    }
+}
+
+fn parse_status(out: &str) -> Vec<StatusEntry> {
+    let mut fields = out.split('\0').filter(|f| !f.is_empty());
+    let mut entries = Vec::new();
+    while let Some(field) = fields.next() {
+        let mut chars = field.chars();
+        let (Some(index), Some(work_tree)) = (chars.next(), chars.next()) else { continue };
+        let path = field.get(3..).unwrap_or_default().to_owned();
+        let orig_path = matches!(index, 'R' | 'C').then(|| fields.next().map(str::to_owned)).flatten();
+        entries.push(StatusEntry { index, work_tree, path, orig_path });
+    }
+    entries
+}
+
+fn git_executable(call: &Call) -> String {
+    let settings = if call.project.is_trusted() {
+        call.project.settings.effective()
+    } else {
+        call.host.global_settings.effective()
+    };
+    let exe = settings.vcs.git.executable.trim().to_owned();
+    if exe.is_empty() { "git".to_owned() } else { exe }
+}
+
+/// `git status` of the repository at `root`, paths relative to it.
+fn read_status(git: &str, root: &Path, untracked: bool, ignored: bool) -> IdeResult<Vec<StatusEntry>> {
+    let mut cmd = read_command(git, root);
+    cmd.args(["-c", "core.quotepath=false", "status", "--porcelain", "-z", "--find-renames"]);
+    // git refuses `--ignored=matching` with `--untracked-files=no`: untracked files are dropped below.
+    cmd.arg(if untracked || ignored { "--untracked-files=all" } else { "--untracked-files=no" });
+    if ignored {
+        cmd.arg("--ignored=matching");
+    }
+    ide_core::process::prepare(&mut cmd);
+    let out = cmd.output().map_err(|e| IdeError::unavailable(format!("cannot run git: {e}")))?;
+    if !out.status.success() {
+        return Err(IdeError::internal(String::from_utf8_lossy(&out.stderr).trim().to_owned()));
+    }
+    let mut entries = parse_status(&String::from_utf8_lossy(&out.stdout));
+    entries.retain(|e| untracked || !e.untracked());
+    Ok(entries)
+}
+
+/// A git repository in the project, for paths outside the repositories IDEA knows: the
+/// closest folder with `.git` from `start` up to the project root.
+fn find_git_root(root: &Path, start: &Path) -> Option<PathBuf> {
+    let (root, start) = (canonical(root), canonical(start));
+    let mut current = if start.is_dir() { start.as_path() } else { start.parent().unwrap_or(&start) };
+    while current.starts_with(&root) {
+        if current.join(".git").exists() {
+            return Some(current.to_path_buf());
+        }
+        current = current.parent()?;
+    }
+    None
+}
+
+fn git_status() -> Tool {
+    Tool::new(
+        "git_status",
+        "Retrieves Git status for one or more repositories in the current project.
+Returns porcelain-style index/worktree status codes and summary counters.
+By default all Git repositories are returned.",
+        |call| async move {
+            let include_untracked = call.flag("includeUntracked", true)?;
+            let include_ignored = call.flag("includeIgnored", false)?;
+            let limit = call.opt_i64("limit")?.unwrap_or(STATUS_DEFAULT_LIMIT);
+            if limit <= 0 {
+                return Err(IdeError::invalid("limit must be > 0"));
+            }
+            let limit = limit as usize;
+            let host = call.host();
+            let h = host.clone();
+            let w = call.window.clone();
+            let repos: Vec<(PathBuf, Option<String>)> = host
+                .blocking(move || crate::ops::vcs::vcs_roots(&h, &w))
+                .await?
+                .into_iter()
+                .map(|r| (r.root.into_path_buf(), r.head))
+                .collect();
+            let wanted = call.opt_str("repositoryPathRelativeToProject")?;
+            let git = git_executable(&call);
+            let mut roots: Vec<(PathBuf, Option<String>)> = match &wanted {
+                None => repos,
+                Some(wanted) => {
+                    let path = call.resolve_inside(wanted)?;
+                    // The innermost repository containing the path.
+                    match innermost_repo(repos, &path) {
+                        Some(repo) => vec![repo],
+                        None => match find_git_root(call.root(), &path) {
+                            Some(root) => {
+                                // JetBrains reads the branch of any repository it reports.
+                                let (git, dir) = (git.clone(), root.clone());
+                                let branch = host.blocking(move || Ok(read_branch(&git, &dir))).await?;
+                                vec![(root, branch)]
+                            }
+                            None => {
+                                return Err(IdeError::not_found(format!("No git repository found for path: {wanted}")));
+                            }
+                        },
+                    }
+                }
+            };
+            roots.sort_by_key(|r| relative_to_project(&call, &r.0));
+            let mut repositories = Vec::new();
+            for (root, branch) in roots {
+                let rel = relative_to_project(&call, &root);
+                let (git, dir) = (git.clone(), root.clone());
+                let entries = host
+                    .blocking(move || read_status(&git, &dir, include_untracked, include_ignored))
+                    .await
+                    .map_err(|e| {
+                        IdeError::internal(format!("Failed to get git status for repository '{rel}': {}", e.message))
+                    })?;
+                let count = |f: fn(&StatusEntry) -> bool| entries.iter().filter(|e| f(e)).count();
+                let listed: Vec<Value> = entries
+                    .iter()
+                    .take(limit)
+                    .map(|e| {
+                        let mut v = json!({
+                            "pathRelativeToRepository": e.path.trim_end_matches('/'),
+                            "indexStatus": e.index.to_string(),
+                            "workTreeStatus": e.work_tree.to_string(),
+                        });
+                        if let Some(orig) = &e.orig_path {
+                            v["originalPathRelativeToRepository"] = orig.clone().into();
+                        }
+                        v
+                    })
+                    .collect();
+                repositories.push(json!({
+                    "repositoryPathRelativeToProject": rel,
+                    "currentBranch": branch,
+                    "isClean": entries.is_empty(),
+                    "totalEntries": entries.len(),
+                    "hasMoreEntries": entries.len() > listed.len(),
+                    "stagedCount": count(StatusEntry::staged),
+                    "unstagedCount": count(StatusEntry::unstaged),
+                    "untrackedCount": count(StatusEntry::untracked),
+                    "ignoredCount": count(StatusEntry::ignored),
+                    "conflictedCount": count(StatusEntry::conflicted),
+                    "entries": listed,
+                }));
+            }
+            Output::json(json!({ "repositories": repositories }))
+        },
+    )
+    .param(Param::optional(
+        "repositoryPathRelativeToProject",
+        ParamType::String,
+        "Optional path relative to project root used to select a single containing repository",
+    ))
+    .param(Param::optional("includeUntracked", ParamType::Boolean, "Whether to include untracked files"))
+    .param(Param::optional("includeIgnored", ParamType::Boolean, "Whether to include ignored files"))
+    .param(Param::optional("limit", ParamType::Integer, "Maximum number of entries returned per repository"))
+}
+
+fn git_diff() -> Tool {
+    Tool::new("git_diff", "Read a Git diff for a file or the working tree. staged=true compares the index with HEAD; otherwise compares disk with the index. Unsaved editor text is not part of this diff.", |call| async move {
+        let wanted = call.opt_str("repositoryPathRelativeToProject")?;
+        let path = wanted.as_deref().map(|p| call.resolve_inside(p)).transpose()?.unwrap_or_else(|| call.root().to_path_buf());
+        let root = find_git_root(call.root(), &path).ok_or_else(|| IdeError::not_found("No git repository found"))?;
+        let file = call.opt_str("filePath")?.map(|p| call.resolve_inside(&p)).transpose()?;
+        if file.as_ref().is_some_and(|p| !p.starts_with(&root)) { return Err(IdeError::invalid("file is outside the repository")); }
+        let staged = call.flag("staged", false)?;
+        let git = git_executable(&call);
+        let cancel = call.cancel.clone();
+        let text = call.host.blocking(move || {
+            let mut cmd = read_command(&git, &root);
+            cmd.args(["--no-pager", "diff", "--no-ext-diff", "--no-textconv"]);
+            if staged { cmd.arg("--cached"); }
+            cmd.arg("--");
+            if let Some(file) = file { cmd.arg(file.strip_prefix(&root).map_err(|e| IdeError::invalid(e.to_string()))?); }
+            ide_core::process::prepare(&mut cmd);
+            if cancel.is_cancelled() { return Err(IdeError::cancelled()); }
+            let out = cmd.output()?;
+            if !out.status.success() { return Err(IdeError::unavailable(String::from_utf8_lossy(&out.stderr).trim())); }
+            Ok(String::from_utf8_lossy(&out.stdout).into_owned())
+        }).await?;
+        Ok(Output::text(text))
+    })
+    .param(Param::optional("repositoryPathRelativeToProject", ParamType::String, "Select the containing repository"))
+    .param(Param::optional("filePath", ParamType::String, "Optional project-relative file; omit for the working tree"))
+    .param(Param::optional("staged", ParamType::Boolean, "Show staged changes"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parses_porcelain_z_with_renames() {
+        let out = "M  a.txt\0R  new.txt\0old.txt\0?? u.txt\0UU c.txt\0";
+        let e = parse_status(out);
+        assert_eq!(e.len(), 4);
+        assert_eq!(e[1].path, "new.txt");
+        assert_eq!(e[1].orig_path.as_deref(), Some("old.txt"));
+        assert!(e[0].staged() && !e[0].unstaged());
+        assert!(e[2].untracked() && !e[2].staged());
+        assert!(e[3].conflicted() && !e[3].staged() && !e[3].unstaged());
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn paths_through_a_symlinked_root_compare_canonically() {
+        // As macOS `/var` → `/private/var`: the project opened through the link, git reporting real paths.
+        let dir = tempfile::tempdir().unwrap();
+        let real = dunce::canonicalize(dir.path()).unwrap().join("real");
+        std::fs::create_dir_all(real.join("sub/.git")).unwrap();
+        std::fs::write(real.join("sub/f.txt"), "x").unwrap();
+        let link = dir.path().join("link");
+        std::os::unix::fs::symlink(&real, &link).unwrap();
+        assert_eq!(relative_to(&link, &real.join("sub")), "sub");
+        assert_eq!(relative_to(&real, &link.join("sub")), "sub");
+        assert_eq!(relative_to(&link, &link), "");
+        let repos = vec![(real.clone(), 1), (real.join("sub"), 2)];
+        assert_eq!(innermost_repo(repos, &link.join("sub/f.txt")).map(|r| r.1), Some(2));
+        assert_eq!(find_git_root(&link, &real.join("sub/f.txt")), Some(real.join("sub")));
+    }
+}
@@ -257,6 +257,10 @@ pub fn unarchive(host: &Host, window: &str, task: String) -> IdeResult<()> {
    host.project(window)?.agents.unarchive(&task)
 }

+pub fn rename(host: &Host, window: &str, task: String, title: String) -> IdeResult<()> {
+    host.project(window)?.agents.rename(&task, &title)
+}
+
 pub async fn delete(host: &Host, window: &str, task: String, remove_worktree: bool) -> IdeResult<()> {
    host.require_trust(window)?;
    host.project(window)?.agents.delete(&task, remove_worktree).await
@@ -309,6 +313,7 @@ pub(crate) fn register(d: &mut Dispatcher) {
        respond(&c.host, &c.window, c.arg("task")?, c.arg("permission")?, c.arg("option")?)
    });
    d.add("agent_unarchive", |c| async move { unarchive(&c.host, &c.window, c.arg("task")?) });
+    d.add("agent_rename", |c| async move { rename(&c.host, &c.window, c.arg("task")?, c.arg("title")?) });
    d.add("agent_archive", |c| async move { archive(&c.host, &c.window, c.arg("task")?) });
    d.add(
        "agent_delete",
@@ -17,14 +17,6 @@ fn join_err(e: tokio::task::JoinError) -> IdeError {
    IdeError::internal(e.to_string())
 }

-/// `JAVA_HOME`: the project JDK, else the installed JDK matching `release` (none
-/// when the project names no version).
-fn java_env(project_jdk: Option<&ide_sdk::java::Jdk>, release: Option<u32>) -> BTreeMap<String, String> {
-    let jdks = ide_sdk::java::installed_jdks();
-    let jdk = project_jdk.or_else(|| release.and_then(|r| ide_sdk::java::pick_jdk(&jdks, Some(r))));
-    jdk.map(|j| BTreeMap::from([("JAVA_HOME".to_owned(), j.home.to_string_lossy().into_owned())])).unwrap_or_default()
-}
-
 /// The build model with the launch settings applied: the JDK (`JAVA_HOME`), and
 /// the Maven home and options from Settings › Maven.
 pub fn load(root: &Path, cache: &Path, settings: &Settings) -> BuildModel {
@@ -40,7 +32,7 @@ pub fn load(root: &Path, cache: &Path, settings: &Settings) -> BuildModel {
        let mvn = ide_sdk::apply::maven_command(root, settings);
        let options = ide_sdk::apply::maven_options(root, settings);
        for p in &mut m.projects {
-            p.env = java_env(jdk.as_ref(), p.java_version);
+            p.env = ide_sdk::apply::maven_build_env(root, settings, p.java_version);
            if let Some(mvn) = &mvn {
                p.command = mvn.to_string_lossy().into_owned();
            }
@@ -64,7 +56,11 @@ pub fn load(root: &Path, cache: &Path, settings: &Settings) -> BuildModel {
    if let Some(m) = &mut model.maven
        && m.sync_error.is_some()
    {
-        let hint = m.projects.iter().find_map(|p| missing(p.java_version));
+        let hint = if settings.languages.java.maven.runner_jre.trim().is_empty() {
+            m.projects.iter().find_map(|p| missing(p.java_version))
+        } else {
+            None
+        };
        explain(&mut m.sync_error, hint);
    }
    for g in &mut model.gradle {
@@ -492,15 +488,32 @@ pub async fn maven_exclude_dependency(
    .map_err(join_err)?
 }

+fn cmake_plan(root: &Path, kind: BuildKind, configs: &[ide_run::RunConfig], id: &str) -> IdeResult<compile::BuildPlan> {
+    let commands = ide_run::cmake_build_configs(configs, id)?;
+    let title = commands.last().map(|c| c.name.clone()).unwrap_or_default();
+    let mut steps = Vec::new();
+    for mut config in commands {
+        let cwd = ide_core::project_roots::resolve(root, config.cwd.as_deref().unwrap_or(Path::new("")));
+        ide_run::prepare_cmake(&config, &cwd)?;
+        if kind == BuildKind::Rebuild && config.args.first().is_some_and(|a| a == "--build") {
+            config.args.insert(2, "--clean-first".into());
+        }
+        steps.push(compile::BuildStep::cmake(&config.command, config.args, cwd, config.env));
+    }
+    Ok(compile::BuildPlan { system: compile::BuildSystem::CMake, title, steps })
+}
+
 /// Build › Build Project / Rebuild Project / Build Module (`file`: a file or folder of the
 /// module) / Build Artifacts, streaming the console and messages on `on_event`; cancellable
 /// with `cancel_request(request)`. Diagnostics of `clear` (the files of the previous build)
 /// are cleared first; the new messages are published as `build` diagnostics.
+#[allow(clippy::too_many_arguments)]
 pub async fn build_run(
    host: &Host,
    window: &str,
    kind: BuildKind,
    file: Option<std::path::PathBuf>,
+    cmake: Option<String>,
    request: RequestId,
    clear: Vec<std::path::PathBuf>,
    on_event: Channel<BuildEvent>,
@@ -519,7 +532,10 @@ pub async fn build_run(
                items: Vec::new(),
            });
        }
-        let plan = if let Some(workspace) = ide_workspace::workspace::Workspace::load(&root)? {
+        let plan = if let Some(id) = cmake {
+            let configs = super::run::project_configs(&root, &settings, &config_dir)?;
+            cmake_plan(&root, kind, &configs, &id)?
+        } else if let Some(workspace) = ide_workspace::workspace::Workspace::load(&root)? {
            let mut combined: Option<compile::BuildPlan> = None;
            for member in workspace.projects.iter().filter(|p| file.as_ref().is_none_or(|f| f.starts_with(p))) {
                let settings = ide_workspace::SettingsStore::load(&config_dir, Some(member)).effective();
@@ -616,6 +632,7 @@ pub(crate) fn register(d: &mut Dispatcher) {
            &c.window,
            c.arg("kind")?,
            c.arg("file")?,
+            c.arg("cmake")?,
            c.arg("request")?,
            c.arg("clear")?,
            c.sender("onEvent")?,
@@ -625,9 +642,45 @@ pub(crate) fn register(d: &mut Dispatcher) {
 }

 #[cfg(test)]
-mod gradle_settings_tests {
+mod build_tool_settings_tests {
    use super::*;

+    #[test]
+    fn cmake_builds_keep_target_configuration_environment_and_directory() {
+        let root = tempfile::tempdir().unwrap();
+        let member = root.path().join("nested project");
+        std::fs::create_dir_all(&member).unwrap();
+        let config = |id: &str, args: &[&str]| -> ide_run::RunConfig {
+            serde_json::from_value(serde_json::json!({
+                "id":id,"name":id,"kind":"cmake","command":"custom-cmake",
+                "args":args,"cwd":"nested project","env":{"PROFILE":"release"},
+                "detected":true,"isTest":false,"debugAdapter":null
+            }))
+            .unwrap()
+        };
+        let configure = config("configure", &["-S", ".", "-B", "release", "-G", "Ninja"]);
+        let mut build =
+            config("target", &["--build", "release", "--target", "hello", "--config", "Release", "-j", "8"]);
+        build.extras.before_launch.push(ide_run::BeforeLaunchTask { kind: "build".into(), target: "configure".into() });
+        let configs = [configure, build];
+        for kind in [BuildKind::Build, BuildKind::Rebuild] {
+            let plan = cmake_plan(root.path(), kind, &configs, "target").unwrap();
+            assert_eq!(plan.system, compile::BuildSystem::CMake);
+            assert_eq!(plan.steps.len(), 2);
+            assert_eq!(plan.steps[0].args, configs[0].args);
+            let mut args = configs[1].args.clone();
+            if kind == BuildKind::Rebuild {
+                args.insert(2, "--clean-first".into());
+            }
+            assert_eq!(plan.steps[1].args, args);
+            for step in plan.steps {
+                assert_eq!(step.program, "custom-cmake");
+                assert_eq!(step.cwd, member);
+                assert_eq!(step.env["PROFILE"], "release");
+            }
+        }
+    }
+
    #[test]
    fn builds_apply_the_same_explicit_toolchains_as_runs() {
        let temp = tempfile::tempdir().unwrap();
@@ -710,6 +763,34 @@ mod gradle_settings_tests {
        }
    }

+    #[test]
+    fn model_for_maven_sync_goals_and_compile_uses_runner_jre() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        std::fs::write(root.join("pom.xml"),
+            r#"<project><modelVersion>4.0.0</modelVersion><groupId>test</groupId><artifactId>app</artifactId><version>1</version></project>"#
+        ).unwrap();
+        for name in ["project-jdk", "runner-jdk"] {
+            let home = root.join(name);
+            std::fs::create_dir_all(home.join("bin")).unwrap();
+            std::fs::write(home.join("bin").join(if cfg!(windows) { "java.exe" } else { "java" }), "").unwrap();
+            std::fs::write(home.join("release"), "JAVA_VERSION=\"21\"\n").unwrap();
+        }
+        let mut settings = Settings::default();
+        settings.languages.java.jdk = "project-jdk".into();
+        for runner in ["", "runner-jdk"] {
+            settings.languages.java.maven.runner_jre = runner.into();
+            let expected = root.join(if runner.is_empty() { "project-jdk" } else { runner });
+            let model = load(&root, &root.join("cache"), &settings);
+            assert_eq!(model.maven.as_ref().unwrap().projects[0].env["JAVA_HOME"], expected.to_string_lossy());
+            let plan = compile::plan(&root, &model, BuildKind::Build, None, None).unwrap();
+            assert!(!plan.steps.is_empty());
+            for step in plan.steps {
+                assert_eq!(step.env["JAVA_HOME"], expected.to_string_lossy());
+            }
+        }
+    }
+
    #[test]
    fn model_for_sync_tasks_and_compile_uses_gradle_settings() {
        let tmp = tempfile::tempdir().unwrap();
@@ -103,7 +103,8 @@ pub(crate) fn register(d: &mut Dispatcher) {
    d.add("db_explain", |c| async move {
        let (request, id, statement) =
            (c.arg::<RequestId>("request")?, c.arg::<String>("id")?, c.arg::<String>("statement")?);
-        explain(&c.host, &c.window, request, &id, &statement).await
+        let schema = c.arg::<Option<String>>("schema")?;
+        explain(&c.host, &c.window, request, &id, &statement, schema.as_deref()).await
    });
    d.add("db_history", |c| async move {
        let id = c.arg::<String>("id")?;
@@ -130,7 +131,8 @@ pub(crate) fn register(d: &mut Dispatcher) {
            c.arg::<Option<u32>>("skip")?.unwrap_or(0),
            c.arg::<u32>("maxRows")?,
        );
-        execute(&c.host, &c.window, request, &id, statements, skip, max_rows).await
+        let schema = c.arg::<Option<String>>("schema")?;
+        execute(&c.host, &c.window, request, &id, statements, skip, max_rows, schema.as_deref()).await
    });
    d.add("db_table_page", |c| async move {
        let (request, id, schema, table) = (
@@ -289,10 +291,11 @@ pub async fn explain(
    request: RequestId,
    id: &str,
    statement: &str,
+    schema: Option<&str>,
 ) -> IdeResult<Vec<PlanNode>> {
    let db = host.project(window)?.db.clone();
    let cancel = host.begin_request(request);
-    let result = db.explain(id, statement, &cancel).await;
+    let result = db.explain(id, statement, &cancel, schema).await;
    host.end_request(request);
    result
 }
@@ -327,7 +330,9 @@ pub fn statements(host: &Host, window: &str, id: &str, text: &str, from: u32, to

 /// Runs `statements` in order on data source `id`, stopping at the first
 /// error. Each result reads past its first `skip` rows (a later page) and keeps
-/// `max_rows`. Cancel with `cancel_request(request)`.
+/// `max_rows`. `schema` is the console's active context: the connection running
+/// each statement is put in it first. Cancel with `cancel_request(request)`.
+#[allow(clippy::too_many_arguments)]
 pub async fn execute(
    host: &Host,
    window: &str,
@@ -336,12 +341,13 @@ pub async fn execute(
    statements: Vec<SqlStatement>,
    skip: u32,
    max_rows: u32,
+    schema: Option<&str>,
 ) -> IdeResult<Vec<StatementOutcome>> {
    let db = host.project(window)?.db.clone();
    let cancel = host.begin_request(request);
    let mut out = Vec::new();
    for statement in statements {
-        match db.execute_from(id, &statement.text, skip as usize, max_rows.max(1) as usize, &cancel).await {
+        match db.execute_from(id, &statement.text, skip as usize, max_rows.max(1) as usize, &cancel, schema).await {
            Ok(result) => out.push(StatementOutcome { statement, result: Some(result), error: None }),
            Err(e) if e.kind == ide_core::error::ErrorKind::Cancelled => {
                host.end_request(request);
@@ -28,9 +28,11 @@ pub async fn debug_start(host: &Host, window: &str, config: LaunchConfig) -> Ide
        let settings = settings.clone();
        config = host
            .blocking(move || {
-                ide_sdk::go::debug_environment(&root, &settings, &mut config.env);
+                ide_sdk::go::configure_environment(&root, &settings, &mut config.env);
                ide_sdk::go::apply_to_debug(
                    &mut config.env,
+                    &mut config.program,
+                    &mut config.args,
                    &mut config.extra_json,
                    &settings.languages.go.build_tags,
                )?;
@@ -1,7 +1,11 @@
 //! Repository version lookups for manifest inspections and completion.
 use crate::{Host, rpc::Dispatcher};
 use ide_core::{CancellationToken, DocId, IdeError, IdeResult, RequestId};
-use ide_workspace::dependencies::{DependencyVersionSource, DependencyVersions, cargo};
+use ide_workspace::dependencies::{DependencyVersionSource, DependencyVersions, cargo, go};
+use std::collections::BTreeMap;
+use std::hash::{DefaultHasher, Hash, Hasher};
+use std::path::{Path, PathBuf};
+use std::process::Command;

 struct CratesIo;
 impl DependencyVersionSource for CratesIo {
@@ -21,6 +25,76 @@ impl DependencyVersionSource for CratesIo {
    }
 }

