chore(plugins): regenerate bindings on top of main

- A marketplace index given as a local Windows path (`C:\market\index.json`)
  resolves its packages next to it; only URLs are joined with `/`.
- HTTP requests to `localhost` try IPv4 loopback first, then IPv6: local
  servers such as Ollama usually listen on IPv4, and on Windows a refused
  `::1` cost about two seconds per request.
- Tests that assumed Unix: an absolute program path is the platform's, a
  manifest rewritten by a test may have CRLF line ends, the precompiled-cache
  test replaces the cache file only after the host that maps it is gone, and
  the MyBatis test lets its first call build the index before asserting.
- The icon theme test's time limits guard against work growing faster than
  the icon count rather than measure the runner.

.agents/skills/issue-fix/SKILL.md

@@ -0,0 +1,91 @@
+---
+name: issue-fix
+description: Triage and fix a GitHub issue (or a user-reported bug) end to end — reproduce, find the root cause, generalise it to every sibling case, fix the class rather than the instance, verify, and open one PR. Use when given an issue URL/number or asked to fix a reported bug and open a PR ("看看这个 issue", "修一下这个 bug", "提 pr").
+---
+
+# Fix an issue: from one case to the whole class
+
+The reported case is one sample of a defect class. A fix that only makes the
+screenshot go away is not done: the next question is always "does this break for other
+languages / platforms / entry points too?". Answer that before anyone asks.
+
+## 1. Read and reproduce
+
+- `gh issue view <n> --comments` (repo `l0ng-ai/openidea`). Read attached logs/screenshots
+  closely: OS, language, toolchain versions, exact error text.
+- Locate the code path and confirm the claim in code, with `file:line` evidence.
+  Say plainly whether it is a real bug, a missing feature, or user environment.
+- Reproduce locally when possible (`fixtures/` projects, `/verify` for runtime). If the
+  reporter's platform (often Windows/Linux) can't be reproduced here, say so up front.
+- Do not ask for a generic environment/log checklist before trying the flow and inspecting the code.
+  Record the attempt and result; ask only for a fact that actually blocks the next diagnostic step.
+  Missing fields, limited time, or unavailable automation are not by themselves reasons to ask the reporter.
+- Treat a maintainer-confirmed bug as an investigation task even if local reproduction fails. Distinguish
+  “not reproduced here” from “not a bug”, and do not require the reporter to prove its existence again.
+
+## 2. Name the root cause as a class
+
+Write one sentence of the form "<mechanism> is missing/wrong, so any <X> hits it",
+not "<this button> is broken". Typical classes in this codebase:
+
+- Per-language config handled for one language only (`languages/*.toml`, `ide-sdk`).
+- Platform gaps: paths, executables, shells, `.cmd`/`.exe`, separators — macOS-only code.
+- Toolchain/version discovery: one probe location, no version check, no rescan.
+- Two features each implementing half a flow and never joined (feature isolation →
+  should go through an action/service).
+- State not reset on project switch / window reuse; events not scoped per window.
+- Failure surfaced as raw stderr/stack trace or retried until "crashed" instead of a
+  clear status with an action.
+- UI: same primitive styled differently in N places.
+
+## 3. Sweep for siblings
+
+Search systematically, not by memory:
+
+- Same pattern elsewhere: `git grep` the function, the config key, the error string,
+  the hard-coded path/flag. Check every `languages/*.toml` entry and every platform branch.
+- Same flow for other languages/runtimes (Java ↔ Kotlin/Gradle, Python ↔ venv/uv,
+  Node ↔ Deno/Bun, Go, Rust …): would they fail the same way?
+- Other callers/entry points of the same flow (menu, context menu, gutter, shortcut, CLI arg).
+- Neighbouring failure modes of the same mechanism (not installed / wrong version /
+  installed but crashes / slow start / installed mid-session).
+  For broad sweeps spawn one Explore agent with the class description, not the instance.
+
+## 4. Decide the fix at the right altitude
+
+- Fix the mechanism once (shared helper, action, config hook) so siblings are fixed
+  by construction; don't patch each call site.
+- Respect `AGENTS.md` rules (crate boundaries, no cross-feature imports, `IdeResult`,
+  UTF-16). If the right fix breaks a rule, pick the rule-respecting design and say why.
+- Compare with how established IDEs solve it when relevant; prefer the established answer.
+- Present: root cause, sibling table, proposed fix, what's deferred. When the user leaves
+  the choice to you, go ahead without asking again.
+
+## 5. Implement and test the class
+
+- Tests cover the class: table-driven over languages/platforms/states, not just the
+  reported input. Include the reporter's case verbatim.
+- Run the scoped checks (`pnpm vitest run <path>`, `cargo nextest run -p <crate>`), then
+  `/verify` in the app for UI or runtime behaviour.
+
+## 6. PR
+
+- One branch `fix/<slug>`, one PR unless the user asks otherwise; `Fixes #<n>` in the body.
+- Don't stage untracked IDE-state dirs (`.ideal/`, `.openidea/`) or screenshots.
+- PR body follows `.github/pull_request_template.md`: `Closes #<n>`, then
+  **What and why** (user-visible change + root cause at class level, 2–4 sentences),
+  **How it was verified** (commands run and results, siblings fixed/deferred, what could break and how
+  it was checked, what was not verified, e.g. "Windows not tested"; for UI changes the before/after
+  screenshot paths from `/verify`), **Review focus** (optional). Short and plain.
+
+## Report format
+
+Reply in the user's language:
+
+```
+Root cause: <one sentence, class level>
+Sibling sweep:
+| Location / case | Affected? | Action |
+Fixed / not covered (why) / not verified (platform)
+PR: <url>
+```

.agents/skills/verify/SKILL.md

@@ -0,0 +1,57 @@
+---
+name: verify
+description: Build, launch and drive the OpenIDEA desktop app through the Tauri MCP bridge to verify a change at runtime.
+---
+
+# Verify OpenIDEA in the running app
+
+## Launch
+
+- Run the app from the worktree that holds the change: `pnpm tauri dev` in the background, logging
+  into your task's scratch subdirectory. Use `pnpm dev:app` instead when your checks call
+  `window.__TAURI__` from `execute_js`. The wrapper gives each worktree its own app identity, data,
+  settings and Vite port, so other worktrees and the installed app don't interfere. If it reports a
+  session already running for this worktree, reuse that one.
+- Once the app is up, `pnpm dev:status` lists this worktree's MCP bridges. Pass the reported
+  `appIdentifier` (the port) on every `mcp__tauri__*` call. The MCP server is shared between
+  sessions: never `driver_session stop` without an `appIdentifier`, and re-check `document.title` /
+  `location.href` before acting if anything looks off.
+- Make sure the binary contains the change: a session already running for this worktree may be an
+  older build. Restart it after Rust changes; frontend changes reload through Vite.
+- After the app restarts, `driver_session start` again for your port (a stale session says "Already connected").
+- If the `pnpm tauri dev` process exits while the app window stays open, Vite is gone and any webview
+  reload shows an empty `#root`. Stop that app and start the session again.
+- Stop everything you started when done and nothing else; never use process-name kills.
+
+## Driving
+
+- `manage_window focus` before screenshots / timing-sensitive steps: a background window throttles timers
+  (debounced LSP / VCS refreshes stall, `setTimeout` promises in `execute_js` time out) and native
+  screenshots come back black.
+- Settings is a separate native window `settings-main`; pass `windowId`, focus it before screenshotting.
+- CodeMirror / xterm ignore MCP `type`. Focus the element, then `document.execCommand('insertText', false, text)`.
+  For xterm Enter, dispatch a `keydown` (`key: 'Enter', keyCode: 13`) on `.xterm-helper-textarea`.
+- MCP clicks arrive with `event.detail === 0`; CodeMirror treats them as line-select clicks. Set the caret
+  through the view instead: `document.querySelector('.cm-content').cmTile.view`.
+- MCP `text` strategy can resolve to a hidden node; prefer coordinates (CSS px = image px × 0.9) or CSS selectors.
+- CSS-module edits often trigger a full page reload in dev: dialogs close, Run sessions and terminal
+  scrollback reset, and each reload spawns a fresh shell. Re-open what you were testing.
+
+## Evidence
+
+- For UI or interaction changes, capture `before.png` (on `main` or with the fix reverted) and
+  `after.png` at the same state and window size, into your task's scratch subdirectory. Multi-step
+  flows: a numbered series (`after-1.png`, `after-2.png`, ...).
+- Report the absolute paths; they go into the PR's **How it was verified** section and the triage
+  acceptance entry. Never commit screenshots to the feature branch.
+
+## Fixture
+
+`fixtures/` has sample projects (go-app, rust-app, ts-app, kotlin-gradle, polyglot). Copy one into
+your scratch directory before editing it, and don't commit the IDE state it creates (`.openidea/`).
+
+## Flows worth driving
+
+⌘⇧O Goto File · ⌘⇧F Find in Files (preview scroll + highlight) · ⌘⇧A Find Action · editor edit/undo/autosave ·
+Terminal (Unicode, venv) · Commit view at the default narrow width · Problems · Run → Stop · Project view
+New / Delete (nested `a/b.txt` names) · ⌘, Settings search (+ Keymap filter) · Git Log on a repo without commits.

.claude/skills/issue-fix

@@ -0,0 +1 @@
+../../.agents/skills/issue-fix

.claude/skills/verify

@@ -0,0 +1 @@
+../../.agents/skills/verify

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,75 @@
+name: Bug report
+description: Something in OpenIDEA doesn't work as expected
+labels: [bug]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for reporting! Keep logs and error messages exactly as they appear.
+
+        One problem per issue, please. If you have several, open one issue for each.
+  - type: checkboxes
+    id: checks
+    attributes:
+      label: Before you start
+      options:
+        - label: I searched [existing issues](https://github.com/l0ng-ai/openidea/issues?q=is%3Aissue) and this hasn't been reported yet.
+          required: true
+        - label: I'm on the [latest release](https://github.com/l0ng-ai/openidea/releases/latest), or I noted below that I can't update.
+          required: true
+  - type: textarea
+    id: environment
+    attributes:
+      label: Environment
+      description: |
+        Open **About OpenIDEA** (macOS: OpenIDEA menu; Windows/Linux: Help menu), click **Copy Info**, and paste it here. Also mention the project type if it matters (e.g. Gradle multi-module, Spring Boot, Go workspace) and whether you use remote development.
+      render: text
+      placeholder: |
+        About OpenIDEA
+        Version: 0.1.33
+        Build: ...
+        Platform: macOS aarch64
+    validations:
+      required: true
+  - type: textarea
+    id: steps
+    attributes:
+      label: Steps to reproduce
+      description: Start from opening OpenIDEA or a project. A small sample project or snippet helps a lot.
+      placeholder: |
+        1. Open a Gradle project whose settings.gradle includes modules in a loop
+        2. Open the Gradle tool window
+        3. ...
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Minimal reproduction
+      description: A link to a small public repository, or the smallest files/snippet that trigger the problem. Optional, but it's the fastest way to get a fix.
+      placeholder: https://github.com/you/repro-project
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected behavior
+    validations:
+      required: true
+  - type: textarea
+    id: actual
+    attributes:
+      label: Actual behavior
+      description: What happened instead. Screenshots or a recording are welcome.
+    validations:
+      required: true
+  - type: textarea
+    id: logs
+    attributes:
+      label: Logs
+      description: |
+        Use **Help → Show Log in Finder / Explorer / Files** to find `openidea.log` and paste the lines around the problem, or attach the file. Include console output or error messages too. Check for tokens or passwords before posting.
+      render: text
+  - type: textarea
+    id: extra
+    attributes:
+      label: Additional context
+      description: Anything else, such as whether it worked in an earlier version.

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Download the latest release
+    url: https://github.com/l0ng-ai/openidea/releases/latest
+    about: Many problems are already fixed. Please check the latest version before reporting.

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,48 @@
+name: Feature request
+description: Suggest a new feature or an improvement
+labels: [enhancement]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        One request per issue, please.
+  - type: checkboxes
+    id: checks
+    attributes:
+      label: Before you start
+      options:
+        - label: I searched [existing issues](https://github.com/l0ng-ai/openidea/issues?q=is%3Aissue) and this hasn't been requested yet.
+          required: true
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem
+      description: What are you trying to do, and what gets in the way today?
+    validations:
+      required: true
+  - type: textarea
+    id: proposal
+    attributes:
+      label: Proposed solution
+      description: How you'd like it to work. Mockups or examples from other tools are welcome.
+    validations:
+      required: true
+  - type: textarea
+    id: acceptance
+    attributes:
+      label: Acceptance criteria
+      description: How we'll know it's done. One observable behavior per line.
+      placeholder: |
+        - [ ] Right-clicking a test class shows "Run with Coverage"
+        - [ ] Coverage results open in the Coverage tool window
+    validations:
+      required: true
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives and workarounds
+      description: Other approaches you considered, or what you do now instead.
+  - type: textarea
+    id: extra
+    attributes:
+      label: Additional context

.github/pull_request_template.md

@@ -0,0 +1,17 @@
+Closes #
+
+## What and why
+
+<!-- 2–4 sentences: the change a user notices, and the root cause.
+     If it doesn't fit, the PR is probably too big; split it. -->
+
+## How it was verified
+
+<!-- Required. Commands you actually ran and their results; what else this could
+     affect and how you checked it still works.
+     UI changes: before/after screenshots. Multi-step interactions: a recording.
+     Backend changes: logs or command output. -->
+
+## Review focus
+
+<!-- Optional: anything you want reviewers to look at closely. -->

.github/workflows/ci.yml

@@ -71,6 +71,57 @@ jobs:
       - run: cargo build --locked -p ide-host --bin openidea-server --target x86_64-unknown-linux-musl
       - run: target/x86_64-unknown-linux-musl/debug/openidea-server --version
 
+  # The plugin SDK, the official plugins and the test fixtures build in their
+  # own workspaces (the root excludes them), so the jobs above don't see them.
+  plugins:
+    name: Plugins (SDK, official, fixtures)
+    runs-on: ubuntu-22.04
+    env:
+      CARGO_TARGET_DIR: ${{ github.workspace }}/target-plugins
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with: { targets: wasm32-wasip2, components: "clippy, rustfmt" }
+      - uses: Swatinem/rust-cache@v2
+        with:
+          key: plugins
+          cache-directories: target-plugins
+          save-if: ${{ github.ref == 'refs/heads/main' }}
+      - name: Format, lint (host and wasm) and test each crate
+        shell: bash
+        run: |
+          set -euo pipefail
+          for dir in sdk/rust/openidea-plugin plugins/official/*/ crates/ide-plugin/tests/fixtures/*/; do
+            [ -f "$dir/Cargo.toml" ] || continue
+            echo "::group::$dir"
+            cargo fmt --check --manifest-path "$dir/Cargo.toml"
+            cargo clippy --locked --all-targets --manifest-path "$dir/Cargo.toml" -- -D warnings
+            cargo clippy --locked --target wasm32-wasip2 --manifest-path "$dir/Cargo.toml" -- -D warnings
+            cargo test --locked --manifest-path "$dir/Cargo.toml"
+            echo "::endgroup::"
+          done
+      - uses: pnpm/action-setup@v4
+        with: { version: 11 }
+      - uses: actions/setup-node@v4
+        with: { node-version: 22 }
+      # Plugin web pages (`web-src/`, their own pnpm projects): typecheck and test.
+      - name: Web pages typecheck and test
+        shell: bash
+        run: |
+          set -euo pipefail
+          for dir in plugins/official/*/web-src/; do
+            [ -f "$dir/package.json" ] || continue
+            echo "::group::$dir"
+            pnpm --dir "$dir" install --frozen-lockfile --ignore-workspace
+            pnpm --dir "$dir" exec tsc --noEmit
+            pnpm --dir "$dir" test
+            echo "::endgroup::"
+          done
+      # The host's tests run the checked-in components: they must be built from these sources.
+      # Web pages aren't checked in: this builds them and checks the result.
+      - name: Checked-in components are up to date, web pages build
+        run: plugins/build.sh --check
+
   deny:
     name: Cargo deny
     runs-on: ubuntu-latest

.github/workflows/pr-check.yml

@@ -0,0 +1,69 @@
+name: PR check
+on:
+  # pull_request_target so the check can label PRs from forks. It never checks out
+  # or runs PR code: it only reads the PR title and description.
+  pull_request_target:
+    types: [opened, edited, reopened, ready_for_review]
+
+permissions:
+  issues: write
+  pull-requests: write
+
+concurrency:
+  group: pr-check-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  check:
+    if: github.event.pull_request.user.type != 'Bot' && !github.event.pull_request.draft
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/github-script@v7
+        with:
+          script: |
+            const pr = context.payload.pull_request;
+            const LABEL = 'needs-info';
+            const MARKER = '<!-- pr-check -->';
+            // Docs, CI and pure refactors may skip the linked issue.
+            const NO_ISSUE_TYPES = /^(docs|ci|build|chore|refactor|style|test)(\(.+\))?!?:/;
+
+            const body = (pr.body || '').replace(/<!--[\s\S]*?-->/g, '');
+            const problems = [];
+
+            const linksIssue =
+              /\b(close[sd]?|fix(e[sd])?|resolve[sd]?)\s*:?\s+(#\d+|https:\/\/github\.com\/[\w.-]+\/[\w.-]+\/issues\/\d+)/i.test(body);
+            if (!linksIssue && !NO_ISSUE_TYPES.test(pr.title)) {
+              problems.push('Link the issue this PR resolves, e.g. `Closes #123`.');
+            }
+
+            const verified = body.match(/^##+\s*How it was verified\s*$([\s\S]*?)(?=^##+\s|(?![\s\S]))/im);
+            if (!verified || !verified[1].trim()) {
+              problems.push('Fill in **How it was verified**: the commands you ran and their results. UI changes need before/after screenshots.');
+            }
+
+            const { owner, repo } = context.repo;
+            const issue_number = pr.number;
+            const comments = await github.paginate(github.rest.issues.listComments, { owner, repo, issue_number });
+            const existing = comments.find(c => c.user.type === 'Bot' && c.body.includes(MARKER));
+            const labeled = pr.labels.some(l => l.name === LABEL);
+
+            if (problems.length) {
+              const text = `${MARKER}\nThanks for the PR. Before review, please update the description (see [CONTRIBUTING.md](https://github.com/${owner}/${repo}/blob/main/CONTRIBUTING.md)):\n\n${problems.map(p => `- ${p}`).join('\n')}\n\nThis check reruns when you edit the description.`;
+              if (existing) {
+                await github.rest.issues.updateComment({ owner, repo, comment_id: existing.id, body: text });
+              } else {
+                await github.rest.issues.createComment({ owner, repo, issue_number, body: text });
+              }
+              if (!labeled) {
+                await github.rest.issues.addLabels({ owner, repo, issue_number, labels: [LABEL] });
+              }
+              return;
+            }
+
+            // Only undo what this check did: the label is cleared only when our comment exists.
+            if (existing) {
+              await github.rest.issues.deleteComment({ owner, repo, comment_id: existing.id });
+              if (labeled) {
+                await github.rest.issues.removeLabel({ owner, repo, issue_number, name: LABEL }).catch(() => {});
+              }
+            }