+struct GoModules {
+    root: PathBuf,
+    env: BTreeMap<String, String>,
+}
+
+impl DependencyVersionSource for GoModules {
+    fn id(&self) -> &'static str {
+        "go-modules"
+    }
+
+    fn cache_key(&self, package: &str) -> Option<String> {
+        let mut hash = DefaultHasher::new();
+        (&self.root, &self.env, package).hash(&mut hash);
+        Some(format!("{}-{:016x}", self.id(), hash.finish()))
+    }
+
+    fn fetch(&self, package: &str, cancel: &CancellationToken) -> IdeResult<Vec<String>> {
+        let search =
+            self.env.get("PATH").map(std::ffi::OsString::from).unwrap_or_else(ide_core::tool_path::search_path);
+        let go = ide_core::tool_path::find_command("go", &search, &self.root)
+            .ok_or_else(|| IdeError::unavailable("Go SDK is unavailable"))?;
+        // A partially edited go.mod is often invalid. Query outside it while
+        // keeping the SDK and proxy/private module configuration.
+        let dir = tempfile::tempdir()?;
+        let mut cmd = Command::new(go);
+        cmd.current_dir(dir.path())
+            .env("PATH", search)
+            .envs(&self.env)
+            .env("GO111MODULE", "on")
+            .env("GOFLAGS", "")
+            .env("GOWORK", "off")
+            .env("GIT_TERMINAL_PROMPT", "0")
+            .args(["list", "-m", "-versions", "-f", "{{range .Versions}}{{println .}}{{end}}", "--", package]);
+        let query = cancel.child_token();
+        // Fetches run on Host::blocking's Tokio pool, which keeps a runtime current.
+        let deadline = tokio::spawn({
+            let query = query.clone();
+            async move {
+                tokio::time::sleep(std::time::Duration::from_secs(10)).await;
+                query.cancel();
+            }
+        });
+        let output = ide_tools::run_streamed(cmd, &query, &|_| {});
+        deadline.abort();
+        Ok(go::listed_versions(&output?))
+    }
+}
+
+#[cfg(all(test, unix))]
+#[path = "dependencies/go_tests.rs"]
+mod go_tests;
+
+fn go_source(project: &crate::Project, config_dir: &Path, path: &Path) -> IdeResult<GoModules> {
+    let member = ide_workspace::workspace::Workspace::load(&project.root)?.and_then(|workspace| {
+        workspace
+            .projects
+            .into_iter()
+            .filter(|root| path.starts_with(root))
+            .max_by_key(|root| root.components().count())
+    });
+    let settings = match &member {
+        Some(root) => ide_workspace::SettingsStore::load(config_dir, Some(root)).effective(),
+        None => project.settings.effective(),
+    };
+    let root = member.unwrap_or_else(|| project.root.clone());
+    let mut env = BTreeMap::new();
+    ide_sdk::go::configure_environment(&root, &settings, &mut env);
+    Ok(GoModules { root, env })
+}
+
 /// `offset` limits a completion request to its version string; inspections omit it.
 pub async fn dependency_versions(
    host: &Host,
@@ -31,11 +105,24 @@ pub async fn dependency_versions(
 ) -> IdeResult<Vec<DependencyVersions>> {
    let project = host.project(window)?;
    let cache = host.dependency_versions.clone();
-    let cancel = host.begin_request(request);
+    let config_dir = host.config_dir.clone();
+    let cancel = host.begin_project_read_request(window, request);
    let result = host
        .blocking(move || {
            let snap = project.documents.snapshot(doc)?;
-            if snap.large || snap.read_only || snap.path.file_name().is_none_or(|n| n != "Cargo.toml") {
+            if snap.large || snap.read_only {
+                return Ok(Vec::new());
+            }
+            if snap.path.file_name().is_some_and(|name| name == "go.mod") {
+                let Some(dependency) = offset.and_then(|offset| go::dependency_at(&snap.text, offset)) else {
+                    return Ok(Vec::new());
+                };
+                project.require_trust()?;
+                let source = go_source(&project, &config_dir, snap.path.as_ref())?;
+                let versions = cache.versions(&source, &dependency.package, &cancel)?;
+                return Ok(vec![DependencyVersions { dependency, versions, update: None }]);
+            }
+            if snap.path.file_name().is_none_or(|name| name != "Cargo.toml") {
                return Ok(Vec::new());
            }
            let mut out = Vec::new();
@@ -0,0 +1,107 @@
+use super::*;
+use ide_workspace::dependencies::VersionCache;
+use std::os::unix::fs::PermissionsExt;
+use std::time::{Duration, Instant};
+
+fn source(dir: &Path, script: &str) -> GoModules {
+    let bin = dir.join("bin");
+    std::fs::create_dir_all(&bin).unwrap();
+    let go = bin.join("go");
+    std::fs::write(&go, format!("#!/bin/sh\n{script}\n")).unwrap();
+    std::fs::set_permissions(&go, std::fs::Permissions::from_mode(0o755)).unwrap();
+    GoModules {
+        root: dir.to_owned(),
+        env: BTreeMap::from([
+            ("PATH".into(), bin.to_string_lossy().into_owned()),
+            ("PROJECT_ROOT".into(), dir.to_string_lossy().into_owned()),
+            ("GOPROXY".into(), "https://user:[email protected]".into()),
+            ("GOPRIVATE".into(), "private.example/token".into()),
+            ("GOWORK".into(), "broken.work".into()),
+            ("GOFLAGS".into(), "-mod=vendor".into()),
+        ]),
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn go_query_is_isolated_and_persists_only_hashed_configuration_and_versions() {
+    let dir = tempfile::tempdir().unwrap();
+    let source = source(
+        dir.path(),
+        r#"set -eu
+[ "$PWD" != "$PROJECT_ROOT" ]
+[ "$GOPROXY" = 'https://user:[email protected]' ]
+[ "$GOPRIVATE" = 'private.example/token' ]
+[ "$GOWORK" = off ]
+[ "$GOFLAGS" = '' ]
+[ "$GO111MODULE" = on ]
+[ "$GIT_TERMINAL_PROMPT" = 0 ]
+[ "$1 $2 $3 $4" = 'list -m -versions -f' ]
+[ "$5" = '{{range .Versions}}{{println .}}{{end}}' ]
+[ "$6 $7" = '-- example.com/Org/Lib/v2' ]
+printf 'v2.9.0\nv2.10.0\n'"#,
+    );
+    let key = source.cache_key("example.com/Org/Lib/v2").unwrap();
+    assert_ne!(key, source.cache_key("example.com/org/lib/v2").unwrap());
+    let mut other = GoModules { root: source.root.join("member"), env: source.env.clone() };
+    assert_ne!(key, other.cache_key("example.com/Org/Lib/v2").unwrap());
+    other.root = source.root.clone();
+    other.env.insert("GOPROXY".into(), "https://other.example".into());
+    assert_ne!(key, other.cache_key("example.com/Org/Lib/v2").unwrap());
+    let cache_dir = dir.path().join("cache");
+    let disk = cache_dir.clone();
+    let versions = tokio::task::spawn_blocking(move || {
+        VersionCache::new(cache_dir).versions(&source, "example.com/Org/Lib/v2", &CancellationToken::new())
+    })
+    .await
+    .unwrap()
+    .unwrap();
+    assert_eq!(versions, ["v2.10.0", "v2.9.0"]);
+    let entries: Vec<_> = std::fs::read_dir(disk).unwrap().map(Result::unwrap).collect();
+    assert_eq!(entries.len(), 1, "the hashed key passes the cache filename filter");
+    assert_eq!(entries[0].file_name().to_str().unwrap(), format!("{key}.json"));
+    let cached = std::fs::read_to_string(entries[0].path()).unwrap();
+    for sensitive in ["secret", "proxy.example", "private.example", "token", "PROJECT_ROOT"] {
+        assert!(!cached.contains(sensitive), "configuration must not be persisted: {sensitive}");
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn failed_go_queries_are_silent_and_not_persisted() {
+    let dir = tempfile::tempdir().unwrap();
+    let source = source(dir.path(), "echo 'private module or offline proxy' >&2\nexit 1");
+    let cache_dir = dir.path().join("cache");
+    let disk = cache_dir.clone();
+    let versions = tokio::task::spawn_blocking(move || {
+        VersionCache::new(cache_dir).versions(&source, "private.example/module", &CancellationToken::new())
+    })
+    .await
+    .unwrap()
+    .unwrap();
+    assert!(versions.is_empty());
+    assert!(!disk.exists());
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn stalled_go_queries_obey_the_deadline_and_parent_cancellation() {
+    for cancel_parent in [false, true] {
+        let dir = tempfile::tempdir().unwrap();
+        let source = source(dir.path(), "exec /bin/sleep 60");
+        let cancel = CancellationToken::new();
+        let query = cancel.clone();
+        let started = Instant::now();
+        let work = tokio::task::spawn_blocking(move || {
+            VersionCache::new(source.root.join("cache")).versions(&source, "example.com/stalled", &query)
+        });
+        if cancel_parent {
+            tokio::time::sleep(Duration::from_millis(150)).await;
+            cancel.cancel();
+            assert!(work.await.unwrap().is_err());
+            assert!(started.elapsed() < Duration::from_secs(3));
+        } else {
+            assert!(work.await.unwrap().unwrap().is_empty());
+            assert!(started.elapsed() >= Duration::from_secs(10));
+            assert!(started.elapsed() < Duration::from_secs(15));
+            assert!(!cancel.is_cancelled(), "a query deadline must not cancel its caller");
+        }
+    }
+}
@@ -91,9 +91,10 @@ async fn resolve_launch(
            }
        }
        info.class_paths = class_paths;
+        apply_library_classpath(&mut info, &project.root, &settings.project_structure.libraries, test);
        let compile_ms = started.elapsed().as_millis() - lsp_ms;
-        // The project JDK, else the JDK jdtls compiles the module against, else one matching its Java version.
-        let project_jdk = ide_sdk::apply::project_jdk(&project.root, &settings);
+        // The module/project JDK, else the JDK jdtls compiles the module against, else one matching its Java version.
+        let project_jdk = ide_sdk::apply::module_jdk(&project.root, &module, &settings);
        let from_jdtls = info.java_home.as_deref().map(ide_sdk::java::java_executable).filter(|p| p.is_file());
        let java = project_jdk.map(|j| ide_sdk::java::java_executable(&j.home)).or(from_jdtls).or_else(|| {
            // The build model's level includes what the module inherits from its parent POMs.
@@ -153,6 +154,41 @@ fn entry_key(path: &str, windows: bool) -> String {
    if windows { key.to_lowercase() } else { key }
 }

+fn apply_library_classpath(
+    info: &mut JavaLaunchInfo,
+    root: &std::path::Path,
+    libraries: &[ide_core::settings::ProjectLibrary],
+    test: bool,
+) {
+    use ide_core::settings::DependencyScope;
+    let entries: Vec<_> = libraries
+        .iter()
+        .flat_map(|lib| {
+            let allowed = match lib.scope {
+                DependencyScope::Compile | DependencyScope::Runtime => true,
+                DependencyScope::Test | DependencyScope::Provided => test,
+            };
+            lib.classes.iter().filter_map(move |entry| {
+                ide_sdk::apply::setting_path(root, entry).map(|path| (path.to_string_lossy().into_owned(), allowed))
+            })
+        })
+        .collect();
+    // JDT may already have returned these archives on either classpath.
+    for paths in [&mut info.class_paths, &mut info.module_paths] {
+        paths.retain(|path| {
+            let matching: Vec<_> = entries.iter().filter(|(entry, _)| same_entry(path, entry, cfg!(windows))).collect();
+            matching.is_empty() || matching.iter().any(|(_, allowed)| *allowed)
+        });
+    }
+    for (entry, allowed) in entries {
+        if allowed
+            && !info.class_paths.iter().chain(&info.module_paths).any(|path| same_entry(path, &entry, cfg!(windows)))
+        {
+            info.class_paths.push(entry);
+        }
+    }
+}
+
 fn same_entry(a: &str, b: &str, windows: bool) -> bool {
    a == b || entry_key(a, windows) == entry_key(b, windows)
 }
@@ -220,6 +256,36 @@ pub(crate) fn register(d: &mut Dispatcher) {
 mod tests {
    use super::*;

+    #[test]
+    fn library_scopes_filter_jdt_classpaths_and_module_paths() {
+        use ide_core::settings::{DependencyScope, ProjectLibrary};
+        let root = tempfile::tempdir().unwrap();
+        let scopes =
+            [DependencyScope::Compile, DependencyScope::Runtime, DependencyScope::Test, DependencyScope::Provided];
+        let libraries: Vec<_> = scopes
+            .iter()
+            .enumerate()
+            .map(|(i, scope)| ProjectLibrary {
+                classes: vec![format!("lib/{i}.jar")],
+                scope: *scope,
+                ..Default::default()
+            })
+            .collect();
+        let paths: Vec<_> =
+            (0..4).map(|i| root.path().join(format!("lib/{i}.jar")).to_string_lossy().into_owned()).collect();
+        for test in [false, true] {
+            let mut info =
+                JavaLaunchInfo { class_paths: paths.clone(), module_paths: paths.clone(), ..Default::default() };
+            apply_library_classpath(&mut info, root.path(), &libraries, test);
+            let expected = if test { &paths[..] } else { &paths[..2] };
+            assert_eq!(info.class_paths, expected);
+            assert_eq!(info.module_paths, expected);
+        }
+        let mut info = JavaLaunchInfo::default();
+        apply_library_classpath(&mut info, root.path(), &libraries, false);
+        assert_eq!(info.class_paths, &paths[..2]);
+    }
+
    /// JDT LS and our build model spell a module output differently on Windows; the
    /// snapshot must still replace it, or resources (MyBatis mapper XML) load twice.
    #[test]
@@ -7,6 +7,7 @@ use ide_core::error::ErrorKind;
 use ide_core::{DocId, IdeResult, Location, Pos, Range, RequestId, ServerId, TextEdit, WorkspaceEdit};
 use ide_lsp::types::*;
 use ide_plugin::ProviderDocument;
+use std::path::Path;

 async fn prepare_actions(
    project: std::sync::Arc<crate::Project>,
@@ -85,7 +86,12 @@ const PLUGIN_SERVER: ServerId = ServerId(0);
 #[derive(serde::Serialize, serde::Deserialize)]
 struct PluginActionRef {
    plugin: String,
-    data: String,
+    data: Option<String>,
+    /// Opened once the action is applied.
+    open: Option<ide_core::IpcPath>,
+    /// Listed by the plugin's `file-actions` export, which resolves it.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    file: bool,
 }

 /// A plugin's `completion-item.kind` (wit/providers.wit lists them).
@@ -390,25 +396,144 @@ pub async fn lsp_references(
    libraries: bool,
    on_partial: super::Channel<References>,
 ) -> IdeResult<References> {
-    let lsp = host.project(window)?.lsp.clone();
+    let project = host.project(window)?;
+    let lsp = project.lsp.clone();
    let cancel = host.begin_request(request);
-    let result = lsp
-        .references_streaming(
-            doc,
-            pos,
-            include_declaration,
-            project_wide,
-            libraries,
-            cancel,
-            Some(&|refs| {
-                let _ = on_partial.send(refs);
-            }),
-        )
-        .await;
+    let result = async {
+        let symbol = indexed_symbol(host, window, doc, pos).await?;
+        if let Some(symbol) = &symbol {
+            let project = project.clone();
+            let snapshot = symbol.clone();
+            let cancellation = cancel.clone();
+            blocking(move || validate_indexed_symbol(&project, &snapshot, Some(&cancellation))).await?;
+            let _ = on_partial.send(merge_indexed_references(References::default(), symbol));
+        }
+        let result = lsp
+            .references_streaming(
+                doc,
+                pos,
+                include_declaration,
+                project_wide,
+                libraries,
+                cancel.clone(),
+                Some(&|refs| {
+                    let refs =
+                        symbol.as_ref().map_or_else(|| refs.clone(), |s| merge_indexed_references(refs.clone(), s));
+                    let _ = on_partial.send(refs);
+                }),
+            )
+            .await;
+        if cancel.is_cancelled() {
+            return Err(ide_core::IdeError::cancelled());
+        }
+        match symbol {
+            None => result,
+            Some(symbol) => {
+                let server = match result {
+                    Ok(server) => server,
+                    Err(e) => References { incomplete: indexed_lsp_error(e)?, ..Default::default() },
+                };
+                blocking(move || {
+                    validate_indexed_symbol(&project, &symbol, Some(&cancel))?;
+                    Ok(merge_indexed_references(server, &symbol))
+                })
+                .await
+            }
+        }
+    }
+    .await;
    host.end_request(request);
    result
 }

+/// Native servers can decline names owned by indexers. A failed native query
+/// keeps the graph usable but must not look like a complete merged result.
+fn indexed_lsp_error(error: ide_core::IdeError) -> IdeResult<Option<ReferencesIncomplete>> {
+    match error.kind {
+        ErrorKind::NotFound | ErrorKind::Unavailable => Ok(None),
+        ErrorKind::Protocol => Ok(Some(ReferencesIncomplete::ServerFailed)),
+        _ => Err(error),
+    }
+}
+
+async fn indexed_symbol(
+    host: &Host,
+    window: &str,
+    doc: DocId,
+    pos: Pos,
+) -> IdeResult<Option<crate::plugins::navigation::IndexedSymbol>> {
+    let Some(plugins) = crate::plugins::editor_plugin_host() else { return Ok(None) };
+    let project = host.project(window)?;
+    let client = window.to_owned();
+    blocking(move || {
+        let Ok((path, _)) = project.documents.identity(doc) else { return Ok(None) };
+        let path = ide_plugin::resolve_real(&path);
+        Ok(plugins.indexed_symbol_at(&project.root, &path, pos, Some(&client)))
+    })
+    .await
+}
+
+fn validate_indexed_symbol(
+    project: &crate::Project,
+    symbol: &crate::plugins::navigation::IndexedSymbol,
+    cancel: Option<&ide_core::CancellationToken>,
+) -> IdeResult<()> {
+    for file in &symbol.files {
+        if cancel.is_some_and(|cancel| cancel.is_cancelled()) {
+            return Err(ide_core::IdeError::cancelled());
+        }
+        let stale = || {
+            ide_core::IdeError::new(ErrorKind::OutOfSync, "indexed document changed; wait for indexing and try again")
+        };
+        if ide_plugin::resolve_in_root(&project.root, &file.path.to_string_lossy()).ok().as_ref() != Some(&file.path) {
+            return Err(stale());
+        }
+        let text = if let Some(doc) = project.documents.by_path(&file.path) {
+            let snapshot = project.documents.text_snapshot(doc)?;
+            if snapshot.large || file.version.is_some_and(|v| v != snapshot.version) {
+                return Err(stale());
+            }
+            snapshot.text
+        } else {
+            let loaded = project
+                .documents
+                .load_file_bounded(&file.path, crate::plugins::navigation::MAX_DOCUMENT_BYTES)
+                .map_err(|_| stale())?;
+            if loaded.binary || loaded.large {
+                return Err(stale());
+            }
+            loaded.text
+        };
+        if text.len() > crate::plugins::navigation::MAX_DOCUMENT_BYTES
+            || crate::plugins::navigation::snapshot_hash(&text) != file.hash
+        {
+            return Err(stale());
+        }
+        let text = ide_text::Document::new(&text);
+        for range in &file.ranges {
+            if [range.start, range.end].into_iter().any(|pos| text.offset_to_pos(text.pos_to_offset(pos)) != pos) {
+                return Err(ide_core::IdeError::invalid("indexed name is not on a UTF-16 character boundary"));
+            }
+        }
+    }
+    Ok(())
+}
+
+fn merge_indexed_references(mut server: References, symbol: &crate::plugins::navigation::IndexedSymbol) -> References {
+    let key =
+        |location: &Location| (dunce::simplified(&location.path).to_path_buf(), location.range, location.uri.clone());
+    let mut seen: std::collections::HashSet<_> = server.locations.iter().map(key).collect();
+    for file in &symbol.files {
+        for range in &file.ranges {
+            let location = Location::file(file.path.clone(), *range);
+            if seen.insert(key(&location)) {
+                server.locations.push(location);
+            }
+        }
+    }
+    server
+}
+
 pub async fn lsp_document_highlights(host: &Host, window: &str, doc: DocId, pos: Pos) -> IdeResult<Vec<Highlight>> {
    host.project(window)?.lsp.document_highlights(doc, pos).await
 }
@@ -443,7 +568,7 @@ pub async fn lsp_code_actions(
    };
    let plugin_actions: Vec<CodeAction> = plugin_actions
        .into_iter()
-        .map(|(plugin, a)| plugin_code_action(&plugin, a))
+        .map(|(plugin, a)| plugin_code_action(&plugin, &project.root, a))
        .filter(|a| {
            only.is_empty()
                || a.kind.as_ref().is_some_and(|k| only.iter().any(|o| k == o || k.starts_with(&format!("{o}."))))
@@ -459,23 +584,26 @@ pub async fn lsp_code_actions(
    prepare_actions(project, doc, version, actions).await
 }

-fn plugin_code_action(plugin: &str, a: ide_plugin::CodeAction) -> CodeAction {
-    // With `data` and no edits, the plugin computes them when the action is picked.
-    let lazy = a.edits.is_empty() && a.data.is_some();
-    let files: Vec<_> = a
-        .edits
-        .into_iter()
-        .map(|(path, edits)| ide_core::FileEdit::Edit { path: path.into(), edits, version: None })
-        .collect();
-    let data = a
-        .data
-        .filter(|_| lazy)
-        .and_then(|data| serde_json::to_value(PluginActionRef { plugin: plugin.to_owned(), data }).ok());
+fn plugin_code_action(plugin: &str, root: &Path, a: ide_plugin::CodeAction) -> CodeAction {
+    // With `data` and nothing to apply, the plugin computes the edits when the action is picked.
+    let lazy = a.edits.is_empty() && a.operations.is_empty() && a.data.is_some();
+    let (files, open, disabled_reason) = match plugin_file_edits(root, &a) {
+        Ok((files, open)) => (files, open, None),
+        Err(reason) => (Vec::new(), None, Some(reason)),
+    };
+    let data = (lazy || open.is_some())
+        .then(|| PluginActionRef {
+            plugin: plugin.to_owned(),
+            data: a.data.filter(|_| lazy),
+            open: open.map(Into::into),
+            file: a.file_action,
+        })
+        .and_then(|r| serde_json::to_value(r).ok());
    CodeAction {
        title: a.title,
        kind: a.kind,
        is_preferred: a.preferred,
-        disabled_reason: None,
+        disabled_reason,
        edit: (!lazy).then(|| WorkspaceEdit { files, preconditions: Vec::new() }),
        command: None,
        data,
@@ -483,6 +611,53 @@ fn plugin_code_action(plugin: &str, a: ide_plugin::CodeAction) -> CodeAction {
    }
 }

+/// The action's file operations, then its text edits, as one workspace edit's files, and the
+/// file to open. An action with file operations or an `open` target stays inside the project
+/// root as a whole: a path outside it disables the action.
+fn plugin_file_edits(
+    root: &Path,
+    a: &ide_plugin::CodeAction,
+) -> Result<(Vec<ide_core::FileEdit>, Option<std::path::PathBuf>), String> {
+    use ide_core::FileEdit;
+    use ide_plugin::FileOperation;
+    let confine = !a.operations.is_empty() || a.open.is_some();
+    let confined = |path: &Path| ide_plugin::resolve_new_in_root(root, &path.to_string_lossy());
+    let mut files = Vec::new();
+    let mut created_with_text = Vec::new();
+    for operation in &a.operations {
+        match operation {
+            FileOperation::Create { path, text, overwrite } => {
+                let path = confined(path)?;
+                files.push(FileEdit::Create { path: path.clone().into(), overwrite: *overwrite });
+                if !text.is_empty() {
+                    let start = Range::point(Pos::new(0, 0));
+                    files.push(FileEdit::Edit {
+                        path: path.clone().into(),
+                        edits: vec![TextEdit { range: start, new_text: text.clone() }],
+                        version: None,
+                    });
+                    created_with_text.push(path);
+                }
+            }
+            FileOperation::Rename { from, to } => {
+                files.push(FileEdit::Rename { from: confined(from)?.into(), to: confined(to)?.into() });
+            }
+            FileOperation::Delete { path } => {
+                files.push(FileEdit::Delete { path: confined(path)?.into(), recursive: false });
+            }
+        }
+    }
+    for (path, edits) in &a.edits {
+        let path = if confine { confined(path)? } else { path.clone() };
+        if created_with_text.contains(&path) {
+            return Err("put the text of a created file in its `create`, not in an edit".into());
+        }
+        files.push(FileEdit::Edit { path: path.into(), edits: edits.clone(), version: None });
+    }
+    let open = a.open.as_deref().map(confined).transpose()?;
+    Ok((files, open))
+}
+
 /// A code action resolved by whoever offered it: its language server, or
 /// the plugin its `data` names.
 async fn resolve_action(host: &Host, window: &str, doc: DocId, action: CodeAction) -> IdeResult<CodeAction> {
@@ -499,11 +674,16 @@ async fn resolve_action(host: &Host, window: &str, doc: DocId, action: CodeActio
        kind: action.kind.clone(),
        preferred: action.is_preferred,
        edits: Vec::new(),
-        data: Some(r.data),
+        operations: Vec::new(),
+        open: None,
+        data: r.data,
+        file_action: r.file,
    };
    let plugin = r.plugin.clone();
-    let resolved = blocking(move || plugins.resolve_code_action(&plugin, &d, pending)).await?;
-    Ok(plugin_code_action(&r.plugin, ide_plugin::CodeAction { data: None, ..resolved }))
+    let invocation = ide_plugin::Invocation { client: Some(window.to_owned()), ..Default::default() };
+    let resolved = blocking(move || plugins.resolve_code_action(&plugin, &d, pending, invocation)).await?;
+    let root = host.project(window)?.root.clone();
+    Ok(plugin_code_action(&r.plugin, &root, ide_plugin::CodeAction { data: None, ..resolved }))
 }

 /// Cancellable code actions with the kinds the servers advertise (Refactor This, refactoring availability).
@@ -526,7 +706,7 @@ pub async fn lsp_code_action_query(
    Ok(result)
 }

-/// Resolves a code action's edit without applying it (intention preview).
+/// Resolves a code action's edit without applying it.
 pub async fn lsp_resolve_code_action(
    host: &Host,
    window: &str,
@@ -554,11 +734,15 @@ pub async fn lsp_apply_code_action(host: &Host, window: &str, doc: DocId, action
    } else {
        action
    };
+    if let Some(reason) = &action.disabled_reason {
+        return Err(ide_core::IdeError::invalid(reason.clone()));
+    }
    if let Some(edit) = &action.edit {
        let documents = project.documents.clone();
        let edit = edit.clone();
        blocking(move || apply_edit(&documents, &edit)).await?;
    }
+    open_plugin_action_target(&action, window);
    if let Some(command) = action.command
        && !(action.edit.is_some() && is_client_follow_up(&project, doc, None, &command).await)
    {
@@ -567,6 +751,24 @@ pub async fn lsp_apply_code_action(host: &Host, window: &str, doc: DocId, action
    Ok(())
 }

+/// The plugin and the file its action asks to show once applied.
+fn plugin_action_open(action: &CodeAction) -> Option<(String, ide_core::IpcPath)> {
+    if action.server != PLUGIN_SERVER {
+        return None;
+    }
+    let r = action.data.clone().and_then(|d| serde_json::from_value::<PluginActionRef>(d).ok())?;
+    Some((r.plugin, r.open?))
+}
+
+/// Opens the file a plugin's action asked to show, now that the action is applied.
+fn open_plugin_action_target(action: &CodeAction, window: &str) {
+    let (Some((plugin, path)), Some(plugins)) = (plugin_action_open(action), crate::plugins::editor_plugin_host())
+    else {
+        return;
+    };
+    plugins.open_file(&plugin, window, path);
+}
+
 /// A command after a code action's edit that no server provides: what other editors'
 /// extensions do once the edit is applied (vtsls' `_typescript.didOrganizeImports`). The edit
 /// is the action; there is nothing to run.
@@ -584,6 +786,14 @@ async fn is_client_follow_up(
 }

 pub async fn lsp_prepare_rename(host: &Host, window: &str, doc: DocId, pos: Pos) -> IdeResult<Option<Range>> {
+    if let Some(symbol) = indexed_symbol(host, window, doc, pos).await? {
+        let project = host.project(window)?;
+        return blocking(move || {
+            validate_indexed_symbol(&project, &symbol, None)?;
+            Ok(Some(symbol.range))
+        })
+        .await;
+    }
    host.project(window)?.lsp.prepare_rename(doc, pos).await
 }

@@ -650,20 +860,133 @@ pub async fn lsp_rename(
    let documents = project.documents.clone();
    let version = blocking(move || documents.version(doc)).await?;
    let cancel = host.begin_request(request);
-    let result = project.lsp.rename(doc, pos, new_name, cancel).await;
-    host.end_request(request);
-    let mut renamed = result?;
-    blocking(move || {
-        if project.documents.version(doc)? != version {
-            return Err(ide_core::IdeError::new(
-                ide_core::error::ErrorKind::OutOfSync,
-                "document changed while computing rename; request it again",
-            ));
+    let result = async {
+        let symbol = indexed_symbol(host, window, doc, pos).await?;
+        let mut native_owned = false;
+        let result = async {
+            if let Some(symbol) = &symbol {
+                let range = tokio::select! {
+                    _ = cancel.cancelled() => return Err(ide_core::IdeError::cancelled()),
+                    range = project.lsp.prepare_rename(doc, pos) => range?,
+                };
+                if range != Some(symbol.range) {
+                    return Ok(Renamed::default());
+                }
+                native_owned = true;
+            }
+            project.lsp.rename(doc, pos, new_name.clone(), cancel.clone()).await
        }
-        project.documents.prepare_workspace_edit(&mut renamed.edit)?;
-        Ok(renamed)
-    })
-    .await
+        .await;
+        if cancel.is_cancelled() {
+            return Err(ide_core::IdeError::cancelled());
+        }
+        let mut renamed = match result {
+            Ok(renamed) => renamed,
+            Err(e) if symbol.is_some() && !native_owned => {
+                Renamed { incomplete: indexed_lsp_error(e)?, ..Default::default() }
+            }
+            Err(e) => return Err(e),
+        };
+        if native_owned
+            && !renamed.edit.files.iter().any(|file| match file {
+                ide_core::FileEdit::Edit { edits, .. } => !edits.is_empty(),
+                _ => true,
+            })
+        {
+            return Err(ide_core::IdeError::invalid("Native server declined rename"));
+        }
+        blocking(move || {
+            if project.documents.version(doc)? != version {
+                return Err(ide_core::IdeError::new(
+                    ErrorKind::OutOfSync,
+                    "document changed while computing rename; request it again",
+                ));
+            }
+            if let Some(symbol) = &symbol {
+                merge_indexed_rename(&mut renamed, symbol, &new_name, &project.documents);
+            }
+            project.documents.prepare_workspace_edit(&mut renamed.edit)?;
+            if let Some(symbol) = &symbol {
+                validate_indexed_symbol(&project, symbol, Some(&cancel))?;
+            }
+            if cancel.is_cancelled() {
+                return Err(ide_core::IdeError::cancelled());
+            }
+            Ok(renamed)
+        })
+        .await
+    }
+    .await;
+    host.end_request(request);
+    result
+}
+
+fn merge_indexed_rename(
+    renamed: &mut Renamed,
+    symbol: &crate::plugins::navigation::IndexedSymbol,
+    new_name: &str,
+    documents: &ide_workspace::Documents,
+) {
+    use ide_core::FileEdit;
+    renamed.preview = true;
+    let server = std::mem::take(&mut renamed.edit.files);
+    let mut additions: Vec<Vec<FileEdit>> = vec![vec![]; server.len() + 1];
+    for file in &symbol.files {
+        let mut path = dunce::simplified(&file.path).to_path_buf();
+        let mut at = server.len();
+        for (index, operation) in server.iter().enumerate() {
+            match operation {
+                FileEdit::Edit { path: target, .. } if dunce::simplified(target) == path.as_path() => {
+                    at = index;
+                    break;
+                }
+                FileEdit::Rename { from, to } => {
+                    if let Ok(suffix) = path.strip_prefix(dunce::simplified(from)) {
+                        path = dunce::simplified(to).join(suffix);
+                    }
+                }
+                _ => {}
+            }
+        }
+        let covered: Vec<_> = server[at..]
+            .iter()
+            .take_while(|operation| matches!(operation, FileEdit::Edit { .. }))
+            .filter_map(|operation| match operation {
+                FileEdit::Edit { path: target, edits, .. } if dunce::simplified(target) == path.as_path() => {
+                    Some(edits)
+                }
+                _ => None,
+            })
+            .flatten()
+            .collect();
+        let edits: Vec<_> = file
+            .ranges
+            .iter()
+            .filter(|range| {
+                !covered.iter().any(|native| {
+                    native.range == **range || (native.range.start < range.end && range.start < native.range.end)
+                })
+            })
+            .map(|range| TextEdit { range: *range, new_text: new_name.to_owned() })
+            .collect();
+        if edits.is_empty() {
+            continue;
+        }
+        additions[at].push(FileEdit::Edit {
+            path: path.into(),
+            version: documents
+                .by_path(&file.path)
+                .and_then(|id| documents.version(id).ok())
+                .and_then(|v| i32::try_from(v).ok()),
+            edits,
+        });
+    }
+    for (index, operation) in server.into_iter().enumerate() {
+        renamed.edit.files.push(operation);
+        renamed.edit.files.append(&mut additions[index]);
+    }
+    renamed.edit.files.append(additions.last_mut().expect("one trailing batch"));
+    renamed.edit.deduplicate();
 }

 pub async fn lsp_format(
@@ -677,7 +1000,22 @@ pub async fn lsp_format(
 }

 pub async fn lsp_inlay_hints(host: &Host, window: &str, doc: DocId, range: Range) -> IdeResult<Vec<InlayHint>> {
-    host.project(window)?.lsp.inlay_hints(doc, range).await
+    let lsp = host.project(window)?.lsp.clone();
+    let Some((plugins, d)) = plugin_providers(host, window, doc, ProviderKind::InlayHints) else {
+        return lsp.inlay_hints(doc, range).await;
+    };
+    let (result, hints) =
+        tokio::join!(lsp.inlay_hints(doc, range), plugin_call(move || plugins.provide_inlay_hints(&d, range)));
+    let hints = hints.unwrap_or_default();
+    if hints.is_empty() {
+        return result;
+    }
+    let server = match result {
+        Ok(server) => server,
+        Err(e) if matches!(e.kind, ErrorKind::NotFound | ErrorKind::Unavailable) => Vec::new(),
+        Err(e) => return Err(e),
+    };
+    Ok(crate::plugins::merge_inlay_hints(server, hints, range))
 }

 pub async fn lsp_semantic_tokens(host: &Host, window: &str, doc: DocId) -> IdeResult<Option<SemanticTokens>> {
@@ -831,6 +1169,8 @@ pub async fn lsp_execute_code_action(
            return Err(ide_core::IdeError::cancelled());
        }
        let edited = action.edit.is_some();
+        // A plugin's action may name a file to show once applied; the caller opens it.
+        let open = plugin_action_open(&action).map(|(_, path)| path);
        if let Some(edit) = action.edit {
            let documents = project.documents.clone();
            tokio::task::spawn_blocking(move || apply_edit(&documents, &edit))
@@ -846,7 +1186,7 @@ pub async fn lsp_execute_code_action(
                .execute_action_command(doc, action.server, command, answers, cancel)
                .await
                .map(|paths| paths.into_iter().map(ide_core::IpcPath::from).collect()),
-            None => Ok(Vec::new()),
+            None => Ok(open.into_iter().collect()),
        }
    }
    .await;
@@ -1003,6 +1343,194 @@ pub(crate) fn register(d: &mut Dispatcher) {
 mod tests {
    use super::*;

+    #[test]
+    fn indexed_names_survive_native_refusal_without_hiding_cancellation_or_staleness() {
+        use ide_core::IdeError;
+        for kind in [ErrorKind::NotFound, ErrorKind::Unavailable] {
+            assert_eq!(indexed_lsp_error(IdeError::new(kind, "no native provider")).unwrap(), None);
+        }
+        assert_eq!(
+            indexed_lsp_error(IdeError::new(ErrorKind::Protocol, "not a native identifier")).unwrap(),
+            Some(ReferencesIncomplete::ServerFailed)
+        );
+        for kind in [ErrorKind::Cancelled, ErrorKind::OutOfSync, ErrorKind::InvalidInput] {
+            assert_eq!(indexed_lsp_error(IdeError::new(kind, "must propagate")).unwrap_err().kind, kind);
+        }
+    }
+
+    #[test]
+    fn indexed_results_merge_with_lsp_locations_edits_and_incompleteness() {
+        use crate::plugins::navigation::{IndexedAnchors, IndexedSymbol};
+        use ide_core::{FileEdit, LanguageId};
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path().canonicalize().unwrap();
+        let shared = root.join("shared.idx");
+        let native = root.join("native.txt");
+        std::fs::write(&shared, "old old").unwrap();
+        std::fs::write(&native, "old").unwrap();
+        let range = Range::new(Pos::new(0, 0), Pos::new(0, 3));
+        let other = Range::new(Pos::new(0, 4), Pos::new(0, 7));
+        let symbol = IndexedSymbol {
+            range,
+            files: vec![IndexedAnchors {
+                path: shared.clone(),
+                version: None,
+                hash: blake3::hash(b"old old"),
+                ranges: vec![range, other],
+            }],
+        };
+        // Native file URIs have ordinary Windows paths; index snapshots retain
+        // canonical verbatim paths. Both identify the same file and edit batch.
+        let server_shared = dunce::simplified(&shared).to_path_buf();
+        let server_native = dunce::simplified(&native).to_path_buf();
+        #[cfg(windows)]
+        assert_ne!(shared, server_shared);
+        let location = Location::file(server_shared.clone(), range);
+        let native_location = Location::file(server_native.clone(), range);
+        let merged = merge_indexed_references(
+            References {
+                locations: vec![location.clone(), native_location.clone()],
+                incomplete: Some(ReferencesIncomplete::Indexing),
+                libraries_skipped: true,
+                ..Default::default()
+            },
+            &symbol,
+        );
+        assert_eq!(merged.locations, vec![location, native_location, Location::file(shared.clone(), other)]);
+        assert_eq!(merged.incomplete, Some(ReferencesIncomplete::Indexing));
+        assert!(merged.libraries_skipped);
+        let edit = |path, range| FileEdit::Edit {
+            path,
+            version: None,
+            edits: vec![TextEdit { range, new_text: "new".into() }],
+        };
+        let mut renamed = Renamed {
+            edit: WorkspaceEdit {
+                files: vec![edit(server_shared.clone().into(), range), edit(server_native.into(), range)],
+                ..Default::default()
+            },
+            incomplete: Some(ReferencesIncomplete::FilesSkipped),
+            ..Default::default()
+        };
+        let docs = ide_workspace::Documents::new(
+            std::sync::Arc::new(ide_core::NullSink),
+            Box::new(|_: &Path, _: Option<&str>| LanguageId::plain_text()),
+        );
+        merge_indexed_rename(&mut renamed, &symbol, "new", &docs);
+        assert!(renamed.preview);
+        assert_eq!(renamed.incomplete, Some(ReferencesIncomplete::FilesSkipped));
+        assert_eq!(renamed.edit.files.len(), 2);
+        docs.prepare_workspace_edit(&mut renamed.edit).unwrap();
+        docs.apply_workspace_edit(&renamed.edit).unwrap();
+        assert_eq!(std::fs::read_to_string(&shared).unwrap(), "new new");
+        assert_eq!(std::fs::read_to_string(&native).unwrap(), "new");
+
+        // Native rewrites preserve syntax (for example a shorthand property key).
+        std::fs::write(&shared, "old old").unwrap();
+        let mut rewritten = Renamed {
+            edit: WorkspaceEdit {
+                files: vec![FileEdit::Edit {
+                    path: shared.clone().into(),
+                    version: None,
+                    edits: vec![TextEdit { range, new_text: "old: new".into() }],
+                }],
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+        merge_indexed_rename(&mut rewritten, &symbol, "new", &docs);
+        docs.prepare_workspace_edit(&mut rewritten.edit).unwrap();
+        docs.apply_workspace_edit(&rewritten.edit).unwrap();
+        assert_eq!(std::fs::read_to_string(&shared).unwrap(), "old: new new");
+        std::fs::write(&shared, "new new").unwrap();
+
+        // A class rename may move its file before editing the new path. Indexed
+        // anchors still describe the original file and must join that text batch.
+        let moved = root.join("moved.idx");
+        let server_moved = dunce::simplified(&moved).to_path_buf();
+        let mut renamed = Renamed {
+            edit: WorkspaceEdit {
+                files: vec![
+                    FileEdit::Rename { from: server_shared.into(), to: server_moved.clone().into() },
+                    FileEdit::Edit {
+                        path: server_moved.into(),
+                        version: None,
+                        edits: vec![TextEdit { range, new_text: "moved".into() }],
+                    },
+                ],
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+        merge_indexed_rename(&mut renamed, &symbol, "moved", &docs);
+        docs.prepare_workspace_edit(&mut renamed.edit).unwrap();
+        docs.apply_workspace_edit(&renamed.edit).unwrap();
+        assert!(!shared.exists());
+        assert_eq!(std::fs::read_to_string(&moved).unwrap(), "moved moved");
+    }
+
+    #[test]
+    fn indexed_edits_yield_to_native_intersections_but_keep_boundary_insertions() {
+        use crate::plugins::navigation::{IndexedAnchors, IndexedSymbol};
+        use ide_core::{FileEdit, LanguageId};
+        let tmp = tempfile::tempdir().unwrap();
+        let path = tmp.path().join("shared.idx");
+        std::fs::write(&path, "old old").unwrap();
+        let range = Range::new(Pos::new(0, 0), Pos::new(0, 3));
+        let symbol = IndexedSymbol {
+            range,
+            files: vec![IndexedAnchors {
+                path: path.clone(),
+                version: None,
+                hash: blake3::hash(b"old old"),
+                ranges: vec![range],
+            }],
+        };
+        let docs = ide_workspace::Documents::new(
+            std::sync::Arc::new(ide_core::NullSink),
+            Box::new(|_: &Path, _: Option<&str>| LanguageId::plain_text()),
+        );
+        for (start, end, expected) in [
+            (0, 3, "native old"),
+            (0, 4, "nativeold"),
+            (1, 4, "onativeold"),
+            (1, 2, "onatived old"),
+            (1, 1, "onativeld old"),
+            (0, 0, "nativeindexed old"),
+            (3, 3, "indexednative old"),
+            (3, 4, "indexednativeold"),
+            (4, 7, "indexed native"),
+        ] {
+            let native =
+                TextEdit { range: Range::new(Pos::new(0, start), Pos::new(0, end)), new_text: "native".into() };
+            let mut renamed = Renamed {
+                edit: WorkspaceEdit {
+                    files: vec![FileEdit::Edit {
+                        path: path.clone().into(),
+                        version: None,
+                        edits: vec![native.clone()],
+                    }],
+                    ..Default::default()
+                },
+                ..Default::default()
+            };
+            merge_indexed_rename(&mut renamed, &symbol, "indexed", &docs);
+            let edits: Vec<_> = renamed
+                .edit
+                .files
+                .iter()
+                .flat_map(|file| match file {
+                    FileEdit::Edit { edits, .. } => edits.clone(),
+                    _ => vec![],
+                })
+                .collect();
+            assert!(edits.contains(&native));
+            let mut text = ide_text::Document::new("old old");
+            text.apply_edits(&edits).unwrap();
+            assert_eq!(text.text(), expected, "native range {start}..{end}");
+        }
+    }
+
    #[test]
    fn a_plugin_action_with_data_and_no_edits_is_resolved_by_its_plugin() {
        let action = |edits: Vec<(std::path::PathBuf, Vec<TextEdit>)>, data: Option<&str>| ide_plugin::CodeAction {
@@ -1010,15 +1538,19 @@ mod tests {
            kind: None,
            preferred: false,
            edits,
+            operations: Vec::new(),
+            open: None,
            data: data.map(str::to_owned),
+            file_action: false,
        };
-        let lazy = plugin_code_action("acme.x", action(Vec::new(), Some("ref")));
+        let root = Path::new("/p");
+        let lazy = plugin_code_action("acme.x", root, action(Vec::new(), Some("ref")));
        assert!(lazy.edit.is_none());
        let r: PluginActionRef = serde_json::from_value(lazy.data.unwrap()).unwrap();
-        assert_eq!((r.plugin.as_str(), r.data.as_str()), ("acme.x", "ref"));
+        assert_eq!((r.plugin.as_str(), r.data.as_deref()), ("acme.x", Some("ref")));
        // With edits, `data` is the plugin's business: applied as is.
        let edit = TextEdit { range: Range::default(), new_text: "x".into() };
-        let eager = plugin_code_action("acme.x", action(vec![("/a".into(), vec![edit])], Some("ref")));
+        let eager = plugin_code_action("acme.x", root, action(vec![("/a".into(), vec![edit])], Some("ref")));
        assert!(eager.edit.is_some() && eager.data.is_none());
    }

@@ -1095,6 +1627,83 @@ mod tests {
        assert!(without_generated_helpers(Vec::new()).is_empty());
    }

+    #[test]
+    fn a_plugin_action_maps_its_file_operations_before_its_edits_and_stays_in_the_project() {
+        use ide_core::FileEdit;
+        use ide_plugin::FileOperation;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path().join("proj");
+        std::fs::create_dir_all(&root).unwrap();
+        let root = root.canonicalize().unwrap();
+        let action = |operations: Vec<FileOperation>| ide_plugin::CodeAction {
+            title: "Create view".into(),
+            kind: Some("quickfix".into()),
+            preferred: false,
+            edits: vec![(root.join("a.txt"), vec![TextEdit { range: Range::default(), new_text: "x".into() }])],
+            operations,
+            open: Some(root.join("views/home.html")),
+            data: None,
+            file_action: true,
+        };
+
+        let created = plugin_code_action(
+            "acme.x",
+            &root,
+            action(vec![
+                FileOperation::Create { path: "views/home.html".into(), text: "<h1/>".into(), overwrite: false },
+                FileOperation::Rename { from: root.join("old.txt"), to: root.join("new.txt") },
+                FileOperation::Delete { path: root.join("gone.txt") },
+            ]),
+        );
+        assert_eq!(created.disabled_reason, None);
+        let files = created.edit.unwrap().files;
+        let home = root.join("views/home.html");
+        assert!(matches!(&files[0], FileEdit::Create { path, overwrite: false } if **path == home));
+        assert!(
+            matches!(&files[1], FileEdit::Edit { path, edits, .. } if **path == home && edits[0].new_text == "<h1/>")
+        );
+        assert!(matches!(&files[2], FileEdit::Rename { to, .. } if **to == root.join("new.txt")));
+        assert!(matches!(&files[3], FileEdit::Delete { recursive: false, .. }));
+        assert!(matches!(&files[4], FileEdit::Edit { path, .. } if **path == root.join("a.txt")));
+        let r: PluginActionRef = serde_json::from_value(created.data.unwrap()).unwrap();
+        assert_eq!(r.data, None);
+        assert!(r.file, "resolved by the file-actions export");
+        let opened = r.open.unwrap().to_path_buf();
+        assert!(opened.components().eq(dunce::simplified(&home).components()), "{opened:?}");
+
+        let outside = tmp.path().join("evil.txt");
+        let mut open_outside = action(Vec::new());
+        open_outside.open = Some(outside.clone());
+        assert!(plugin_code_action("acme.x", &root, open_outside).disabled_reason.is_some());
+        let mut edit_outside = action(vec![FileOperation::Delete { path: root.join("gone.txt") }]);
+        edit_outside.edits.push((outside, Vec::new()));
+        assert!(plugin_code_action("acme.x", &root, edit_outside).disabled_reason.is_some());
+        let mut edit_created =
+            action(vec![FileOperation::Create { path: root.join("n.txt"), text: "x".into(), overwrite: false }]);
+        edit_created.edits = vec![(root.join("n.txt"), Vec::new())];
+        assert!(plugin_code_action("acme.x", &root, edit_created).disabled_reason.is_some());
+
+        for outside in [tmp.path().join("evil.txt"), "../evil.txt".into()] {
+            for operation in [
+                FileOperation::Create { path: outside.clone(), text: String::new(), overwrite: false },
+                FileOperation::Rename { from: root.join("old.txt"), to: outside.clone() },
+                FileOperation::Delete { path: outside.clone() },
+            ] {
+                let rejected = plugin_code_action("acme.x", &root, action(vec![operation]));
+                assert!(rejected.disabled_reason.is_some_and(|r| r.contains("outside the project root")));
+                assert!(rejected.edit.unwrap().files.is_empty());
+            }
+        }
+
+        // `data` and nothing to apply: the file-actions export computes it when picked.
+        let mut lazy = action(Vec::new());
+        (lazy.edits, lazy.open, lazy.data) = (Vec::new(), None, Some("ref".into()));
+        let lazy = plugin_code_action("acme.x", &root, lazy);
+        assert!(lazy.edit.is_none());
+        let r: PluginActionRef = serde_json::from_value(lazy.data.unwrap()).unwrap();
+        assert_eq!((r.data.as_deref(), r.file), (Some("ref"), true));
+    }
+
    #[test]
    fn every_completion_kind_the_plugin_api_documents_is_understood() {
        let wit = include_str!("../../../../wit/providers.wit");
@@ -9,14 +9,20 @@ use std::time::Duration;
 pub fn configs(host: &Host, window: &str) -> IdeResult<Vec<RunConfig>> {
    host.require_trust(window)?;
    let project = host.project(window)?;
-    let root = project.root.clone();
-    let user = ide_run::load_user_configs(&root)?;
-    let root_suppressed = ide_run::load_suppressed_config_ids(&root)?;
-    let settings = project.settings.effective();
-    let mut all = detected_and_saved(&root, &settings, &user, &root_suppressed);
-    if let Some(workspace) = ide_workspace::workspace::Workspace::load(&root)? {
+    project_configs(&project.root, &project.settings.effective(), &host.config_dir)
+}
+
+pub(super) fn project_configs(
+    root: &std::path::Path,
+    settings: &ide_core::settings::Settings,
+    config_dir: &std::path::Path,
+) -> IdeResult<Vec<RunConfig>> {
+    let user = ide_run::load_user_configs(root)?;
+    let root_suppressed = ide_run::load_suppressed_config_ids(root)?;
+    let mut all = detected_and_saved(root, settings, &user, &root_suppressed);
+    if let Some(workspace) = ide_workspace::workspace::Workspace::load(root)? {
        for member in workspace.projects.into_iter().filter(|p| p.is_dir()) {
-            let settings = ide_workspace::SettingsStore::load(&host.config_dir, Some(&member)).effective();
+            let settings = ide_workspace::SettingsStore::load(config_dir, Some(&member)).effective();
            let saved = ide_run::load_user_configs(&member)?;
            let suppressed = ide_run::load_suppressed_config_ids(&member)?;
            let configs = detected_and_saved(&member, &settings, &saved, &suppressed);
@@ -24,7 +30,7 @@ pub fn configs(host: &Host, window: &str) -> IdeResult<Vec<RunConfig>> {
            let name = member.file_name().unwrap_or_default().to_string_lossy();
            for mut config in configs {
                for task in &mut config.extras.before_launch {
-                    if task.kind == "run" {
+                    if matches!(task.kind.as_str(), "run" | "build") && !task.target.is_empty() {
                        task.target = format!("workspace:{}:{}", key, task.target);
                    }
                }
@@ -181,6 +181,16 @@ pub async fn run_tomcat_home(host: &Host, window: &str, home: String) -> IdeResu
        .map_err(|e| IdeError::internal(e.to_string()))?
 }

+pub async fn run_tomcat_installations(
+    host: &Host,
+    window: &str,
+) -> IdeResult<Vec<ide_run::tomcat::TomcatInstallation>> {
+    host.require_trust(window)?;
+    tokio::task::spawn_blocking(ide_run::tomcat::detect_installations)
+        .await
+        .map_err(|e| IdeError::internal(e.to_string()))
+}
+
 pub async fn run_tomcat_artifacts(host: &Host, window: &str) -> IdeResult<Vec<ide_build::web::WebArtifact>> {
    host.require_trust(window)?;
    let project = host.project(window)?;
@@ -212,7 +222,7 @@ pub async fn run_tomcat_build(host: &Host, window: &str, config: RunConfig) -> I
            &project.root,
            &model,
            id,
-            &ide_run::tomcat::base_dir(&project.cache_dir, &config.id),
+            &ide_run::tomcat::effective_base_dir(&project.root, &project.cache_dir, &config)?,
        )?;
        plan.env.extend(config.env.clone());
        let mut build = RunConfig {
@@ -278,7 +288,7 @@ pub async fn run_tomcat_sync(
        let module = dunce::canonicalize(project.root.join(module))?;
        let class_paths: Vec<_> =
            class_paths.iter().filter_map(|p| dunce::canonicalize(project.root.join(p)).ok()).collect();
-        let base = ide_run::tomcat::base_dir(&project.cache_dir, &config.id);
+        let base = ide_run::tomcat::effective_base_dir(&project.root, &project.cache_dir, &config)?;
        ide_run::tomcat::sync_outputs(&base, &module, &class_paths, resources_only)
    })
    .await
@@ -297,6 +307,7 @@ pub(crate) fn register(d: &mut Dispatcher) {
        run_application_publish(&c.host, &c.window, c.arg("config")?, c.arg("classPaths")?, c.arg("mainClass")?).await
    });
    d.add("run_tomcat_home", |c| async move { run_tomcat_home(&c.host, &c.window, c.arg("home")?).await });
+    d.add("run_tomcat_installations", |c| async move { run_tomcat_installations(&c.host, &c.window).await });
    d.add("run_tomcat_artifacts", |c| async move { run_tomcat_artifacts(&c.host, &c.window).await });
    d.add("run_tomcat_build", |c| async move { run_tomcat_build(&c.host, &c.window, c.arg("config")?).await });
    d.add("run_tomcat_sync", |c| async move {
@@ -6,19 +6,32 @@ use ide_core::remote_settings::{RunTarget, RunTargetKind};
 use ide_core::{IdeError, IdeResult};
 use ide_docker::DockerEndpoint;
 use ide_remote::docker::{
-    ContainerRun, compose_container_root, container_config, container_name, default_container_root,
+    ContainerDebug, ContainerRun, DEBUG_BOOTSTRAP, DEBUG_BOOTSTRAP_NAME, compose_container_root, container_config,
+    container_name, default_container_root,
 };
 use ide_run::RunConfig;
 use std::collections::BTreeMap;
 use std::path::{Path, PathBuf};

+/// Set by the Debug action on a configuration that runs on a container target: the
+/// program starts under debugpy and waits for the debugger.
+const DEBUG_PARAM: &str = "containerDebug";
+
 /// `config` rewritten to run in a new container of `target`'s image or service.
 pub(super) async fn prepare(host: &Host, root: &Path, target: RunTarget, config: RunConfig) -> IdeResult<RunConfig> {
    if config.kind == "dotnet" || config.kind == "dotnet-test" {
        return Err(IdeError::invalid(".NET Project requires the local machine"));
    }
+    let debug = config.extras.params.get(DEBUG_PARAM).is_some_and(|v| v == "true");
+    if debug && config.debug_adapter.as_deref() != Some("debugpy") {
+        return Err(IdeError::invalid(format!(
+            "'{}' can't be debugged in a container: only Python run configurations can",
+            config.name
+        )));
+    }
    let endpoint = endpoint(&host.data_dir, &target)?;
    let root = root.to_path_buf();
+    let data_dir = host.data_dir.clone();
    host.blocking(move || {
        if !ide_docker::endpoint_is_local(&endpoint)? {
            return Err(IdeError::invalid(format!(
@@ -39,6 +52,7 @@ pub(super) async fn prepare(host: &Host, root: &Path, target: RunTarget, config:
        };
        let file_env = env_files(&root, &config)?;
        let name = container_name(&config.id, &unique());
+        let debugging = if debug { Some(Debugging::prepare(&data_dir)?) } else { None };
        container_config(
            &config,
            &ContainerRun {
@@ -50,12 +64,45 @@ pub(super) async fn prepare(host: &Host, root: &Path, target: RunTarget, config:
                file_env: &file_env,
                name: &name,
                user: user(&root, &target),
+                debug: debugging.as_ref().map(|d| ContainerDebug {
+                    port: d.port,
+                    bootstrap_dir: &d.bootstrap_dir,
+                    debugpy: d.debugpy.as_deref(),
+                }),
            },
        )
    })
    .await
 }

+/// What a debug run mounts and publishes.
+struct Debugging {
+    port: u16,
+    bootstrap_dir: PathBuf,
+    debugpy: Option<PathBuf>,
+}
+
+impl Debugging {
+    fn prepare(data_dir: &Path) -> IdeResult<Self> {
+        // The bootstrap is (re)written on each run, so it matches this version of the IDE.
+        let bootstrap_dir = data_dir.join("container-debug");
+        std::fs::create_dir_all(&bootstrap_dir)?;
+        std::fs::write(bootstrap_dir.join(DEBUG_BOOTSTRAP_NAME), DEBUG_BOOTSTRAP)?;
+        // The managed install the local debugger falls back to (`ide_dap::adapter::prepare_debugpy`).
+        let tools = ide_dap::adapter::tools_root().unwrap_or_else(|| ide_tools::tools_dir(data_dir));
+        let lib = ide_tools::python_lib_dir(&tools, ide_dap::adapter::DEBUGPY_TOOL);
+        let debugpy = lib.join("debugpy").join("__init__.py").is_file().then_some(lib);
+        Ok(Self { port: free_port()?, bootstrap_dir, debugpy })
+    }
+}
+
+/// A port nobody listens on here: debugpy listens on the same port in the container,
+/// published on the loopback interface.
+fn free_port() -> IdeResult<u16> {
+    let listener = std::net::TcpListener::bind(("127.0.0.1", 0))?;
+    Ok(listener.local_addr()?.port())
+}
+
 /// The target's Docker connection (Services tool window), by id; none = the CLI's daemon.
 fn endpoint(data_dir: &Path, target: &RunTarget) -> IdeResult<DockerEndpoint> {
    let id = target.docker_connection.trim();
@@ -45,6 +45,15 @@ pub async fn sdk_detect(host: &Host, window: &str, kind: SdkKind) -> IdeResult<V
    .map_err(join_err)
 }

+/// An existing Python executable or virtualenv folder as an SDK; `None` if Python cannot run.
+pub async fn sdk_python_interpreter(host: &Host, window: &str, path: PathBuf) -> IdeResult<Option<Sdk>> {
+    host.require_trust(window)?;
+    let root = host.project(window).ok().map(|p| p.root.clone());
+    tokio::task::spawn_blocking(move || Ok(ide_sdk::python_interpreter_sdk(&path, root.as_deref())))
+        .await
+        .map_err(join_err)?
+}
+
 /// The interpreter the project uses: the configured one, else its virtualenv.
 pub fn sdk_python_effective(host: &Host, window: &str, near: Option<PathBuf>) -> IdeResult<Option<ide_core::IpcPath>> {
    host.require_trust(window)?;
@@ -149,25 +158,62 @@ pub async fn sdk_php_composer_install(

 /// SDK / library source folders shown under "External Libraries" in the Project view,
 /// with the Maven / Gradle dependency jars of the build model.
-pub async fn sdk_project_libraries(host: &Host, window: &str) -> IdeResult<Vec<ide_sdk::libraries::LibraryGroup>> {
+pub async fn sdk_project_libraries(
+    host: &Host,
+    window: &str,
+    request: RequestId,
+    on_groups: Channel<Vec<ide_sdk::libraries::LibraryGroup>>,
+) -> IdeResult<Vec<ide_sdk::libraries::LibraryGroup>> {
    host.require_trust(window)?;
    let project = host.project(window)?;
    let (root, cache, settings) = (project.root.clone(), project.build_cache_dir(), project.settings.effective());
-    tokio::task::spawn_blocking(move || {
-        let model = crate::ops::build::load(&root, &cache, &settings);
-        let deps: Vec<ide_sdk::libraries::BuildDependency> = ide_build::dependency_coordinates(&root, &model)
-            .into_iter()
-            .map(|c| ide_sdk::libraries::BuildDependency {
-                gradle: c.gradle,
-                group: c.group_id,
-                artifact: c.artifact_id,
-                version: c.version,
+    let cancel = host.begin_project_request(window, request);
+    let libraries = {
+        let (root, settings, cancel, on_groups) = (root.clone(), settings.clone(), cancel.clone(), on_groups.clone());
+        tokio::task::spawn_blocking(move || {
+            ide_sdk::libraries::project_libraries_stream(&root, &settings, &[], &cancel, &|groups| {
+                let _ = on_groups.send(groups);
            })
-            .collect();
-        ide_sdk::libraries::project_libraries(&root, &settings, &deps)
-    })
-    .await
-    .map_err(join_err)
+        })
+    };
+    let dependencies = {
+        let cancel = cancel.clone();
+        tokio::task::spawn_blocking(move || {
+            if cancel.is_cancelled() {
+                return Vec::new();
+            }
+            let model = crate::ops::build::load(&root, &cache, &settings);
+            let deps: Vec<ide_sdk::libraries::BuildDependency> = ide_build::dependency_coordinates(&root, &model)
+                .into_iter()
+                .map(|c| ide_sdk::libraries::BuildDependency {
+                    gradle: c.gradle,
+                    group: c.group_id,
+                    artifact: c.artifact_id,
+                    version: c.version,
+                })
+                .collect();
+            if cancel.is_cancelled() {
+                return Vec::new();
+            }
+            let groups = ide_sdk::libraries::dependency_groups(&root, &settings, &deps);
+            if !cancel.is_cancelled() {
+                let _ = on_groups.send(groups.clone());
+            }
+            groups
+        })
+    };
+    let (libraries, dependencies) = tokio::join!(libraries, dependencies);
+    host.end_request(request);
+    if cancel.is_cancelled() {
+        return Err(IdeError::cancelled());
+    }
+    let groups =
+        ide_sdk::libraries::merge_groups([libraries.map_err(join_err)?, dependencies.map_err(join_err)?].concat());
+    if host.project(window).is_ok_and(|current| std::sync::Arc::ptr_eq(&current, &project)) {
+        host.mcp_reports
+            .set_libraries(window, groups.iter().flat_map(|g| g.roots.iter().map(|r| r.path.0.clone())).collect());
+    }
+    Ok(groups)
 }