.github/workflows/release.yml

@@ -70,6 +70,12 @@ jobs:
           - name: Linux x64
             os: ubuntu-22.04
             target: x86_64-unknown-linux-gnu
+          - name: Linux arm64
+            os: ubuntu-22.04-arm
+            target: aarch64-unknown-linux-gnu
+          - name: Windows arm64
+            os: windows-11-arm
+            target: aarch64-pc-windows-msvc
           - name: Windows x64
             os: windows-latest
             target: x86_64-pc-windows-msvc
@@ -174,6 +180,69 @@ jobs:
           if command -v sha256sum >/dev/null; then sha256sum "$ASSET"; else shasum -a 256 "$ASSET"; fi > "$ASSET.sha256"
           gh release upload "$TAG" "$ASSET" "$ASSET.sha256" --clobber
 
+  # The official plugins, signed, and the marketplace index released apps read
+  # (releases/latest/download/plugins-index.json). They are not in the
+  # installers: users install them from Settings › Plugins. Without the
+  # signing key (secret PLUGIN_SIGNING_KEY: the file `openidea-plugin keygen`
+  # writes) nothing is published and the release goes on.
+  plugins:
+    needs: create-release
+    name: Official plugins
+    runs-on: ubuntu-22.04
+    env:
+      SIGNING_KEY: ${{ secrets.PLUGIN_SIGNING_KEY }}
+    steps:
+      - id: key
+        run: |
+          if [ -z "$SIGNING_KEY" ]; then
+            echo "::warning::PLUGIN_SIGNING_KEY is not set: the official plugins are not published"
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+          fi
+      - uses: actions/checkout@v4
+        if: steps.key.outputs.skip != 'true'
+        with: { ref: "${{ env.TAG }}" }
+      - uses: dtolnay/rust-toolchain@stable
+        if: steps.key.outputs.skip != 'true'
+        with: { targets: wasm32-wasip2 }
+      - uses: Swatinem/rust-cache@v2
+        if: steps.key.outputs.skip != 'true'
+        with: { key: release-plugins }
+      - uses: pnpm/action-setup@v4
+        if: steps.key.outputs.skip != 'true'
+        with: { version: 11 }
+      - uses: actions/setup-node@v4
+        if: steps.key.outputs.skip != 'true'
+        with: { node-version: 22 }
+      # Builds the web pages; fails when a checked-in component isn't built from these sources.
+      - name: Build
+        if: steps.key.outputs.skip != 'true'
+        run: |
+          plugins/build.sh --check
+          cargo build --release --locked -p ide-host --bin openidea-plugin
+      - name: Pack, index and upload
+        if: steps.key.outputs.skip != 'true'
+        shell: bash
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          tool="$PWD/target/release/openidea-plugin"
+          key="$RUNNER_TEMP/openidea.key"
+          out="$RUNNER_TEMP/market"
+          (umask 077 && printf '%s' "$SIGNING_KEY" > "$key")
+          trap 'rm -f "$key"' EXIT
+          mkdir -p "$out"
+          for dir in plugins/official/*/; do
+            id="$(sed -n 's/^id *= *"\(.*\)".*/\1/p' "$dir/plugin.toml" | head -1)"
+            version="$(sed -n 's/^version *= *"\(.*\)".*/\1/p' "$dir/plugin.toml" | head -1)"
+            "$tool" pack "$dir" --key "$key" --publisher openidea --out "$out/$id-$version.oiplugin"
+          done
+          # The published index's revocations and earlier keys carry over.
+          curl -fsSL "https://github.com/$GITHUB_REPOSITORY/releases/latest/download/plugins-index.json" \
+            -o "$out/plugins-index.json" || rm -f "$out/plugins-index.json"
+          "$tool" index "$out" --publisher openidea --name OpenIDEA --key "$key" --out "$out/plugins-index.json"
+          gh release upload "$TAG" "$out"/*.oiplugin "$out/plugins-index.json" --clobber
+
   # The updater manifest (latest.json), built once from the signed bundles every build uploaded.
   # Fails when a platform is missing, so a release never ships a manifest without it.
   updater-manifest:
@@ -196,11 +265,16 @@ jobs:
             }
             // Bundle suffix → updater platform keys, as tauri-action names them.
             const kinds = [
+              [/_aarch64\.AppImage$/, ["linux-aarch64", "linux-aarch64-appimage"]],
+              [/_arm64\.deb$/, ["linux-aarch64-deb"]],
+              [/\.aarch64\.rpm$/, ["linux-aarch64-rpm"]],
               [/_amd64\.AppImage$/, ["linux-x86_64", "linux-x86_64-appimage"]],
               [/_amd64\.deb$/, ["linux-x86_64-deb"]],
               [/\.x86_64\.rpm$/, ["linux-x86_64-rpm"]],
               [/_aarch64\.app\.tar\.gz$/, ["darwin-aarch64", "darwin-aarch64-app"]],
               [/_x64\.app\.tar\.gz$/, ["darwin-x86_64", "darwin-x86_64-app"]],
+              [/_arm64_en-US\.msi$/, ["windows-aarch64", "windows-aarch64-msi"]],
+              [/_arm64-setup\.exe$/, ["windows-aarch64-nsis"]],
               [/_x64_en-US\.msi$/, ["windows-x86_64", "windows-x86_64-msi"]],
               [/_x64-setup\.exe$/, ["windows-x86_64-nsis"]],
             ];
@@ -232,7 +306,7 @@ jobs:
             core.info(`latest.json: ${Object.keys(platforms).sort().join(", ")}`);
 
   publish:
-    needs: [create-release, build, server, updater-manifest]
+    needs: [create-release, build, server, plugins, updater-manifest]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/github-script@v7

.gitignore

@@ -10,6 +10,9 @@ lerna-debug.log*
 node_modules
 dist
 dist-ssr
+# Plugin components are checked in (plugins/build.sh --check keeps them current).
+!plugins/official/*/dist
+!crates/ide-plugin/tests/fixtures/*/dist
 *.local
 
 # Editor directories and files
@@ -30,9 +33,13 @@ target/
 test-results/
 playwright-report/
 
-# Local AI agent files
-CLAUDE.md
-.claude/
+# Local AI agent files. Shared skills live in .agents/skills; .claude/skills links to them.
+CLAUDE.local.md
+.claude/*
+!.claude/skills/
+.claude/skills/*
+!.claude/skills/verify
+!.claude/skills/issue-fix
 
 # Local reference screenshots
 pycharm-screenshots/

.oxfmtrc.json

@@ -10,10 +10,13 @@
     "target",
     "src/bindings.ts",
     "src/editor/core/cm/angular/parser*.ts",
+    "src/editor/core/cm/jsp/parser*.ts",
     "docs/plugins/themes.md",
     "pnpm-lock.yaml",
     "**/*.toml",
     "fixtures",
+    "plugins/*/web",
+    "plugins/official/*/web",
     "crates/**/tests/fixtures"
   ],
   "overrides": [

AGENTS.md

@@ -0,0 +1,118 @@
+# OpenIDEA — contributor guide
+
+Rust + Tauri 2 desktop IDE with full-featured, multi-language code intelligence.
+Visual style: dark, low-contrast greys, one cool accent
+(`src/styles/tokens.css` is the source of truth for colours and metrics).
+
+## Layout
+
+- `crates/ide-*` — backend crates; one domain each. Depend on `ide-core` for shared
+  types; never reach into another crate's internals.
+- `src-tauri/` — glue only: `state.rs` (AppState / Project), `commands/<domain>.rs`
+  (thin typed IPC adapters), `events.rs`. No domain logic here.
+- `src/bindings.ts` — generated by tauri-specta (`pnpm gen:bindings`). Never edit.
+- `src/platform/` — ipc (`call`, `onIdeEvent`, `nextRequestId`), actions registry,
+  keymap + dispatcher, context keys / `when` clauses, project store.
+- `src/workbench/contributions.ts` — extension points (tool windows, status items,
+  overlays, editor kinds) and cross-feature services (editor, tool windows, notifications).
+- `src/ui/` — design-system primitives. `src/features/<name>/` — one feature each,
+  exporting `activate()` registered in `src/features/index.ts`.
+- `languages/<id>.toml` — language definitions (detection, comments, LSP, DAP).
+- `crates/ide-host` — the `openidea-server` binary for remote development.
+- `wit/` — plugin interface definitions; `plugins/` — sample and bundled plugins;
+  `templates/` — plugin starter templates.
+- `e2e/` — Playwright UI tests (`pnpm e2e`). `fixtures/` — sample projects per language
+  for manual and automated testing.
+
+## Rules
+
+- IPC coordinates: 0-based lines, **UTF-16** columns/offsets everywhere (`ide-core::text`).
+- Every command returns `IdeResult<T>`; convert internal errors at the crate edge.
+- Streaming → `tauri::ipc::Channel<T>`; cancellable → UI-allocated `RequestId` +
+  `cancel_request`. Backend → UI notifications → `IdeEvent` via `EventSink`.
+- Long work never blocks the UI thread or a Tauri command thread: use
+  `spawn_blocking`/rayon, honour `CancellationToken`.
+- Frontend features never import each other; communicate via actions, contributions
+  and services. All user-invocable behaviour is an action with a stable id; default
+  shortcuts live in `src/platform/keymaps/`.
+- Styling: CSS Modules + tokens only (no hex literals in components). Inline SVG
+  icons from `src/ui/icons.tsx`, never emoji. Real `<button>`/`<input>`; `aria-label` on icon buttons.
+- User-visible text goes through the text catalog: add every new string to both
+  `src/platform/locales/text/en.json` and `zh.json` (`textCatalog.test.ts` enforces it).
+- Keep comments sparse and purposeful; match surrounding style.
+- For GUI verification, prefer Tauri MCP; use Computer Use only when Tauri MCP is
+  unavailable or cannot cover the required checks.
+
+## Issues & PRs
+
+Follow `CONTRIBUTING.md` and `.github/pull_request_template.md`: one issue per PR with
+`Closes #<n>`, reproduce first, keep the diff focused, short plain description, and a
+**How it was verified** section with commands run, results and (for UI) before/after screenshots.
+Unclear product decisions → `needs-decision` and stop.
+
+## Skills
+
+Shared agent skills live in `.agents/skills/` (`.claude/skills/` links to them):
+`verify` drives the running app through Tauri MCP and captures screenshot evidence;
+`issue-fix` takes an issue from reproduction to one PR.
+
+## Commands
+
+- `pnpm tauri dev` — run the app with worktree isolation (Node 22.18+).
+  `pnpm dev:app` also enables the global Tauri API. `pnpm dev:status` reports
+  this worktree's running MCP bridges and actual ports.
+- `pnpm build` — typecheck + bundle frontend.
+- `cargo nextest run --workspace` (or `cargo test`), `cargo clippy --workspace --all-targets -- -D warnings`, `cargo fmt --all`.
+- `pnpm test`, `pnpm e2e`, `pnpm lint`, `pnpm format:check`, `pnpm knip`, `pnpm typecheck`,
+  `pnpm gen:bindings`.
+- `pnpm perf` (UI interaction latency / frames / leaks), `pnpm perf:rust` (criterion
+  benches vs budgets). Budgets: `perf/budgets.json`.
+
+## Before opening a PR
+
+Run what CI runs for the parts you touched:
+
+- Rust: `cargo fmt --all --check`, `cargo clippy --workspace --all-targets -- -D warnings`,
+  `cargo nextest run --workspace`. After changing IPC types, run `pnpm gen:bindings` and
+  commit `src/bindings.ts`; CI fails if it differs.
+- Frontend: `pnpm typecheck`, `pnpm lint`, `pnpm format:check`, `pnpm knip`, `pnpm test`,
+  `pnpm build`, and `pnpm e2e` for UI flows.
+- UI or runtime behaviour: verify in the running app (`.agents/skills/verify`).
+
+## Pitfalls
+
+- Run a subset of frontend tests with `pnpm vitest run <path>`. `pnpm test -- <path>` ignores
+  the filter and runs the whole suite, which takes several minutes.
+- Don't run clippy while iterating: `pnpm tauri dev` compiles anyway. Run
+  `cargo fmt --all` + `cargo clippy -p <crate> --all-targets -- -D warnings` once, right
+  before committing. A cold build cache can take around 5 minutes. Run long checks one at
+  a time, not chained in one shell call that may hit the 10-minute tool timeout.
+- `pnpm tauri dev` does a full debug build. Clippy only checks the code, so a passing clippy
+  doesn't make the first launch fast.
+
+## Parallel worktrees
+
+Several worktrees can be developed and run side by side.
+
+- Create one per task: `git worktree add ../<name> -b <branch> origin/main`, then
+  `pnpm install` in it.
+- Launch with `pnpm tauri dev` / `pnpm dev:app`, not the raw `pnpm exec tauri dev` CLI. The
+  wrapper starts Vite on a worktree-derived port (advancing if occupied), passes its actual
+  URL to Tauri, and reports an existing launcher instead of starting another for the same
+  worktree. HMR uses the Vite port.
+- Debug app identity, data, settings, logs and single-instance scope follow the canonical
+  worktree path captured at build time, independent of launch cwd. Launching the same debug
+  binary again focuses its existing instance and forwards its path argument. Different
+  worktrees and the installed release can coexist. `--release` uses normal release identity
+  and bypasses the development wrapper.
+- MCP bridge ports are dynamic (9223–9322). Use `pnpm dev:status`, connect to the reported
+  port, verify identifier/cwd, and pass `appIdentifier: <port>` explicitly. Do not assume the
+  default MCP session belongs to this worktree.
+- Keep each worktree's Cargo output directory separate; do not point `CARGO_TARGET_DIR` or
+  `target` symlinks at a shared directory.
+- Each worktree's first build is cold (around 5 minutes) and its Cargo output takes
+  15–30 GB. Avoid running several heavy builds on one machine at the same time.
+- Stop only processes started for the current worktree/session. Never use broad
+  process-name kills such as `pkill openidea`.
+- When done: stop that worktree's app and dev session, delete its build output, then
+  `git worktree remove ../<name>`.

CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

CONTRIBUTING.md

@@ -0,0 +1,35 @@
+# Contributing to OpenIDEA
+
+These rules apply to everyone, and to any coding agent working on their behalf.
+Project layout, coding rules, commands and checks are in [AGENTS.md](AGENTS.md).
+
+## Issues
+
+- One problem or request per issue. Use the issue forms.
+- Bugs: steps that reproduce the problem from a fresh start. A minimal sample
+  project is the fastest way to get a fix.
+- Features: state the problem and the acceptance criteria. A feature is ready to
+  build once a maintainer labels it `planned`.
+- Labels track status: `needs-info` waits on the reporter, `needs-decision` waits
+  on a maintainer, `planned` is accepted, `needs-acceptance` has a fix waiting to be
+  checked.
+
+## Pull requests
+
+- One issue per PR, linked with `Closes #123`. Feature PRs need a `planned` issue.
+  Docs, CI and pure refactors may skip the issue.
+- Reproduce the problem first, or write a test that fails before the fix.
+- Fix the cause, and check whether the same cause breaks anything nearby.
+- Keep the diff focused. Unrelated refactors go in their own PR.
+- Title: [Conventional Commits](https://www.conventionalcommits.org/), e.g.
+  `fix(editor): keep the caret visible after folding`.
+- Fill in the template. Keep the description short and in plain words. If it
+  doesn't fit in a few sentences, the PR is probably too big.
+- **How it was verified** is required: the commands you ran and their results,
+  and what else the change could affect. UI changes need before/after screenshots;
+  multi-step interactions need a recording.
+- If a change needs a product decision you can't make, ask in the issue and stop
+  rather than guessing.
+
+A check on each PR adds `needs-info` when the issue link or the verification
+section is missing, and removes it once they're filled in.

Cargo.lock

@@ -4038,7 +4038,7 @@ checksum = "3d3067d79b975e8844ca9eb072e16b31c3c1c36928edf9c6789548c524d0d954"
 
 [[package]]
 name = "ide-agent"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4061,7 +4061,7 @@ dependencies = [
 
 [[package]]
 name = "ide-analysis"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ast-grep-core",
  "ide-core",
@@ -4075,22 +4075,22 @@ dependencies = [
 
 [[package]]
 name = "ide-build"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "dirs 6.0.0",
  "dunce",
  "ide-core",
- "libc",
  "serde",
  "serde_json",
  "specta",
  "tempfile",
  "tracing",
+ "zip",
 ]
 
 [[package]]
 name = "ide-clipboard"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "objc2 0.6.5",
  "objc2-app-kit 0.3.2",
@@ -4099,10 +4099,11 @@ dependencies = [
 
 [[package]]
 name = "ide-core"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "dunce",
  "encoding_rs",
+ "libc",
  "serde",
  "serde_json",
  "specta",
@@ -4115,7 +4116,7 @@ dependencies = [
 
 [[package]]
 name = "ide-coverage"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
  "ide-run",
@@ -4129,7 +4130,7 @@ dependencies = [
 
 [[package]]
 name = "ide-dap"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
  "ide-jsonrpc",
@@ -4147,7 +4148,7 @@ dependencies = [
 
 [[package]]
 name = "ide-db"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "bb8",
  "dirs 6.0.0",
@@ -4169,10 +4170,9 @@ dependencies = [
 
 [[package]]
 name = "ide-docker"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
- "libc",
  "serde",
  "serde_json",
  "specta",
@@ -4181,24 +4181,44 @@ dependencies = [
  "which",
 ]
 
+[[package]]
+name = "ide-extension"
+version = "0.1.35"
+dependencies = [
+ "base64 0.22.1",
+ "blake3",
+ "ed25519-dalek",
+ "ide-core",
+ "parking_lot",
+ "semver",
+ "serde",
+ "serde_json",
+ "specta",
+ "specta-typescript",
+ "tempfile",
+ "toml 0.9.12+spec-1.1.0",
+ "tracing",
+ "zip",
+]
+
 [[package]]
 name = "ide-fonts"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "objc2-core-foundation",
  "objc2-core-text",
  "serde",
+ "serde_json",
  "specta",
  "windows",
 ]
 
 [[package]]
 name = "ide-github"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
  "ide-vcs",
- "libc",
  "serde",
  "serde_json",
  "specta",
@@ -4208,11 +4228,15 @@ dependencies = [
 
 [[package]]
 name = "ide-host"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
+ "base64 0.22.1",
+ "criterion",
  "dirs 6.0.0",
  "dunce",
  "encoding_rs",
+ "getrandom 0.3.4",
+ "globset",
  "ide-agent",
  "ide-analysis",
  "ide-build",
@@ -4220,12 +4244,14 @@ dependencies = [
  "ide-coverage",
  "ide-dap",
  "ide-db",
+ "ide-extension",
  "ide-http",
  "ide-index",
  "ide-jsonrpc",
  "ide-language",
  "ide-lsp",
  "ide-notebook",
+ "ide-plugin",
  "ide-remote",
  "ide-run",
  "ide-sdk",
@@ -4239,21 +4265,27 @@ dependencies = [
  "ide-vcs",
  "ide-vfs",
  "ide-workspace",
+ "ignore",
  "parking_lot",
+ "reqwest",
+ "rustix",
  "serde",
  "serde_json",
  "specta",
  "specta-typescript",
  "tempfile",
  "tokio",
+ "toml 0.9.12+spec-1.1.0",
  "tracing",
  "tracing-subscriber",
  "uuid",
+ "windows-sys 0.61.2",
+ "zip",
 ]
 
 [[package]]
 name = "ide-http"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
  "parking_lot",
@@ -4271,7 +4303,7 @@ dependencies = [
 
 [[package]]
 name = "ide-index"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "blake3",
  "criterion",
@@ -4293,7 +4325,7 @@ dependencies = [
 
 [[package]]
 name = "ide-jsonrpc"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "encoding_rs",
  "futures",
@@ -4309,11 +4341,12 @@ dependencies = [
 
 [[package]]
 name = "ide-language"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "blake3",
  "criterion",
  "ide-core",
+ "ide-extension",
  "ide-text",
  "parking_lot",
  "regex-lite",
@@ -4364,14 +4397,17 @@ dependencies = [
 
 [[package]]
 name = "ide-lsp"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
+ "dunce",
  "futures",
  "globset",
  "ide-core",
  "ide-jsonrpc",
  "ide-language",
  "ide-text",
+ "ide-vfs",
+ "ignore",
  "lsp-types",
  "parking_lot",
  "percent-encoding",
@@ -4382,11 +4418,12 @@ dependencies = [
  "tokio",
  "toml 0.9.12+spec-1.1.0",
  "tracing",
+ "zip",
 ]
 
 [[package]]
 name = "ide-notebook"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "futures",
  "ide-core",
@@ -4409,17 +4446,19 @@ dependencies = [
 
 [[package]]
 name = "ide-plugin"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
+ "blake3",
  "ide-core",
- "ide-language",
+ "ide-extension",
  "parking_lot",
+ "semver",
  "serde",
  "serde_json",
  "specta",
  "tempfile",
  "thiserror 2.0.21",
- "toml 0.9.12+spec-1.1.0",
+ "tokio",
  "tracing",
  "wasmtime",
  "wasmtime-wasi",
@@ -4427,7 +4466,7 @@ dependencies = [
 
 [[package]]
 name = "ide-profiler"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
  "ide-run",
@@ -4440,7 +4479,7 @@ dependencies = [
 
 [[package]]
 name = "ide-remote"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "globset",
  "ide-core",
@@ -4457,9 +4496,11 @@ dependencies = [
 
 [[package]]
 name = "ide-run"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
+ "dunce",
  "encoding_rs",
+ "ide-build",
  "ide-core",
  "libc",
  "parking_lot",
@@ -4478,7 +4519,7 @@ dependencies = [
 
 [[package]]
 name = "ide-sdk"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "dunce",
  "ide-core",
@@ -4497,7 +4538,7 @@ dependencies = [
 
 [[package]]
 name = "ide-search"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "criterion",
  "globset",
@@ -4517,7 +4558,7 @@ dependencies = [
 
 [[package]]
 name = "ide-spell"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
  "parking_lot",
@@ -4530,7 +4571,7 @@ dependencies = [
 
 [[package]]
 name = "ide-ssh"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "dirs 6.0.0",
  "flate2",
@@ -4549,7 +4590,7 @@ dependencies = [
 
 [[package]]
 name = "ide-syntax"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
  "ide-language",
@@ -4564,7 +4605,7 @@ dependencies = [
 
 [[package]]
 name = "ide-terminal"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
  "libc",
@@ -4577,7 +4618,7 @@ dependencies = [
 
 [[package]]
 name = "ide-text"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "criterion",
  "ide-core",
@@ -4589,7 +4630,7 @@ dependencies = [
 
 [[package]]
 name = "ide-tools"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "flate2",
  "hex",
@@ -4610,7 +4651,7 @@ dependencies = [
 
 [[package]]
 name = "ide-vcs"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4629,7 +4670,7 @@ dependencies = [
 
 [[package]]
 name = "ide-vfs"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "chardetng",
  "dunce",
@@ -4651,7 +4692,7 @@ dependencies = [
 
 [[package]]
 name = "ide-web"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "ide-core",
  "open",
@@ -4667,7 +4708,7 @@ dependencies = [
 
 [[package]]
 name = "ide-workspace"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
  "blake3",
  "dunce",
@@ -4677,6 +4718,7 @@ dependencies = [
  "ide-text",
  "ide-vfs",
  "parking_lot",
+ "semver",
  "serde",
  "serde_json",
  "specta",
@@ -5802,6 +5844,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2a180dd8642fa45cdb7dd721cd4c11b1cadd4929ce112ebd8b9f5803cc79d536"
 dependencies = [
  "bitflags 2.13.2",
+ "block2 0.6.2",
  "dispatch2",
  "objc2 0.6.5",
 ]
@@ -6137,11 +6180,14 @@ dependencies = [
 
 [[package]]
 name = "openidea"
-version = "0.1.28"
+version = "0.1.35"
 dependencies = [
+ "base64 0.22.1",
  "blake3",
+ "block2 0.6.2",
  "dirs 6.0.0",
  "dunce",
+ "gtk",
  "ide-agent",
  "ide-analysis",
  "ide-build",
@@ -6151,6 +6197,7 @@ dependencies = [
  "ide-dap",
  "ide-db",
  "ide-docker",
+ "ide-extension",
  "ide-fonts",
  "ide-github",
  "ide-host",
@@ -6176,7 +6223,14 @@ dependencies = [
  "ide-vfs",
  "ide-web",
  "ide-workspace",
+ "objc2 0.6.5",
+ "objc2-app-kit 0.3.2",
+ "objc2-core-foundation",
+ "objc2-foundation 0.3.2",
+ "objc2-web-kit 0.3.2",
  "parking_lot",
+ "percent-encoding",
+ "security-framework",
  "serde",
  "serde_json",
  "specta",
@@ -6194,6 +6248,7 @@ dependencies = [
  "tracing",
  "tracing-appender",
  "tracing-subscriber",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]

Cargo.toml

@@ -1,9 +1,11 @@
 [workspace]
 resolver = "3"
 members = ["crates/*", "src-tauri"]
+# Plugins and the guest SDK build for wasm32-wasip2 in their own workspaces.
+exclude = ["sdk", "plugins"]
 
 [workspace.package]
-version = "0.1.28"
+version = "0.1.35"
 edition = "2024"
 rust-version = "1.96"
 license = "Apache-2.0"
@@ -41,6 +43,8 @@ ide-ssh = { path = "crates/ide-ssh" }
 ide-remote = { path = "crates/ide-remote" }
 ide-host = { path = "crates/ide-host" }
 ide-notebook = { path = "crates/ide-notebook" }
+ide-extension = { path = "crates/ide-extension" }
+ide-plugin = { path = "crates/ide-plugin" }
 
 # serialization & IPC typing
 serde = { version = "1", features = ["derive"] }
@@ -69,6 +73,7 @@ ropey = "1.6"
 encoding_rs = "0.8"
 chardetng = "0.1"
 ignore = "0.4"
+base64 = "0.22"
 globset = "0.4"
 notify = "8"
 notify-debouncer-full = "0.6"

README.md

@@ -14,8 +14,6 @@
    · 
   <a href="#benchmark">Benchmark</a>
   &nbsp;·&nbsp;
-  <a href="#build">Build</a>
-  &nbsp;·&nbsp;
   <a href="https://discord.gg/2Zy4yn7gP">Discord</a>
 </p>
 
@@ -47,24 +45,6 @@ IDEA analyses Python more deeply, so "ready" doesn't mean the same work on
 both sides. Both are measured from the outside, the same way: see
 [`perf/compare`](perf/compare) to run it on your machine and projects.
 
-## Build
-
-```sh
-pnpm install
-pnpm tauri dev
-```
-
-Rust 1.96, Node 22, pnpm and the [Tauri prerequisites](https://v2.tauri.app/start/prerequisites/).
-
-Native notebook execution tests are opt-in and need two distinct Python environments
-with `ipykernel` installed:
-
-```sh
-OPENIDEA_TEST_PYTHON=/first/env/bin/python \
-OPENIDEA_TEST_PYTHON_SECOND=/second/env/bin/python \
-cargo test -p ide-notebook --test kernel_runtime -- --ignored --test-threads=1
-```
-
 ## License
 
 [Apache 2.0](LICENSE). Bundled third-party assets are listed in [`THIRD_PARTY_LICENSES.md`](THIRD_PARTY_LICENSES.md).

THIRD_PARTY_LICENSES.md

@@ -1,5 +1,14 @@
 # Third-party licenses
 
+## Project Lombok
+
+`plugins/lombok/lombok-1.18.48-openidea.2.jar` contains Project Lombok v1.18.48 with the Equinox
+classloader fix from [projectlombok/lombok#4059](https://github.com/projectlombok/lombok/pull/4059)
+and the ECJ constructor-call fix from [projectlombok/lombok#4089](https://github.com/projectlombok/lombok/pull/4089).
+Copyright (C) 2009-2021 The Project Lombok Authors. MIT license and bundled component
+notices are retained in [plugins/lombok/LICENSE](plugins/lombok/LICENSE) and inside the jar.
+Source tag, patch commits and build instructions: [plugins/lombok/README.md](plugins/lombok/README.md).
+
 ## JetBrains IntelliJ Platform icons
 
 `src/ui/expui/**` contains SVG icons from the IntelliJ Platform "new UI" (expui)
@@ -12,12 +21,13 @@ icon set, copied unmodified (some renamed) from JetBrains' open-source repositor
   `python/python-requirements` (`fileTypes/requirements`); `python/pipenv`
   (`fileTypes/pipenv`); `python/python-pyproject` (`expui/toml.svg` →
   `fileTypes/pyprojectToml`); `plugins/kotlin/base` (`fileTypes/kotlin`,
-  `kotlinScript`, `kotlinGradleScript`); `java/openapi` (`fileTypes/maven`);
+  `kotlinScript`, `kotlinGradleScript`, `icons/expui/objectKotlin` → `kotlin/objectKotlin`); `java/openapi` (`fileTypes/maven`);
   `plugins/markdown` (`fileTypes/markdown`); `plugins/toml` (`fileTypes/toml`);
   `plugins/terminal` (`toolwindows/terminal`); `plugins/maven`
   (`images/expui/toolwindow/maven` → `toolwindows/maven`, `images/expui/build/maven*`
   → `maven/`); `plugins/gradle` (`icons/expui/gradle` → `toolwindows/gradle`,
-  `icons/expui/gradleLoadChanges` → `build/gradleLoadChanges`);
+  `icons/expui/gradleLoadChanges` → `build/gradleLoadChanges`,
+  `icons/expui/gradle`, `icons/gradleSubproject` → `gradle/`);
   `platform/external-system-impl` (`icons/newui/task` → `externalSystem/task`).
   Copyright 2000-2026 JetBrains s.r.o. and contributors. Apache License 2.0 (below).
 - [intellij-plugins](https://github.com/JetBrains/intellij-plugins) (each plugin
@@ -26,6 +36,20 @@ icon set, copied unmodified (some renamed) from JetBrains' open-source repositor
   `fileTypes/hashiCorp`, Apache-2.0); `makefile` (`expui/makefile` →
   `fileTypes/makefile`, MIT, Copyright (c) 2016 Victor Kropp — full text below).
 
+The read/write usage filter assets (`actions/showReadAccess{,_dark}.svg` and
+`actions/showWriteAccess{,_dark}.svg`) are copied unmodified from
+`platform/icons/src/expui/actions/` at intellij-community commit
+[`e992ff4750b4c36afe2caadfa8b191a8f36fb7a2`](https://github.com/JetBrains/intellij-community/tree/e992ff4750b4c36afe2caadfa8b191a8f36fb7a2/platform/icons/src/expui/actions).
+Their original copyright headers and Apache-2.0 licensing are retained.
+
+- [intellij-rust](https://github.com/intellij-rust/intellij-rust) (MIT):
+  `src/main/resources/icons/expui/rustFile{,_dark}.svg` →
+  `src/ui/expui/fileTypes/rust{,_dark}.svg`;
+  `src/main/resources/icons/expui/cargo{,_dark}.svg` and `cargoLock{,_dark}.svg` →
+  `src/ui/expui/fileTypes/cargo{,_dark}.svg` and `cargoLock{,_dark}.svg`.
+  Copyright (c) 2015 Aleksey Kladov, Evgeny Kurbatsky, Alexey Kudinkin and contributors;
+  Copyright (c) 2016 JetBrains. MIT licence, full text below.
+
 At render time `src/ui/icons.tsx` may recolour monochrome icons to `currentColor`.
 
 ## JetBrains IntelliJ Platform diff algorithm
@@ -41,8 +65,13 @@ from its tests (`LineComparisonUtilTest`, `WordComparisonUtilTest`,
 `SplitComparisonUtilTest`). Modified from the originals. Copyright 2000-2026
 JetBrains s.r.o. and contributors. Apache License 2.0 (below).
 
+`src/features/vcs/mergeDiff3.ts`, `chunkOptimizer.ts` and `mergeModel.ts` also adapt
+the IntelliJ Platform merge implementation (`MergeRangeUtil`, `MergeResolveUtil`,
+`ChunkOptimizer.LineChunkOptimizer` and `MergeConflictModel`). Modified from the
+originals. Copyright 2000-2026 JetBrains s.r.o. and contributors. Apache License 2.0 (below).
+
 `src/ui/openidea/**` holds OpenIDEA's own file-type icons drawn in the expui style for
-languages whose JetBrains icons are not open source (Go, Rust, Ruby, Dart, Lua, Zig,
+languages whose JetBrains icons are not open source (Go, Ruby, Dart, Lua, Zig,
 Svelte, …). Those using the page-with-corner-badge layout (`goMod`, `goWork`,
 `dotenv`, `readme`, `lock`, `license`) reuse the page outline of the Apache-2.0
 expui `fileTypes/h.svg`; that outline is modified from the original by JetBrains.
@@ -53,6 +82,31 @@ The lettering in `src-tauri/icons/source/openidea-wordmark*.svg` is outlined fro
 Inter Tight (Copyright 2022 The Inter Project Authors, SIL Open Font License 1.1,
 https://github.com/rsms/inter-tight).
 
+### MIT License (Rust and Cargo icons)
+
+The MIT License (MIT)
+
+Copyright (c) 2015 Aleksey Kladov, Evgeny Kurbatsky, Alexey Kudinkin and contributors
+Copyright (c) 2016 JetBrains
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
 ### MIT License (makefile icon)
 
 Copyright (c) 2016 Victor Kropp

crates/ide-agent/src/config.rs

@@ -1,7 +1,9 @@
 //! Session settings (model, mode, thinking effort…), slash commands and context use, as
 //! the agent reports them over ACP.
 