 /// Looks up `names` (bare command names): `node_modules/.bin` above `near`, then the search path.
@@ -257,6 +303,10 @@ pub async fn sdk_python_pip(
 /// Commands of this module the remote server answers.
 pub(crate) fn register(d: &mut Dispatcher) {
    d.add("sdk_detect", |c| async move { sdk_detect(&c.host, &c.window, c.arg("kind")?).await });
+    d.add(
+        "sdk_python_interpreter",
+        |c| async move { sdk_python_interpreter(&c.host, &c.window, c.arg("path")?).await },
+    );
    d.add("sdk_python_effective", |c| async move { sdk_python_effective(&c.host, &c.window, c.arg("near")?) });
    d.add("sdk_php_effective", |c| async move { sdk_php_effective(&c.host, &c.window) });
    d.add("sdk_php_xdebug", |c| async move { sdk_php_xdebug(&c.host, &c.window, c.arg("php")?, c.arg("cwd")?).await });
@@ -268,7 +318,9 @@ pub(crate) fn register(d: &mut Dispatcher) {
        "sdk_php_composer_install",
        |c| async move { sdk_php_composer_install(&c.host, &c.window, c.arg("path")?).await },
    );
-    d.add("sdk_project_libraries", |c| async move { sdk_project_libraries(&c.host, &c.window).await });
+    d.add("sdk_project_libraries", |c| async move {
+        sdk_project_libraries(&c.host, &c.window, c.arg("request")?, c.sender("onGroups")?).await
+    });
    d.add("sdk_locate_tools", |c| async move {
        sdk_locate_tools(&c.host, &c.window, c.arg("names")?, c.arg("near")?).await
    });
@@ -301,3 +353,69 @@ pub(crate) fn register(d: &mut Dispatcher) {
        .await
    });
 }
+
+#[cfg(all(test, unix))]
+mod tests {
+    use super::*;
+    use crate::HostConfig;
+    use std::path::Path;
+    use std::sync::Arc;
+
+    fn fake_venv(root: &Path, name: &str) -> PathBuf {
+        use std::os::unix::fs::PermissionsExt;
+        let venv = root.join(name);
+        std::fs::create_dir_all(venv.join("bin")).unwrap();
+        std::fs::write(venv.join("pyvenv.cfg"), "home = /usr/bin\nversion = 3.12.1\n").unwrap();
+        let python = venv.join("bin/python");
+        std::fs::write(&python, "#!/bin/sh\necho 3.12.1\n").unwrap();
+        std::fs::set_permissions(&python, std::fs::Permissions::from_mode(0o755)).unwrap();
+        python
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn a_hand_picked_venv_is_resolved_like_a_detected_interpreter() {
+        let temp = tempfile::tempdir().unwrap();
+        let base = dunce::canonicalize(temp.path()).unwrap();
+        let root = base.join("project");
+        std::fs::create_dir(&root).unwrap();
+        let host = Host::new(HostConfig {
+            config_dir: base.join("config"),
+            data_dir: base.join("data"),
+            local_data_dir: base.join("local"),
+            languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+            syntax: Arc::default(),
+            sink_for: Box::new(|_| Arc::new(|_| {})),
+            owner: |w| w,
+            runtime: tokio::runtime::Handle::current(),
+            project_environment: false,
+        });
+        host.trust.decide(&root, true, false).unwrap();
+        host.open_project("main", &root).unwrap();
+
+        let sdk = sdk_python_interpreter(&host, "main", fake_venv(&root, ".venv")).await.unwrap().unwrap();
+        assert_eq!((sdk.name.as_str(), sdk.source.as_str()), ("Python 3.12 (project)", "venv"));
+        let python = fake_venv(&base, "erp19py3.12");
+        let sdk = sdk_python_interpreter(&host, "main", python.parent().unwrap().parent().unwrap().into())
+            .await
+            .unwrap()
+            .unwrap();
+        assert_eq!((sdk.name.as_str(), sdk.source.as_str()), ("Python 3.12 (erp19py3.12)", "venv"));
+        assert_eq!(&*sdk.path, python.as_path());
+        host.project("main")
+            .unwrap()
+            .settings
+            .set(
+                ide_workspace::SettingsScope::Project,
+                "languages.python.interpreter",
+                serde_json::to_value(&sdk.path).unwrap(),
+            )
+            .unwrap();
+        host.close_project("main");
+        host.open_project("main", &root).unwrap();
+        let detected = sdk_detect(&host, "main", SdkKind::Python).await.unwrap();
+        assert!(detected.iter().any(|s| s.path == sdk.path && s.name == sdk.name));
+        assert_eq!(sdk_python_effective(&host, "main", None).unwrap(), Some(sdk.path));
+        assert!(sdk_python_interpreter(&host, "main", root.join("README.md")).await.unwrap().is_none());
+        host.close_project("main");
+    }
+}
@@ -24,3 +24,37 @@ pub async fn status(host: &Host, window: &str) -> IdeResult<Vec<FileStatus>> {