-use crate::model::{AgentCommand, AgentConfigOption, AgentConfigValue, AgentConfigVia, AgentUsage};
+use crate::model::{
+    AgentCommand, AgentConfigOption, AgentConfigValue, AgentConfigVia, AgentCost, AgentLimit, AgentUsage,
+};
 use serde_json::{Value, json};
 
 /// Cursor exposes execution modes over ACP, but leaves approval policy to its client.
@@ -150,7 +152,27 @@ pub(crate) fn commands_of(update: &Value) -> Vec<AgentCommand> {
 /// `usage_update`: `{ used, size }`.
 pub(crate) fn usage_of(update: &Value) -> Option<AgentUsage> {
     let tokens = |key: &str| update.get(key)?.as_f64().map(|n| n.clamp(0.0, f64::from(u32::MAX)) as u32);
-    Some(AgentUsage { used: tokens("used")?, size: tokens("size").filter(|s| *s > 0)? })
+    let cost = update.get("cost").and_then(|c| {
+        Some(Box::new(AgentCost {
+            amount: c.get("amount")?.as_f64().filter(|a| a.is_finite() && *a >= 0.0)?,
+            currency: c.get("currency")?.as_str().filter(|c| !c.is_empty())?.to_owned(),
+        }))
+    });
+    Some(AgentUsage { used: tokens("used")?, size: tokens("size").filter(|s| *s > 0)?, cost })
+}
+
+/// The usage-limit windows a [`crate::LIMITS_UPDATE`] carries; malformed entries are skipped.
+pub(crate) fn limits_of(update: &Value) -> Vec<AgentLimit> {
+    let limits = update.get("limits").and_then(Value::as_array).into_iter().flatten();
+    limits
+        .filter_map(|l| {
+            Some(AgentLimit {
+                window: l.get("window")?.as_str().filter(|w| !w.is_empty())?.to_owned(),
+                used_percent: l.get("usedPercent")?.as_f64().filter(|p| p.is_finite())?.clamp(0.0, 100.0),
+                resets_ms: l.get("resetsMs").and_then(Value::as_f64),
+            })
+        })
+        .collect()
 }
 
 fn legacy(

crates/ide-agent/src/lib.rs

@@ -29,7 +29,7 @@ use serde::{Deserialize, Serialize};
 use serde_json::{Value, json};
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet, VecDeque};
 use std::path::{Path, PathBuf};
-use std::sync::atomic::{AtomicBool, AtomicU32, Ordering};
+use std::sync::atomic::{AtomicBool, AtomicU32, AtomicU64, Ordering};
 use std::sync::{Arc, Weak};
 use std::time::Duration;
 
@@ -44,11 +44,16 @@ const REPLAY_GRACE: Duration = Duration::from_millis(300);
 /// can trail its `session/prompt` response by this much.
 const TURN_GRACE: Duration = Duration::from_millis(100);
 const STDERR_LINES: usize = 20;
+/// An agent idle this long after its turn is stopped when it can reload its session
+/// (`session/load`): the next message starts it again where it left off.
+const IDLE_RELEASE: Duration = Duration::from_secs(5 * 60);
 /// Updates of a session's state rather than its conversation.
 const SESSION_STATE: [&str; 5] =
     ["session_info_update", "config_option_update", "current_mode_update", "available_commands_update", "usage_update"];
 /// A native agent's own update: it is about to retry a failed API request (see [`AgentRetry`]).
 pub(crate) const RETRY_UPDATE: &str = "openidea_retry";
+/// A native agent's own update: the usage limits of its account (see [`AgentLimit`]).
+pub(crate) const LIMITS_UPDATE: &str = "openidea_limits";
 /// Referenced files up to this size are embedded in the prompt (when the agent takes it).
 const MAX_EMBED: u64 = 256 * 1024;
 /// How long a probe waits for the agent to answer `initialize`.
@@ -90,6 +95,8 @@ struct Shared {
     providers: RwLock<Vec<provider::ProviderSpec>>,
     /// Last probe of each provider.
     probes: Mutex<HashMap<String, AgentProbe>>,
+    /// [`IDLE_RELEASE`], in milliseconds (shorter in tests).
+    idle_release_ms: AtomicU64,
 }
 
 /// What an agent offered in its last session, for the New Task page.
@@ -205,6 +212,8 @@ struct Live {
     capabilities: AgentCapabilities,
     /// `promptCapabilities.embeddedContext`: referenced files are sent with their text.
     embedded: bool,
+    /// `session/load`: the process can be stopped between turns and the session reloaded.
+    resumable: bool,
 }
 
 struct Task {
@@ -226,6 +235,8 @@ struct Task {
     cancel_pending: AtomicBool,
     /// The agent reported something for the current turn.
     turn_started: AtomicBool,
+    /// Turns sent so far: an idle release scheduled before the latest one is void.
+    turns: AtomicU64,
     /// Settings already sent this session (`(option, value)`), so a refusal is not retried.
     config_sent: Mutex<HashSet<(String, String)>>,
     dirty: Mutex<BTreeSet<(Session, usize)>>,
@@ -236,6 +247,11 @@ struct Task {
 }
 
 impl AgentManager {
+    #[cfg(test)]
+    fn set_idle_release(&self, delay: Duration) {
+        self.shared.idle_release_ms.store(delay.as_millis() as u64, Ordering::Relaxed);
+    }
+
     /// Loads the project's saved tasks. Spawned work runs on `runtime`.
     pub fn new(paths: AgentPaths, runtime: tokio::runtime::Handle) -> Self {
         let connector: Connector = Arc::new(|spec, cwd, client, on_stderr| match spec.driver {
@@ -260,6 +276,7 @@ impl AgentManager {
             known: Mutex::new(known),
             providers,
             probes: Mutex::new(HashMap::new()),
+            idle_release_ms: AtomicU64::new(IDLE_RELEASE.as_millis() as u64),
         });
         let mut tasks = HashMap::new();
         for file in std::fs::read_dir(&shared.paths.store_dir).into_iter().flatten().flatten() {
@@ -301,23 +318,41 @@ impl AgentManager {
         let specs = provider::load(self.shared.paths.custom_agents_dir.as_deref());
         let list = specs
             .iter()
-            .map(|p| AgentProvider {
-                id: p.id.clone(),
-                name: p.name.clone(),
-                command: std::iter::once(p.command.as_str())
-                    .chain(p.args.iter().map(String::as_str))
-                    .collect::<Vec<_>>()
-                    .join(" "),
-                installed: provider::installed(&p.command),
-                config: self.shared.known_config(&p.id),
-                commands: self.shared.known_commands(&p.id),
-                source: p.source.clone(),
+            .map(|p| {
+                let mut info = provider::describe(p);
+                info.config = self.shared.known_config(&p.id);
+                info.commands = self.shared.known_commands(&p.id);
+                info
             })
             .collect();
-        *self.shared.providers.write() = specs;
+        let mut prev = self.shared.providers.write();
+        let mut probes = self.shared.probes.lock();
+        probes.retain(|id, _| {
+            let old = prev.iter().find(|p| &p.id == id);
+            let new = specs.iter().find(|p| &p.id == id);
+            matches!((old, new), (Some(a), Some(b)) if a.command == b.command && a.args == b.args && a.env == b.env)
+        });
+        *prev = specs;
         list
     }
 
+    /// Overrides built-in `id`'s command with `command` (the driver and arguments stay
+    /// the built-in's) through its agent file, or returns it to auto-detection with `None`.
+    pub fn set_builtin_command(&self, id: &str, command: Option<String>) -> IdeResult<()> {
+        let Some(dir) = self.shared.paths.custom_agents_dir.clone() else {
+            return Err(IdeError::unavailable("there is no custom agents directory"));
+        };
+        provider::set_builtin_command(&dir, id, command.as_deref())
+    }
+
+    /// Re-reads configured/installed agents, drops cached probes, and notifies subscribers.
+    pub fn reload_providers(&self) {
+        let specs = provider::load(self.shared.paths.custom_agents_dir.as_deref());
+        *self.shared.providers.write() = specs;
+        self.shared.probes.lock().clear();
+        self.shared.emit(AgentEvent::Providers);
+    }
+
     /// The slash commands to complete for `provider`, in `task`'s directory or (without one)
     /// in the project: what the agent offered last time there, unadvertised builtins,
     /// and, for Claude Code, skills and custom commands on disk it has not listed.
@@ -808,7 +843,8 @@ impl AgentManager {
         // A copy of the task (a fork) may work in the same worktree.
         let shared = self.tasks.read().values().any(|t| t.id != id && t.state.lock().task.cwd.0 == cwd);
         if remove_worktree && !shared && isolation == Isolation::Worktree && cwd.exists() {
-            blocking(move || worktree::remove(&root, &cwd)).await?;
+            let worktrees = self.shared.paths.worktrees_dir.clone();
+            blocking(move || worktree::remove(&root, &worktrees, &cwd)).await?;
         }
         self.tasks.write().remove(id);
         *task.deleted.lock() = true;
@@ -867,6 +903,7 @@ impl Task {
             send_now: AtomicBool::new(false),
             cancel_pending: AtomicBool::new(false),
             turn_started: AtomicBool::new(false),
+            turns: AtomicU64::new(0),
             config_sent: Mutex::new(HashSet::new()),
             dirty: Mutex::new(BTreeSet::new()),
             flush_scheduled: AtomicBool::new(false),
@@ -1009,12 +1046,42 @@ impl Task {
             }
             match (next, result) {
                 (Some(queued), _) => prompt = queued.prompt,
-                (None, Ok(_)) => return self.set_status(AgentStatus::Ready, None),
+                (None, Ok(_)) => {
+                    self.set_status(AgentStatus::Ready, None);
+                    return self.release_when_idle();
+                }
                 (None, Err(failure)) => return self.fail(failure),
             }
         }
     }
 
+    /// Stops the agent's process once the task has stayed idle for [`IDLE_RELEASE`], so
+    /// finished tasks don't keep an agent (and what it started) running. Only an agent that
+    /// reloads its session: the next message starts it again with the conversation intact.
+    fn release_when_idle(self: &Arc<Self>) {
+        let turn = self.turns.load(Ordering::Acquire);
+        let delay = Duration::from_millis(self.shared.idle_release_ms.load(Ordering::Relaxed));
+        let task = Arc::downgrade(self);
+        self.shared.runtime.spawn(async move {
+            tokio::time::sleep(delay).await;
+            let Some(task) = task.upgrade() else { return };
+            if task.turns.load(Ordering::Acquire) != turn
+                || task.state.lock().busy
+                || !task.permissions.lock().is_empty()
+            {
+                return;
+            }
+            let live = {
+                let mut live = task.live.lock();
+                if live.as_ref().is_some_and(|l| l.resumable && !l.peer.is_closed()) { live.take() } else { None }
+            };
+            if let Some(live) = live {
+                tracing::debug!("agent task {}: idle, stopping the agent until the next message", task.id);
+                live.peer.kill();
+            }
+        });
+    }
+
     /// Ends a turn that failed: nothing it started stays open.
     fn fail(self: &Arc<Self>, failure: Failure) {
         self.cancel_permissions();
@@ -1075,6 +1142,7 @@ impl Task {
 
     /// Sends one prompt, starting the agent first if needed; returns the stop reason.
     async fn turn(self: &Arc<Self>, prompt: &AgentPrompt) -> Result<String, Failure> {
+        self.turns.fetch_add(1, Ordering::AcqRel);
         self.turn_started.store(false, Ordering::Release);
         self.state.lock().task.resets_ms = None;
         let attachments = prompt
@@ -1271,7 +1339,7 @@ impl Task {
         }
         self.persist();
         self.emit_task();
-        let live = Live { peer, session: session_id, capabilities, embedded };
+        let live = Live { peer, session: session_id, capabilities, embedded, resumable: can_load };
         *self.live.lock() = Some(live.clone());
         Ok(live)
     }
@@ -1353,6 +1421,13 @@ impl Task {
             }
             return;
         }
+        if kind == LIMITS_UPDATE {
+            if !self.replaying.load(Ordering::Acquire) {
+                let provider = self.state.lock().task.provider.clone();
+                self.shared.emit(AgentEvent::Limits { provider, limits: config::limits_of(update) });
+            }
+            return;
+        }
         if kind == "session_info_update" {
             // The agent's own title for the session replaces the first line of the prompt.
             let title = update.get("title").and_then(Value::as_str).map(str::trim).filter(|t| !t.is_empty());

crates/ide-agent/src/model.rs

@@ -154,6 +154,30 @@ pub struct AgentUsage {
     pub used: u32,
     /// Size of the context window.
     pub size: u32,
+    /// What the session has cost so far (ACP `usage_update.cost`), when the agent reports it.
+    // Boxed so that `AgentEvent::Task` stays within clippy's `large_enum_variant` bound on Windows.
+    #[serde(default)]
+    pub cost: Option<Box<AgentCost>>,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct AgentCost {
+    pub amount: f64,
+    /// ISO 4217 code, e.g. `USD`.
+    pub currency: String,
+}
+
+/// One usage-limit window of an agent's account.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct AgentLimit {
+    /// The window as the agent names it: `five_hour`, `seven_day`, `seven_day_opus`…
+    pub window: String,
+    /// Share of the window used, 0–100.
+    pub used_percent: f64,
+    /// When the window resets (ms since the epoch), if the agent said.
+    pub resets_ms: Option<f64>,
 }
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
@@ -322,6 +346,15 @@ pub struct AgentProvider {
     pub name: String,
     /// The command line that starts its ACP server.
     pub command: String,
+    /// Executable and arguments actually launched, without flattening paths containing spaces.
+    pub program: String,
+    pub args: Vec<String>,
+    pub default_program: Option<String>,
+    pub default_args: Vec<String>,
+    pub login_hint: Option<String>,
+    pub command_overridden: bool,
+    pub command_editable: bool,
+    pub command_read_only_reason: Option<AgentCommandReadOnlyReason>,
     /// Whether the command was found (on `PATH`).
     pub installed: bool,
     /// Settings (models, modes…) the agent offered last time it ran; empty before its first session.
@@ -331,6 +364,15 @@ pub struct AgentProvider {
     pub source: AgentSource,
 }
 
+/// Why the executable cannot be changed in built-in agent settings.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum AgentCommandReadOnlyReason {
+    PackageRunner,
+    Registry,
+    CustomAgent,
+}
+
 /// Where an agent comes from.
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(tag = "kind", rename_all = "camelCase")]
@@ -413,4 +455,11 @@ pub enum AgentEvent {
         index: u32,
         entry: AgentEntry,
     },
+    /// An agent reported the usage limits of its account (shared by every task of `provider`).
+    Limits {
+        provider: String,
+        limits: Vec<AgentLimit>,
+    },
+    /// The installed or configured agent providers changed.
+    Providers,
 }

crates/ide-agent/src/native/claude/cli.rs

@@ -98,6 +98,8 @@ impl Cli for Process {
         use std::process::Stdio;
         let mut cmd = tokio::process::Command::new(&l.program);
         ide_core::process::prepare(cmd.as_std_mut());
+        // `claude` may be a wrapper (`claude.cmd` → node): stopping it stops what it started.
+        ide_core::process::own_group(cmd.as_std_mut());
         cmd.args(&l.args)
             .current_dir(&l.cwd)
             .envs(ide_core::process::shell_env())
@@ -120,6 +122,9 @@ impl Cli for Process {
             tokio::select! {
                 _ = child.wait() => {}
                 _ = token.cancelled() => {
+                    if let Some(pid) = child.id() {
+                        let _ = tokio::task::spawn_blocking(move || ide_core::process::kill_tree_of(pid)).await;
+                    }
                     let _ = child.start_kill();
                     let _ = child.wait().await;
                 }

crates/ide-agent/src/native/claude/mod.rs

@@ -904,6 +904,7 @@ impl Session {
                     if info.get("status").and_then(Value::as_str) == Some("rejected") {
                         st.limit_resets_ms = info.get("resetsAt").and_then(Value::as_f64).map(|s| s * 1000.0);
                     }
+                    updates.extend(st.tr.on_rate_limit(&info));
                 }
                 "command_lifecycle" => {
                     let uuid = msg.get("command_uuid").and_then(Value::as_str);
@@ -915,7 +916,11 @@ impl Session {
                         } else {
                             "end_turn"
                         };
-                        finished = st.turn.take().map(|t| (t, TurnEnd::Stop(stop)));
+                        finished = st.turn.take().map(|mut t| {
+                            // Claude Code reports a turn that failed as cancelled here.
+                            let failure = t.failure.take().filter(|_| !t.cancelled);
+                            (t, failure.unwrap_or(TurnEnd::Stop(stop)))
+                        });
                     }
                 }
                 "assistant" if msg.get("parent_tool_use_id").is_none_or(Value::is_null) => {
@@ -1139,7 +1144,8 @@ where
 /// Whether `result` ends `turn`: it answers the turn's last message, or (stopped) any of
 /// its messages, or names none (the CLI's own error before the turn began).
 fn belongs(turn: &Turn, result: &Value) -> bool {
-    if result.get("origin").is_some_and(|o| !o.is_null()) {
+    // Prompts are sent with the origin `human`, and their results echo it.
+    if result.get("origin").is_some_and(|o| !o.is_null() && o.get("kind").and_then(Value::as_str) != Some("human")) {
         return false;
     }
     let mut uuids = strings(result.get("user_message_uuids"));

crates/ide-agent/src/native/claude/tests.rs

@@ -738,6 +738,50 @@ async fn a_stop_ahead_of_its_prompt_cancels_it() {
     assert!(cli.sent.lock()[0].iter().all(|m| m["type"] != "user"), "nothing was sent");
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn a_failed_turn_reports_its_failure() {
+    let text = "Failed to authenticate: OAuth session expired and could not be refreshed";
+    let lifecycle = |uuid: &str, state: &str| {
+        Frame::Cli(json!({ "type": "command_lifecycle", "command_uuid": uuid, "state": state }))
+    };
+    let result = |uuid: &str| {
+        Frame::Cli(json!({
+            "type": "result", "subtype": "success", "is_error": true, "result": text, "stop_reason": "stop_sequence",
+            "terminal_reason": "api_error", "origin": { "kind": "human" }, "user_message_uuids": [uuid],
+        }))
+    };
+    // As Claude Code sends it, and with the turn's end ahead of its result.
+    for lifecycle_first in [false, true] {
+        let mut process = load_fixture("simple").remove(0);
+        process.truncate(6);
+        let Some(Frame::Shim(prompt)) = process.last() else { panic!("the fixture's prompt") };
+        let uuid = prompt["uuid"].as_str().unwrap().to_owned();
+        process.push(Frame::Cli(json!({
+            "type": "assistant", "error": "authentication_failed", "parent_tool_use_id": null,
+            "message": { "id": "m", "model": "<synthetic>", "content": [{ "type": "text", "text": text }] },
+        })));
+        if lifecycle_first {
+            process.extend([lifecycle(&uuid, "cancelled"), result(&uuid)]);
+        } else {
+            process.extend([result(&uuid), lifecycle(&uuid, "cancelled")]);
+        }
+        let cli = Arc::new(Replay {
+            processes: Mutex::new(VecDeque::from([process])),
+            sent: Arc::default(),
+            launched: Mutex::default(),
+            errors: Arc::default(),
+        });
+        let (dir, cwd) = (tempfile::tempdir().unwrap(), tempfile::tempdir().unwrap());
+        let h =
+            Harness::connect(cli.clone(), dir.path().into(), dir.path().join("p"), cwd.path().into(), Vec::new()).await;
+        let s = h.new_session().await;
+        let Err(RpcError::Server { message, .. }) = h.prompt(&s, "hi").await else {
+            panic!("the turn should fail (lifecycle first: {lifecycle_first})");
+        };
+        assert_eq!(message, format!("Claude Code authentication failed: {text}"));
+    }
+}
+
 /// Fork and undo against the real CLI, across connections, in a symlinked directory
 /// (macOS `/tmp`).
 #[tokio::test(flavor = "multi_thread")]
@@ -829,6 +873,7 @@ fn which_result_ends_a_turn() {
     assert!(!belongs(&t, &json!({"user_message_uuids": ["a"]})), "a steer superseded it");
     assert!(belongs(&t, &json!({"subtype": "error_during_execution"})), "names no message");
     assert!(!belongs(&t, &json!({"origin": {"kind": "task-notification"}})), "Claude Code's own turn");
+    assert!(belongs(&t, &json!({"origin": {"kind": "human"}, "user_message_uuids": ["b"]})), "the prompt's own result");
     assert!(belongs(&turn(&["a", "b"], true), &json!({"user_message_uuids": ["a"]})));
 }
 
@@ -968,6 +1013,39 @@ fn streamed_text_is_not_sent_twice() {
     assert_eq!(usage[0].update, json!({"sessionUpdate": "usage_update", "used": 15, "size": 1000}));
 }
 