 mod commands;
 pub use commands::*;
+
+fn check_worktree_removal(project_root: &std::path::Path, path: &std::path::Path) -> IdeResult<()> {
+    fn canonical_path(path: &std::path::Path) -> std::io::Result<std::path::PathBuf> {
+        let mut existing = path.to_path_buf();
+        let mut tail = Vec::new();
+        let mut real = loop {
+            match dunce::canonicalize(&existing) {
+                Ok(real) => break real,
+                Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+                    let Some(part) = existing.components().next_back() else { return Err(e) };
+                    tail.push(part.as_os_str().to_owned());
+                    if !existing.pop() {
+                        return Err(e);
+                    }
+                }
+                Err(e) => return Err(e),
+            }
+        };
+        // The project or worktree may already be gone; resolve its missing tail too.
+        for part in tail.into_iter().rev() {
+            if part == ".." {
+                real.pop();
+            } else if part != "." {
+                real.push(part);
+            }
+        }
+        Ok(real)
+    }
+
+    if canonical_path(project_root)?.starts_with(canonical_path(path)?) {
+        return Err(ide_core::IdeError::invalid("Cannot remove a worktree containing the open project."));
+    }
+    Ok(())
+}
@@ -1041,6 +1041,12 @@ pub async fn vcs_remove_worktree(
    host.require_trust(window)?;
    let project = host.project(window)?;
    blocking(move || {
+        let path = if path.is_absolute() {
+            path
+        } else {
+            project.with_repo_at(repo.as_deref(), |r| Ok(r.root().join(&path)))?
+        };
+        check_worktree_removal(&project.root, &path)?;
        let result = project.with_repo_at(repo.as_deref(), |r| r.remove_worktree(&path, force));
        project.refresh_repositories();
        result
@@ -0,0 +1,245 @@
+//! Versioned, project-scoped diagnostics for unsaved editor buffers.
+use super::{PluginHost, ProviderKind, editor_plugin_host};
+use ide_core::{CancellationToken, Diagnostic, DocId, IdeEvent, SharedSink};
+use ide_plugin::ProviderDocument;
+use ide_text::AppliedChange;
+use ide_workspace::documents::DocumentObserver;
+use ide_workspace::{DocumentInfo, Documents};
+use parking_lot::Mutex;
+use std::collections::{HashMap, HashSet};
+use std::path::Path;
+use std::sync::{Arc, Weak};
+use std::time::Duration;
+
+const DEBOUNCE: Duration = Duration::from_millis(300);
+
+struct Document {
+    snapshot: ProviderDocument,
+    cancel: CancellationToken,
+    sources: HashSet<String>,
+}
+
+#[derive(Default)]
+pub(super) struct State {
+    closed: bool,
+    documents: HashMap<DocId, Document>,
+    generations: HashMap<String, u64>,
+}
+
+/// One incarnation of one project's documents, shared by all its editors.
+pub(crate) struct Diagnostics {
+    state: Arc<Mutex<State>>,
+    sink: SharedSink,
+    runtime: tokio::runtime::Handle,
+    documents: Weak<Documents>,
+    root: std::path::PathBuf,
+}
+
+impl Diagnostics {
+    pub fn new(
+        sink: SharedSink,
+        runtime: tokio::runtime::Handle,
+        documents: &Arc<Documents>,
+        root: &Path,
+    ) -> Arc<Self> {
+        Arc::new(Self {
+            state: Arc::default(),
+            sink,
+            runtime,
+            documents: Arc::downgrade(documents),
+            root: root.to_path_buf(),
+        })
+    }
+
+    fn emit(&self, path: &Path, plugin: &str, items: Vec<Diagnostic>) {
+        self.sink.emit(IdeEvent::Diagnostics {
+            path: path.to_path_buf().into(),
+            source: format!("plugin-provider:{plugin}"),
+            items,
+        });
+    }
+
+    fn clear_document(&self, doc: &Document) {
+        doc.cancel.cancel();
+        for plugin in &doc.sources {
+            self.emit(&doc.snapshot.path, plugin, Vec::new());
+        }
+    }
+
+    pub fn close(&self) {
+        let mut state = self.state.lock();
+        state.closed = true;
+        for (_, doc) in state.documents.drain() {
+            self.clear_document(&doc);
+        }
+    }
+
+    fn schedule(&self, id: DocId, state: &mut State) {
+        let Some(doc) = state.documents.get_mut(&id) else { return };
+        doc.cancel.cancel();
+        doc.cancel = CancellationToken::new();
+        let Some(host) = editor_plugin_host() else { return };
+        if host.providers.plugins_for(ProviderKind::Diagnostics, &doc.snapshot.language).is_empty() {
+            return;
+        }
+        // Register only once per project incarnation; no project is retained by the host.
+        let weak = Arc::downgrade(&self.state);
+        {
+            let mut projects = host.diagnostic_projects.lock();
+            projects.retain(|(state, _)| state.strong_count() > 0);
+            if !projects.iter().any(|(state, _)| state.ptr_eq(&weak)) {
+                projects.push((weak.clone(), self.sink.clone()));
+            }
+        }
+        let root = self.root.clone();
+        let (mut snapshot, cancel, sink, documents) =
+            (doc.snapshot.clone(), doc.cancel.clone(), self.sink.clone(), self.documents.clone());
+        let lifecycle_generations = state.generations.clone();
+        self.runtime.spawn(async move {
+            tokio::time::sleep(DEBOUNCE).await;
+            if cancel.is_cancelled() || weak.strong_count() == 0 {
+                return;
+            }
+            let _ = tokio::task::spawn_blocking(move || {
+                let Some(documents) = documents.upgrade() else { return };
+                let Ok(current) = documents.snapshot(id) else { return };
+                if u64::from(current.version) != snapshot.version
+                    || current.path.0 != snapshot.path
+                    || current.language.as_str() != snapshot.language
+                    || cancel.is_cancelled()
+                {
+                    return;
+                }
+                snapshot.text = current.text;
+                drop(documents);
+
+                let generations = host.providers.diagnostic_generations(&snapshot.language);
+                let results = if snapshot.text.len() <= super::navigation::MAX_DOCUMENT_BYTES {
+                    host.provide_project_diagnostics(Some(&root), &snapshot, &cancel)
+                } else {
+                    Vec::new()
+                };
+                let Some(state) = weak.upgrade() else { return };
+                let mut state = state.lock();
+                if state.closed || cancel.is_cancelled() {
+                    return;
+                }
+                let matching: HashSet<_> = host
+                    .diagnostic_plugins(Some(&root), &snapshot.language)
+                    .into_iter()
+                    .map(|p| p.id().to_owned())
+                    .filter(|p| lifecycle_generations.get(p) == state.generations.get(p))
+                    .collect();
+                let latest = host.providers.diagnostic_generations(&snapshot.language);
+                let Some(doc) = state.documents.get_mut(&id) else { return };
+                if doc.snapshot.version != snapshot.version || doc.snapshot.path != snapshot.path {
+                    return;
+                }
+                let mut current = HashSet::new();
+                for (plugin, items) in results {
+                    if !matching.contains(&plugin)
+                        || !generations.get(&plugin).is_some_and(|seq| latest.get(&plugin) == Some(seq))
+                    {
+                        continue;
+                    }
+                    current.insert(plugin.clone());
+                    sink.emit(IdeEvent::Diagnostics {
+                        path: snapshot.path.clone().into(),
+                        source: format!("plugin-provider:{plugin}"),
+                        items,
+                    });
+                }
+                for plugin in doc.sources.difference(&current) {
+                    sink.emit(IdeEvent::Diagnostics {
+                        path: snapshot.path.clone().into(),
+                        source: format!("plugin-provider:{plugin}"),
+                        items: Vec::new(),
+                    });
+                }
+                doc.sources = current;
+            })
+            .await;
+        });
+    }
+}
+
+impl DocumentObserver for Diagnostics {
+    fn opened(&self, info: &DocumentInfo) {
+        let mut state = self.state.lock();
+        if state.closed {
+            return;
+        }
+        if let Some(old) = state.documents.remove(&info.id) {
+            self.clear_document(&old);
+        }
+        if info.large || info.uri.is_some() {
+            return;
+        }
+        state.documents.insert(
+            info.id,
+            Document {
+                snapshot: ProviderDocument {
+                    path: info.path.0.clone(),
+                    language: info.language.to_string(),
+                    version: u64::from(info.version),
+                    text: String::new(),
+                },
+                cancel: CancellationToken::new(),
+                sources: HashSet::new(),
+            },
+        );
+        self.schedule(info.id, &mut state);
+    }
+
+    fn changed(&self, id: DocId, path: &Path, version: u32, _: &[AppliedChange], _text: &dyn Fn() -> String) {
+        let mut state = self.state.lock();
+        if state.closed {
+            return;
+        }
+        let Some(doc) = state.documents.get_mut(&id) else { return };
+        if doc.snapshot.path != path {
+            self.clear_document(doc);
+            doc.sources.clear();
+        }
+        doc.snapshot.path = path.to_path_buf();
+        doc.snapshot.version = u64::from(version);
+        self.schedule(id, &mut state);
+    }
+
+    fn closed(&self, id: DocId, _: &Path) {
+        if let Some(doc) = self.state.lock().documents.remove(&id) {
+            self.clear_document(&doc);
+        }
+    }
+}
+
+impl Drop for Diagnostics {
+    fn drop(&mut self) {
+        self.close();
+    }
+}
+
+pub(super) type ProjectState = (Weak<Mutex<State>>, SharedSink);
+
+impl PluginHost {
+    pub(super) fn clear_provider_diagnostics(&self, plugin: &str) {
+        // Clone before taking a project's state lock (edits register in the other order).
+        let projects = self.diagnostic_projects.lock().clone();
+        for (state, sink) in projects {
+            if let Some(state) = state.upgrade() {
+                let mut state = state.lock();
+                // A completed answer can still be waiting for another provider.
+                *state.generations.entry(plugin.to_owned()).or_default() += 1;
+                for doc in state.documents.values_mut() {
+                    if doc.sources.remove(plugin) {
+                        sink.emit(IdeEvent::Diagnostics {
+                            path: doc.snapshot.path.clone().into(),
+                            source: format!("plugin-provider:{plugin}"),
+                            items: Vec::new(),
+                        });
+                    }
+                }
+            }
+        }
+    }
+}
@@ -0,0 +1,318 @@
+//! `[[contributes.endpoints]]`: HTTP routes a plugin finds in a project. The UI
+//! asks for them (`plugin_endpoints`); the host caches each plugin's list per
+//! project until a file matching its globs changes, then emits `EndpointsChanged`.
+use super::{PluginEvent, PluginHost};
+use ide_core::{IdeResult, ipc_path::to_ipc};
+use ide_extension::{Capability, Package, UiDecl, decode};
+use ide_plugin::{Endpoint, HostError, Invocation};
+use serde::{Deserialize, Serialize};
+use std::{
+    collections::BTreeMap,
+    path::{Path, PathBuf},
+    sync::Arc,
+    time::Duration,
+};
+
+pub(super) const POINT: &str = "endpoints";
+
+#[derive(Deserialize, Serialize)]
+#[serde(deny_unknown_fields)]
+struct Decl {
+    files: Vec<String>,
+}
+
+pub(super) fn declaration(pkg: &Package, value: toml::Value) -> Result<UiDecl, String> {
+    let d: Decl = decode(POINT, value)?;
+    pkg.manifest.needs_api("contributes.endpoints", 3)?;
+    if pkg.manifest.wasm.is_none() || d.files.is_empty() || d.files.len() > 64 {
+        return Err("contributes.endpoints needs code and 1–64 file globs".into());
+    }
+    for file in &d.files {
+        if file.is_empty()
+            || file.len() > 1024
+            || file.starts_with('/')
+            || file.contains('\\')
+            || file.contains(':')
+            || file.split('/').any(|p| p == "..")
+        {
+            return Err("endpoint file globs must be project-relative".into());
+        }
+        matcher(file).map_err(|e| e.to_string())?;
+    }
+    let key = serde_json::to_string(&d.files).map_err(|e| e.to_string())?;
+    Ok(UiDecl::new(key, "HTTP endpoints", serde_json::to_value(d).map_err(|e| e.to_string())?))
+}
+
+fn matcher(glob: &str) -> Result<globset::GlobMatcher, globset::Error> {
+    Ok(globset::GlobBuilder::new(glob).literal_separator(true).build()?.compile_matcher())
+}
+
+/// A route as the UI gets it.
+#[derive(Clone, Debug, PartialEq, Serialize, specta::Type)]
+#[serde(rename_all = "camelCase")]
+pub struct PluginEndpoint {
+    /// `None` accepts any method.
+    pub method: Option<String>,
+    /// Path parameters in braces: `/photos/{id}`.
+    pub path: String,
+    pub framework: String,
+    /// Display name, e.g. `PhotosController#show`.
+    pub handler: Option<String>,
+    /// Where the route is declared.
+    pub location: ide_core::Location,
+}
+
+#[derive(Default)]
+pub(super) struct Endpoints {
+    /// Bumped by every invalidation: a list computed across one is kept but not trusted.
+    epoch: u64,
+    cache: BTreeMap<(String, PathBuf), Cached>,
+}
+
+struct Cached {
+    list: Arc<Vec<PluginEndpoint>>,
+    fresh: bool,
+}
+
+impl PluginHost {
+    /// `plugin`'s routes in the project `root`: the cached list while no file
+    /// matching its globs changed, else computed again. Runs plugin code, so
+    /// call it on a blocking thread. A failed or invalid run keeps the last list.
+    pub fn endpoints(&self, plugin: &str, root: &Path) -> IdeResult<Arc<Vec<PluginEndpoint>>> {
+        let Some(workspace) = self.shared.workspace() else { return Ok(Arc::default()) };
+        let open = |root: &Path| workspace.projects().iter().any(|r| r == root) && workspace.trusted(root);
+        let loaded = self.get(plugin)?;
+        let key = (plugin.to_owned(), root.to_path_buf());
+        let epoch = {
+            let mut state = self.endpoints.lock();
+            state.cache.retain(|(_, r), _| open(r));
+            if !open(root) || !self.endpoint_eligible(&loaded, root) {
+                return Ok(Arc::default());
+            }
+            if let Some(cached) = state.cache.get(&key).filter(|c| c.fresh) {
+                return Ok(cached.list.clone());
+            }
+            state.epoch
+        };
+        let invocation = Invocation { workspace_root: Some(root.to_path_buf()), ..Default::default() };
+        let result = self
+            .code_call(plugin, invocation, "endpoints", |rt, ctx| rt.endpoints(ctx, Duration::from_secs(2)))
+            .and_then(|items| {
+                validate(root, items, &*workspace).map_err(|e| ide_core::IdeError::invalid(e.to_string()))
+            });
+        let mut state = self.endpoints.lock();
+        // Disabled, replaced or closed meanwhile: its routes are gone.
+        let current = self.plugins.read().get(plugin).is_some_and(|p| Arc::ptr_eq(p, &loaded));
+        if !current || !open(root) || !self.endpoint_eligible(&loaded, root) {
+            state.cache.remove(&key);
+            return Ok(Arc::default());
+        }
+        let fresh = state.epoch == epoch;
+        let list = match result {
+            Ok(list) => Arc::new(list),
+            Err(e) => {
+                tracing::warn!(plugin, "endpoints failed: {e}");
+                state.cache.get(&key).map(|c| c.list.clone()).unwrap_or_default()
+            }
+        };
+        state.cache.insert(key, Cached { list: list.clone(), fresh });
+        Ok(list)
+    }
+
+    pub(super) fn clear_plugin_endpoints(&self, plugin: &str) {
+        let mut state = self.endpoints.lock();
+        state.epoch += 1;
+        let roots: Vec<PathBuf> = state.cache.keys().filter(|(id, _)| id == plugin).map(|(_, r)| r.clone()).collect();
+        state.cache.retain(|(id, _), _| id != plugin);
+        drop(state);
+        for root in roots {
+            self.emit(None, PluginEvent::EndpointsChanged { plugin_id: plugin.to_owned(), root: to_ipc(&root).into() });
+        }
+    }
+
+    /// Called by the project's file watcher; doesn't run plugin code.
+    pub fn invalidate_endpoints(&self, root: &Path, paths: &[PathBuf]) {
+        let rel: Vec<&Path> = paths.iter().filter_map(|p| p.strip_prefix(root).ok()).collect();
+        if rel.is_empty() {
+            return;
+        }
+        let declarations = self.ui.items(POINT, None);
+        let mut state = self.endpoints.lock();
+        state.epoch += 1;
+        let mut changed = Vec::new();
+        for ((plugin, project), cached) in &mut state.cache {
+            let matches = project == root
+                && declarations.iter().filter(|d| &d.plugin_id == plugin).any(|d| {
+                    d.decl["files"].as_array().is_some_and(|globs| {
+                        globs
+                            .iter()
+                            .filter_map(|g| matcher(g.as_str()?).ok())
+                            .any(|m| rel.iter().any(|p| m.is_match(p)))
+                    })
+                });
+            if matches && cached.fresh {
+                cached.fresh = false;
+                changed.push(plugin.clone());
+            }
+        }
+        drop(state);
+        for plugin_id in changed {
+            self.emit(None, PluginEvent::EndpointsChanged { plugin_id, root: to_ipc(root).into() });
+        }
+    }
+
+    fn endpoint_eligible(&self, plugin: &super::LoadedPlugin, root: &Path) -> bool {
+        plugin.status().is_live()
+            && plugin.dev_root.as_deref().is_none_or(|r| r == root)
+            && !self.ui.items(POINT, Some(plugin.id())).is_empty()
+            && {
+                let meta = plugin.meta.lock();
+                meta.pending.is_empty() && meta.granted.contains(&Capability::ProjectRead)
+            }
+    }
+}
+
+fn validate(
+    root: &Path,
+    items: Vec<Endpoint>,
+    workspace: &dyn super::PluginWorkspace,
+) -> Result<Vec<PluginEndpoint>, HostError> {
+    if items.len() > 10_000 {
+        return Err(HostError::Invalid("at most 10,000 endpoints".into()));
+    }
+    let mut bytes = 0usize;
+    let mut document_bytes = 0usize;
+    let mut texts: BTreeMap<PathBuf, Vec<usize>> = BTreeMap::new();
+    let mut validated = Vec::with_capacity(items.len());
+    for e in items {
+        bytes += e.path.len()
+            + e.method.as_ref().map_or(0, String::len)
+            + e.framework.len()
+            + e.handler.as_ref().map_or(0, String::len)
+            + e.location.path.as_os_str().len();
+        if bytes > 4 << 20
+            || e.path.len() > 8192
+            || !e.path.starts_with('/')
+            || e.path.chars().any(char::is_whitespace)
+            || e.path.chars().any(char::is_control)
+            || e.method.as_ref().is_some_and(|m| {
+                m.is_empty() || m.len() > 32 || !m.bytes().all(|b| b.is_ascii_uppercase() || b == b'-')
+            })
+            || e.framework.is_empty()
+            || e.framework.len() > 256
+            || e.framework.chars().any(char::is_control)
+            || e.handler.as_ref().is_some_and(|h| h.len() > 1024 || h.chars().any(char::is_control))
+        {
+            return Err(HostError::Invalid("invalid endpoint or batch larger than 4 MiB".into()));
+        }
+        let path = ide_plugin::resolve_in_root(root, &e.location.path.to_string_lossy()).map_err(HostError::Invalid)?;
+        if !texts.contains_key(&path) {
+            let text = workspace
+                .buffer_text(&path)
+                .map(Ok)
+                .unwrap_or_else(|| ide_plugin::read_text(&path).map_err(HostError::Invalid));
+            let text = text?;
+            document_bytes += text.len();
+            if document_bytes > 16 << 20 {
+                return Err(HostError::Invalid("endpoint declaration documents exceed 16 MiB".into()));
+            }
+            texts.insert(
+                path.clone(),
+                text.split('\n').map(|line| line.trim_end_matches('\r').encode_utf16().count()).collect(),
+            );
+        }
+        let lines = &texts[&path];
+        let range = e.location.range;
+        if range.start > range.end
+            || [range.start, range.end]
+                .iter()
+                .any(|p| lines.get(p.line as usize).is_none_or(|len| p.col as usize > *len))
+        {
+            return Err(HostError::Invalid("endpoint location is outside its UTF-16 document range".into()));
+        }
+        validated.push(PluginEndpoint {
+            method: e.method,
+            path: e.path,
+            framework: e.framework,
+            handler: e.handler,
+            location: ide_core::Location { path: to_ipc(&path).into(), range, uri: None },
+        });
+    }
+    Ok(validated)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use ide_core::{Pos, Range};
+    struct Workspace;
+    impl super::super::PluginWorkspace for Workspace {
+        fn projects(&self) -> Vec<PathBuf> {
+            vec![]
+        }
+        fn buffer_text(&self, _: &Path) -> Option<String> {
+            None
+        }
+        fn document(&self, _: &Path) -> Option<(u64, String)> {
+            None
+        }
+        fn trusted(&self, _: &Path) -> bool {
+            true
+        }
+        fn project_of(&self, _: &str) -> Option<PathBuf> {
+            None
+        }
+        fn apply_edits(&self, _: &Path, _: u64, _: &[ide_core::TextEdit]) -> Result<u64, HostError> {
+            unreachable!()
+        }
+        fn publish_diagnostics(&self, _: &str, _: &Path, _: Vec<ide_core::Diagnostic>) -> Result<(), HostError> {
+            unreachable!()
+        }
+    }
+    fn endpoint(path: PathBuf) -> Endpoint {
+        Endpoint {
+            method: Some("GET".into()),
+            path: "/users/{id}".into(),
+            framework: "Rails".into(),
+            handler: None,
+            location: ide_plugin::Location { path, range: Range::new(Pos::new(0, 2), Pos::new(0, 3)) },
+        }
+    }
+    #[test]
+    fn validates_entire_rooted_batch_with_utf16_positions() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path().canonicalize().unwrap();
+        let file = root.join("routes.rb");
+        std::fs::write(&file, "😀x\n").unwrap();
+        let good = endpoint(file.clone());
+        let items = validate(&root, vec![good.clone()], &Workspace).unwrap();
+        assert_eq!(items[0].location.range.end.col, 3);
+        assert!(items[0].handler.is_none());
+        for bad in [
+            Endpoint { method: Some("GET\nPOST".into()), ..good.clone() },
+            Endpoint { path: "https://example.com".into(), ..good.clone() },
+            Endpoint { path: "/bad\r\nPOST /".into(), ..good.clone() },
+            Endpoint { handler: Some("bad\nhandler".into()), ..good.clone() },
+            Endpoint {
+                location: ide_plugin::Location {
+                    path: file.clone(),
+                    range: Range::new(Pos::new(0, 0), Pos::new(0, 4)),
+                },
+                ..good.clone()
+            },
+            Endpoint {
+                location: ide_plugin::Location { path: root.join("../outside"), range: Range::default() },
+                ..good.clone()
+            },
+        ] {
+            assert!(validate(&root, vec![good.clone(), bad], &Workspace).is_err());
+        }
+        assert!(validate(&root, vec![good.clone(); 10_001], &Workspace).is_err());
+        #[cfg(unix)]
+        {
+            let outside = tempfile::NamedTempFile::new().unwrap();
+            std::os::unix::fs::symlink(outside.path(), root.join("escape")).unwrap();
+            assert!(validate(&root, vec![endpoint(root.join("escape"))], &Workspace).is_err());
+        }
+    }
+}
@@ -0,0 +1,201 @@
+//! Project-relative event filters, kept with runtime subscriptions across idle reclaim.
+use super::{LoadedPlugin, PluginHost};
+use globset::{GlobBuilder, GlobMatcher};
+use ide_plugin::{EventKind, HostError, WorkbenchEvent};
+use std::{
+    collections::{BTreeSet, HashMap},
+    path::Path,
+};
+
+#[derive(Clone, Default)]
+pub(super) struct Subscriptions {
+    pub kinds: HashMap<String, BTreeSet<EventKind>>,
+    pub paths: HashMap<String, HashMap<String, PathFilter>>,
+}
+
+#[derive(Clone)]
+pub(super) struct PathFilter {
+    pub globs: Vec<String>,
+    matchers: Vec<GlobMatcher>,
+}
+
+impl PathFilter {
+    pub fn new(kind: &str, globs: Vec<String>) -> Result<Self, HostError> {
+        if !matches!(kind, "file-opened" | "file-saved" | "files-changed") {
+            return Err(HostError::Invalid(
+                "subscribe-paths supports file-opened, file-saved and files-changed".into(),
+            ));
+        }
+        if globs.len() > 64 {
+            return Err(HostError::Invalid("at most 64 event path globs".into()));
+        }
+        let mut matchers = Vec::new();
+        for input in &globs {
+            let glob = input.trim_start_matches("./");
+            if glob.is_empty()
+                || input.len() > 1024
+                || glob.starts_with('/')
+                || glob.contains('\\')
+                || glob.contains(':')
+                || glob.chars().any(char::is_control)
+                || glob.split('/').any(|c| c == "..")
+            {
+                return Err(HostError::Invalid(
+                    "event globs must be project-relative paths, at most 1024 bytes each".into(),
+                ));
+            }
+            matchers.push(
+                GlobBuilder::new(glob)
+                    .literal_separator(true)
+                    .build()
+                    .map_err(|e| HostError::Invalid(format!("invalid event glob: {e}")))?
+                    .compile_matcher(),
+            );
+        }
+        Ok(Self { globs, matchers })
+    }
+
+    pub fn matches(&self, root: &Path, path: &Path) -> bool {
+        let path = ide_plugin::resolve_real(path);
+        let root = ide_plugin::resolve_real(root);
+        path.strip_prefix(&root).is_ok_and(|relative| self.matchers.iter().any(|m| m.is_match(relative)))
+    }
+}
+
+impl Subscriptions {
+    pub fn remove(&mut self, plugin: &str) -> bool {
+        self.kinds.remove(plugin).is_some() | self.paths.remove(plugin).is_some()
+    }
+    /// Subscribes to every event of `kind`, dropping its path filter.
+    pub fn set(&mut self, plugin: &str, kind: EventKind) -> bool {
+        let removed = self.paths.get_mut(plugin).is_some_and(|filters| filters.remove(kind.name()).is_some());
+        self.kinds.entry(plugin.to_owned()).or_default().insert(kind) | removed
+    }
+    pub fn set_paths(&mut self, plugin: &str, kind: &str, filter: PathFilter) -> bool {
+        let mut changed = false;
+        if let Some(kind) = EventKind::parse(kind) {
+            changed = self.kinds.entry(plugin.to_owned()).or_default().insert(kind);
+        }
+        let previous = self.paths.entry(plugin.to_owned()).or_default().insert(kind.to_owned(), filter.clone());
+        previous.is_none_or(|old| old.globs != filter.globs) | changed
+    }
+    pub fn unsubscribe(&mut self, plugin: &str, kind: &str) -> bool {
+        let removed = self.paths.get_mut(plugin).is_some_and(|filters| filters.remove(kind).is_some());
+        let off = EventKind::parse(kind)
+            .is_some_and(|kind| self.kinds.get_mut(plugin).is_some_and(|kinds| kinds.remove(&kind)));
+        removed | off
+    }
+}
+
+impl PluginHost {
+    pub(super) fn filter_path_events(
+        shared: &super::api::Shared,
+        plugin: &LoadedPlugin,
+        client: Option<&str>,
+        events: &[WorkbenchEvent],
+        subs: &Subscriptions,
+    ) -> Vec<WorkbenchEvent> {
+        let Some(filters) = subs.paths.get(plugin.id()) else { return events.to_vec() };
+        let workspace = shared.workspace();
+        events
+            .iter()
+            .filter_map(|event| {
+                if let WorkbenchEvent::FilesChanged(batch) = event {
+                    let Some(filter) = filters.get(event.kind().name()) else { return Some(event.clone()) };
+                    let root = workspace.as_ref()?.project_of(client?)?;
+                    if plugin.dev_root.as_deref().is_some_and(|r| r != root) {
+                        return None;
+                    }
+                    let paths = |paths: &[String]| {
+                        paths
+                            .iter()
+                            .filter(|path| {
+                                let path = Path::new(path);
+                                path.is_absolute() && filter.matches(&root, path)
+                            })
+                            .cloned()
+                            .collect::<Vec<_>>()
+                    };
+                    let batch = ide_plugin::FilesChanged {
+                        created: paths(&batch.created),
+                        modified: paths(&batch.modified),
+                        removed: paths(&batch.removed),
+                    };
+                    return (!(batch.created.is_empty() && batch.modified.is_empty() && batch.removed.is_empty()))
+                        .then_some(WorkbenchEvent::FilesChanged(batch));
+                }
+                let path = match event {
+                    WorkbenchEvent::FileOpened(path) | WorkbenchEvent::FileSaved(path) => Path::new(path),
+                    _ => return Some(event.clone()),
+                };
+                let Some(filter) = filters.get(event.kind().name()) else { return Some(event.clone()) };
+                if !path.is_absolute() {
+                    return None;
+                }
+                let workspace = workspace.as_ref()?;
+                let root = match client {
+                    Some(client) => workspace.project_of(client),
+                    None => {
+                        let real = ide_plugin::resolve_real(path);
+                        workspace
+                            .projects()
+                            .into_iter()
+                            .filter(|r| real.starts_with(ide_plugin::resolve_real(r)))
+                            .max_by_key(|r| r.components().count())
+                    }
+                }?;
+                if plugin.dev_root.as_deref().is_some_and(|r| r != root) {
+                    return None;
+                }
+                filter.matches(&root, path).then(|| event.clone())
+            })
+            .collect()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn glob_validation_is_bounded_and_project_relative() {
+        for invalid in ["", "/etc/*", "../*", "a/../b", "C:/a", "a\\b", "a\nb", "["] {
+            assert!(PathFilter::new("file-opened", vec![invalid.into()]).is_err(), "{invalid:?}");
+        }
+        assert!(PathFilter::new("editor-focused", vec!["*".into()]).is_err());
+        assert!(PathFilter::new("file-saved", vec!["*".into(); 65]).is_err());
+        assert!(PathFilter::new("file-saved", vec!["./".repeat(513)]).is_err());
+        assert!(PathFilter::new("file-saved", vec![]).is_ok());
+        assert!(PathFilter::new("files-changed", vec![]).is_ok());
+    }
+
+    #[test]
+    fn matchers_use_or_semantics_and_component_boundaries() {
+        let root = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(root.path()).unwrap();
+        let filter = PathFilter::new("file-opened", vec!["./config/*.yaml".into(), "src/**/*.rs".into()]).unwrap();
+        for path in ["config/a.yaml", "src/main.rs", "src/深い/a.rs"] {
+            assert!(filter.matches(&root, &root.join(path)), "{path}");
+        }
+        for path in ["config/nested/a.yaml", "other/a.yaml", "src/a.ts"] {
+            assert!(!filter.matches(&root, &root.join(path)), "{path}");
+        }
+        assert!(!filter.matches(&root, &root.with_extension("other").join("config/a.yaml")));
+        assert!(!PathFilter::new("file-opened", vec![]).unwrap().matches(&root, &root.join("a")));
+    }
+
+    #[test]
+    fn subscriptions_replace_atomically_and_legacy_subscribe_clears_filters() {
+        let mut subs = Subscriptions::default();
+        subs.set_paths("plugin", "file-opened", PathFilter::new("file-opened", vec!["*.rs".into()]).unwrap());
+        assert!(subs.kinds["plugin"].contains(&EventKind::FileOpened));
+        subs.set_paths("plugin", "file-opened", PathFilter::new("file-opened", vec![]).unwrap());
+        assert!(subs.paths["plugin"]["file-opened"].globs.is_empty());
+        subs.set("plugin", EventKind::FileOpened);
+        assert!(subs.paths["plugin"].is_empty());
+        subs.set_paths("plugin", "file-saved", PathFilter::new("file-saved", vec!["*".into()]).unwrap());
+        assert!(subs.unsubscribe("plugin", "file-saved"));
+        assert!(subs.remove("plugin"));
+        assert!(subs.paths.is_empty() && subs.kinds.is_empty());
+    }
+}
@@ -0,0 +1,663 @@
+//! Filesystem batches retain their project incarnation until delivery.
+use super::{PluginHost, WorkbenchEvent};
+use ide_core::ipc_path::to_ipc;
+use ide_plugin::FilesChanged;
+use std::path::{Path, PathBuf};
+use std::sync::{
+    Arc, Weak,
+    atomic::{AtomicBool, Ordering},
+};
+
+#[derive(Clone)]
+pub(super) struct Source {
+    active: Weak<AtomicBool>,
+}
+
+impl Source {
+    pub fn same(&self, other: &Self) -> bool {
+        self.active.ptr_eq(&other.active)
+    }
+    fn live(&self) -> bool {
+        self.active.upgrade().is_some_and(|active| active.load(Ordering::Acquire))
+    }
+}
+
+pub(super) fn retain_live(events: &mut Vec<WorkbenchEvent>, source: Option<&Source>) {
+    if source.is_some_and(|source| !source.live()) {
+        events.retain(|e| !matches!(e, WorkbenchEvent::FilesChanged(_)));
+    }
+}
+
+pub(super) fn append(events: &mut Vec<WorkbenchEvent>, incoming: Vec<WorkbenchEvent>) {
+    for event in incoming {
+        if let WorkbenchEvent::FilesChanged(batch) = &event
+            && let Some(WorkbenchEvent::FilesChanged(previous)) =
+                events.iter_mut().find(|e| matches!(e, WorkbenchEvent::FilesChanged(_)))
+        {
+            use std::collections::BTreeMap;
+            #[derive(Clone, Copy)]
+            enum Change {
+                Created,
+                Modified,
+                Removed,
+            }
+            use Change::*;
+            let mut paths = BTreeMap::new();
+            for (kind, entries) in
+                [(Created, &previous.created), (Modified, &previous.modified), (Removed, &previous.removed)]
+            {
+                for path in entries {
+                    paths.insert(path.clone(), kind);
+                }
+            }
+            for (next, entries) in [(Created, &batch.created), (Modified, &batch.modified), (Removed, &batch.removed)] {
+                for path in entries {
+                    let kind = match (paths.get(path), next) {
+                        (Some(Created), Created | Modified) => Created,
+                        (Some(Removed), Created) | (Some(Modified), Created | Modified) => Modified,
+                        (Some(Removed), Modified) => Removed,
+                        (_, next) => next,
+                    };
+                    paths.insert(path.clone(), kind);
+                }
+            }
+            *previous = FilesChanged::default();
+            for (path, kind) in paths {
+                match kind {
+                    Created => previous.created.push(path),
+                    Modified => previous.modified.push(path),
+                    Removed => previous.removed.push(path),
+                }
+            }
+        } else {
+            events.push(event);
+        }
+    }
+}
+
+impl PluginHost {
+    pub(crate) fn post_files_changed(
+        &self,
+        client: &str,
+        root: &Path,
+        active: &Arc<AtomicBool>,
+        batch: &ide_vfs::FsBatch,
+    ) {
+        if !active.load(Ordering::Acquire) || self.shared.project_of(client).as_deref() != Some(root) {
+            return;
+        }
+        let paths =
+            |paths: &[PathBuf]| paths.iter().filter(|p| p.starts_with(root)).map(|p| to_ipc(p)).collect::<Vec<_>>();
+        let batch = FilesChanged {
+            created: paths(&batch.created),
+            modified: paths(&batch.modified),
+            removed: paths(&batch.removed),
+        };
+        if batch.created.is_empty() && batch.modified.is_empty() && batch.removed.is_empty() {
+            return;
+        }
+        self.post_events_from(
+            Some(client),
+            vec![WorkbenchEvent::FilesChanged(batch)],
+            Some(Source { active: Arc::downgrade(active) }),
+        );
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn files_changed_host(root: &Path) -> PluginHost {
+        use super::super::Consent;
+        let host =
+            PluginHost::new(root.join("plugins"), Arc::new(|_: Option<&str>, _| {}), Default::default()).unwrap();
+        host.set_workspace(Some(Arc::new(Workspace(root.to_path_buf()))));
+        let fixture = Path::new(env!("CARGO_MANIFEST_DIR")).join("../ide-plugin/tests/fixtures/files-events");
+        host.install_from_dir(&fixture, &Consent::all()).unwrap();
+        host
+    }
+
+    fn delta(kind: usize, path: &str) -> WorkbenchEvent {
+        let mut batch = FilesChanged::default();
+        match kind {
+            0 => batch.created.push(path.into()),
+            1 => batch.modified.push(path.into()),
+            _ => batch.removed.push(path.into()),
+        }
+        WorkbenchEvent::FilesChanged(batch)
+    }
+
+    #[test]
+    fn files_changed_preserves_ordered_path_transitions() {
+        for (first, next, expected) in
+            [(0, 0, 0), (0, 1, 0), (0, 2, 2), (1, 0, 1), (1, 1, 1), (1, 2, 2), (2, 0, 1), (2, 1, 2), (2, 2, 2)]
+        {
+            let mut events = vec![delta(first, "/project/path")];
+            append(&mut events, vec![delta(next, "/project/path")]);
+            assert_eq!(events, [delta(expected, "/project/path")], "transition {first} -> {next}");
+        }
+        let mut events = vec![delta(0, "/project/transient"), delta(2, "/project/old-name")];
+        append(&mut events, vec![delta(2, "/project/transient"), delta(0, "/project/new-name")]);
+        append(&mut events, vec![delta(1, "/project/transient")]);
+        // Seed through append too: one coalesced batch keeps both sides of a rename.
+        let mut merged = vec![];
+        append(&mut merged, events);
+        assert_eq!(
+            merged,
+            [WorkbenchEvent::FilesChanged(FilesChanged {
+                created: vec!["/project/new-name".into()],
+                removed: vec!["/project/old-name".into(), "/project/transient".into()],
+                ..Default::default()
+            })]
+        );
+    }
+
+    #[test]
+    fn files_changed_stale_admission_cannot_replace_reopened_queue() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        let host = files_changed_host(&root);
+        let old = Arc::new(AtomicBool::new(true));
+        let new = Arc::new(AtomicBool::new(true));
+        let (entered, waiting) = std::sync::mpsc::channel();
+        let (release, released) = std::sync::mpsc::channel();
+        std::thread::scope(|scope| {
+            let host = &host;
+            let old = &old;
+            let root = &root;
+            scope.spawn(move || {
+                assert!(old.load(Ordering::Acquire));
+                entered.send(()).unwrap();
+                released.recv().unwrap();
+                host.post_events_from(
+                    Some("main"),
+                    vec![delta(0, &to_ipc(&root.join("stale.rs")))],
+                    Some(Source { active: Arc::downgrade(old) }),
+                );
+            });
+            waiting.recv().unwrap();
+            old.store(false, Ordering::Release);
+            host.post_files_changed(
+                "main",
+                root,
+                &new,
+                &ide_vfs::FsBatch { created: vec![root.join("new.rs")], ..Default::default() },
+            );
+            release.send(()).unwrap();
+        });
+        let queues = host.queues.lock();
+        let queue = queues.values().next().expect("new session queue");
+        assert!(queue.files_source.as_ref().unwrap().same(&Source { active: Arc::downgrade(&new) }));
+        assert_eq!(queue.events, [delta(0, &to_ipc(&root.join("new.rs")))]);
+    }
+
+    #[test]
+    fn files_changed_restarts_after_an_actor_drops_queued_work() {
+        use std::time::Duration;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        let host = files_changed_host(&root);
+        let plugin = host.get("files-events").unwrap();
+        let (actor, _) = host.ensure_active(&plugin, Some("main")).unwrap();
+        let (entered, waiting) = std::sync::mpsc::channel();
+        let (release, released) = std::sync::mpsc::channel();
+        let crash = actor
+            .submit(None, move |_| {
+                entered.send(()).unwrap();
+                released.recv().unwrap();
+                Err::<(), _>(ide_plugin::CallError::Trap(ide_plugin::CANCELLED.into()))
+            })
+            .unwrap();
+        waiting.recv_timeout(Duration::from_secs(10)).unwrap();
+        host.post_events(Some("main"), vec![delta(0, &to_ipc(&root.join("discarded.rs")))]);
+        host.flush_events();
+        release.send(()).unwrap();
+        assert!(crash.wait().is_err());
+        host.flush_events();
+        host.post_events(Some("main"), vec![delta(0, &to_ipc(&root.join("after-restart.rs")))]);
+        host.flush_events();
+        assert!(host.wait_events(Duration::from_secs(1)), "dropped actor work must not keep its mailbox alive");
+        let data = host.run_command("files-events", "events", None, Default::default()).unwrap().unwrap();
+        let batches: Vec<FilesChanged> = serde_json::from_str(&data).unwrap();
+        assert_eq!(
+            batches,
+            [FilesChanged { created: vec![to_ipc(&root.join("after-restart.rs"))], ..Default::default() }]
+        );
+    }
+
+    #[test]
+    fn files_changed_actor_mailbox_is_bounded_and_yields_to_commands() {
+        use std::time::Duration;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        let host = files_changed_host(&root);
+        let plugin = host.get("files-events").unwrap();
+        let (actor, _) = host.ensure_active(&plugin, Some("main")).unwrap();
+        let (entered, waiting) = std::sync::mpsc::channel();
+        let (release, released) = std::sync::mpsc::channel();
+        actor.post(
+            move |_| {
+                entered.send(()).unwrap();
+                released.recv().unwrap();
+                Ok(())
+            },
+            |_| {},
+        );
+        waiting.recv_timeout(Duration::from_secs(10)).unwrap();
+        for i in 0..600 {
+            host.post_events(Some("main"), vec![delta(i % 3, &to_ipc(&root.join(format!("path-{i}"))))]);
+            host.flush_events();
+        }
+        let pending = plugin.batches.lock().pending;
+        // A command gets a scheduling turn after one coalesced delivery.
+        let command = actor.submit(None, move |rt| rt.run_command("events", None, Default::default())).unwrap();
+        release.send(()).unwrap();
+        let data = command.wait().unwrap().unwrap();
+        assert_eq!(pending, 1, "flushes must not grow the actor job queue");
+        let batches: Vec<FilesChanged> = serde_json::from_str(&data).unwrap();
+        assert_eq!(batches.len(), 1);
+        assert_eq!(batches[0].created.len(), 200);
+        assert_eq!(batches[0].modified.len(), 200);
+        assert_eq!(batches[0].removed.len(), 200);
+        assert!(host.wait_events(Duration::from_secs(10)));
+    }
+
+    #[test]
+    fn files_changed_rechecks_filters_after_a_busy_actor_command() {
+        use std::time::Duration;
+        for globs in ["", "other/**", "config/*.yaml"] {
+            let tmp = tempfile::tempdir().unwrap();
+            let root = dunce::canonicalize(tmp.path()).unwrap();
+            let host = files_changed_host(&root);
+            let plugin = host.get("files-events").unwrap();
+            let (actor, _) = host.ensure_active(&plugin, Some("main")).unwrap();
+            let (entered, waiting) = std::sync::mpsc::channel();
+            let (release, released) = std::sync::mpsc::channel();
+            actor.post(
+                move |_| {
+                    entered.send(()).unwrap();
+                    released.recv().unwrap();
+                    Ok(())
+                },
+                |_| {},
+            );
+            waiting.recv_timeout(Duration::from_secs(10)).unwrap();
+            let filter =
+                actor.submit(None, move |rt| rt.run_command("filter", Some(globs), Default::default())).unwrap();
+            host.post_events(
+                Some("main"),
+                vec![WorkbenchEvent::FilesChanged(FilesChanged {
+                    created: vec![to_ipc(&root.join("config/a.yaml")), to_ipc(&root.join("src/a.rs"))],
+                    modified: vec![to_ipc(&root.join("config/b.yaml"))],
+                    removed: vec![to_ipc(&root.join("config/c.yaml"))],
+                })],
+            );
+            host.flush_events();
+            release.send(()).unwrap();
+            filter.wait().unwrap();
+            assert!(host.wait_events(Duration::from_secs(10)));
+            let data = host.run_command("files-events", "events", None, Default::default()).unwrap();
+            if globs == "config/*.yaml" {
+                let batches: Vec<FilesChanged> = serde_json::from_str(&data.unwrap()).unwrap();
+                assert_eq!(
+                    batches,
+                    [FilesChanged {
+                        created: vec![to_ipc(&root.join("config/a.yaml"))],
+                        modified: vec![to_ipc(&root.join("config/b.yaml"))],
+                        removed: vec![to_ipc(&root.join("config/c.yaml"))],
+                    }]
+                );
+            } else {
+                assert_eq!(data, None, "excluded batches must not invoke the guest handler");
+            }
+        }
+    }
+
+    #[test]
+    fn files_changed_delivery_honors_filters_registered_during_activation() {
+        use super::super::Consent;
+        use std::time::{Duration, Instant};
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        let host =
+            PluginHost::new(root.join("plugins"), Arc::new(|_: Option<&str>, _| {}), Default::default()).unwrap();
+        host.set_workspace(Some(Arc::new(Workspace(root.clone()))));
+        let fixture = Path::new(env!("CARGO_MANIFEST_DIR")).join("../ide-plugin/tests/fixtures/path-events");
+        let copy = root.join("activation-fixture");
+        std::fs::create_dir_all(copy.join("dist")).unwrap();
+        std::fs::write(
+            copy.join("plugin.toml"),
+            std::fs::read_to_string(fixture.join("plugin.toml"))
+                .unwrap()
+                .replace("[\"on-command:*\"]", "[\"on-command:*\", \"on-event:file-opened\"]"),
+        )
+        .unwrap();
+        std::fs::copy(fixture.join("dist/plugin.wasm"), copy.join("dist/plugin.wasm")).unwrap();
+        host.install_from_dir(&copy, &Consent::all()).unwrap();
+        host.post_events(Some("main"), vec![WorkbenchEvent::FileOpened(to_ipc(&root.join("src/excluded.rs")))]);
+        host.flush_events_at(Instant::now() + Duration::from_secs(3));
+        assert!(host.wait_events(Duration::from_secs(10)));
+        assert_eq!(host.run_command("test.path-events", "count", None, Default::default()).unwrap(), None);
+    }
+
+    #[test]
+    fn files_changed_rechecks_runtime_unsubscribe_on_busy_actor() {
+        use super::super::Consent;
+        use std::time::Duration;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        let host =
+            PluginHost::new(root.join("plugins"), Arc::new(|_: Option<&str>, _| {}), Default::default()).unwrap();
+        host.set_workspace(Some(Arc::new(Workspace(root.clone()))));
+        let fixture = Path::new(env!("CARGO_MANIFEST_DIR")).join("../ide-plugin/tests/fixtures/files-events");
+        let copy = root.join("runtime-fixture");
+        std::fs::create_dir_all(copy.join("dist")).unwrap();
+        std::fs::write(
+            copy.join("plugin.toml"),
+            std::fs::read_to_string(fixture.join("plugin.toml")).unwrap().replace(", \"on-event:files-changed\"", ""),
+        )
+        .unwrap();
+        std::fs::copy(fixture.join("dist/plugin.wasm"), copy.join("dist/plugin.wasm")).unwrap();
+        host.install_from_dir(&copy, &Consent::all()).unwrap();
+        host.run_command("files-events", "filter", Some("**"), Default::default()).unwrap();
+        let plugin = host.get("files-events").unwrap();
+        let (actor, _) = host.ensure_active(&plugin, Some("main")).unwrap();
+        let (entered, waiting) = std::sync::mpsc::channel();
+        let (release, released) = std::sync::mpsc::channel();
+        actor.post(
+            move |_| {
+                entered.send(()).unwrap();
+                released.recv().unwrap();
+                Ok(())
+            },
+            |_| {},
+        );
+        waiting.recv_timeout(Duration::from_secs(10)).unwrap();
+        let off = actor.submit(None, |rt| rt.run_command("unsubscribe", None, Default::default())).unwrap();
+        host.post_events(Some("main"), vec![delta(0, &to_ipc(&root.join("excluded.rs")))]);
+        host.flush_events();
+        release.send(()).unwrap();
+        off.wait().unwrap();
+        assert!(host.wait_events(Duration::from_secs(10)));
+        assert_eq!(host.run_command("files-events", "events", None, Default::default()).unwrap(), None);
+    }
+
+    #[test]
+    fn files_changed_dropped_actor_job_releases_mailbox_before_restart() {
+        use std::time::Duration;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        let host = files_changed_host(&root);
+        let plugin = host.get("files-events").unwrap();
+        let (actor, _) = host.ensure_active(&plugin, Some("main")).unwrap();
+        let (entered, waiting) = std::sync::mpsc::channel();
+        let (release, released) = std::sync::mpsc::channel();
+        actor.post(
+            move |_| {
+                entered.send(()).unwrap();
+                released.recv().unwrap();
+                Err::<(), _>(ide_plugin::CallError::Trap("test actor exit".into()))
+            },
+            |_| {},
+        );
+        waiting.recv_timeout(Duration::from_secs(10)).unwrap();
+        host.post_events(Some("main"), vec![delta(0, &to_ipc(&root.join("dropped.rs")))]);
+        host.flush_events();
+        assert_eq!(plugin.batches.lock().pending, 1);
+        release.send(()).unwrap();
+        actor.stop(true);
+        assert_eq!(plugin.batches.lock().pending, 0, "dropped closures must release their batch ticket");
+        assert!(plugin.batches.lock().files_pending.is_empty());
+        host.set_enabled("files-events", false).unwrap();
+        host.set_enabled("files-events", true).unwrap();
+        host.post_events(Some("main"), vec![delta(0, &to_ipc(&root.join("fresh.rs")))]);
+        host.flush_events();
+        assert!(host.wait_events(Duration::from_secs(10)));
+        let data = host.run_command("files-events", "events", None, Default::default()).unwrap().unwrap();
+        let batches: Vec<FilesChanged> = serde_json::from_str(&data).unwrap();
+        assert_eq!(batches, [FilesChanged { created: vec![to_ipc(&root.join("fresh.rs"))], ..Default::default() }]);
+    }
+
+    #[test]
+    fn files_changed_old_ticket_cannot_clear_successor_mailbox_or_running_state() {
+        use super::super::{BatchTicket, Batches, PendingFiles};
+        let batches = Arc::new(parking_lot::Mutex::new(Batches::default()));
+        let key = (Some("main".into()), Some(PathBuf::from("/project")));
+        let old = Arc::new(());
+        let new = Arc::new(());
+        let ticket = BatchTicket { batches: batches.clone(), files_key: Some(key.clone()), token: old };
+        {
+            let mut state = batches.lock();
+            state.pending = 2;
+            state.running = Some([ide_plugin::EventKind::FilesChanged].into());
+            state.running_token = Some(new.clone());
+            state.files_pending.insert(
+                key.clone(),
+                PendingFiles {
+                    queue: super::super::EventQueue {
+                        since: std::time::Instant::now(),
+                        events: vec![delta(0, "/project/new")],
+                        files_source: None,
+                    },
+                    actor: std::sync::Weak::new(),
+                    token: new.clone(),
+                },
+            );
+        }
+        drop(ticket);
+        let state = batches.lock();
+        assert_eq!(state.pending, 1);
+        assert!(Arc::ptr_eq(&state.files_pending[&key].token, &new));
+        assert!(Arc::ptr_eq(state.running_token.as_ref().unwrap(), &new));
+        assert!(state.running.is_some());
+    }
+
+    #[test]
+    fn every_runtime_event_has_a_matching_manifest_activation() {
+        for kind in ide_plugin::EventKind::ALL {
+            if kind != ide_plugin::EventKind::Scheduled {
+                assert!(ide_extension::EVENT_KINDS.contains(&kind.name()));
+            }
+        }
+        for kind in ide_extension::EVENT_KINDS {
+            assert!(ide_plugin::EventKind::parse(kind).is_some());
+        }
+    }
+
+    #[test]
+    fn batches_coalesce_without_losing_categories_or_paths() {
+        let mut events = vec![];
+        for i in 0..600 {
+            append(
+                &mut events,
+                vec![WorkbenchEvent::FilesChanged(FilesChanged {
+                    created: vec![format!("/project/{i}")],
+                    modified: vec!["/project/shared".into()],
+                    removed: vec!["/project/gone".into()],
+                })],
+            );
+        }
+        let [WorkbenchEvent::FilesChanged(batch)] = events.as_slice() else { panic!("one coalesced batch") };
+        assert_eq!(batch.created.len(), 600);
+        assert_eq!(batch.modified, ["/project/shared"]);
+        assert_eq!(batch.removed, ["/project/gone"]);
+    }
+
+    #[test]
+    fn closed_incarnations_drop_only_filesystem_events() {
+        let active = Arc::new(AtomicBool::new(true));
+        let source = Source { active: Arc::downgrade(&active) };
+        let mut events = vec![WorkbenchEvent::FilesChanged(FilesChanged::default()), WorkbenchEvent::Scheduled];
+        retain_live(&mut events, Some(&source));
+        assert_eq!(events.len(), 2);
+        active.store(false, Ordering::Release);
+        retain_live(&mut events, Some(&source));
+        assert_eq!(events, [WorkbenchEvent::Scheduled]);
+        assert!(!source.same(&Source { active: Arc::downgrade(&Arc::new(AtomicBool::new(true))) }));
+    }
+    struct Workspace(PathBuf);
+    impl super::super::PluginWorkspace for Workspace {
+        fn projects(&self) -> Vec<PathBuf> {
+            vec![self.0.clone(), self.0.join("other")]
+        }
+        fn buffer_text(&self, _: &Path) -> Option<String> {
+            None
+        }
+        fn document(&self, _: &Path) -> Option<(u64, String)> {
+            None
+        }
+        fn apply_edits(&self, _: &Path, _: u64, _: &[ide_core::TextEdit]) -> Result<u64, ide_plugin::HostError> {
+            unreachable!()
+        }
+        fn trusted(&self, _: &Path) -> bool {
+            true
+        }
+        fn project_of(&self, window: &str) -> Option<PathBuf> {
+            match window {
+                "main" => Some(self.0.clone()),
+                "other" => Some(self.0.join("other")),
+                _ => None,
+            }
+        }
+        fn publish_diagnostics(
+            &self,
+            _: &str,
+            _: &Path,
+            _: Vec<ide_core::Diagnostic>,
+        ) -> Result<(), ide_plugin::HostError> {
+            Ok(())
+        }
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn host_shutdown_discards_queued_filesystem_batches() {
+        use super::super::Consent;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap().join("project");
+        std::fs::create_dir(&root).unwrap();
+        let backend = crate::Host::new(crate::HostConfig {
+            config_dir: tmp.path().join("config"),
+            data_dir: tmp.path().join("data"),
+            local_data_dir: tmp.path().join("data"),
+            languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+            syntax: Arc::default(),
+            sink_for: Box::new(|_| Arc::new(ide_core::NullSink)),
+            owner: |window| window,
+            runtime: tokio::runtime::Handle::current(),
+            project_environment: false,
+        });
+        backend.open_project("main", &root).unwrap();
+        let active = backend.project("main").unwrap().files_events_active.clone();
+        let plugins =
+            PluginHost::new(tmp.path().join("plugins"), Arc::new(|_: Option<&str>, _| {}), Default::default()).unwrap();
+        plugins.set_workspace(Some(Arc::new(Workspace(root.clone()))));
+        let fixture = Path::new(env!("CARGO_MANIFEST_DIR")).join("../ide-plugin/tests/fixtures/files-events");
+        plugins.install_from_dir(&fixture, &Consent::all()).unwrap();
+        let batch = ide_vfs::FsBatch { created: vec![root.join("new.rs")], ..Default::default() };
+        plugins.post_files_changed("main", &root, &active, &batch);
+        assert!(!plugins.queues.lock().is_empty());
+        backend.shutdown().await;
+        plugins.flush_events();
+        assert_eq!(plugins.instances(), 0, "host shutdown must discard queued filesystem batches");
+        plugins.post_files_changed("main", &root, &active, &batch);
+        assert!(plugins.queues.lock().is_empty(), "a retained watcher cannot post after host shutdown");
+    }
+
+    #[test]
+    fn producer_respects_project_incarnation_window_and_dev_root() {
+        use super::super::{Consent, PluginSource};
+        use std::time::Duration;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        std::fs::create_dir(root.join("other")).unwrap();
+        let host =
+            PluginHost::new(root.join("plugins"), Arc::new(|_: Option<&str>, _| {}), Default::default()).unwrap();
+        host.set_workspace(Some(Arc::new(Workspace(root.clone()))));
+        host.set_project_policy(Arc::new(|_| true));
+        let fixture = Path::new(env!("CARGO_MANIFEST_DIR")).join("../ide-plugin/tests/fixtures/files-events");
+        host.load_dir(&fixture, PluginSource::Dev, Some(root.clone()));
+        host.grant("files-events", &Consent::all()).unwrap();
+        let active = Arc::new(AtomicBool::new(true));
+        let batch = ide_vfs::FsBatch {
+            created: vec![root.join("new.rs"), root.parent().unwrap().join("outside.rs")],
+            ..Default::default()
+        };
+        host.post_files_changed("closed", &root, &active, &batch);
+        host.post_files_changed("main", &root.join("wrong"), &active, &batch);
+        host.post_files_changed(
+            "other",
+            &root.join("other"),
+            &active,
+            &ide_vfs::FsBatch { modified: vec![root.join("other/a.rs")], ..Default::default() },
+        );
+        host.post_files_changed(
+            "main",
+            &root,
+            &active,
+            &ide_vfs::FsBatch {
+                vcs: vec![root.join(".git/HEAD")],
+                ignored: vec![root.join(".env")],
+                ..Default::default()
+            },
+        );
+        host.flush_events();
+        assert_eq!(host.instances(), 0, "unrelated windows, roots, and metadata do not wake a dev plugin");
+        host.post_files_changed("main", &root, &active, &batch);
+        active.store(false, Ordering::Release);
+        host.flush_events();
+        assert_eq!(host.instances(), 0, "closing before delivery discards the batch");
+        host.post_files_changed("main", &root, &active, &batch);
+        assert!(host.queues.lock().is_empty(), "a closing watcher cannot post more events");
+        let reopened = Arc::new(AtomicBool::new(true));
+        host.post_files_changed("main", &root, &reopened, &batch);
+        host.flush_events();
+        assert!(host.wait_events(Duration::from_secs(10)));
+        let inv = ide_plugin::Invocation {
+            client: Some("main".into()),
+            workspace_root: Some(root.clone()),
+            ..Default::default()
+        };
+        let data = host.run_command("files-events", "events", None, inv).unwrap().unwrap();
+        let received: Vec<FilesChanged> = serde_json::from_str(&data).unwrap();
+        assert_eq!(received, [FilesChanged { created: vec![to_ipc(&root.join("new.rs"))], ..Default::default() }]);
+    }
+    #[test]
+    fn queued_filter_replacement_and_pause_do_not_activate() {
+        use super::super::{Consent, event_paths::PathFilter};
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        let host =
+            PluginHost::new(root.join("plugins"), Arc::new(|_: Option<&str>, _| {}), Default::default()).unwrap();
+        host.set_workspace(Some(Arc::new(Workspace(root.clone()))));
+        let fixture = Path::new(env!("CARGO_MANIFEST_DIR")).join("../ide-plugin/tests/fixtures/files-events");
+        host.install_from_dir(&fixture, &Consent::all()).unwrap();
+        let active = Arc::new(AtomicBool::new(true));
+        let filter = |globs: Vec<String>| {
+            host.shared.subscriptions.lock().set_paths(
+                "files-events",
+                "files-changed",
+                PathFilter::new("files-changed", globs).unwrap(),
+            );
+        };
+        let batch = ide_vfs::FsBatch {
+            created: vec![root.join("config/a.yaml"), root.join("src/unrelated.rs")],
+            modified: vec![root.join("config/b.yaml")],
+            removed: vec![root.join("config/c.yaml")],
+            ..Default::default()
+        };
+        filter(vec!["config/*.yaml".into()]);
+        host.post_files_changed("main", &root, &active, &batch);
+        assert!(!host.queues.lock().is_empty());
+        filter(vec!["src/**".into()]);
+        host.flush_events();
+        assert_eq!(host.instances(), 0, "replacement excludes paths already queued");
+        filter(vec!["config/*.yaml".into()]);
+        host.post_files_changed("main", &root, &active, &batch);
+        filter(vec![]);
+        host.flush_events();
+        assert_eq!(host.instances(), 0, "pausing suppresses a queued batch before activation");
+        host.post_files_changed("main", &root, &active, &batch);
+        assert!(host.queues.lock().is_empty(), "paused paths never queue work");
+    }
+}
@@ -510,6 +510,8 @@ fn check_value(key: &str, value: &str) -> Result<(), String> {
    if lower.contains("javascript:")
        || lower.contains("expression(")
        || lower.contains("@import")
+        // These CSS image/URL functions accept bare strings, bypassing url().
+        || ["image(", "image-set(", "src("].iter().any(|function| lower.contains(function))
        || value.contains('\\')
    {
        return Err("unsafe value".into());
@@ -607,6 +609,10 @@ mod tests {
            r##"<svg><use xlink:href="data:image/svg+xml,..."/></svg>"##,
            r##"<svg><rect style="fill:url(https://evil)"/></svg>"##,
            r##"<svg><rect fill="url( 'http://x' )"/></svg>"##,
+            r##"<svg><rect style="background-image:image-set('https://evil/x.png' 1x)"/></svg>"##,
+            r##"<svg><rect style="background-image:-webkit-image-set('https://evil/x.png' 1x)"/></svg>"##,
+            r##"<svg><rect style="background-image:image('https://evil/x.png')"/></svg>"##,
+            r##"<svg><rect style="fill:src('https://evil/x.svg')"/></svg>"##,
            r##"<!DOCTYPE svg [<!ENTITY x "y">]><svg/>"##,
            r##"<svg><![CDATA[x]]></svg>"##,
            r##"<svg><a href="#x"/></svg>"##,
@@ -83,23 +83,14 @@ pub async fn plugin_navigation_index(
                }
                (snapshot.text, Some(snapshot.version), snapshot.language)
            } else {
-                use std::io::Read;
-                if !std::fs::metadata(&path)
-                    .is_ok_and(|m| m.is_file() && m.len() <= crate::plugins::navigation::MAX_DOCUMENT_BYTES as u64)
-                {
-                    continue;
-                }
-                let Ok(file) = std::fs::File::open(&path) else {
+                let Ok(loaded) = project.documents.load_file_bounded(&path, super::navigation::MAX_DOCUMENT_BYTES)
+                else {
                    continue;
                };
-                let mut text = String::new();
-                if file
-                    .take((crate::plugins::navigation::MAX_DOCUMENT_BYTES + 1) as u64)
-                    .read_to_string(&mut text)
-                    .is_err()
-                {
+                if loaded.binary || loaded.large {
                    continue;
                }
+                let text = loaded.text;
                let language = project.languages.detect(&path, text.lines().next());
                (text, None, language)
            };
@@ -126,6 +117,7 @@ pub async fn plugin_navigation_index(
                    workspace_root: Some(project.root.clone()),
                    editor: None,
                    selected_paths: Vec::new(),
+                    global_settings: false,
                },
            )?;
            // A document edit while WASM was executing must not publish stale ranges.
@@ -140,6 +132,17 @@ pub async fn plugin_navigation_index(
    result
 }