+#[test]
+fn rate_limits_and_cost() {
+    let mut t = Translator::new("s", PathBuf::from("/w"), false);
+    let info = json!({"status": "allowed", "rateLimitType": "five_hour", "unifiedWindows": {
+        "five_hour": {"utilization": 0.19, "resetsAt": 100, "status": "allowed"},
+        "seven_day": {"utilization": 0.09, "resetsAt": 200, "status": "allowed"},
+    }});
+    let limits = t.on_rate_limit(&info).unwrap();
+    assert_eq!(limits.session, "s");
+    assert_eq!(limits.update["sessionUpdate"], crate::LIMITS_UPDATE);
+    let windows: Vec<(&str, i64, f64)> = limits.update["limits"]
+        .as_array()
+        .unwrap()
+        .iter()
+        .map(|l| {
+            (
+                l["window"].as_str().unwrap(),
+                l["usedPercent"].as_f64().unwrap().round() as i64,
+                l["resetsMs"].as_f64().unwrap(),
+            )
+        })
+        .collect();
+    assert_eq!(windows, [("five_hour", 19, 100_000.0), ("seven_day", 9, 200_000.0)]);
+    // Older versions report the window that applies, alone.
+    let single = t.on_rate_limit(&json!({"rateLimitType": "seven_day", "utilization": 0.5})).unwrap();
+    assert_eq!(single.update["limits"], json!([{"window": "seven_day", "usedPercent": 50.0, "resetsMs": null}]));
+    assert_eq!(t.on_rate_limit(&json!({"status": "allowed", "resetsAt": 100})), None, "no utilization, no update");
+
+    t.used = Some(10);
+    let usage = t.on_result(&json!({"total_cost_usd": 0.5, "modelUsage": {"x": {"contextWindow": 1000}}}));
+    assert_eq!(usage[0].update["cost"], json!({"amount": 0.5, "currency": "USD"}));
+}
+
 #[test]
 fn tool_calls_plans_and_subagents() {
     let mut t = Translator::new("s", PathBuf::from("/w"), true);

crates/ide-agent/src/native/claude/translate.rs

@@ -5,7 +5,7 @@
 //! Agent tool use that launched them: their messages carry it as `parent_tool_use_id`.
 
 use super::tools;
-use crate::RETRY_UPDATE;
+use crate::{LIMITS_UPDATE, RETRY_UPDATE};
 use serde_json::{Value, json};
 use std::collections::{HashMap, VecDeque};
 use std::path::PathBuf;
@@ -58,6 +58,8 @@ pub(super) struct Translator {
     pub used: Option<u64>,
     pub model: Option<String>,
     windows: HashMap<String, u64>,
+    /// The session's cost so far in USD, as the last `result` reported it.
+    cost_usd: Option<f64>,
 }
 
 impl Translator {
@@ -75,6 +77,7 @@ impl Translator {
             used: None,
             model: None,
             windows: HashMap::new(),
+            cost_usd: None,
         }
     }
 
@@ -169,7 +172,7 @@ impl Translator {
                     Some("tool_use") => {
                         // The input streams after this: shown by name until the message has it.
                         let (id, name) = (str_of(&block, "id"), str_of(&block, "name"));
-                        if !id.is_empty() && !tools::is_plan(&name) && !(tools::is_agent(&name) && self.subagents) {
+                        if !(id.is_empty() || tools::is_plan(&name) || tools::is_agent(&name) && self.subagents) {
                             out.extend(self.ensure_call(&id, &name, &json!({}), &session));
                         }
                     }
@@ -543,6 +546,9 @@ impl Translator {
                 self.windows.insert(model.clone(), w);
             }
         }
+        if let Some(cost) = result.get("total_cost_usd").and_then(Value::as_f64).filter(|c| c.is_finite()) {
+            self.cost_usd = Some(cost);
+        }
         self.usage_update().into_iter().collect()
     }
 
@@ -557,9 +563,33 @@ impl Translator {
                     .or_else(|| self.windows.iter().find(|(k, _)| k.starts_with(m.as_str())).map(|(_, v)| v))
             })
             .or_else(|| (self.windows.len() == 1).then(|| self.windows.values().next()).flatten())?;
-        Some(Update {
+        let mut update = json!({ "sessionUpdate": "usage_update", "used": used, "size": size });
+        if let Some(amount) = self.cost_usd {
+            update["cost"] = json!({ "amount": amount, "currency": "USD" });
+        }
+        Some(Update { session: self.root.clone(), update })
+    }
+
+    /// The usage-limit windows a `rate_limit_event` reports, as a [`LIMITS_UPDATE`]: every
+    /// window of `unifiedWindows`, or the single `rateLimitType` window older versions send.
+    pub fn on_rate_limit(&self, info: &Value) -> Option<Update> {
+        let window = |name: &str, w: &Value| {
+            let utilization = w.get("utilization")?.as_f64()?;
+            Some(json!({
+                "window": name,
+                "usedPercent": utilization * 100.0,
+                "resetsMs": w.get("resetsAt").and_then(Value::as_f64).map(|s| s * 1000.0),
+            }))
+        };
+        let limits: Vec<Value> = match info.get("unifiedWindows").and_then(Value::as_object) {
+            Some(windows) => windows.iter().filter_map(|(name, w)| window(name, w)).collect(),
+            None => {
+                info.get("rateLimitType").and_then(Value::as_str).and_then(|t| window(t, info)).into_iter().collect()
+            }
+        };
+        (!limits.is_empty()).then(|| Update {
             session: self.root.clone(),
-            update: json!({ "sessionUpdate": "usage_update", "used": used, "size": size }),
+            update: json!({ "sessionUpdate": LIMITS_UPDATE, "limits": limits }),
         })
     }
 }

crates/ide-agent/src/native/mod.rs

@@ -27,7 +27,8 @@ pub(crate) fn newest_install(command: &str) -> String {
     let path = ide_core::process::host_var_os("PATH")
         .or_else(|| ide_core::process::shell_env().find(|(k, _)| *k == "PATH").map(|(_, v)| v.to_owned()))
         .unwrap_or_default();
-    newest_install_in(command, &path)
+    // Windows: read afresh, so a tool the user installed since the IDE started is found too.
+    newest_install_in(command, &ide_core::process::with_user_path(&path))
 }
 
 fn newest_install_in(command: &str, search: &std::ffi::OsStr) -> String {

crates/ide-agent/src/provider.rs

@@ -2,7 +2,8 @@
 //! `<config>/agents/<id>.toml` (written by hand, or by installing one from the ACP
 //! Registry, see `registry`).
 
-use crate::AgentSource;
+use crate::{AgentCommandReadOnlyReason, AgentProvider, AgentSource};
+use ide_core::{IdeError, IdeResult};
 use serde::{Deserialize, Serialize};
 use std::collections::BTreeMap;
 use std::path::{Path, PathBuf};
@@ -80,9 +81,92 @@ fn builtins() -> Vec<ProviderSpec> {
         .collect()
 }
 
-/// Whether `id` names a built-in agent.
+/// 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`.
 pub(crate) fn is_builtin(id: &str) -> bool {
-    BUILTIN.iter().any(|b| b.0 == id)
+    BUILTIN.iter().any(|&(bid, _, driver, cmd, _)| bid == id && (driver != Driver::Acp || cmd.first() == Some(&"npx")))
+}
+
+/// Display name of a built-in agent, when `id` is one.
+pub(crate) fn builtin_name(id: &str) -> Option<&'static str> {
+    BUILTIN.iter().find(|&&(bid, _, _, _, _)| bid == id).map(|&(_, name, _, _, _)| name)
+}
+
+/// The built-in spec of `id`.
+pub(crate) fn builtin_spec(id: &str) -> Option<ProviderSpec> {
+    builtins().into_iter().find(|s| s.id == id)
+}
+
+/// Public launch metadata, keeping the built-in defaults separate from agent-file overrides.
+pub(crate) fn describe(spec: &ProviderSpec) -> AgentProvider {
+    let builtin = builtin_spec(&spec.id);
+    let reason = if matches!(spec.source, AgentSource::Registry { .. }) {
+        Some(AgentCommandReadOnlyReason::Registry)
+    } else if let Some(default) = &builtin {
+        matches!(default.command.as_str(), "npx" | "bunx" | "uvx").then_some(AgentCommandReadOnlyReason::PackageRunner)
+    } else {
+        Some(AgentCommandReadOnlyReason::CustomAgent)
+    };
+    AgentProvider {
+        id: spec.id.clone(),
+        name: spec.name.clone(),
+        command: std::iter::once(spec.command.as_str())
+            .chain(spec.args.iter().map(String::as_str))
+            .collect::<Vec<_>>()
+            .join(" "),
+        program: spec.command.clone(),
+        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()),
+        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),
+        config: vec![],
+        commands: vec![],
+        source: spec.source.clone(),
+    }
+}
+
+/// Overrides built-in `id`'s command through its agent file, preserving other
+/// customizations. `None` restores the built-in command and removes a redundant file.
+pub(crate) fn set_builtin_command(custom_dir: &Path, id: &str, command: Option<&str>) -> IdeResult<()> {
+    let Some(builtin) = builtin_spec(id) else {
+        return Err(IdeError::invalid(format!("{id} is not a built-in agent")));
+    };
+    let file = custom_dir.join(format!("{id}.toml"));
+    let mut agent = if file.try_exists()? {
+        CustomAgent::read(&file).map_err(IdeError::invalid)?
+    } else {
+        CustomAgent {
+            name: Some(builtin.name.clone()),
+            driver: builtin.driver,
+            command: builtin.command.clone(),
+            args: builtin.args.clone(),
+            env: BTreeMap::new(),
+            registry: None,
+        }
+    };
+    if agent.registry.is_some() {
+        return Err(IdeError::invalid(format!("{id} is installed from the ACP Registry")));
+    }
+    if command.is_none()
+        && agent.name.as_deref() == Some(builtin.name.as_str())
+        && agent.driver == builtin.driver
+        && agent.args == builtin.args
+        && agent.env.is_empty()
+    {
+        match std::fs::remove_file(&file) {
+            Err(e) if e.kind() != std::io::ErrorKind::NotFound => return Err(e.into()),
+            _ => {}
+        }
+        return Ok(());
+    }
+    agent.command = command.unwrap_or(&builtin.command).to_owned();
+    agent.write(&file)?;
+    Ok(())
 }
 
 /// An agent file, `<config>/agents/<id>.toml`.
@@ -162,7 +246,7 @@ pub(crate) fn load(custom_dir: Option<&Path>) -> Vec<ProviderSpec> {
             Some(r) => AgentSource::Registry { version: r.version, update: None },
             None => AgentSource::Custom,
         };
-        let spec = ProviderSpec {
+        let mut spec = ProviderSpec {
             name: agent.name.unwrap_or_else(|| id.clone()),
             driver: agent.driver,
             command: agent.command,
@@ -173,7 +257,13 @@ pub(crate) fn load(custom_dir: Option<&Path>) -> Vec<ProviderSpec> {
             id,
         };
         match specs.iter_mut().find(|s| s.id == spec.id) {
-            Some(existing) => *existing = spec,
+            Some(existing) => {
+                spec.login_hint = existing.login_hint.clone();
+                if spec.source == AgentSource::Custom {
+                    spec.source = AgentSource::Builtin;
+                }
+                *existing = spec;
+            }
             None => specs.push(spec),
         }
     }
@@ -211,6 +301,54 @@ fn is_executable(p: &Path) -> bool {
 mod tests {
     use super::*;
 
+    #[test]
+    fn launch_metadata_distinguishes_defaults_overrides_and_read_only_agents() {
+        let dir = tempfile::tempdir().unwrap();
+        let list = || load(Some(dir.path())).iter().map(describe).collect::<Vec<_>>();
+        let defaults = list();
+        let codex = defaults.iter().find(|p| p.id == "codex").unwrap();
+        assert_eq!(codex.program, "codex");
+        assert_eq!(codex.default_program.as_deref(), Some("codex"));
+        assert_eq!(codex.args, ["app-server"]);
+        assert_eq!(codex.default_args, codex.args);
+        assert_eq!(codex.command, "codex app-server");
+        assert_eq!(codex.login_hint.as_deref(), Some("Run `codex login` in a terminal."));
+        assert!(!codex.command_overridden);
+        assert!(codex.command_editable);
+        for p in &defaults {
+            assert_eq!(p.source, AgentSource::Builtin);
+            assert!(p.default_program.is_some());
+            assert_eq!(p.command_editable, !p.id.ends_with("-acp"));
+            assert_eq!(
+                p.command_read_only_reason,
+                p.id.ends_with("-acp").then_some(AgentCommandReadOnlyReason::PackageRunner)
+            );
+        }
+        set_builtin_command(dir.path(), "codex", Some("/path with spaces/codex")).unwrap();
+        let overridden = list().into_iter().find(|p| p.id == "codex").unwrap();
+        assert_eq!(overridden.program, "/path with spaces/codex");
+        assert_eq!(overridden.args, codex.args);
+        assert_eq!(overridden.default_program, codex.default_program);
+        assert!(overridden.command_overridden && overridden.command_editable);
+        assert_eq!(overridden.source, AgentSource::Builtin);
+        set_builtin_command(dir.path(), "codex", Some("codex")).unwrap();
+        assert!(!list().iter().find(|p| p.id == "codex").unwrap().command_overridden);
+        std::fs::write(
+            dir.path().join("gemini.toml"),
+            "command = \"/registry/gemini\"\n[registry]\nid = \"gemini\"\nversion = \"1.0\"\n",
+        )
+        .unwrap();
+        let registry = list().into_iter().find(|p| p.id == "gemini").unwrap();
+        assert_eq!(registry.default_program.as_deref(), Some("gemini"));
+        assert!(!registry.command_editable);
+        assert_eq!(registry.command_read_only_reason, Some(AgentCommandReadOnlyReason::Registry));
+        assert!(matches!(registry.source, AgentSource::Registry { .. }));
+        std::fs::write(dir.path().join("mine.toml"), "command = \"mine\"\n").unwrap();
+        let custom = list().into_iter().find(|p| p.id == "mine").unwrap();
+        assert_eq!(custom.default_program, None);
+        assert_eq!(custom.command_read_only_reason, Some(AgentCommandReadOnlyReason::CustomAgent));
+    }
+
     #[test]
     fn custom_agents_extend_and_override_the_builtins() {
         let dir = tempfile::tempdir().unwrap();
@@ -230,6 +368,90 @@ mod tests {
         assert!(installed("sh"));
     }
 
+    #[test]
+    fn set_builtin_command_overrides_and_clears_a_builtin() {
+        let dir = tempfile::tempdir().unwrap();
+        set_builtin_command(dir.path(), "not-a-builtin", Some("/x")).unwrap_err();
+        set_builtin_command(dir.path(), "claude", Some("/opt/claude")).unwrap();
+        let claude = load(Some(dir.path())).into_iter().find(|s| s.id == "claude").unwrap();
+        assert_eq!((claude.command.as_str(), claude.driver), ("/opt/claude", Driver::Claude));
+        assert!(claude.args.is_empty());
+        // A registry install is neither overwritten nor removed by a command override.
+        let path = dir.path().join("codex.toml");
+        CustomAgent {
+            name: None,
+            driver: Driver::Acp,
+            command: "amp".into(),
+            args: vec![],
+            env: BTreeMap::new(),
+            registry: Some(RegistryRef { id: "amp-acp".into(), version: "1.0.0".into() }),
+        }
+        .write(&path)
+        .unwrap();
+        set_builtin_command(dir.path(), "codex", Some("/x")).unwrap_err();
+        set_builtin_command(dir.path(), "codex", None).unwrap_err();
+        assert!(path.exists());
+        // Clearing (twice) returns the built-in to auto-detection.
+        set_builtin_command(dir.path(), "claude", None).unwrap();
+        set_builtin_command(dir.path(), "claude", None).unwrap();
+        assert!(!dir.path().join("claude.toml").exists());
+        assert_eq!(load(Some(dir.path())).iter().find(|s| s.id == "claude").unwrap().command, "claude");
+    }
+
+    #[test]
+    fn set_builtin_command_preserves_other_customizations_on_save_and_reset() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("claude.toml");
+        for field in ["name", "driver", "args", "env", "unnamed"] {
+            let mut agent = CustomAgent {
+                name: Some("Claude Code".into()),
+                driver: Driver::Claude,
+                command: "/old/claude".into(),
+                args: vec![],
+                env: BTreeMap::new(),
+                registry: None,
+            };
+            match field {
+                "name" => agent.name = Some("My Claude".into()),
+                "driver" => agent.driver = Driver::Acp,
+                "args" => agent.args.push("--verbose".into()),
+                "env" => {
+                    agent.env.insert("K".into(), "v".into());
+                }
+                "unnamed" => agent.name = None,
+                _ => unreachable!(),
+            }
+            agent.write(&path).unwrap();
+
+            set_builtin_command(dir.path(), "claude", Some("/new/claude")).unwrap();
+            agent.command = "/new/claude".into();
+            assert_eq!(CustomAgent::read(&path).unwrap(), agent, "{field}");
+
+            set_builtin_command(dir.path(), "claude", None).unwrap();
+            agent.command = "claude".into();
+            assert_eq!(CustomAgent::read(&path).unwrap(), agent, "{field}");
+        }
+    }
+
+    #[test]
+    fn resetting_a_command_only_override_removes_the_file() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("codex.toml");
+        std::fs::write(
+            &path,
+            "name = \"Codex\"\ndriver = \"codex\"\ncommand = \"/custom/codex\"\nargs = [\"app-server\"]\n",
+        )
+        .unwrap();
+
+        set_builtin_command(dir.path(), "codex", None).unwrap();
+
+        assert!(!path.exists());
+        assert_eq!(
+            load(Some(dir.path())).into_iter().find(|s| s.id == "codex").unwrap(),
+            builtin_spec("codex").unwrap()
+        );
+    }
+
     #[test]
     fn agent_files_round_trip_with_their_registry_table() {
         let dir = tempfile::tempdir().unwrap();

crates/ide-agent/src/registry.rs

@@ -165,6 +165,13 @@ fn parse(text: &str) -> IdeResult<Vec<Entry>> {
         .into_iter()
         .filter_map(|v| serde_json::from_value::<Entry>(v).ok())
         .filter(|e| safe_segment(&e.id) && safe_segment(&e.version))
+        .map(|mut e| {
+            e.id = canonical_id(&e.id).to_owned();
+            if let Some(name) = provider::builtin_name(&e.id) {
+                e.name = name.to_owned();
+            }
+            e
+        })
         .collect())
 }
 