+/// The HTTP routes `plugin_id` reports for this window's project.
+pub async fn plugin_endpoints(
+    host: &crate::Host,
+    plugins: Arc<PluginHost>,
+    window: &str,
+    plugin_id: String,
+) -> IdeResult<Vec<crate::plugins::endpoints::PluginEndpoint>> {
+    let project = host.project(window)?;
+    blocking(move || Ok(plugins.endpoints(&plugin_id, &project.root)?.as_ref().clone())).await
+}
+
 pub async fn plugin_navigation_goto(
    host: &crate::Host,
    plugins: Arc<PluginHost>,
@@ -0,0 +1,94 @@
+use ide_core::Range;
+use ide_lsp::types::{InlayHint, InlayKind};
+use ide_plugin::PluginInlayHint;
+
+pub(crate) fn merge(server: Vec<InlayHint>, plugin: Vec<PluginInlayHint>, range: Range) -> Vec<InlayHint> {
+    let inside = |h: &PluginInlayHint| {
+        let at = (h.position.line, h.position.col);
+        (range.start.line, range.start.col) <= at && at <= (range.end.line, range.end.col)
+    };
+    let mut out = server;
+    out.extend(plugin.into_iter().filter(inside).map(|h| InlayHint {
+        position: h.position,
+        label: h.label,
+        kind: match h.kind.as_str() {
+            "type" => InlayKind::Type,
+            "parameter" => InlayKind::Parameter,
+            _ => InlayKind::Other,
+        },
+        padding_left: h.padding_left,
+        padding_right: h.padding_right,
+        tooltip: h.tooltip,
+        parts: Vec::new(),
+    }));
+    out.sort_by_key(|h| (h.position.line, h.position.col));
+    out
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use ide_core::Pos;
+
+    fn plugin(line: u32, col: u32, label: &str, kind: &str) -> PluginInlayHint {
+        PluginInlayHint {
+            position: Pos::new(line, col),
+            label: label.into(),
+            kind: kind.into(),
+            tooltip: Some("from the plugin".into()),
+            padding_left: true,
+            padding_right: false,
+        }
+    }
+
+    fn server(line: u32, col: u32, label: &str) -> InlayHint {
+        InlayHint {
+            position: Pos::new(line, col),
+            label: label.into(),
+            kind: InlayKind::Parameter,
+            padding_left: false,
+            padding_right: true,
+            tooltip: None,
+            parts: Vec::new(),
+        }
+    }
+
+    fn summary(hints: &[InlayHint]) -> Vec<(u32, u32, String)> {
+        hints.iter().map(|h| (h.position.line, h.position.col, h.label.clone())).collect()
+    }
+
+    #[test]
+    fn plugin_hints_join_the_servers_in_position_order() {
+        let range = Range::new(Pos::new(0, 0), Pos::new(10, 0));
+        let merged = merge(
+            vec![server(2, 4, "name:"), server(5, 1, "id:")],
+            vec![plugin(3, 9, ": string", "type"), plugin(2, 1, "GET /orders", "other")],
+            range,
+        );
+        assert_eq!(
+            summary(&merged),
+            [
+                (2, 1, "GET /orders".to_owned()),
+                (2, 4, "name:".to_owned()),
+                (3, 9, ": string".to_owned()),
+                (5, 1, "id:".to_owned())
+            ]
+        );
+        let typed = merged.iter().find(|h| h.label == ": string").unwrap();
+        assert!(matches!(typed.kind, InlayKind::Type));
+        assert!(typed.padding_left && !typed.padding_right);
+        assert_eq!(typed.tooltip.as_deref(), Some("from the plugin"));
+    }
+
+    #[test]
+    fn unknown_kinds_are_other_and_hints_outside_the_range_are_dropped() {
+        let range = Range::new(Pos::new(2, 5), Pos::new(4, 3));
+        let merged = merge(
+            Vec::new(),
+            vec![plugin(2, 4, "before", "type"), plugin(3, 0, "in", "route"), plugin(4, 4, "after", "type")],
+            range,
+        );
+        assert_eq!(summary(&merged), [(3, 0, "in".to_owned())]);
+        assert!(matches!(merged[0].kind, InlayKind::Other));
+    }
+}
@@ -24,6 +24,134 @@ pub const ACTIVE_FILE: &str = "active";
 /// `<root>/previous`: the version an update replaced (for rollback).
 pub const PREVIOUS_FILE: &str = "previous";

+#[derive(serde::Serialize, serde::Deserialize)]
+pub(super) struct PendingUninstall {
+    pub id: String,
+    pub name: String,
+    pub version: String,
+    pub flat: bool,
+    pub secrets: Vec<String>,
+    #[serde(default)]
+    pub error: Option<String>,
+}
+
+impl PendingUninstall {
+    fn validate(&self) -> io::Result<()> {
+        if self.id.is_empty()
+            || self.id.starts_with('.')
+            || Path::new(&self.id).components().count() != 1
+            || !matches!(Path::new(&self.id).components().next(), Some(std::path::Component::Normal(_)))
+        {
+            return Err(io::ErrorKind::InvalidData.into());
+        }
+        version_dir(&self.version)?;
+        Ok(())
+    }
+
+    pub(super) fn package_dir(&self, root: &Path) -> PathBuf {
+        let dir = root.join(&self.id);
+        if self.flat { dir } else { dir.join(&self.version) }
+    }
+}
+
+pub(super) fn check_not_symlink(path: &Path) -> io::Result<()> {
+    match std::fs::symlink_metadata(path) {
+        Ok(meta) => {
+            #[cfg(windows)]
+            let reparse = {
+                use std::os::windows::fs::MetadataExt;
+                meta.file_attributes() & windows_sys::Win32::Storage::FileSystem::FILE_ATTRIBUTE_REPARSE_POINT != 0
+            };
+            #[cfg(not(windows))]
+            let reparse = false;
+            if meta.file_type().is_symlink() || reparse {
+                Err(io::Error::other("refusing symlink in plugin cleanup path"))
+            } else {
+                Ok(())
+            }
+        }
+        Err(e) if e.kind() == io::ErrorKind::NotFound => Ok(()),
+        Err(e) => Err(e),
+    }
+}
+
+pub(super) fn check_cleanup_parent(root: &Path, path: &Path) -> io::Result<()> {
+    let relative = path.strip_prefix(root).map_err(io::Error::other)?;
+    let mut parent = root.to_path_buf();
+    for part in relative.parent().unwrap_or(Path::new("")).components() {
+        if !matches!(part, std::path::Component::Normal(_)) {
+            return Err(io::Error::other("invalid plugin cleanup path"));
+        }
+        parent.push(part);
+        check_not_symlink(&parent)?;
+    }
+    Ok(())
+}
+
+fn uninstall_file(root: &Path, id: &str) -> PathBuf {
+    root.join(".uninstall").join(format!("{id}.json"))
+}
+
+pub(super) fn remember_uninstall(root: &Path, pending: &PendingUninstall, dir: &Path) -> io::Result<()> {
+    use std::io::Write;
+    pending.validate()?;
+    if pending.package_dir(root) != dir {
+        return Err(io::ErrorKind::InvalidData.into());
+    }
+    let file = uninstall_file(root, &pending.id);
+    check_not_symlink(file.parent().unwrap())?;
+    std::fs::create_dir_all(file.parent().unwrap())?;
+    check_not_symlink(&file)?;
+    let mut out = tempfile::NamedTempFile::new_in(file.parent().unwrap())?;
+    out.write_all(&serde_json::to_vec(pending)?)?;
+    out.as_file().sync_all()?;
+    out.persist(file).map(|_| ()).map_err(|e| e.error)
+}
+
+pub(super) fn pending_uninstalls(root: &Path) -> Vec<PendingUninstall> {
+    if check_not_symlink(&root.join(".uninstall")).is_err() {
+        return Vec::new();
+    }
+    let Ok(entries) = std::fs::read_dir(root.join(".uninstall")) else { return Vec::new() };
+    entries
+        .flatten()
+        .filter_map(|entry| {
+            let path = entry.path();
+            if path.extension().is_none_or(|ext| ext != "json") {
+                return None;
+            }
+            let read = || -> io::Result<PendingUninstall> {
+                check_not_symlink(&path)?;
+                let pending: PendingUninstall = serde_json::from_slice(&std::fs::read(&path)?)?;
+                pending.validate()?;
+                if path != uninstall_file(root, &pending.id) {
+                    return Err(io::Error::from(io::ErrorKind::InvalidData));
+                }
+                Ok(pending)
+            };
+            match read() {
+                Ok(pending) => Some(pending),
+                Err(e) => {
+                    tracing::warn!(path = %path.display(), "cannot recover pending plugin uninstall: {e}");
+                    None
+                }
+            }
+        })
+        .collect()
+}
+
+pub(super) fn uninstall_pending(root: &Path, id: &str) -> io::Result<bool> {
+    uninstall_file(root, id).try_exists()
+}
+
+pub(super) fn forget_uninstall(root: &Path, id: &str) -> io::Result<()> {
+    check_not_symlink(&root.join(".uninstall"))?;
+    match std::fs::remove_file(uninstall_file(root, id)) {
+        Err(e) if e.kind() == io::ErrorKind::NotFound => Ok(()),
+        result => result,
+    }
+}
+
 fn nonce() -> String {
    let n = SystemTime::now().duration_since(UNIX_EPOCH).map(|d| d.as_nanos()).unwrap_or_default();
    format!("{n:x}-{}", std::process::id())
@@ -219,6 +347,99 @@ pub fn recover(dir: &Path) {
 mod tests {
    use super::*;

+    #[test]
+    fn pending_uninstall_records_reject_paths_outside_the_package() {
+        let tmp = tempfile::tempdir().unwrap();
+        let mut pending = PendingUninstall {
+            id: "p".into(),
+            name: "Plugin".into(),
+            version: "1.0.0".into(),
+            flat: false,
+            secrets: vec!["key".into()],
+            error: None,
+        };
+        remember_uninstall(tmp.path(), &pending, &tmp.path().join("p/1.0.0")).unwrap();
+        assert_eq!(pending_uninstalls(tmp.path())[0].secrets, ["key"]);
+        for (id, version) in [
+            ("../outside", "1"),
+            ("/outside", "1"),
+            (".data", "p"),
+            ("other", "1"),
+            ("p", "../outside"),
+            ("p", "1/nested"),
+        ] {
+            pending.id = id.into();
+            pending.version = version.into();
+            std::fs::write(uninstall_file(tmp.path(), "p"), serde_json::to_vec(&pending).unwrap()).unwrap();
+            assert!(pending_uninstalls(tmp.path()).is_empty(), "{id}/{version}");
+        }
+        pending.id = "invalid-1-0-0".into();
+        assert!(remember_uninstall(tmp.path(), &pending, &tmp.path().join("other/1.0.0")).is_err());
+        forget_uninstall(tmp.path(), "p").unwrap();
+        assert!(pending_uninstalls(tmp.path()).is_empty());
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn pending_uninstall_records_do_not_follow_symlinks() {
+        use std::os::unix::fs::symlink;
+        let tmp = tempfile::tempdir().unwrap();
+        let outside = tempfile::tempdir().unwrap();
+        let pending = PendingUninstall {
+            id: "p".into(),
+            name: "Plugin".into(),
+            version: "1.0.0".into(),
+            flat: false,
+            secrets: Vec::new(),
+            error: None,
+        };
+        let record = outside.path().join("p.json");
+        std::fs::write(&record, "untouched").unwrap();
+        let parent = tmp.path().join(".uninstall");
+        symlink(outside.path(), &parent).unwrap();
+        assert!(remember_uninstall(tmp.path(), &pending, &tmp.path().join("p/1.0.0")).is_err());
+        assert!(forget_uninstall(tmp.path(), "p").is_err());
+        assert!(pending_uninstalls(tmp.path()).is_empty());
+        std::fs::remove_file(&parent).unwrap();
+        std::fs::create_dir(&parent).unwrap();
+        symlink(&record, uninstall_file(tmp.path(), "p")).unwrap();
+        assert!(remember_uninstall(tmp.path(), &pending, &tmp.path().join("p/1.0.0")).is_err());
+        assert!(pending_uninstalls(tmp.path()).is_empty());
+        forget_uninstall(tmp.path(), "p").unwrap();
+        symlink(&record, parent.join("p.tmp")).unwrap();
+        remember_uninstall(tmp.path(), &pending, &tmp.path().join("p/1.0.0")).unwrap();
+        assert_eq!(pending_uninstalls(tmp.path()).len(), 1);
+        assert_eq!(std::fs::read_to_string(&record).unwrap(), "untouched");
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn pending_uninstall_records_do_not_follow_junctions() {
+        let tmp = tempfile::tempdir().unwrap();
+        let outside = tempfile::tempdir().unwrap();
+        let record = outside.path().join("p.json");
+        std::fs::write(&record, "untouched").unwrap();
+        let status = std::process::Command::new("cmd")
+            .args(["/C", "mklink", "/J"])
+            .arg(tmp.path().join(".uninstall"))
+            .arg(outside.path())
+            .status()
+            .unwrap();
+        assert!(status.success());
+        let pending = PendingUninstall {
+            id: "p".into(),
+            name: "Plugin".into(),
+            version: "1.0.0".into(),
+            flat: false,
+            secrets: Vec::new(),
+            error: None,
+        };
+        assert!(remember_uninstall(tmp.path(), &pending, &tmp.path().join("p/1.0.0")).is_err());
+        assert!(forget_uninstall(tmp.path(), "p").is_err());
+        assert!(pending_uninstalls(tmp.path()).is_empty());
+        assert_eq!(std::fs::read_to_string(record).unwrap(), "untouched");
+    }
+
    #[test]
    fn failed_swap_keeps_the_old_version() {
        let tmp = tempfile::tempdir().unwrap();
@@ -429,6 +429,7 @@ impl PluginHost {
                                level: ide_plugin::NotificationLevel::Warning,
                                title: format!("{} was disabled", plugin.manifest().name),
                                body: format!("The marketplace revoked this plugin: {reason}"),
+                                actions: Vec::new(),
                            },
                        );
                    }
@@ -17,12 +17,17 @@

 mod api;
 pub mod commit;
+pub(crate) mod diagnostics;
+pub mod endpoints;
+mod event_paths;
+mod files_changed;
 mod hover;
 mod icon_extensions;
 mod icon_patterns;
 mod icon_settings;
 mod icons;
 pub mod index_ops;
+mod inlay_hints;
 mod install;
 pub mod intellij;
 mod market;
@@ -44,6 +49,7 @@ pub(crate) use hover::merge as merge_hover;
 pub use icons::{
    MAX_PLUGIN_ICON, map_asset as icon_theme_map_asset, plugin_icon, sanitize_svg, svg_prefix as icon_theme_svg_prefix,
 };
+pub(crate) use inlay_hints::merge as merge_inlay_hints;
 pub use market::{
    INDEX_FILE as MARKET_INDEX_FILE, MarketPlugin, OFFICIAL_INDEX as OFFICIAL_MARKET_INDEX, OFFICIAL_PUBLISHER,
    read_url as read_market_url, resolve as resolve_market_href,
@@ -109,6 +115,7 @@ struct Links {
 }

 struct Meta {
+    uninstalling: bool,
    status: PluginStatus,
    error: Option<String>,
    warnings: Vec<String>,
@@ -136,6 +143,7 @@ struct Meta {
 impl Meta {
    fn new() -> Self {
        Self {
+            uninstalling: false,
            status: PluginStatus::Disabled,
            error: None,
            warnings: Vec::new(),
@@ -182,6 +190,7 @@ const LATENCY_WINDOW: usize = 128;
 struct EventQueue {
    since: Instant,
    events: Vec<WorkbenchEvent>,
+    files_source: Option<files_changed::Source>,
 }

 /// Most events queued per plugin and window; older ones are dropped.
@@ -212,6 +221,39 @@ struct Batches {
    pending: u32,
    /// Kinds of the batch being handled right now.
    running: Option<BTreeSet<EventKind>>,
+    files_pending: HashMap<FilesQueueKey, PendingFiles>,
+    running_token: Option<Arc<()>>,
+}
+
+type FilesQueueKey = (Option<String>, Option<PathBuf>);
+
+struct PendingFiles {
+    queue: EventQueue,
+    actor: std::sync::Weak<Actor>,
+    token: Arc<()>,
+}
+
+/// Dropping a posted job must release its mailbox even when the actor never runs it.
+struct BatchTicket {
+    batches: Arc<Mutex<Batches>>,
+    files_key: Option<FilesQueueKey>,
+    token: Arc<()>,
+}
+
+impl Drop for BatchTicket {
+    fn drop(&mut self) {
+        let mut batches = self.batches.lock();
+        if let Some(key) = &self.files_key
+            && batches.files_pending.get(key).is_some_and(|p| Arc::ptr_eq(&p.token, &self.token))
+        {
+            batches.files_pending.remove(key);
+        }
+        batches.pending = batches.pending.saturating_sub(1);
+        if batches.running_token.as_ref().is_some_and(|token| Arc::ptr_eq(token, &self.token)) {
+            batches.running = None;
+            batches.running_token = None;
+        }
+    }
 }

 impl LoadedPlugin {
@@ -321,6 +363,9 @@ pub struct PluginHost {
    /// `[[contributes.providers]]` of enabled plugins.
    providers: Arc<providers::Providers>,
    navigation: Mutex<navigation::NavigationIndex>,
+    endpoints: Mutex<endpoints::Endpoints>,
+    web_ptys: Mutex<BTreeMap<String, Vec<web::WebPtySession>>>,
+    diagnostic_projects: Mutex<Vec<diagnostics::ProjectState>>,
    /// Validated UI declarations of installed packages (start-up reuses them).
    index: Arc<ContributionIndex>,
    ledger: Mutex<Ledger>,
@@ -377,7 +422,8 @@ impl PluginHost {
        let ui = UiStore::new();
        let index = Arc::new(ContributionIndex::new(
            plugins_dir.join(".cache").join("contributions"),
-            env!("CARGO_PKG_VERSION"),
+            // Revalidate SVGs accepted before URL-valued CSS functions were rejected.
+            concat!(env!("CARGO_PKG_VERSION"), ":svg-2"),
        ));
        ui.set_index(Some(index.clone()));
        let languages = PluginLanguages::new();
@@ -410,6 +456,9 @@ impl PluginHost {
            run_detectors,
            providers,
            navigation: Mutex::default(),
+            endpoints: Mutex::default(),
+            web_ptys: Mutex::default(),
+            diagnostic_projects: Mutex::default(),
            index,
            plugins: RwLock::default(),
            state: Mutex::new(state),
@@ -445,6 +494,47 @@ impl PluginHost {
    /// Instantiates no Wasm: code runs on its activation events.
    pub fn load_all(&self) {
        let _guard = self.lifecycle.lock();
+        for pending in install::pending_uninstalls(&self.plugins_dir) {
+            if self.plugins.read().contains_key(&pending.id) {
+                continue;
+            }
+            let dir = pending.package_dir(&self.plugins_dir);
+            let mut manifest = placeholder_manifest(&dir);
+            manifest.id = pending.id.clone();
+            manifest.name = pending.name;
+            manifest.version = pending.version;
+            manifest.contributes.insert(
+                providers::SECRETS_POINT.into(),
+                toml::Value::Array(
+                    pending
+                        .secrets
+                        .into_iter()
+                        .map(|name| {
+                            toml::Value::Table(toml::Table::from_iter([("name".into(), toml::Value::String(name))]))
+                        })
+                        .collect(),
+                ),
+            );
+            let mut meta = Meta::new();
+            meta.status = PluginStatus::Failed;
+            meta.uninstalling = true;
+            meta.error = Some(
+                pending.error.unwrap_or_else(|| "Uninstall incomplete; retry Uninstall to finish cleanup.".into()),
+            );
+            self.plugins.write().insert(
+                pending.id,
+                Arc::new(LoadedPlugin {
+                    pkg: Package::new(manifest, dir),
+                    icon: None,
+                    invalid: false,
+                    source: PluginSource::Installed,
+                    dev_root: None,
+                    meta: Mutex::new(meta),
+                    batches: Arc::default(),
+                    runtime: Mutex::new(None),
+                }),
+            );
+        }
        let dirs = package_dirs(&self.plugins_dir);
        self.migrate_grants(&dirs);
        for dir in dirs {
@@ -698,9 +788,19 @@ impl PluginHost {
        Ok(self.ui.assets_with_prefix(id, prefix).into_iter().map(|(k, v)| (k, v.to_string())).collect())
    }

+    /// The UI language windows run in, as `locale()` reports it to plugin code.
+    pub fn set_ui_locale(&self, tag: &str) {
+        *self.shared.locale.write() = tag.to_owned();
+    }
+
+    pub fn ui_locale(&self) -> String {
+        self.shared.locale.read().clone()
+    }
+
    pub fn set_enabled(&self, id: &str, enabled: bool) -> IdeResult<()> {
        let _guard = self.lifecycle.lock();
        let plugin = self.get(id)?;
+        self.check_not_uninstalling(&plugin)?;
        {
            let mut state = self.state.lock();
            if enabled {
@@ -724,6 +824,7 @@ impl PluginHost {
    pub fn reload(&self, id: &str) -> IdeResult<PluginInfo> {
        let _guard = self.lifecycle.lock();
        let plugin = self.get(id)?;
+        self.check_not_uninstalling(&plugin)?;
        let (dir, source, root) = (plugin.dir().to_path_buf(), plugin.source, plugin.dev_root.clone());
        self.unload(id);
        let new_id = self.load_dir(&dir, source, root);
@@ -785,6 +886,11 @@ impl PluginHost {
        let _guard = self.lifecycle.lock();
        let (pkg, set) = self.validate_package(src)?;
        let id = pkg.id().to_owned();
+        if let Some(plugin) = self.plugins.read().get(&id) {
+            self.check_not_uninstalling(plugin)?;
+        } else {
+            self.check_uninstall_pending(&id)?;
+        }
        if let Some(existing) = self.plugins.read().get(&id)
            && existing.source != PluginSource::Installed
        {
@@ -859,6 +965,13 @@ impl PluginHost {
    /// Makes `previous` the active version of `id` again and drops `failed`
    /// (its directory, its consent). Called with the plugin unloaded or not.
    fn roll_back(&self, id: &str, previous: &str, failed: &str, grant: Option<ledger::Grant>) {
+        let ready = match self.get(id) {
+            Ok(plugin) => self.check_not_uninstalling(&plugin),
+            Err(_) => self.check_uninstall_pending(id),
+        };
+        if ready.is_err() {
+            return;
+        }
        let root = self.plugins_dir.join(id);
        self.unload(id);
        if let Err(e) = install::activate_version(&root, previous) {
@@ -902,6 +1015,7 @@ impl PluginHost {
                level: ide_plugin::NotificationLevel::Warning,
                title: format!("{name} update rolled back"),
                body: message.clone(),
+                actions: Vec::new(),
            },
        );
        self.changed();
@@ -912,6 +1026,7 @@ impl PluginHost {
    pub fn roll_back_update(&self, id: &str) -> IdeResult<PluginInfo> {
        let _guard = self.lifecycle.lock();
        let plugin = self.get(id)?;
+        self.check_not_uninstalling(&plugin)?;
        if plugin.source != PluginSource::Installed {
            return Err(IdeError::invalid("only installed plugins have versions to roll back to"));
        }
@@ -930,6 +1045,7 @@ impl PluginHost {
    pub fn grant(&self, id: &str, consent: &Consent) -> IdeResult<PluginInfo> {
        let _guard = self.lifecycle.lock();
        let plugin = self.get(id)?;
+        self.check_not_uninstalling(&plugin)?;
        if plugin.invalid {
            return Err(IdeError::invalid("the plugin's manifest is invalid"));
        }
@@ -950,6 +1066,7 @@ impl PluginHost {
    pub fn set_capability(&self, id: &str, capability: &str, granted: bool) -> IdeResult<PluginInfo> {
        let _guard = self.lifecycle.lock();
        let plugin = self.get(id)?;
+        self.check_not_uninstalling(&plugin)?;
        let cap: Capability = capability.parse().map_err(IdeError::invalid)?;
        if !plugin.manifest().declares(&cap) && !plugin.meta.lock().declared_extra.contains(&cap) {
            return Err(IdeError::invalid(format!("plugin {id:?} does not declare {cap}")));
@@ -988,6 +1105,13 @@ impl PluginHost {
            .map_err(|e| IdeError::new(ide_core::error::ErrorKind::PermissionDenied, e))
    }

+    fn check_uninstall_pending(&self, id: &str) -> IdeResult<()> {
+        if install::uninstall_pending(&self.plugins_dir, id)? {
+            return Err(IdeError::unavailable(std::io::Error::from(std::io::ErrorKind::ResourceBusy).to_string()));
+        }
+        Ok(())
+    }
+
    pub fn uninstall(&self, id: &str) -> IdeResult<()> {
        let _guard = self.lifecycle.lock();
        let plugin = self.get(id)?;
@@ -1006,21 +1130,65 @@ impl PluginHost {
            .flatten()
            .filter_map(|s| s.get("name")?.as_str().map(str::to_owned))
            .collect();
-        self.unload(id);
+        let mut pending = install::PendingUninstall {
+            id: id.to_owned(),
+            name: plugin.manifest().name.clone(),
+            version: plugin.manifest().version.clone(),
+            flat: plugin.dir() == self.plugins_dir.join(id),
+            secrets: secrets.clone(),
+            error: None,
+        };
+        // A broken manifest has no trusted identity to journal; keep its existing removal path.
+        if !plugin.invalid {
+            install::remember_uninstall(&self.plugins_dir, &pending, plugin.dir())?;
+        }
+        // Retain registration for retry, but prevent concurrent on-demand activation.
        {
+            let _runtime = plugin.runtime.lock();
+            let mut meta = plugin.meta.lock();
+            meta.uninstalling = true;
+            meta.status = PluginStatus::Disabled;
+        }
+        self.stop(&plugin);
+        let cleanup = || -> std::io::Result<()> {
+            install::check_cleanup_parent(&self.plugins_dir, &self.shared.data_dir.join(id))?;
+            install::check_cleanup_parent(&self.plugins_dir, plugin.dir())?;
+            install::check_not_symlink(&self.shared.data_dir.join(id))?;
+            for file in ["secrets.json", "secrets.tmp"] {
+                install::check_not_symlink(&self.shared.data_dir.join(id).join(file))?;
+            }
            let store = self.shared.secrets.read().clone();
            for name in &secrets {
                if let Err(e) = store.set(id, name, None) {
-                    tracing::warn!(plugin = %id, "cannot delete secret {name:?}: {e}");
+                    return Err(std::io::Error::other(format!("cannot delete secret {name:?}: {e}")));
                }
            }
+            // Keep the installed package and registration available until cleanup succeeds.
+            let data = self.shared.data_dir.join(id);
+            match std::fs::remove_dir_all(&data) {
+                Ok(()) => {}
+                Err(e) if e.kind() == std::io::ErrorKind::NotFound && !data.exists() => {}
+                Err(e) => return Err(e),
+            }
+            // Every version (`<id>/<version>`), or the flat directory of an older install.
+            let target = self.plugins_dir.join(id);
+            match std::fs::remove_dir_all(&target) {
+                Err(e) if e.kind() == std::io::ErrorKind::NotFound && !target.exists() => Ok(()),
+                result => result,
+            }
+        };
+        if let Err(e) = cleanup() {
+            pending.error = Some(e.to_string());
+            if !plugin.invalid
+                && let Err(record_error) = install::remember_uninstall(&self.plugins_dir, &pending, plugin.dir())
+            {
+                tracing::warn!(plugin = %id, "cannot save uninstall error: {record_error}");
+            }
+            self.set_failed(&plugin, e.to_string());
+            self.changed();
+            return Err(e.into());
        }
-        // Every version (`<id>/<version>`), or the flat directory of an older install.
-        let root = self.plugins_dir.join(id);
-        std::fs::remove_dir_all(if root.is_dir() { root } else { plugin.dir().to_path_buf() })?;
        self.updates.lock().remove(id);
-        // Its storage goes with it.
-        let _ = std::fs::remove_dir_all(self.shared.data_dir.join(id));
        {
            let mut ledger = self.ledger.lock();
            ledger.remove(&plugin.subject());
@@ -1034,6 +1202,12 @@ impl PluginHost {
            }
        }
        self.save_state();
+        if let Err(e) = install::forget_uninstall(&self.plugins_dir, id) {
+            self.set_failed(&plugin, e.to_string());
+            self.changed();
+            return Err(e.into());
+        }
+        self.unload(id);
        self.changed();
        Ok(())
    }
@@ -1080,8 +1254,7 @@ impl PluginHost {
        })
    }

-    /// The Services pane of node `key` of the plugin's `location = "services"`
-    /// view `view`.
+    /// The detail tabs of item `key` of a Services or `detail = true` view.
    pub fn service_detail(
        &self,
        id: &str,
@@ -1089,9 +1262,9 @@ impl PluginHost {
        key: &str,
        invocation: Invocation,
    ) -> IdeResult<Vec<ide_plugin::ServiceTab>> {
-        self.services_view(id, view)?;
+        self.detail_view(id, view)?;
        let (view, key) = (view.to_owned(), key.to_owned());
-        self.code_call(id, invocation, "rendering the service's pane", move |rt, inv| {
+        self.code_call(id, invocation, "rendering the item's detail pane", move |rt, inv| {
            rt.service_detail(&view, &key, inv)
        })
    }
@@ -1147,16 +1320,16 @@ impl PluginHost {
        if declared { Ok(()) } else { Err(IdeError::not_found(format!("plugin {id:?} declares no view {view:?}"))) }
    }

-    fn services_view(&self, id: &str, view: &str) -> IdeResult<()> {
-        let services = self
-            .ui
-            .items(ui_points::VIEWS, Some(id))
-            .iter()
-            .any(|i| i.key == view && i.decl["location"].as_str() == Some(ui_points::SERVICES_LOCATION));
-        if services {
+    fn detail_view(&self, id: &str, view: &str) -> IdeResult<()> {
+        let detail = self.ui.items(ui_points::VIEWS, Some(id)).iter().any(|i| {
+            i.key == view
+                && (i.decl["location"].as_str() == Some(ui_points::SERVICES_LOCATION)
+                    || i.decl["detail"].as_bool() == Some(true))
+        });
+        if detail {
            Ok(())
        } else {
-            Err(IdeError::not_found(format!("plugin {id:?} declares no services view {view:?}")))
+            Err(IdeError::not_found(format!("plugin {id:?} declares no detail view {view:?}")))
        }
    }

@@ -1349,11 +1522,12 @@ impl PluginHost {
        self.shared.reopen_client(label);
    }

-    /// Window `label` closed: drops its context keys and queued events, and ignores
-    /// context writes of commands still running for it.
+    /// Window `label` closed: cancels its prompts, drops its context keys and queued
+    /// events, and ignores context writes of commands still running for it.
    pub fn forget_client(&self, label: &str) {
        self.queues.lock().retain(|(_, client), _| client.as_deref() != Some(label));
        self.shared.forget_client(label);
+        self.forget_web_ptys(label);
    }

    /// The user cancelled a plugin task (`task_id` from `TaskStarted`).
@@ -1435,7 +1609,7 @@ impl PluginHost {
        let mut out = BTreeSet::new();
        for p in self.plugins.read().values() {
            for kind in EventKind::ALL {
-                if self.wants(p, kind, subs.get(p.id())) {
+                if Self::wants(p, kind, subs.kinds.get(p.id())) {
                    out.insert(kind);
                }
            }
@@ -1445,7 +1619,7 @@ impl PluginHost {

    /// Whether `plugin` gets `kind` events: subscribed at run time or with
    /// `on-event:<kind>`, the capability granted, and able to run.
-    fn wants(&self, plugin: &LoadedPlugin, kind: EventKind, runtime: Option<&BTreeSet<EventKind>>) -> bool {
+    fn wants(plugin: &LoadedPlugin, kind: EventKind, runtime: Option<&BTreeSet<EventKind>>) -> bool {
        let declared =
            plugin.manifest().activation.iter().any(|a| matches!(a, ActivationEvent::Event(k) if k == kind.name()));
        if !declared && !runtime.is_some_and(|s| s.contains(&kind)) {
@@ -1459,6 +1633,15 @@ impl PluginHost {
    /// Queues workbench events from window `client` for the plugins that want
    /// them; [`flush_events`](Self::flush_events) delivers them in batches.
    pub fn post_events(&self, client: Option<&str>, events: Vec<WorkbenchEvent>) {
+        self.post_events_from(client, events, None);
+    }
+
+    fn post_events_from(
+        &self,
+        client: Option<&str>,
+        events: Vec<WorkbenchEvent>,
+        source: Option<files_changed::Source>,
+    ) {
        if events.is_empty() {
            return;
        }
@@ -1466,31 +1649,60 @@ impl PluginHost {
        let plugins: Vec<_> = self.plugins.read().values().cloned().collect();
        let now = Instant::now();
        let mut queues = self.queues.lock();
+        let mut events = events;
+        files_changed::retain_live(&mut events, source.as_ref());
        for p in plugins {
-            let wanted: Vec<WorkbenchEvent> =
-                events.iter().filter(|e| self.wants(&p, e.kind(), subs.get(p.id()))).cloned().collect();
+            let wanted: Vec<WorkbenchEvent> = events
+                .iter()
+                .filter(|e| Self::wants(&p, e.kind(), subs.kinds.get(p.id())))
+                .filter(|e| {
+                    !matches!(e, WorkbenchEvent::FilesChanged(_))
+                        || p.dev_root
+                            .as_ref()
+                            .is_none_or(|root| client.and_then(|c| self.shared.project_of(c)).as_ref() == Some(root))
+                })
+                .cloned()
+                .collect();
+            let wanted = Self::filter_path_events(&self.shared, &p, client, &wanted, &subs);
            if wanted.is_empty() {
                continue;
            }
-            let queue = queues
-                .entry((p.id().to_owned(), client.map(str::to_owned)))
-                .or_insert_with(|| EventQueue { since: now, events: Vec::new() });
-            queue.events.extend(wanted);
+            let queue = queues.entry((p.id().to_owned(), client.map(str::to_owned))).or_insert_with(|| EventQueue {
+                since: now,
+                events: Vec::new(),
+                files_source: None,
+            });
+            if let Some(source) = &source {
+                if !queue.files_source.as_ref().is_some_and(|old| old.same(source)) {
+                    queue.events.retain(|e| !matches!(e, WorkbenchEvent::FilesChanged(_)));
+                }
+                queue.files_source = Some(source.clone());
+            }
+            files_changed::append(&mut queue.events, wanted);
            let excess = queue.events.len().saturating_sub(MAX_QUEUED_EVENTS);
-            queue.events.drain(..excess);
+            let mut remaining = excess;
+            queue.events.retain(|event| {
+                if remaining > 0 && !matches!(event, WorkbenchEvent::FilesChanged(_)) {
+                    remaining -= 1;
+                    false
+                } else {
+                    true
+                }
+            });
        }
    }

    /// Delivers queued events: to running plugins right away, to idle ones
    /// (which must be activated) after [`IDLE_BATCH`], so frequent events
-    /// don't keep waking them. Call it a few times a second.
+    /// don't keep waking them. Filesystem events are already debounced by
+    /// the watcher and bypass that delay. Call it a few times a second.
    pub fn flush_events(&self) {
        self.flush_events_at(Instant::now());
    }

    #[doc(hidden)]
    pub fn flush_events_at(&self, now: Instant) {
-        let due: Vec<(QueueKey, Vec<WorkbenchEvent>)> = {
+        let due: Vec<(QueueKey, EventQueue)> = {
            let mut queues = self.queues.lock();
            let plugins = self.plugins.read();
            let keys: Vec<_> = queues
@@ -1501,15 +1713,17 @@ impl PluginHost {
                    running
                        || now.saturating_duration_since(q.since) >= IDLE_BATCH
                        || q.events.len() >= MAX_QUEUED_EVENTS / 2
-                        || q.events.contains(&WorkbenchEvent::Scheduled)
+                        || q.events
+                            .iter()
+                            .any(|e| matches!(e, WorkbenchEvent::FilesChanged(_) | WorkbenchEvent::Scheduled))
                })
                .map(|(k, _)| k.clone())
                .collect();
-            keys.into_iter().filter_map(|k| queues.remove(&k).map(|q| (k, q.events))).collect()
+            keys.into_iter().filter_map(|k| queues.remove(&k).map(|q| (k, q))).collect()
        };
        let mut changed = false;
-        for ((id, client), events) in due {
-            changed |= self.deliver(&id, client, events);
+        for ((id, client), queue) in due {
+            changed |= self.deliver(&id, client, queue);
        }
        // Batches that crashed since.
        let plugins: Vec<_> = self.plugins.read().values().cloned().collect();
@@ -1542,12 +1756,52 @@ impl PluginHost {
        }
    }

+    fn filter_delivery_events(
+        shared: &api::Shared,
+        plugin: &LoadedPlugin,
+        client: Option<&str>,
+        events: &[WorkbenchEvent],
+        subs: &event_paths::Subscriptions,
+    ) -> Vec<WorkbenchEvent> {
+        Self::filter_path_events(shared, plugin, client, events, subs)
+            .into_iter()
+            .filter(|event| {
+                !matches!(
+                    event,
+                    WorkbenchEvent::FileOpened(_) | WorkbenchEvent::FileSaved(_) | WorkbenchEvent::FilesChanged(_)
+                ) || Self::wants(plugin, event.kind(), subs.kinds.get(plugin.id()))
+            })
+            .collect()
+    }
+
    /// Hands one batch to the plugin's `event-handler.handle` without waiting
    /// for it. A newer batch of the same kinds cooperatively cancels the one
    /// being handled (a save while the previous save is still being checked).
+    /// Filesystem deltas must all run: a newer delta cannot replace an older one.
    /// Returns whether the plugin was activated.
-    fn deliver(&self, id: &str, client: Option<String>, events: Vec<WorkbenchEvent>) -> bool {
+    fn deliver(&self, id: &str, client: Option<String>, mut queue: EventQueue) -> bool {
+        files_changed::retain_live(&mut queue.events, queue.files_source.as_ref());
+        if queue.events.is_empty() {
+            return false;
+        }
+        if queue.events.iter().any(|e| matches!(e, WorkbenchEvent::FilesChanged(_)))
+            && queue.events.iter().any(|e| !matches!(e, WorkbenchEvent::FilesChanged(_)))
+        {
+            let (files, other) = queue.events.into_iter().partition(|e| matches!(e, WorkbenchEvent::FilesChanged(_)));
+            let changed =
+                self.deliver(id, client.clone(), EventQueue { since: queue.since, events: other, files_source: None });
+            return self.deliver(
+                id,
+                client,
+                EventQueue { since: queue.since, events: files, files_source: queue.files_source },
+            ) | changed;
+        }
        let Ok(plugin) = self.get(id) else { return false };
+        let subs = self.shared.subscriptions.lock().clone();
+        let eligible = Self::filter_delivery_events(&self.shared, &plugin, client.as_deref(), &queue.events, &subs);
+        if eligible.is_empty() {
+            return false;
+        }
        if !plugin.meta.lock().pending.is_empty() {
            return false;
        }
@@ -1557,21 +1811,94 @@ impl PluginHost {
            client: client.clone(),
            editor: None,
            selected_paths: Vec::new(),
+            global_settings: false,
        };
-        let kinds: BTreeSet<EventKind> = events.iter().map(WorkbenchEvent::kind).collect();
+        let kinds: BTreeSet<EventKind> = queue.events.iter().map(WorkbenchEvent::kind).collect();
+        let filesystem = kinds.contains(&EventKind::FilesChanged);
+        let mailbox_key = (client.clone(), invocation.workspace_root.clone());
+        let mut ordinary = None;
+        let token = Arc::new(());
        {
            let mut batches = plugin.batches.lock();
-            if batches.running.as_ref() == Some(&kinds) && !kinds.contains(&EventKind::Scheduled) {
+            if batches.running.as_ref() == Some(&kinds)
+                && !kinds.contains(&EventKind::Scheduled)
+                && !kinds.contains(&EventKind::FilesChanged)
+            {
                actor.cancel_soft();
            }
+            if filesystem {
+                files_changed::retain_live(&mut queue.events, queue.files_source.as_ref());
+                if queue.events.is_empty() {
+                    return activated;
+                }
+                if let Some(pending) = batches.files_pending.get_mut(&mailbox_key)
+                    && pending.actor.upgrade().is_some_and(|owner| Arc::ptr_eq(&owner, &actor))
+                {
+                    let pending = &mut pending.queue;
+                    if queue
+                        .files_source
+                        .as_ref()
+                        .is_some_and(|source| !pending.files_source.as_ref().is_some_and(|old| old.same(source)))
+                    {
+                        pending.events.clear();
+                        pending.files_source = queue.files_source.clone();
+                    }
+                    files_changed::append(&mut pending.events, queue.events);
+                    return activated;
+                }
+                batches.files_pending.insert(
+                    mailbox_key.clone(),
+                    PendingFiles { queue, actor: Arc::downgrade(&actor), token: token.clone() },
+                );
+            } else {
+                ordinary = Some(queue);
+            }
            batches.pending += 1;
        }
        let started = Instant::now();
-        let (start, finish) = (plugin.batches.clone(), plugin.batches.clone());
+        let start = plugin.batches.clone();
+        let ticket = BatchTicket {
+            batches: plugin.batches.clone(),
+            files_key: filesystem.then(|| mailbox_key.clone()),
+            token: token.clone(),
+        };
        let done_plugin = plugin.clone();
+        let delivery_plugin = plugin.clone();
+        let shared = self.shared.clone();
        actor.post(
            move |rt| {
-                start.lock().running = Some(kinds);
+                let _ticket = ticket;
+                let mut queue = {
+                    let mut batches = start.lock();
+                    let queue = if filesystem {
+                        if !batches.files_pending.get(&mailbox_key).is_some_and(|p| Arc::ptr_eq(&p.token, &token)) {
+                            return Ok(());
+                        }
+                        batches.files_pending.remove(&mailbox_key).expect("owned filesystem batch").queue
+                    } else {
+                        ordinary.expect("ordinary event batch")
+                    };
+                    batches.running = Some(kinds);
+                    batches.running_token = Some(token);
+                    queue
+                };
+                files_changed::retain_live(&mut queue.events, queue.files_source.as_ref());
+                if filesystem
+                    && invocation.workspace_root != invocation.client.as_deref().and_then(|c| shared.project_of(c))
+                {
+                    return Ok(());
+                }
+                let subs = shared.subscriptions.lock().clone();
+                let events = Self::filter_delivery_events(
+                    &shared,
+                    &delivery_plugin,
+                    invocation.client.as_deref(),
+                    &queue.events,
+                    &subs,
+                );
+                if events.is_empty() {
+                    return Ok(());
+                }
                rt.handle_events(events, invocation)
            },
            move |result| {
@@ -1588,9 +1915,6 @@ impl PluginHost {
                    }
                    _ => {}
                }
-                let mut batches = finish.lock();
-                batches.pending = batches.pending.saturating_sub(1);
-                batches.running = None;
            },
        );
        activated
@@ -1733,6 +2057,7 @@ impl PluginHost {
        let actors: Vec<_> = self.plugins.read().values().filter_map(|p| p.runtime.lock().take()).collect();
        for id in self.plugins.read().keys() {
            self.shared.block_prompts(id);
+            self.stop_web_ptys(id);
        }
        for a in &actors {
            a.stop(false);
@@ -1740,6 +2065,7 @@ impl PluginHost {
        for a in actors {
            a.stop(true);
        }
+        self.shared.finish_process_shutdowns();
    }

    /// Periodic upkeep (every few seconds): reports crashes nobody waited
@@ -1786,7 +2112,7 @@ impl PluginHost {
                self.queues
                    .lock()
                    .entry((p.id().to_owned(), None))
-                    .or_insert_with(|| EventQueue { since: now, events: Vec::new() })
+                    .or_insert_with(|| EventQueue { since: now, events: Vec::new(), files_source: None })
                    .events
                    .push(WorkbenchEvent::Scheduled);
            }
@@ -1854,7 +2180,17 @@ impl PluginHost {
    fn load_dir(&self, dir: &Path, source: PluginSource, dev_root: Option<PathBuf>) -> String {
        let (manifest, error) = match Manifest::load(dir) {
            Ok(m) => (m, None),
-            Err(e) => (placeholder_manifest(dir), Some(e)),
+            Err(e) => {
+                let mut manifest = placeholder_manifest(dir);
+                // Installed directory names retain identity when discovery metadata is damaged.
+                if source == PluginSource::Installed
+                    && let Ok(relative) = dir.strip_prefix(&self.plugins_dir)
+                    && let Some(name) = relative.components().next().and_then(|p| p.as_os_str().to_str())
+                {
+                    manifest.id = name.to_owned();
+                }
+                (manifest, Some(e))
+            }
        };
        let invalid = error.is_some();
        let id = manifest.id.clone();
@@ -1904,10 +2240,27 @@ impl PluginHost {
        self.stop(&plugin);
    }