@@ -222,14 +229,26 @@ fn choose<'a>(entry: &'a Entry, platform: Platform, on_path: &dyn Fn(&str) -> bo
     {
         return Some(Choice::Uvx(p));
     }
+    // Last resort: npx and uvx run natively, this one under OS emulation.
+    if platform.os == Os::Windows
+        && platform.arch == Arch::Arm64
+        && let Some(b) = d.binary.get("windows-x86_64")
+    {
+        return Some(Choice::Binary(b));
+    }
     None
 }
 
-/// Registry agents that are built-in ones under another id.
-const BUILTIN_ALIASES: &[&str] = &["github-copilot-cli", "qwen-code", "mistral-vibe"];
+/// Registry ids that map to a shorter built-in provider id (`<config>/agents/<id>.toml`).
+const BUILTIN_ALIASES: &[(&str, &str)] =
+    &[("github-copilot-cli", "copilot"), ("qwen-code", "qwen"), ("mistral-vibe", "vibe")];
+
+fn canonical_id(id: &str) -> &str {
+    BUILTIN_ALIASES.iter().find_map(|&(alias, canonical)| (alias == id).then_some(canonical)).unwrap_or(id)
+}
 
 fn is_builtin(id: &str) -> bool {
-    provider::is_builtin(id) || BUILTIN_ALIASES.contains(&id)
+    provider::is_builtin(canonical_id(id))
 }
 
 fn on_path(command: &str) -> bool {
@@ -380,6 +399,7 @@ fn write_atomic(path: &Path, bytes: &[u8]) -> std::io::Result<()> {
 /// Installs (or updates to) the registry's current version of `id`, streaming progress
 /// through `emit`, and points the agent file at it.
 pub fn install(paths: &RegistryPaths, id: &str, cancel: &CancellationToken, emit: Emit) -> IdeResult<()> {
+    let id = canonical_id(id);
     // The saved index is what the user picked from; fetch only when there is none.
     let text = match fs::read_to_string(&paths.cache_file) {
         Ok(text) => text,
@@ -611,6 +631,7 @@ fn install_uv(
 
 /// Deletes a registry agent's file and installed files.
 pub fn remove(paths: &RegistryPaths, id: &str) -> IdeResult<()> {
+    let id = canonical_id(id);
     if !safe_segment(id) {
         return Err(IdeError::invalid(format!("invalid agent id {id}")));
     }
@@ -689,6 +710,20 @@ mod tests {
     const LINUX: Platform = Platform { os: Os::Linux, arch: Arch::X64 };
     const WINDOWS: Platform = Platform { os: Os::Windows, arch: Arch::X64 };
 
+    #[test]
+    fn windows_arm_binary_prefers_native_then_x64() {
+        let mut entry = parse(INDEX).unwrap().remove(0);
+        let arm = Platform { os: Os::Windows, arch: Arch::Arm64 };
+        assert!(matches!(choose(&entry, arm, &|_| false), Some(Choice::Binary(_))));
+        assert!(choose(&entry, Platform { os: Os::Linux, arch: Arch::Arm64 }, &|_| false).is_none());
+        entry.distribution.npx = Some(serde_json::from_str(r#"{"package":"amp-acp"}"#).unwrap());
+        assert!(matches!(choose(&entry, arm, &|_| true), Some(Choice::Npx(_))));
+        let mut native = entry.distribution.binary["windows-x86_64"].clone();
+        native.cmd = "native.exe".into();
+        entry.distribution.binary.insert("windows-aarch64".into(), native);
+        assert!(matches!(choose(&entry, arm, &|_| false), Some(Choice::Binary(b)) if b.cmd == "native.exe"));
+    }
+
     const INDEX: &str = r#"{"version":"1.0.0","agents":[
         {"id":"amp-acp","name":"Amp","version":"0.10.0","description":"Amp over ACP",
          "repository":"https://github.com/x/amp-acp","authors":["x"],"license":"Apache-2.0",
@@ -791,15 +826,7 @@ mod tests {
         let mut providers: Vec<AgentProvider> = provider::load(Some(&p.agents_dir))
             .into_iter()
             .filter(|s| s.id == "amp-acp")
-            .map(|s| AgentProvider {
-                id: s.id,
-                name: s.name,
-                command: s.command,
-                installed: false,
-                config: vec![],
-                commands: vec![],
-                source: s.source,
-            })
+            .map(|s| provider::describe(&s))
             .collect();
         mark_updates(&p, &mut providers);
         assert_eq!(
@@ -925,4 +952,56 @@ mod tests {
         assert!(remove(&p, "amp-acp").is_err());
         assert!(p.agent_file("amp-acp").exists());
     }
+
+    #[test]
+    fn maps_github_copilot_cli_to_builtin_copilot_and_tracks_updates() {
+        let dir = tempfile::tempdir().unwrap();
+        let p = paths(dir.path());
+        let index = r#"{"agents":[
+            {"id":"github-copilot-cli","name":"Copilot","version":"1.0.105",
+             "description":"GitHub's AI pair programmer",
+             "distribution":{"npx":{"package":"@github/[email protected]","args":["--acp"]}}}
+        ]}"#;
+        let entries = parse(index).unwrap();
+        assert_eq!(entries.len(), 1);
+        assert_eq!((entries[0].id.as_str(), entries[0].name.as_str()), ("copilot", "GitHub Copilot"));
+
+        let shown = visible(&p, &entries, MAC_ARM, &|c| c == "npm" || c == "node");
+        assert_eq!(shown.len(), 1);
+        assert_eq!(
+            (shown[0].id.as_str(), shown[0].name.as_str(), shown[0].installed.as_deref()),
+            ("copilot", "GitHub Copilot", None)
+        );
+
+        CustomAgent {
+            name: Some("GitHub Copilot".into()),
+            driver: Driver::Acp,
+            command: "/data/tools/copilot/1.0.104/node_modules/.bin/copilot".into(),
+            args: vec!["--acp".into()],
+            env: BTreeMap::new(),
+            registry: Some(RegistryRef { id: "copilot".into(), version: "1.0.104".into() }),
+        }
+        .write(&p.agent_file("copilot"))
+        .unwrap();
+
+        let shown = visible(&p, &entries, MAC_ARM, &|c| c == "npm" || c == "node");
+        assert_eq!((shown[0].installed.as_deref(), shown[0].update), (Some("1.0.104"), true));
+
+        write_atomic(&p.cache_file, index.as_bytes()).unwrap();
+        let spec = provider::load(Some(&p.agents_dir)).into_iter().find(|s| s.id == "copilot").unwrap();
+        assert_eq!(spec.name, "GitHub Copilot");
+        assert_eq!(spec.login_hint, "Run `copilot` in a terminal and sign in.");
+        assert_eq!(spec.source, AgentSource::Registry { version: "1.0.104".into(), update: None });
+
+        let mut providers = vec![provider::describe(&spec)];
+        mark_updates(&p, &mut providers);
+        assert_eq!(
+            providers[0].source,
+            AgentSource::Registry { version: "1.0.104".into(), update: Some("1.0.105".into()) }
+        );
+
+        remove(&p, "github-copilot-cli").unwrap();
+        let fallback = provider::load(Some(&p.agents_dir)).into_iter().find(|s| s.id == "copilot").unwrap();
+        assert_eq!(fallback.source, AgentSource::Builtin);
+    }
 }

crates/ide-agent/src/tests.rs

@@ -9,6 +9,8 @@ struct FakeAgent {
     /// Every connection's agent side, kept open.
     servers: Mutex<Vec<Peer>>,
     calls: Mutex<Vec<String>>,
+    /// Without `loadSession` (a session lives only as long as its process).
+    no_load: bool,
 }
 
 impl FakeAgent {
@@ -89,7 +91,7 @@ impl Handler for FakeAgent {
                 if params.pointer("/clientCapabilities/subagents").is_some_and(Value::is_object) {
                     self.calls.lock().push("subagents".into());
                 }
-                Ok(json!({"protocolVersion": 1, "agentCapabilities": {"loadSession": true,
+                Ok(json!({"protocolVersion": 1, "agentCapabilities": {"loadSession": !self.no_load,
                     "sessionCapabilities": {"fork": {}}, "_meta": {"openidea": {"rollback": true, "steer": true}}}}))
             }
             "session/new" => Ok(json!({"sessionId": "s1",
@@ -145,7 +147,16 @@ impl Handler for FakeAgent {
                     json!({"sessionUpdate": "available_commands_update",
                     "availableCommands": [{"name": "review", "description": "Review", "input": {"hint": "focus"}}]}),
                 );
-                self.update(&session, json!({"sessionUpdate": "usage_update", "used": 50, "size": 1000}));
+                self.update(
+                    &session,
+                    json!({"sessionUpdate": "usage_update", "used": 50, "size": 1000,
+                    "cost": {"amount": 0.25, "currency": "USD"}}),
+                );
+                self.update(
+                    &session,
+                    json!({"sessionUpdate": LIMITS_UPDATE,
+                    "limits": [{"window": "five_hour", "usedPercent": 19.0, "resetsMs": 5000.0}]}),
+                );
                 self.update(&session, json!({"sessionUpdate": "session_info_update", "title": "Lexer fix"}));
                 self.say(&session, "Hi");
                 self.update(
@@ -358,6 +369,10 @@ async fn a_task_runs_asks_for_permission_and_survives_a_restart() {
         assert_eq!((modes.via, modes.current.as_deref()), (AgentConfigVia::Mode, Some("ask")));
         assert_eq!(t.commands.iter().map(|c| c.name.as_str()).collect::<Vec<_>>(), ["review"]);
         assert_eq!(t.usage.as_ref().map(|u| (u.used, u.size)), Some((50, 1000)));
+        assert_eq!(
+            t.usage.as_ref().and_then(|u| u.cost.clone()),
+            Some(Box::new(AgentCost { amount: 0.25, currency: "USD".into() }))
+        );
         assert_eq!(t.title, "Lexer fix", "the agent's title replaces the prompt's first line");
     }
     mgr.set_config(&task.id, "mode", "code".into()).await.unwrap();
@@ -370,6 +385,18 @@ async fn a_task_runs_asks_for_permission_and_survives_a_restart() {
         assert!(
             events.iter().any(|e| matches!(e, AgentEvent::Task { task } if task.status == AgentStatus::NeedsInput))
         );
+        let limits = events.iter().find_map(|e| match e {
+            AgentEvent::Limits { provider, limits } => Some((provider.as_str(), limits.clone())),
+            _ => None,
+        });
+        assert_eq!(
+            limits,
+            Some((
+                task.provider.as_str(),
+                vec![AgentLimit { window: "five_hour".into(), used_percent: 19.0, resets_ms: Some(5000.0) }]
+            )),
+            "an agent's usage limits are its provider's"
+        );
         let last_entry = events.iter().rev().find_map(|e| match e {
             AgentEvent::Entry { index, entry, .. } if !matches!(entry, AgentEntry::User { .. }) => {
                 Some((*index, entry.clone()))
@@ -772,6 +799,18 @@ fn retry_updates_become_a_countdown() {
     assert_eq!(retry_of(&json!({"sessionUpdate": RETRY_UPDATE}), 0.0), None, "no attempt");
 }
 
+#[test]
+fn usage_limits_and_cost_skip_what_is_malformed() {
+    let limits = config::limits_of(&json!({"sessionUpdate": LIMITS_UPDATE, "limits": [
+        {"window": "seven_day", "usedPercent": 140.0},
+        {"window": "", "usedPercent": 10.0},
+        {"window": "five_hour"},
+    ]}));
+    assert_eq!(limits, [AgentLimit { window: "seven_day".into(), used_percent: 100.0, resets_ms: None }]);
+    let usage = config::usage_of(&json!({"used": 1, "size": 2, "cost": {"amount": -1.0, "currency": "USD"}}));
+    assert_eq!(usage.map(|u| u.cost), Some(None), "a negative cost is dropped, the context use kept");
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn cursor_approval_switch_resolves_pending_and_survives_restart() {
     let tmp = tempfile::tempdir().unwrap();
@@ -942,3 +981,131 @@ async fn task_project_root_controls_local_and_worktree_repositories() {
     }
     assert_eq!(git(&["worktree", "list", "--porcelain"]).matches("worktree ").count(), 1);
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn reload_providers_updates_registry_install_clears_stale_probes_and_notifies_subscribers() {
+    let tmp = tempfile::tempdir().unwrap();
+    let agents_dir = tmp.path().join("agents");
+    std::fs::create_dir_all(&agents_dir).unwrap();
+    let fake_bin = tmp.path().join(if cfg!(windows) { "copilot.cmd" } else { "copilot" });
+    std::fs::write(&fake_bin, "").unwrap();
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        std::fs::set_permissions(&fake_bin, std::fs::Permissions::from_mode(0o755)).unwrap();
+    }
+
+    let agent = Arc::new(FakeAgent::default());
+    let connector: Connector = {
+        let agent = agent.clone();
+        Arc::new(move |_spec, _cwd, client, _stderr| {
+            let (a, b) = duplex(1 << 20);
+            let (ar, aw) = tokio::io::split(a);
+            let (br, bw) = tokio::io::split(b);
+            let server = Peer::connect_framed(br, bw, agent.clone(), Framing::Lines);
+            agent.servers.lock().push(server);
+            Ok(Peer::connect_framed(ar, aw, client, Framing::Lines))
+        })
+    };
+    let mgr = AgentManager::with_connector(
+        AgentPaths {
+            project_root: tmp.path().to_path_buf(),
+            store_dir: tmp.path().join("store"),
+            worktrees_dir: tmp.path().join("worktrees"),
+            models_file: tmp.path().join("models.json"),
+            custom_agents_dir: Some(agents_dir.clone()),
+            home_dir: None,
+        },
+        tokio::runtime::Handle::current(),
+        connector,
+    );
+
+    // Seed a stale failed probe for copilot before installing its custom TOML.
+    mgr.shared.probes.lock().insert(
+        "copilot".into(),
+        AgentProbe {
+            provider: "copilot".into(),
+            name: None,
+            version: None,
+            protocol: "ACP".into(),
+            capabilities: AgentCapabilities::default(),
+            auth_methods: Vec::new(),
+            error: Some("copilot --acp was not found on PATH.".into()),
+        },
+    );
+
+    let events = Arc::new(Mutex::new(Vec::new()));
+    let events_sink = events.clone();
+    mgr.subscribe(Arc::new(move |ev| events_sink.lock().push(ev)));
+
+    let toml = format!(
+        "name = \"GitHub Copilot\"\ncommand = {:?}\nargs = [\"--acp\", \"--stdio\"]\n",
+        fake_bin.to_string_lossy()
+    );
+    std::fs::write(agents_dir.join("copilot.toml"), toml).unwrap();
+
+    mgr.reload_providers();
+
+    assert!(events.lock().iter().any(|ev| matches!(ev, AgentEvent::Providers)));
+    assert!(!mgr.shared.probes.lock().contains_key("copilot"));
+
+    let copilot = mgr.providers().into_iter().find(|p| p.id == "copilot").unwrap();
+    assert!(copilot.installed);
+    assert!(copilot.command.contains(&*fake_bin.to_string_lossy()));
+
+    let probe = mgr.probe("copilot", false).await.unwrap();
+    assert!(probe.error.is_none());
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn idle_agents_stop_and_resume_their_session_on_the_next_message() {
+    let new = || NewAgentTask {
+        project_root: None,
+        prompt: text("again"),
+        provider: "claude".into(),
+        config: Vec::new(),
+        isolation: Isolation::Local,
+        base: None,
+    };
+    let live =
+        |mgr: &AgentManager, id: &str| mgr.task(id).unwrap().live.lock().as_ref().is_some_and(|l| !l.peer.is_closed());
+
+    let tmp = tempfile::tempdir().unwrap();
+    let agent = Arc::new(FakeAgent::default());
+    let mgr = manager(tmp.path(), agent.clone());
+    mgr.set_idle_release(Duration::from_millis(200));
+    let task = mgr.create(new()).await.unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    assert!(live(&mgr, &task.id));
+    // The process is stopped once the task stays idle…
+    tokio::time::sleep(Duration::from_millis(600)).await;
+    assert!(!live(&mgr, &task.id));
+    assert!(agent.servers.lock()[0].is_closed(), "its connection is closed");
+    assert_eq!(mgr.task(&task.id).unwrap().state.lock().task.status, AgentStatus::Ready, "not an error");
+    // …and the next message starts it again on the same session.
+    mgr.prompt(&task.id, text("again"), false).await.unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    assert!(agent.calls.lock().contains(&"session/load".to_owned()));
+    assert_eq!(
+        mgr.entries(&task.id, None).unwrap().iter().filter(|e| matches!(e, AgentEntry::Agent { .. })).count(),
+        2
+    );
+
+    // A new turn before the delay ran out keeps the agent.
+    mgr.prompt(&task.id, text("again"), false).await.unwrap();
+    tokio::time::sleep(Duration::from_millis(100)).await;
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    assert!(live(&mgr, &task.id));
+    mgr.shutdown();
+
+    // An agent that can't reload its session keeps running: stopping it would lose the conversation.
+    let tmp = tempfile::tempdir().unwrap();
+    let agent = Arc::new(FakeAgent { no_load: true, ..FakeAgent::default() });
+    let mgr = manager(tmp.path(), agent.clone());
+    mgr.set_idle_release(Duration::from_millis(200));
+    let task = mgr.create(new()).await.unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    tokio::time::sleep(Duration::from_millis(600)).await;
+    assert!(live(&mgr, &task.id));
+    mgr.shutdown();
+}

crates/ide-agent/src/worktree.rs

@@ -48,8 +48,24 @@ pub(crate) fn create(project_root: &Path, worktrees_dir: &Path, title: &str, bas
     Ok(Created { path, branch, base, base_commit })
 }
 
-pub(crate) fn remove(project_root: &Path, path: &Path) -> IdeResult<()> {
-    repo_at(project_root)?.remove_worktree(path, true)
+/// `git worktree remove --force -- <path>`. When git no longer recognizes the
+/// worktree (a pruned registration, a moved repository, a deleted `.git` file)
+/// it fails with "is not a working tree". A folder under `worktrees_dir` is still
+/// ours, so it is removed directly to keep the task deletable (a stale
+/// registration prunes later); anything else keeps git's error.
+pub(crate) fn remove(project_root: &Path, worktrees_dir: &Path, path: &Path) -> IdeResult<()> {
+    let repo = repo_at(project_root)?;
+    let err = match repo.remove_worktree(path, true) {
+        Ok(()) => return Ok(()),
+        Err(e) => e,
+    };
+    if !path.exists() {
+        return Ok(());
+    }
+    if !path.starts_with(worktrees_dir) || path == worktrees_dir {
+        return Err(err);
+    }
+    std::fs::remove_dir_all(path).map_err(|e| IdeError::internal(e.to_string()))
 }
 
 /// Files under `cwd` that differ from `base` (untracked files included), with line counts.
@@ -153,7 +169,7 @@ mod tests {
         assert!(snapshot(&dir).unwrap().is_empty());
         assert_eq!(file_at(&dir, &dir.join("a.txt"), "HEAD").unwrap(), None);
         assert!(create(&dir, &tmp.path().join("wt"), "Edit A", None).is_err());
-        assert!(remove(&dir, &dir).is_err());
+        assert!(remove(&dir, tmp.path(), &dir).is_err());
     }
 
     fn git(dir: &Path, args: &[&str]) {
@@ -202,7 +218,38 @@ mod tests {
 
         // A second task with the same title gets its own worktree.
         assert_eq!(create(&repo, &tmp.path().join("wt"), "Edit A", None).unwrap().branch, "agent/edit-a-2");
-        remove(&repo, &created.path).unwrap();
+        remove(&repo, &tmp.path().join("wt"), &created.path).unwrap();
         assert!(!created.path.exists());
     }
+
+    #[test]
+    fn a_broken_worktree_registration_still_leaves_a_deletable_folder() {
+        let tmp = tempfile::tempdir().unwrap();
+        let repo = tmp.path().join("repo");
+        std::fs::create_dir(&repo).unwrap();
+        git(&repo, &["init", "-q", "-b", "main"]);
+        std::fs::write(repo.join("a.txt"), "one\n").unwrap();
+        git(&repo, &["add", "."]);
+        git(&repo, &["commit", "-q", "-m", "init"]);
+
+        // A pruned registration (the repository moved, `git worktree prune` ran).
+        let created = create(&repo, &tmp.path().join("wt"), "Edit A", None).unwrap();
+        let registration = repo.join(".git/worktrees").join(created.path.file_name().unwrap());
+        std::fs::remove_dir_all(registration).unwrap();
+        remove(&repo, &tmp.path().join("wt"), &created.path).unwrap();
+        assert!(!created.path.exists());
+
+        // A deleted `.git` file in the worktree itself.
+        let created = create(&repo, &tmp.path().join("wt"), "Edit B", None).unwrap();
+        std::fs::remove_file(created.path.join(".git")).unwrap();
+        remove(&repo, &tmp.path().join("wt"), &created.path).unwrap();
+        assert!(!created.path.exists());
+
+        // A folder outside the worktrees directory is never deleted by hand.
+        let elsewhere = tmp.path().join("elsewhere");
+        std::fs::create_dir(&elsewhere).unwrap();
+        std::fs::write(elsewhere.join("keep.txt"), "x\n").unwrap();
+        assert!(remove(&repo, &tmp.path().join("wt"), &elsewhere).is_err());
+        assert!(elsewhere.join("keep.txt").exists());
+    }
 }

crates/ide-build/Cargo.toml

@@ -8,14 +8,12 @@ license.workspace = true
 [dependencies]
 dunce.workspace = true
 ide-core.workspace = true
+zip.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 specta.workspace = true
 tracing.workspace = true
 dirs.workspace = true
 
-[target.'cfg(unix)'.dependencies]
-libc = "0.2"
-
 [dev-dependencies]
 tempfile.workspace = true

crates/ide-build/src/application_update.rs

@@ -0,0 +1,218 @@
+//! Resource processing by the project's build tool, then publishing to the live JVM's output directory.
+use crate::BuildModel;
+use ide_core::{IdeError, IdeResult};
+use std::collections::BTreeMap;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+pub struct ResourceBuild {
+    pub command: String,
+    pub args: Vec<String>,
+    pub cwd: String,
+    pub env: BTreeMap<String, String>,
+    pub kind: &'static str,
+}
+
+fn literal(value: &str) -> String {
+    format!("'{}'", value.replace('\\', "\\\\").replace('\'', "\\'"))
+}
+
+pub fn plan(root: &Path, model: &BuildModel, module: &Path, cache: &Path) -> IdeResult<ResourceBuild> {
+    fs::create_dir_all(cache)?;
+    let manifest = cache.join("resource-output.txt");
+    if manifest.exists() {
+        fs::remove_file(&manifest)?;
+    }
+    let module = dunce::canonicalize(root.join(module))?;
+    if let Some(p) = model.maven.as_ref().and_then(|m| m.projects.iter().find(|p| root.join(&p.dir) == module)) {
+        let mut args = p.options.clone();
+        args.extend([
+            "process-resources".into(),
+            "help:evaluate".into(),
+            "-Dexpression=project.build.outputDirectory".into(),
+            format!("-Doutput={}", manifest.display()),
+        ]);
+        return Ok(ResourceBuild {
+            command: p.command.clone(),
+            args,
+            cwd: p.dir.clone(),
+            env: p.env.clone(),
+            kind: "maven",
+        });
+    }
+    if let Some(g) = &model.gradle
+        && let Some(p) = g.projects.iter().find(|p| root.join(&p.dir) == module)
+    {
+        let script = cache.join("resources.init.gradle");
+        fs::write(
+            &script,
+            format!(
+                r#"gradle.projectsEvaluated {{
+    def p = gradle.rootProject.project({})
+    def resources = p.tasks.named('processResources')
+    p.tasks.register('openideaUpdateResources') {{
+        dependsOn resources
+        doLast {{ new File({}).setText(resources.get().destinationDir.absolutePath, 'UTF-8') }}
+    }}
+}}
+"#,
+                literal(&p.path),
+                literal(&manifest.to_string_lossy())
+            ),
+        )?;
+        return Ok(ResourceBuild {
+            command: g.command.clone(),
+            args: vec![
+                "--init-script".into(),
+                script.to_string_lossy().into_owned(),
+                format!("{}:openideaUpdateResources", p.path.trim_end_matches(':')),
+            ],
+            cwd: g.dir.clone(),
+            env: g.env.clone(),
+            kind: "gradle",
+        });
+    }
+    Err(IdeError::invalid("The Spring Boot module must belong to a linked Maven or Gradle build"))
+}
+
+pub fn publish(root: &Path, cache: &Path, class_paths: &[String], main_class: &str) -> IdeResult<()> {
+    let output = PathBuf::from(fs::read_to_string(cache.join("resource-output.txt"))?.trim());
+    if !output.is_absolute() || !output.is_dir() {
+        return Err(IdeError::invalid("The resource build did not report an output directory"));
+    }
+    let output = dunce::canonicalize(output)?;
+    let paths: Vec<_> = class_paths.iter().filter_map(|p| dunce::canonicalize(root.join(p)).ok()).collect();
+    // A separate resource directory is already on the runtime classpath (e.g. build/resources/main).
+    if paths.contains(&output) {
+        return Ok(());
+    }
+    // jdtls uses bin/main for Gradle, rather than Gradle's build/resources/main.
+    let class_file = main_class.split('.').collect::<PathBuf>().with_extension("class");
+    let destination = paths.iter().find(|p| p.join(&class_file).is_file()).ok_or_else(|| {
+        IdeError::invalid("Cannot find the running main class output directory; restart the application")
+    })?;
+    let previous: Vec<String> = fs::read(cache.join("published-resources.json"))
+        .ok()
+        .and_then(|bytes| serde_json::from_slice(&bytes).ok())
+        .unwrap_or_default();
+    let mut current = Vec::new();
+    copy_resources(&output, &output, destination, &mut current)?;
+    for rel in previous.iter().filter(|p| !current.contains(p)) {
+        let path = destination.join(rel);
+        if path.is_file() {
+            fs::remove_file(path)?;
+        }
+    }
+    fs::write(
+        cache.join("published-resources.json"),
+        serde_json::to_vec(&current).map_err(|e| IdeError::internal(e.to_string()))?,
+    )?;
+    Ok(())
+}
+
+fn copy_resources(root: &Path, from: &Path, to: &Path, copied: &mut Vec<String>) -> IdeResult<()> {
+    for entry in fs::read_dir(from)? {
+        let entry = entry?;
+        let path = entry.path();
+        let kind = entry.file_type()?;
+        if kind.is_symlink() {
+            continue;
+        }
+        if kind.is_dir() {
+            copy_resources(root, &path, to, copied)?;
+        } else if kind.is_file() && path.extension().is_none_or(|e| e != "class") {
+            let rel = path.strip_prefix(root).map_err(|e| IdeError::internal(e.to_string()))?;
+            let dest = to.join(rel);
+            if let Some(parent) = dest.parent() {
+                fs::create_dir_all(parent)?;
+            }
+            fs::copy(&path, dest)?;
+            copied.push(rel.to_string_lossy().into_owned());
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn resource_plans_use_the_selected_module_and_build_configuration() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        fs::create_dir(root.join("app")).unwrap();
+        let mut model = BuildModel {
+            maven: Some(crate::MavenModel {
+                projects: vec![crate::MavenProject {
+                    dir: "app".into(),
+                    command: "/tools/mvnw".into(),
+                    options: vec!["-Pdev".into()],
+                    env: BTreeMap::from([("JAVA_HOME".into(), "/jdk".into())]),
+                    ..Default::default()
+                }],
+                ..Default::default()
+            }),
+            ..Default::default()
+        };
+        let cache = root.join("cache");
+        let maven = plan(&root, &model, Path::new("app"), &cache).unwrap();
+        assert_eq!(maven.command, "/tools/mvnw");
+        assert_eq!(maven.cwd, "app");
+        assert_eq!(maven.args[0..2], ["-Pdev", "process-resources"]);
+        assert!(maven.args.contains(&"-Dexpression=project.build.outputDirectory".into()));
+        assert_eq!(maven.env["JAVA_HOME"], "/jdk");
+        model.maven = None;
+        model.gradle = Some(crate::GradleModel {
+            command: "/tools/gradlew".into(),
+            projects: vec![crate::GradleProject { path: ":app".into(), dir: "app".into(), ..Default::default() }],
+            ..Default::default()
+        });
+        let gradle = plan(&root, &model, Path::new("app"), &cache).unwrap();
+        assert_eq!(gradle.command, "/tools/gradlew");
+        assert_eq!(gradle.args.last().unwrap(), ":app:openideaUpdateResources");
+        let script = fs::read_to_string(cache.join("resources.init.gradle")).unwrap();
+        assert!(script.contains("processResources") && script.contains("destinationDir.absolutePath"));
+        assert!(!script.contains("build/resources/main")); // The task owns custom output locations.
+    }
+
+    #[test]
+    fn publishes_maven_and_gradle_resource_outputs_to_the_runtime_classpath() {
+        for layout in ["target/classes", "build/resources/main", "custom resource output"] {
+            let tmp = tempfile::tempdir().unwrap();
+            let root = tmp.path();
+            let cache = root.join("cache");
+            let output = root.join(layout);
+            let runtime = if layout == "target/classes" { output.clone() } else { root.join("bin/main") };
+            fs::create_dir_all(output.join("static")).unwrap();
+            fs::create_dir_all(runtime.join("example")).unwrap();
+            fs::create_dir_all(&cache).unwrap();
+            fs::write(cache.join("resource-output.txt"), output.to_string_lossy().as_bytes()).unwrap();
+            fs::write(output.join("static/index.html"), "after").unwrap();
+            fs::write(output.join("unrelated.class"), "do not publish").unwrap();
+            fs::write(runtime.join("example/Application.class"), "running").unwrap();
+            publish(root, &cache, &[runtime.to_string_lossy().into_owned()], "example.Application").unwrap();
+            assert_eq!(fs::read_to_string(runtime.join("static/index.html")).unwrap(), "after");
+            assert_eq!(fs::read_to_string(runtime.join("example/Application.class")).unwrap(), "running");
+            if output != runtime {
+                assert!(!runtime.join("unrelated.class").exists());
+                fs::remove_file(output.join("static/index.html")).unwrap();
+                publish(root, &cache, &[runtime.to_string_lossy().into_owned()], "example.Application").unwrap();
+                assert!(!runtime.join("static/index.html").exists());
+            }
+        }
+    }
+
+    #[test]
+    fn leaves_separate_runtime_resource_directories_in_place_and_rejects_jar_only_runs() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let output = root.join("build/resources/main");
+        let cache = root.join("cache");
+        fs::create_dir_all(&output).unwrap();
+        fs::create_dir(&cache).unwrap();
+        fs::write(cache.join("resource-output.txt"), output.to_string_lossy().as_bytes()).unwrap();
+        publish(root, &cache, &[output.to_string_lossy().into_owned()], "a.Main").unwrap();
+        assert!(publish(root, &cache, &["app.jar".into()], "a.Main").is_err());
+    }
+}