+    fn check_not_uninstalling(&self, plugin: &LoadedPlugin) -> IdeResult<()> {
+        if plugin.meta.lock().uninstalling {
+            return Err(IdeError::unavailable("Uninstall incomplete; retry Uninstall to finish cleanup."));
+        }
+        if plugin.source == PluginSource::Installed {
+            self.check_uninstall_pending(plugin.id())?;
+        }
+        Ok(())
+    }
+
    /// Validates, checks grants and commits the contributions; activates code
    /// whose activation event already fired.
    fn start(&self, plugin: &Arc<LoadedPlugin>) {
+        if let Err(e) = self.check_not_uninstalling(plugin) {
+            if !plugin.meta.lock().uninstalling {
+                self.set_failed(plugin, e.message);
+            }
+            return;
+        }
        self.registry.dispose_plugin(plugin.id());
+        self.clear_provider_diagnostics(plugin.id());
        if plugin.source == PluginSource::Installed
            && let Some(reason) = self.revoked_reason(plugin.id(), &plugin.manifest().version, plugin.dir())
        {
@@ -1965,6 +2318,7 @@ impl PluginHost {
    /// first if needed. Returns whether it was activated now.
    fn ensure_active(&self, plugin: &Arc<LoadedPlugin>, client: Option<&str>) -> IdeResult<(Arc<Actor>, bool)> {
        let mut runtime = plugin.runtime.lock();
+        self.check_not_uninstalling(plugin)?;
        if let Some(actor) = runtime.as_ref() {
            if actor.is_alive() {
                return Ok((actor.clone(), false));
@@ -2073,6 +2427,7 @@ impl PluginHost {
        }
        let Some(error) = actor.take_crash() else { return };
        self.clear_plugin_navigation(plugin.id());
+        self.clear_plugin_endpoints(plugin.id());
        if error.starts_with(CANCELLED) {
            // Cancelled on request: restart on next use, no backoff.
            let mut meta = plugin.meta.lock();
@@ -2089,6 +2444,7 @@ impl PluginHost {
    /// A trap dropped the plugin's instance: restart it on next use after a
    /// backoff, or stop it for the session after too many crashes in a row.
    fn crashed(&self, plugin: &LoadedPlugin, error: &str, client: Option<&str>) {
+        self.clear_provider_diagnostics(plugin.id());
        let failures = {
            let mut meta = plugin.meta.lock();
            meta.failures += 1;
@@ -2118,6 +2474,7 @@ impl PluginHost {
                    level: NotificationLevel::Warning,
                    title: format!("Plugin \u{201c}{}\u{201d} crashed", plugin.manifest().name),
                    body: format!("{error}\nIt restarts the next time it is needed."),
+                    actions: Vec::new(),
                },
            );
        }
@@ -2134,6 +2491,8 @@ impl PluginHost {
            *runtime = None;
        }
        actor.stop(false);
+        // Its handles go with its instance; an idle reclaim is one.
+        self.shared.kill_processes(plugin.id());
        let mut meta = plugin.meta.lock();
        if meta.status == PluginStatus::Active {
            meta.status = PluginStatus::Inactive;
@@ -2144,28 +2503,36 @@ impl PluginHost {
    }

    fn stop(&self, plugin: &LoadedPlugin) {
+        self.stop_web_ptys(plugin.id());
        self.clear_plugin_navigation(plugin.id());
+        self.clear_plugin_endpoints(plugin.id());
        // A call waiting on the user would keep the join below waiting.
        self.shared.block_prompts(plugin.id());
        if let Some(actor) = plugin.runtime.lock().take() {
            actor.stop(true);
        }
        self.registry.dispose_plugin(plugin.id());
+        self.clear_provider_diagnostics(plugin.id());
        self.shared.clear_plugin(plugin.id(), true);
        self.queues.lock().retain(|(id, _), _| id != plugin.id());
    }

    fn set_failed(&self, plugin: &LoadedPlugin, error: String) {
        self.clear_plugin_navigation(plugin.id());
+        self.clear_plugin_endpoints(plugin.id());
        tracing::warn!(plugin = %plugin.id(), "{error}");
        self.registry.dispose_plugin(plugin.id());
+        self.clear_provider_diagnostics(plugin.id());
        let mut meta = plugin.meta.lock();
        meta.status = PluginStatus::Failed;
        meta.error = Some(error);
+        drop(meta);
+        self.stop_web_ptys(plugin.id());
    }

    fn fail(&self, plugin: &LoadedPlugin, error: &str, client: Option<&str>) {
        self.clear_plugin_navigation(plugin.id());
+        self.clear_plugin_endpoints(plugin.id());
        tracing::warn!(plugin = %plugin.id(), "disabled after failure: {error}");
        if let Some(actor) = plugin.runtime.lock().take() {
            actor.stop(false);
@@ -2179,6 +2546,7 @@ impl PluginHost {
                level: NotificationLevel::Error,
                title: format!("Plugin \u{201c}{}\u{201d} was disabled", plugin.manifest().name),
                body: error.to_owned(),
+                actions: Vec::new(),
            },
        );
        self.changed();
@@ -2523,6 +2891,70 @@ impl ide_language::ExternalSyntax for PluginSyntax {
 mod tests {
    use super::*;

+    #[test]
+    fn host_panics_stop_actor_and_reply_on_every_call_path() {
+        let tmp = tempfile::tempdir().unwrap();
+        let host =
+            PluginHost::new(tmp.path().join("plugins"), Arc::new(|_: Option<&str>, _| {}), Limits::default()).unwrap();
+        let fixture = Path::new(env!("CARGO_MANIFEST_DIR")).join("../ide-plugin/tests/fixtures/diagnostics");
+        host.install_from_dir(&fixture, &Consent::all()).unwrap();
+        let plugin = host.get("test.diagnostics").unwrap();
+        for mode in 0..5 {
+            let (actor, _) = host.ensure_active(&plugin, None).unwrap();
+            let cancel = ide_core::CancellationToken::new();
+            let next_actor = actor.clone();
+            let (queued_tx, queued_rx) = std::sync::mpsc::channel();
+            let panic = move |_: &mut Runtime| -> Result<(), CallError> {
+                let pending = next_actor.submit(None, |_| Ok("must not run")).unwrap();
+                queued_tx.send(pending).unwrap();
+                panic!("host call panic")
+            };
+            let result = match mode {
+                0 => actor.call(None, panic),
+                1 => actor.call_cancellable(&cancel, Duration::ZERO, panic),
+                2 => actor.call_edit_cancellable(&cancel, Duration::ZERO, Duration::from_secs(5), panic),
+                _ => {
+                    let (tx, rx) = std::sync::mpsc::channel();
+                    if mode == 3 {
+                        actor.post(panic, move |result| {
+                            let _ = tx.send(result);
+                        });
+                    } else {
+                        actor.post(
+                            |_| Ok(()),
+                            move |result| {
+                                let _ = tx.send(result);
+                                panic!("completion callback panic");
+                            },
+                        );
+                    }
+                    rx.recv_timeout(Duration::from_secs(5)).expect("actor must reply")
+                }
+            };
+            if mode < 4 {
+                let queued = queued_rx.recv_timeout(Duration::from_secs(5)).unwrap();
+                assert!(matches!(queued.wait(), Err(ActorError::Stopped)), "poisoned runtime must not run queued work");
+            }
+            actor.stop(true);
+            if mode < 4 {
+                assert!(
+                    matches!(result, Err(ActorError::Call(CallError::Trap(ref message))) if message.contains("host call panic")),
+                    "{result:?}"
+                );
+            }
+            assert!(!actor.is_alive());
+            assert!(!actor.is_busy());
+            assert!(matches!(actor.call(None, |_| Ok(())), Err(ActorError::Stopped)));
+            let crash = actor.take_crash().expect("supervisor must see the panic");
+            assert!(crash.contains(if mode == 4 { "completion callback panic" } else { "host call panic" }));
+            assert!(actor.take_crash().is_none());
+            cancel.cancel();
+            // Re-enable to reset the supervisor before testing the next call path.
+            host.set_enabled("test.diagnostics", false).unwrap();
+            host.set_enabled("test.diagnostics", true).unwrap();
+        }
+    }
+
    #[test]
    fn globs() {
        assert!(glob_match("**/*Mapper.xml", "src/main/UserMapper.xml"));
@@ -28,6 +28,7 @@ pub use ide_plugin::indexing::*;
 struct File {
    version: Option<u32>,
    scope: String,
+    hash: blake3::Hash,
    edges: Edges,
 }
 #[derive(Default)]
@@ -61,6 +62,11 @@ impl Graph {
        }
        targets
    }
+    fn scoped_targets(&self, key: &str, scope: &str) -> Vec<&Location> {
+        let targets = self.targets(key);
+        let local = targets.iter().any(|t| self.files.get(&t.path.0).is_some_and(|f| f.scope == scope));
+        targets.into_iter().filter(|t| !local || self.files.get(&t.path.0).is_some_and(|f| f.scope == scope)).collect()
+    }
    fn remove(&mut self, path: &Path) {
        if let Some(file) = self.files.remove(path) {
            self.edges -= file.edges.definitions.len()
@@ -303,7 +309,7 @@ impl PluginHost {
            {
                return Err(IdeError::unavailable("navigation association limit reached"));
            }
-            graph.insert(path.to_owned(), File { version, scope: scope.to_owned(), edges });
+            graph.insert(path.to_owned(), File { version, scope: scope.to_owned(), hash: snapshot_hash(text), edges });
        }
        Ok(())
    }
@@ -365,6 +371,70 @@ impl PluginHost {
        }
        result.filter(|r| !r.targets.is_empty())
    }
+    /// Definitions and references of each indexed key under the caret. Markers
+    /// are navigation affordances, not name anchors, and never participate.
+    pub fn indexed_symbol_at(&self, root: &Path, path: &Path, pos: Pos, client: Option<&str>) -> Option<IndexedSymbol> {
+        if !(self.project_policy.read())(root) {
+            return None;
+        }
+        let plugins = self.plugins.read();
+        let index = self.navigation.lock();
+        let graphs = index.projects.get(&(root.to_owned(), client.map(str::to_owned)))?;
+        let mut result: Option<IndexedSymbol> = None;
+        for (id, graph) in graphs {
+            let Some(plugin) = plugins.get(id) else { continue };
+            if !plugin.status().is_live() || !graph.instance.ptr_eq(&Arc::downgrade(plugin)) {
+                continue;
+            }
+            let Some(source) = graph.files.get(path) else { continue };
+            let anchors: Vec<_> = source
+                .edges
+                .definitions
+                .iter()
+                .chain(&source.edges.references)
+                .filter(|anchor| contains(anchor.range, pos))
+                .collect();
+            let Some(primary) = anchors.first() else { continue };
+            let keys: std::collections::HashSet<_> = anchors.iter().map(|anchor| anchor.key.as_str()).collect();
+            let targets: std::collections::HashSet<_> =
+                keys.iter().flat_map(|key| graph.scoped_targets(key, &source.scope)).collect();
+            let answer = result.get_or_insert_with(|| IndexedSymbol { range: primary.range, files: vec![] });
+            for (path, file) in &graph.files {
+                let mut ranges = std::collections::BTreeSet::new();
+                for candidate in &file.edges.definitions {
+                    if targets.contains(&Location::file(path.clone(), candidate.range))
+                        || (targets.is_empty() && file.scope == source.scope && keys.contains(candidate.key.as_str()))
+                    {
+                        ranges.insert(candidate.range);
+                    }
+                }
+                let mut matches = HashMap::new();
+                for candidate in &file.edges.references {
+                    let same = *matches.entry(candidate.key.as_str()).or_insert_with(|| {
+                        let resolved = graph.scoped_targets(&candidate.key, &file.scope);
+                        resolved.iter().any(|target| targets.contains(target))
+                            || (targets.is_empty()
+                                && resolved.is_empty()
+                                && file.scope == source.scope
+                                && keys.contains(candidate.key.as_str()))
+                    });
+                    if same {
+                        ranges.insert(candidate.range);
+                    }
+                }
+                if !ranges.is_empty() {
+                    answer.files.push(IndexedAnchors {
+                        path: path.clone(),
+                        version: file.version,
+                        hash: file.hash,
+                        ranges: ranges.into_iter().collect(),
+                    });
+                }
+            }
+        }
+        result
+    }
+
    /// Gutter markers of visible files. Uses only existing graph entries; never executes WASM.
    pub fn navigation_markers(
        &self,
@@ -423,6 +493,24 @@ impl PluginHost {
    }
 }

+#[derive(Clone)]
+pub struct IndexedSymbol {
+    pub range: Range,
+    pub files: Vec<IndexedAnchors>,
+}
+
+#[derive(Clone)]
+pub struct IndexedAnchors {
+    pub path: PathBuf,
+    pub version: Option<u32>,
+    pub hash: blake3::Hash,
+    pub ranges: Vec<Range>,
+}
+
+pub(crate) fn snapshot_hash(text: &str) -> blake3::Hash {
+    blake3::hash(ide_text::normalize_line_endings(text).as_bytes())
+}
+
 #[derive(Clone, Deserialize)]
 #[serde(deny_unknown_fields)]
 struct Decl {
@@ -59,6 +59,7 @@ pub fn register_builtin_points(
    registry.register(Arc::new(super::navigation::IndexersPoint))?;
    registry.register(Arc::new(super::providers::ProvidersPoint::new(providers.clone())))?;
    registry.register(Arc::new(UiPoint::new(super::providers::SECRETS_POINT, ui.clone(), super::providers::secret)))?;
+    registry.register(Arc::new(UiPoint::new(super::endpoints::POINT, ui.clone(), super::endpoints::declaration)))?;
    use super::ui_points as p;
    registry.register(Arc::new(UiPoint::new(p::MENUS, ui.clone(), p::menu)))?;
    registry.register(Arc::new(UiPoint::new(p::KEYMAPS, ui.clone(), p::keymap)))?;
@@ -66,8 +67,10 @@ pub fn register_builtin_points(
    registry.register(Arc::new(UiPoint::new(p::SETTINGS, ui.clone(), p::settings)))?;
    registry.register(Arc::new(UiPoint::new(p::VIEWS, ui.clone(), p::view)))?;
    registry.register(Arc::new(UiPoint::new(p::CUSTOM_EDITORS, ui.clone(), p::custom_editor)))?;
+    registry.register(Arc::new(UiPoint::new(p::MARKER_ICONS, ui.clone(), p::marker_icon)))?;
    registry.register(Arc::new(UiPoint::new(p::FILE_ICONS, ui.clone(), p::file_icon)))?;
    registry.register(Arc::new(UiPoint::new(p::FILE_TEMPLATES, ui.clone(), p::file_template)))?;
    registry.register(Arc::new(UiPoint::new(p::COMMIT_CHECKS, ui.clone(), p::commit_check)))?;
+    registry.register(Arc::new(UiPoint::new(ide_extension::LOCALES_POINT, ui.clone(), p::locales)))?;
    Ok(())
 }
@@ -22,6 +22,7 @@
 use ide_extension::{Disposable, ExtensionPoint, Package, Placement, Prepared, UiDecl, decode, validate_item_id};
 use parking_lot::RwLock;
 use serde::{Deserialize, Serialize};
+use std::collections::{HashMap, HashSet};
 use std::sync::Arc;
 use std::sync::atomic::{AtomicU64, Ordering};

@@ -39,6 +40,8 @@ pub enum ProviderKind {
    LineMarkers,
    SemanticTokens,
    Hover,
+    InlayHints,
+    Diagnostics,
 }

 #[derive(Clone, Debug, Deserialize)]
@@ -72,13 +75,26 @@ impl Providers {

    /// Plugins providing `kind` for `language`, in declaration order.
    pub fn plugins_for(&self, kind: ProviderKind, language: &str) -> Vec<String> {
-        let mut out: Vec<String> = Vec::new();
-        for (_, plugin, kinds, languages) in self.items.read().iter() {
-            if kinds.contains(&kind) && languages.iter().any(|l| l == "*" || l == language) && !out.contains(plugin) {
-                out.push(plugin.clone());
-            }
-        }
-        out
+        self.matching::<Vec<_>>(kind, language).into_iter().map(|(plugin, _)| plugin).collect()
+    }
+
+    /// One coherent declaration snapshot, preserving the first match per plugin.
+    fn matching<T: FromIterator<(String, u64)>>(&self, kind: ProviderKind, language: &str) -> T {
+        let items = self.items.read();
+        let mut seen = HashSet::new();
+        items
+            .iter()
+            .filter(|(_, plugin, kinds, languages)| {
+                kinds.contains(&kind)
+                    && languages.iter().any(|l| l == "*" || l == language)
+                    && seen.insert(plugin.as_str())
+            })
+            .map(|(seq, plugin, ..)| (plugin.clone(), *seq))
+            .collect()
+    }
+
+    pub(super) fn diagnostic_generations(&self, language: &str) -> HashMap<String, u64> {
+        self.matching(ProviderKind::Diagnostics, language)
    }

    /// Whether any plugin provides `kind` (for any language).
@@ -117,9 +133,15 @@ impl ExtensionPoint for ProvidersPoint {
        if d.kinds.contains(&ProviderKind::SemanticTokens) {
            pkg.manifest.needs_api("contributes.providers: semantic-tokens", 3)?;
        }
+        if d.kinds.contains(&ProviderKind::Diagnostics) {
+            pkg.manifest.needs_api("contributes.providers: diagnostics", 3)?;
+        }
        if d.kinds.contains(&ProviderKind::Hover) {
            pkg.manifest.needs_api("contributes.providers: hover", 3)?;
        }
+        if d.kinds.contains(&ProviderKind::InlayHints) {
+            pkg.manifest.needs_api("contributes.providers: inlay-hints", 3)?;
+        }
        for l in &d.languages {
            if l != "*"
                && (l.is_empty()
@@ -165,11 +187,11 @@ pub(super) fn secret(_pkg: &Package, decl: toml::Value) -> Result<UiDecl, String

 // ---- dispatch ---------------------------------------------------------------

-use super::{LoadedPlugin, PluginHost, PluginStatus};
+use super::{LoadedPlugin, PluginEvent, PluginHost, PluginStatus};
 use ide_core::CancellationToken;
 use ide_plugin::{
    ActorError, CallError, CodeAction, CompletionItem, InlineSuggestion, LineMarker, Location, Pending, PluginHover,
-    ProviderDocument, Runtime, SemanticToken,
+    PluginInlayHint, ProviderDocument, Runtime, SemanticToken,
 };
 use std::sync::Weak;
 use std::time::{Duration, Instant};
@@ -198,7 +220,7 @@ pub(crate) fn editor_plugin_host() -> Option<Arc<PluginHost>> {

 impl PluginHost {
    /// Usable plugins declaring `kind` for `language`.
-    fn provider_plugins(&self, kind: ProviderKind, language: &str) -> Vec<Arc<LoadedPlugin>> {
+    pub(super) fn provider_plugins(&self, kind: ProviderKind, language: &str) -> Vec<Arc<LoadedPlugin>> {
        self.providers
            .plugins_for(kind, language)
            .into_iter()
@@ -311,14 +333,21 @@ impl PluginHost {
        plugin_id: &str,
        doc: &ProviderDocument,
        action: CodeAction,
+        invocation: ide_plugin::Invocation,
    ) -> ide_core::IdeResult<CodeAction> {
        let d = Arc::new(doc.clone());
        let timeout = self.limits.timeout;
-        self.code_call(plugin_id, ide_plugin::Invocation::default(), "resolving the code action", move |rt, _| {
-            rt.resolve_code_action(&d, &action, timeout)
+        self.code_call(plugin_id, invocation, "resolving the code action", move |rt, inv| {
+            rt.resolve_code_action(&d, &action, inv, timeout)
        })
    }

+    /// Shows `path` in window `client` after a code action of `plugin_id` was applied.
+    pub fn open_file(&self, plugin_id: &str, client: &str, path: ide_core::IpcPath) {
+        let event = PluginEvent::OpenLocation { plugin_id: plugin_id.to_owned(), path, line: 0, column: 0 };
+        self.emit(Some(client), event);
+    }
+
    pub fn provide_definition(&self, doc: &ProviderDocument, at: ide_core::Pos) -> Vec<Location> {
        let d = Arc::new(doc.clone());
        self.edit_calls(ProviderKind::Definition, &doc.language, move |rt, timeout| {
@@ -349,6 +378,59 @@ impl PluginHost {
        .collect()
    }

+    pub fn provide_diagnostics(
+        &self,
+        doc: &ProviderDocument,
+        cancel: &CancellationToken,
+    ) -> Vec<(String, Vec<ide_core::Diagnostic>)> {
+        self.provide_project_diagnostics(None, doc, cancel)
+    }
+
+    pub(super) fn diagnostic_plugins(
+        &self,
+        project: Option<&std::path::Path>,
+        language: &str,
+    ) -> Vec<Arc<LoadedPlugin>> {
+        self.provider_plugins(ProviderKind::Diagnostics, language)
+            .into_iter()
+            .filter(|p| p.dev_root.is_none() || p.dev_root.as_deref() == project)
+            .collect()
+    }
+
+    pub(super) fn provide_project_diagnostics(
+        &self,
+        project: Option<&std::path::Path>,
+        doc: &ProviderDocument,
+        cancel: &CancellationToken,
+    ) -> Vec<(String, Vec<ide_core::Diagnostic>)> {
+        std::thread::scope(|scope| {
+            let calls: Vec<_> = self
+                .diagnostic_plugins(project, &doc.language)
+                .into_iter()
+                .map(|p| {
+                    scope.spawn(move || {
+                        if cancel.is_cancelled() {
+                            return None;
+                        }
+                        let (actor, activated) = self.ensure_active(&p, None).ok()?;
+                        if activated {
+                            self.changed();
+                        }
+                        let (d, timeout) = (doc.clone(), self.limits.edit_hard);
+                        let started = Instant::now();
+                        let result =
+                            actor.call_edit_cancellable(cancel, CANCEL_GRACE, self.limits.edit_soft, move |rt| {
+                                rt.provide_diagnostics(&d, timeout)
+                            });
+                        let items = self.finish_provider_call(&p, &actor, started, result)?;
+                        (!cancel.is_cancelled()).then(|| (p.id().to_owned(), items))
+                    })
+                })
+                .collect();
+            calls.into_iter().filter_map(|call| call.join().ok().flatten()).collect()
+        })
+    }
+
    pub fn provide_hover(&self, doc: &ProviderDocument, at: ide_core::Pos) -> Vec<PluginHover> {
        let d = Arc::new(doc.clone());
        self.edit_calls(ProviderKind::Hover, &doc.language, move |rt, timeout| rt.provide_hover(&d, at, timeout))
@@ -357,6 +439,16 @@ impl PluginHost {
            .collect()
    }

+    pub fn provide_inlay_hints(&self, doc: &ProviderDocument, range: ide_core::Range) -> Vec<PluginInlayHint> {
+        let d = Arc::new(doc.clone());
+        self.edit_calls(ProviderKind::InlayHints, &doc.language, move |rt, timeout| {
+            rt.provide_inlay_hints(&d, range, timeout)
+        })
+        .into_iter()
+        .flat_map(|(_, hints)| hints)
+        .collect()
+    }
+
    /// Ghost text from the first plugin that has some. Not bound by the
    /// edit-path soft deadline (it may need the network) but by `cancel`:
    /// the editor cancels a request as soon as the user types on.
@@ -385,3 +477,41 @@ impl PluginHost {
        None
    }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn provider_snapshots_preserve_order_first_generation_and_language_matching() {
+        let providers = Arc::new(Providers::default());
+        let declare = |plugin: &str, kind, language: &str| {
+            providers.add(plugin.into(), Decl { kinds: vec![kind], languages: vec![language.into()] })
+        };
+        let mut declarations = Vec::new();
+        declarations.push(declare("unrelated", ProviderKind::Hover, "*"));
+        declarations.push(declare("other-language", ProviderKind::Diagnostics, "rust"));
+        for i in 0..256 {
+            let plugin = format!("plugin-{i}");
+            declarations.push(declare(&plugin, ProviderKind::Diagnostics, "text"));
+            declarations.push(declare(&plugin, ProviderKind::Diagnostics, "*"));
+        }
+        let expected: Vec<_> = (0..256).map(|i| format!("plugin-{i}")).collect();
+        assert_eq!(providers.plugins_for(ProviderKind::Diagnostics, "text"), expected);
+        let before = providers.diagnostic_generations("text");
+        assert_eq!(before.len(), 256);
+        assert_eq!(before["plugin-0"], 2);
+        assert_eq!(providers.diagnostic_generations("rust").len(), 257);
+        assert_eq!(providers.plugins_for(ProviderKind::Hover, "text"), ["unrelated"]);
+        // Removing the first matching declaration must invalidate its generation,
+        // even while a second declaration still provides the same language.
+        drop(declarations.remove(2));
+        let after = providers.diagnostic_generations("text");
+        assert_eq!(after["plugin-0"], 3);
+        assert_ne!(before["plugin-0"], after["plugin-0"]);
+        drop(declarations);
+        assert!(providers.diagnostic_generations("text").is_empty());
+        let _reloaded = declare("plugin-0", ProviderKind::Diagnostics, "text");
+        assert_ne!(providers.diagnostic_generations("text")["plugin-0"], after["plugin-0"]);
+    }
+}
@@ -14,8 +14,8 @@
 //! The commands a window needs at run time (`plugin_run_command`,
 //! `plugin_post_events`, `plugin_event_kinds`, `plugin_status_items`,
 //! `plugin_context_keys`, `plugin_cancel_task`, `plugin_answer_prompt`, `plugin_set_active_file`,
-//! `plugin_line_markers`, `plugin_view_render`, `plugin_view_event`, `plugin_service_detail`,
-//! `plugin_service_log`, `plugin_answer_commit`, `plugin_commit_checks`)
+//! `plugin_line_markers`, `plugin_set_ui_locale`, `plugin_view_render`, `plugin_view_event`,
+//! `plugin_service_detail`, `plugin_service_log`, `plugin_answer_commit`, `plugin_commit_checks`)
 //! carry the desktop commands' names and arguments, so a remote window's UI
 //! routes them here unchanged. Plugin results come back as `plugin`
 //! notifications ([`PluginEventMessage`]); secrets stay in the desktop's
@@ -31,6 +31,7 @@ use ide_core::{IdeError, IdeResult};
 use ide_extension::{MANIFEST_FILE, ledger};
 use ide_jsonrpc::Peer;
 use ide_plugin::{Invocation, Limits};
+use ide_workspace::settings::SettingsScope;
 use parking_lot::Mutex;
 use serde::{Deserialize, Serialize};
 use std::collections::{BTreeMap, BTreeSet};
@@ -117,12 +118,15 @@ pub fn forwarded(event: &PluginEvent) -> bool {
            | PluginEvent::ViewMessage { .. }
            | PluginEvent::OpenTerminal { .. }
            | PluginEvent::OpenLocation { .. }
+            | PluginEvent::OpenLogTab { .. }
            | PluginEvent::CopyToClipboard { .. }
            | PluginEvent::OpenUrl { .. }
+            | PluginEvent::OpenProject { .. }
            | PluginEvent::PromptRequested { .. }
            | PluginEvent::PromptClosed { .. }
            | PluginEvent::RevealView { .. }
            | PluginEvent::CommitRequested { .. }
+            | PluginEvent::EndpointsChanged { .. }
    )
 }

@@ -374,16 +378,26 @@ impl RemotePlugins {
                let arg: Option<String> = c.arg("arg")?;
                let editor: Option<PluginEditor> = c.arg("editor")?;
                let paths: Option<Vec<PathBuf>> = c.arg("paths")?;
+                let settings_scope: Option<SettingsScope> = c.arg("settingsScope")?;
                let invocation = Invocation {
                    client: Some(c.window.clone()),
                    workspace_root: c.host.project(&c.window).ok().map(|p| p.root.clone()),
                    editor: editor.map(PluginEditor::context),
                    selected_paths: paths.unwrap_or_default(),
+                    global_settings: matches!(settings_scope, Some(SettingsScope::Global)),
                };
                blocking(move || host.run_command(&plugin_id, &command_id, arg.as_deref(), invocation)).await
            }
        });
        let h = host.clone();
+        d.add("plugin_set_ui_locale", move |c| {
+            let h = h.clone();
+            async move {
+                alive(&h)?.set_ui_locale(&c.arg::<String>("tag")?);
+                Ok(())
+            }
+        });
+        let h = host.clone();
        d.add("plugin_post_events", move |c| {
            let h = h.clone();
            async move {
@@ -558,6 +572,11 @@ impl RemotePlugins {
                super::index_ops::plugin_navigation_markers(&c.host, alive(&h)?, &c.window, c.arg("paths")?).await
            }
        });
+        let h = host.clone();
+        d.add("plugin_endpoints", move |c| {
+            let h = h.clone();
+            async move { super::index_ops::plugin_endpoints(&c.host, alive(&h)?, &c.window, c.arg("pluginId")?).await }
+        });
        d.add("plugin_line_markers", |c| async move {
            crate::ops::lsp::plugin_line_markers(&c.host, &c.window, c.arg("doc")?).await
        });
@@ -168,11 +168,22 @@ pub enum PluginEvent {
    CommandsChanged,
    /// Cached document associations were disposed (reload, disable or failure).
    DocumentIndexesChanged,
+    /// The routes `plugin_id` reports for the project `root` may have changed:
+    /// ask `plugin_endpoints` again.
+    #[serde(rename_all = "camelCase")]
+    EndpointsChanged { plugin_id: String, root: ide_core::IpcPath },
    /// The marketplace offers newer versions of installed plugins (announced
    /// once per set of versions).
    UpdatesAvailable { updates: Vec<PluginUpdate> },
    #[serde(rename_all = "camelCase")]
-    Notification { plugin_id: String, level: NotificationLevel, title: String, body: String },
+    Notification {
+        plugin_id: String,
+        level: NotificationLevel,
+        title: String,
+        body: String,
+        /// Buttons running the plugin's own commands (`ui.notify`).
+        actions: Vec<ide_plugin::NotificationAction>,
+    },
    /// A plugin's status bar item was set (`item`) or removed.
    #[serde(rename_all = "camelCase")]
    StatusItemChanged { plugin_id: String, id: String, item: Option<StatusItem> },
@@ -213,6 +224,10 @@ pub enum PluginEvent {
    },
    #[serde(rename_all = "camelCase")]
    OpenLocation { plugin_id: String, path: ide_core::IpcPath, line: u32, column: u32 },
+    /// Open (or focus) the log tab `key` following `log` (`views.open-log-tab`);
+    /// it starts the program with `plugin_log_tab_spawn`.
+    #[serde(rename_all = "camelCase")]
+    OpenLogTab { plugin_id: String, key: String, title: String, log: ide_plugin::ServiceLog },
    /// Plugin languages, or the servers they may start, changed: re-fetch
    /// `languages` (the host re-detects open documents: [`crate::Host::plugin_languages_changed`]).
    LanguagesChanged,
@@ -222,6 +237,9 @@ pub enum PluginEvent {
    /// Open `url` (`http(s)://`) in the system browser.
    #[serde(rename_all = "camelCase")]
    OpenUrl { plugin_id: String, url: String },
+    /// A window command/event requests the normal File > Open flow.
+    #[serde(rename_all = "camelCase")]
+    OpenProject { plugin_id: String, path: String, new_window: bool },
    /// A command waits for the user's answer: show `prompt`, then report it with
    /// `plugin_answer_prompt(prompt_id, …)`.
    #[serde(rename_all = "camelCase")]