crates/ide-build/src/compile/fingerprint.rs

@@ -0,0 +1,321 @@
+//! Metadata fingerprints for successful Maven launch builds.
+use super::*;
+use std::fs;
+use std::hash::{Hash, Hasher};
+use std::time::SystemTime;
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct LaunchFingerprint {
+    version: u32,
+    parameters: String,
+    files: BTreeMap<PathBuf, Option<(u64, SystemTime)>>,
+}
+
+fn scan(
+    path: &Path,
+    files: &mut BTreeMap<PathBuf, Option<(u64, SystemTime)>>,
+    ancestors: &mut HashSet<PathBuf>,
+    cancel: &CancellationToken,
+) -> IdeResult<()> {
+    if cancel.is_cancelled() {
+        return Err(IdeError::cancelled());
+    }
+    let meta = match fs::metadata(path) {
+        Ok(meta) => meta,
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+            files.insert(path.to_path_buf(), None);
+            return Ok(());
+        }
+        Err(e) => return Err(e.into()),
+    };
+    if meta.is_dir() {
+        let canonical = dunce::canonicalize(path)?;
+        if !ancestors.insert(canonical.clone()) {
+            return Err(IdeError::internal("cyclic launch input directory"));
+        }
+        // Directory mtimes change on irrelevant JDT writes. File paths detect additions/deletions.
+        files.insert(path.to_path_buf(), None);
+        for entry in fs::read_dir(path)? {
+            scan(&entry?.path(), files, ancestors, cancel)?;
+        }
+        ancestors.remove(&canonical);
+    } else if meta.is_file() {
+        files.insert(path.to_path_buf(), Some((meta.len(), meta.modified()?)));
+    } else {
+        return Err(IdeError::internal("unsupported launch input file"));
+    }
+    Ok(())
+}
+
+/// `None` means an input cannot be resolved safely: build normally without reuse.
+/// All filesystem work belongs on the caller's blocking thread.
+pub fn launch_fingerprint(
+    root: &Path,
+    model: &BuildModel,
+    module: &Path,
+    test: bool,
+    local_repo: Option<PathBuf>,
+    cancel: &CancellationToken,
+) -> IdeResult<Option<LaunchFingerprint>> {
+    let Some(m) = &model.maven else { return Ok(None) };
+    let projects = maven_launch_projects(root, m, module, test);
+    if projects.is_empty() {
+        return Ok(None);
+    }
+    let Some(mut inputs) = maven::launch_inputs(root, &projects, local_repo) else { return Ok(None) };
+    let plan = launch_plan(root, model, module, test)?;
+    let mut environment: BTreeMap<String, String> = std::env::vars()
+        .map(|(key, value)| (key.to_ascii_uppercase(), value))
+        .filter(|(key, _)| {
+            key.starts_with("MAVEN_")
+                || key.starts_with("JAVA_")
+                || key.starts_with("JDK_")
+                || matches!(
+                    key.as_str(),
+                    "PATH" | "HOME" | "LANG" | "LC_ALL" | "_JAVA_OPTIONS" | "M2_HOME" | "MAVEN_HOME"
+                )
+        })
+        .collect();
+    // Explicit step values override the inherited environment just as they do in Command.
+    for step in &plan.steps {
+        environment.extend(step.env.iter().map(|(key, value)| (key.to_ascii_uppercase(), value.clone())));
+        for dir in step.cwd.ancestors() {
+            inputs.extend([dir.join(".mvn"), dir.join("mvnw"), dir.join("mvnw.cmd")]);
+            if dir == root {
+                break;
+            }
+        }
+        let program = process::program_path(&step.program, &step.env);
+        inputs.push(program.clone());
+        // Maven installed via a symlink still reads conf from its distribution.
+        if let Ok(program) = dunce::canonicalize(program)
+            && let Some(home) = program.parent().and_then(Path::parent)
+        {
+            for conf in ["conf", "libexec/conf"] {
+                inputs.extend([home.join(conf).join("settings.xml"), home.join(conf).join("toolchains.xml")]);
+            }
+        }
+        if !environment.contains_key("JAVA_HOME") {
+            let java = process::program_path(if cfg!(windows) { "java.exe" } else { "java" }, &step.env);
+            inputs.push(java.clone());
+            if let Ok(java) = dunce::canonicalize(java)
+                && let Some(home) = java.parent().and_then(Path::parent)
+            {
+                inputs.push(home.join("release"));
+            }
+        }
+        for (i, arg) in step.args.iter().enumerate() {
+            if matches!(arg.as_str(), "-s" | "--settings" | "-gs" | "--global-settings" | "-t" | "--toolchains")
+                && let Some(file) = step.args.get(i + 1)
+            {
+                inputs.push(step.cwd.join(file));
+            }
+            for prefix in ["--settings=", "--global-settings=", "--toolchains="] {
+                if let Some(file) = arg.strip_prefix(prefix) {
+                    inputs.push(step.cwd.join(file));
+                }
+            }
+        }
+    }
+    if let Some(home) = dirs::home_dir() {
+        inputs.extend([home.join(".m2/settings.xml"), home.join(".m2/toolchains.xml")]);
+    }
+    for key in ["MAVEN_HOME", "M2_HOME"] {
+        if let Some(home) = environment.get(key) {
+            inputs.extend([Path::new(home).join("conf/settings.xml"), Path::new(home).join("conf/toolchains.xml")]);
+        }
+    }
+    if let Some(home) = environment.get("JAVA_HOME") {
+        inputs.extend([
+            Path::new(home).join("release"),
+            Path::new(home).join("lib/modules"),
+            Path::new(home).join("lib/tools.jar"),
+            Path::new(home).join(if cfg!(windows) { "bin/java.exe" } else { "bin/java" }),
+        ]);
+    }
+    let steps: Vec<_> =
+        plan.steps.iter().map(|s| (process::program_path(&s.program, &s.env), &s.args, &s.cwd, &s.env)).collect();
+    // Profiles and plugins can read arbitrary environment variables. Keep a signature
+    // of the inherited environment without persisting unrelated credentials.
+    let inherited: BTreeMap<_, _> = std::env::vars_os().collect();
+    let mut inherited_hash = std::hash::DefaultHasher::new();
+    inherited.hash(&mut inherited_hash);
+    let parameters =
+        serde_json::to_string(&(root, module, test, steps, environment, inherited_hash.finish(), projects))
+            .map_err(|e| IdeError::internal(e.to_string()))?;
+    let mut files = BTreeMap::new();
+    for path in inputs {
+        scan(&path, &mut files, &mut HashSet::new(), cancel)?;
+    }
+    // Store project inputs relative to the project, including each file's relative path.
+    let files = files.into_iter().map(|(p, stamp)| (p.strip_prefix(root).unwrap_or(&p).to_path_buf(), stamp)).collect();
+    Ok(Some(LaunchFingerprint { version: 1, parameters, files }))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn write(root: &Path, rel: &str, value: &str) {
+        let path = root.join(rel);
+        fs::create_dir_all(path.parent().unwrap()).unwrap();
+        fs::write(path, value).unwrap();
+    }
+
+    fn fixture(root: &Path) -> BuildModel {
+        write(
+            root,
+            "pom.xml",
+            r#"<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version>
+            <packaging>pom</packaging><modules><module>lib</module><module>app</module></modules></project>"#,
+        );
+        write(
+            root,
+            "lib/pom.xml",
+            r#"<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version></parent>
+            <artifactId>lib</artifactId><build><sourceDirectory>code</sourceDirectory><resources><resource><directory>conf</directory></resource></resources></build></project>"#,
+        );
+        write(
+            root,
+            "app/pom.xml",
+            r#"<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version></parent>
+            <artifactId>app</artifactId><dependencies><dependency><groupId>demo</groupId><artifactId>lib</artifactId><version>1</version></dependency></dependencies></project>"#,
+        );
+        write(root, "lib/src/main/kotlin/Channel.kt", "value");
+        write(root, "app/src/main/resources/app.properties", "key=value");
+        write(root, "lib/conf/custom.properties", "custom=value");
+        write(root, "lib/code/Custom.java", "class Custom {}");
+        BuildModel { maven: Some(maven::load(root)), ..Default::default() }
+    }
+
+    fn fingerprint(root: &Path, model: &BuildModel) -> Option<LaunchFingerprint> {
+        launch_fingerprint(root, model, &root.join("app"), false, None, &CancellationToken::new()).unwrap()
+    }
+
+    #[test]
+    fn unchanged_inputs_match_but_source_resource_pom_add_delete_and_mtime_invalidate() {
+        for rel in [
+            "lib/src/main/kotlin/Channel.kt",
+            "app/src/main/resources/app.properties",
+            "lib/conf/custom.properties",
+            "lib/code/Custom.java",
+            "app/pom.xml",
+            "lib/pom.xml",
+            "pom.xml",
+            ".mvn/maven.config",
+            "lib/src/main/groovy/New.groovy",
+            "app/src/test/scala/Test.scala",
+        ] {
+            let dir = tempfile::tempdir().unwrap();
+            let root = dir.path();
+            let model = fixture(root);
+            let before = fingerprint(root, &model);
+            assert!(before.is_some());
+            assert_eq!(before, fingerprint(root, &model), "unchanged {rel}");
+            let serialized = serde_json::to_vec(&before).unwrap();
+            assert_eq!(before, serde_json::from_slice(&serialized).unwrap());
+            let value = if rel.ends_with("pom.xml") {
+                format!("{}<!-- changed -->", fs::read_to_string(root.join(rel)).unwrap())
+            } else {
+                "changed input".to_owned()
+            };
+            write(root, rel, &value);
+            let changed = fingerprint(root, &model);
+            assert_ne!(before, changed, "changed/added {rel}");
+            let file = fs::OpenOptions::new().write(true).open(root.join(rel)).unwrap();
+            file.set_modified(SystemTime::UNIX_EPOCH + std::time::Duration::from_secs(42)).unwrap();
+            let touched = fingerprint(root, &model);
+            assert_ne!(changed, touched, "mtime-only {rel}");
+            fs::remove_file(root.join(rel)).unwrap();
+            assert_ne!(touched, fingerprint(root, &model), "deleted {rel}");
+        }
+    }
+
+    #[test]
+    fn profile_options_jdk_goal_and_wrapper_invalidate_without_using_class_outputs() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let mut model = fixture(root);
+        let before = fingerprint(root, &model);
+        write(root, "lib/target/classes/Channel.class", "JDT stub");
+        write(root, "app/target/classes/Main.class", "JDT stub");
+        assert_eq!(before, fingerprint(root, &model));
+        let mut previous = before.clone();
+        for option in ["-Pdev", "-Pprod", "-DskipTests", "-o"] {
+            model.maven.as_mut().unwrap().projects[0].options = vec![option.into()];
+            let current = fingerprint(root, &model);
+            assert_ne!(previous, current, "{option}");
+            previous = current;
+        }
+        model.maven.as_mut().unwrap().projects[0].options.clear();
+        model.maven.as_mut().unwrap().projects[0]
+            .env
+            .insert("JAVA_HOME".into(), root.join("jdk").to_string_lossy().into_owned());
+        let jdk = fingerprint(root, &model);
+        assert_ne!(before, jdk);
+        write(root, "jdk/release", "JAVA_VERSION=21");
+        assert_ne!(jdk, fingerprint(root, &model));
+        model.maven.as_mut().unwrap().projects[0].env.clear();
+        let test = launch_fingerprint(root, &model, &root.join("app"), true, None, &CancellationToken::new())
+            .unwrap()
+            .unwrap();
+        assert_ne!(before, Some(test));
+        write(root, "mvnw", "wrapper changed");
+        assert_ne!(before, fingerprint(root, &model));
+    }
+
+    #[test]
+    fn unresolved_roots_and_cancel_never_claim_up_to_date() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        write(
+            root,
+            "lib/pom.xml",
+            "<project><artifactId>lib</artifactId><build><sourceDirectory>${unknown}/src</sourceDirectory></build></project>",
+        );
+        assert!(
+            launch_fingerprint(root, &model, &root.join("app"), false, None, &CancellationToken::new())
+                .unwrap()
+                .is_none()
+        );
+        let model = fixture(root);
+        let cancel = CancellationToken::new();
+        cancel.cancel();
+        assert!(launch_fingerprint(root, &model, &root.join("app"), false, None, &cancel).is_err());
+    }
+    #[test]
+    fn external_parent_and_selected_settings_files_invalidate() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path().join("project");
+        let repo = dir.path().join("repository");
+        write(
+            &repo,
+            "demo/parent/1/parent-1.pom",
+            "<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version></project>",
+        );
+        write(
+            &root,
+            "pom.xml",
+            "<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version><relativePath/></parent><artifactId>app</artifactId></project>",
+        );
+        let mut model = crate::load(&root, &root.join("cache"), Some(repo.clone()));
+        let settings = dir.path().join("custom-settings.xml");
+        fs::write(&settings, "<settings/>").unwrap();
+        model.maven.as_mut().unwrap().projects[0].options = vec!["-s".into(), settings.to_string_lossy().into_owned()];
+        let get =
+            || launch_fingerprint(&root, &model, &root, false, Some(repo.clone()), &CancellationToken::new()).unwrap();
+        let before = get();
+        assert!(before.is_some());
+        write(
+            &repo,
+            "demo/parent/1/parent-1.pom",
+            "<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version><!-- changed --></project>",
+        );
+        let parent = get();
+        assert_ne!(before, parent);
+        fs::write(settings, "<settings><activeProfiles><activeProfile>dev</activeProfile></activeProfiles></settings>")
+            .unwrap();
+        assert_ne!(parent, get());
+    }
+}

crates/ide-build/src/compile/mod.rs

@@ -3,8 +3,11 @@
 //! background with cancellation and parses the compiler output into messages
 //! for the Build tool window, the Problems view and the editor.
 
+mod fingerprint;
 mod parse;
 
+pub use fingerprint::{LaunchFingerprint, launch_fingerprint};
+
 use crate::process::{self, Stream};
 use crate::{BuildModel, maven};
 use ide_core::{CancellationToken, Diagnostic, IdeError, IdeResult, Pos, Range, Severity};
@@ -155,8 +158,11 @@ fn detect_dir(dir: &Path, model: &BuildModel, root: &Path) -> Option<BuildSystem
 }
 
 /// `root/rel`, without a trailing separator for the root itself.
+/// `root` / `rel`, joined per `/`-separated component: on Windows a single join of
+/// `a/b` keeps the `/`, and such a path does not compare equal to the same directory
+/// as other tools (JDT LS) spell it.
 fn subdir(root: &Path, rel: &str) -> PathBuf {
-    if rel.is_empty() { root.to_path_buf() } else { root.join(rel) }
+    rel.split('/').filter(|part| !part.is_empty()).fold(root.to_path_buf(), |path, part| path.join(part))
 }
 
 fn rel_str(root: &Path, dir: &Path) -> String {
@@ -182,8 +188,10 @@ pub fn plan(root: &Path, model: &BuildModel, kind: BuildKind, file: Option<&Path
         None => None,
     };
     let dir = module_dir.clone().unwrap_or_else(|| root.to_path_buf());
+    // A folder of sibling projects has no build file itself; its Maven projects are built one by one.
     let system = detect_dir(&dir, model, root)
         .or_else(|| if model.gradle.is_some() { Some(BuildSystem::Gradle) } else { None })
+        .or_else(|| model.maven.as_ref().filter(|m| !m.projects.is_empty()).map(|_| BuildSystem::Maven))
         .ok_or_else(|| IdeError::not_found("no supported build system (Maven, Gradle, Cargo, Go, TypeScript) found"))?;
     let module = module_dir.as_deref().filter(|d| *d != root);
     let title = match module {
@@ -237,12 +245,7 @@ fn maven_steps(root: &Path, model: &BuildModel, kind: BuildKind, module: Option<
     if !m.projects.iter().any(|p| p.dir == rel) {
         return Err(IdeError::not_found("no linked Maven project found for module"));
     }
-    let top = tops
-        .iter()
-        .filter(|t| t.dir.is_empty() || rel == t.dir || rel.starts_with(&format!("{}/", t.dir)))
-        .max_by_key(|t| t.dir.len())
-        .copied()
-        .unwrap_or(tops[0]);
+    let top = maven_reactor(m, &rel).ok_or_else(|| IdeError::not_found("no linked Maven project found for module"))?;
     let top_dir = subdir(root, &top.dir);
     if module == top_dir {
         return Ok(vec![step(top, &[])]);
@@ -611,6 +614,90 @@ pub fn has_non_java_sources(module: &Path) -> bool {
     walk(&module.join("src"), 12)
 }
 
+fn reactor_projects<'a>(m: &'a maven::MavenModel, top: &'a maven::MavenProject) -> Vec<&'a maven::MavenProject> {
+    let mut projects = Vec::new();
+    let mut pending = vec![top];
+    let mut seen = HashSet::new();
+    while let Some(p) = pending.pop() {
+        if !seen.insert(&p.pom) {
+            continue;
+        }
+        projects.push(p);
+        pending.extend(m.projects.iter().filter(|child| p.modules.contains(&child.pom)));
+    }
+    projects
+}
+
+fn maven_reactor<'a>(m: &'a maven::MavenModel, module: &str) -> Option<&'a maven::MavenProject> {
+    m.projects.iter().filter(|p| !p.aggregated).find(|top| reactor_projects(m, top).iter().any(|p| p.dir == module))
+}
+
+/// Launch module first, followed by its upstream modules in the same Maven reactor.
+/// External artifacts and unrelated linked reactors are never rebuilt for this launch.
+fn maven_launch_projects<'a>(
+    root: &Path,
+    m: &'a maven::MavenModel,
+    module: &Path,
+    test: bool,
+) -> Vec<&'a maven::MavenProject> {
+    let rel = rel_str(root, module);
+    let Some(top) = maven_reactor(m, &rel) else { return Vec::new() };
+    let reactor = reactor_projects(m, top);
+    let Some(start) = reactor.iter().find(|p| p.dir == rel) else { return Vec::new() };
+    let mut pending = vec![*start];
+    let mut seen = HashSet::new();
+    let mut projects = Vec::new();
+    while let Some(p) = pending.pop() {
+        if !seen.insert(&p.pom) {
+            continue;
+        }
+        projects.push(p);
+        for dep in &p.dependencies {
+            if !dep.resolved() || (dep.scope == "test" && (!test || p.pom != start.pom)) {
+                continue;
+            }
+            if let Some(upstream) = reactor.iter().find(|u| {
+                u.group_id == dep.group_id
+                    && u.artifact_id == dep.artifact_id
+                    && dep.version.as_ref().is_none_or(|v| *v == u.version)
+            }) {
+                pending.push(*upstream);
+            }
+        }
+    }
+    projects
+}
+
+/// Whether a launch requires the external JVM compiler. Maven includes upstream
+/// reactor dependencies; adapter selection remains a separate, module-local decision.
+pub fn launch_has_non_java_sources(root: &Path, model: &BuildModel, module: &Path, test: bool) -> bool {
+    if let Some(m) = &model.maven {
+        let projects = maven_launch_projects(root, m, module, test);
+        if !projects.is_empty() {
+            return projects.iter().any(|p| has_non_java_sources(&subdir(root, &p.dir)));
+        }
+    }
+    has_non_java_sources(module)
+}
+
+fn launch_plan(root: &Path, model: &BuildModel, module: &Path, test: bool) -> IdeResult<BuildPlan> {
+    let kind = if model.maven.as_ref().is_some_and(|m| m.projects.iter().any(|p| subdir(root, &p.dir) == module)) {
+        // JDT may have left newer error stubs in Maven's output directories.
+        BuildKind::Rebuild
+    } else {
+        BuildKind::Build
+    };
+    let mut plan = plan(root, model, kind, Some(module))?;
+    if plan.system == BuildSystem::Maven && !test {
+        for step in &mut plan.steps {
+            if let Some(goal) = step.args.last_mut() {
+                *goal = "compile".into();
+            }
+        }
+    }
+    Ok(plan)
+}
+
 /// Compiles the module at `module` with its build system before a JVM launch and
 /// returns the class directories it wrote, to put ahead of the jdtls classpath.
 pub fn build_for_launch(
@@ -620,7 +707,7 @@ pub fn build_for_launch(
     test: bool,
     cancel: &CancellationToken,
 ) -> IdeResult<Vec<PathBuf>> {
-    let plan = plan(root, model, BuildKind::Build, Some(module))?;
+    let plan = launch_plan(root, model, module, test)?;
     let result = run(root, &plan, cancel, &|_| {})?;
     if !result.success {
         let errors: Vec<String> = result
@@ -635,6 +722,14 @@ pub fn build_for_launch(
             .collect();
         return Err(IdeError::internal(format!("Build failed:\n{}", errors.join("\n"))));
     }
+    if plan.system == BuildSystem::Maven
+        && let Some(m) = &model.maven
+    {
+        return Ok(maven_launch_projects(root, m, module, test)
+            .iter()
+            .flat_map(|p| launch_class_dirs(plan.system, &subdir(root, &p.dir), test && subdir(root, &p.dir) == module))
+            .collect());
+    }
     Ok(launch_class_dirs(plan.system, module, test))
 }
 
@@ -645,11 +740,11 @@ fn launch_class_dirs(system: BuildSystem, module: &Path, test: bool) -> Vec<Path
             .iter()
             .flat_map(|s| {
                 ["classes/kotlin", "classes/groovy", "classes/scala", "classes/java", "resources"]
-                    .map(|d| module.join("build").join(d).join(s))
+                    .map(|d| subdir(module, &format!("build/{d}/{s}")))
             })
             .collect(),
-        BuildSystem::Maven if test => vec![module.join("target/test-classes"), module.join("target/classes")],
-        BuildSystem::Maven => vec![module.join("target/classes")],
+        BuildSystem::Maven if test => vec![subdir(module, "target/test-classes"), subdir(module, "target/classes")],
+        BuildSystem::Maven => vec![subdir(module, "target/classes")],
         _ => Vec::new(),
     };
     dirs.into_iter().filter(|d| d.is_dir()).collect()
@@ -659,6 +754,30 @@ fn launch_class_dirs(system: BuildSystem, module: &Path, test: bool) -> Vec<Path
 mod tests {
     use super::*;
 
+    /// Launch outputs use the platform separator throughout, so they compare equal to
+    /// the same directories as JDT LS reports them.
+    #[test]
+    fn launch_dirs_use_one_separator() {
+        let root = tempfile::tempdir().unwrap();
+        let module = subdir(root.path(), "parent/app");
+        for dir in ["target/classes", "target/test-classes", "build/classes/java/main", "build/resources/test"] {
+            std::fs::create_dir_all(subdir(&module, dir)).unwrap();
+        }
+        let foreign = if std::path::MAIN_SEPARATOR == '\\' { '/' } else { '\\' };
+        let dirs = [
+            launch_class_dirs(BuildSystem::Maven, &module, true),
+            launch_class_dirs(BuildSystem::Gradle, &module, true),
+        ]
+        .concat();
+        assert_eq!(dirs.len(), 4, "{dirs:?}");
+        for dir in &dirs {
+            let suffix = dir.strip_prefix(root.path()).unwrap().to_string_lossy().into_owned();
+            assert!(!suffix.contains(foreign), "{suffix}");
+        }
+        assert_eq!(subdir(root.path(), ""), root.path());
+        assert_eq!(subdir(root.path(), "a//b/"), root.path().join("a").join("b"));
+    }
+
     fn write(root: &Path, rel: &str, text: &str) {
         let p = root.join(rel);
         std::fs::create_dir_all(p.parent().unwrap()).unwrap();
@@ -724,6 +843,17 @@ mod tests {
             ("pnpm", &["run".to_owned(), "build".to_owned()][..])
         );
 
+        let siblings = tmp.path().join("siblings");
+        write(&siblings, "core/pom.xml", "<project><artifactId>core</artifactId></project>");
+        write(&siblings, "system/pom.xml", "<project><artifactId>system</artifactId></project>");
+        let model = crate::load(&siblings, &tmp.path().join("cache3"), None);
+        let p = plan(&siblings, &model, BuildKind::Build, None).unwrap();
+        assert_eq!(p.system, BuildSystem::Maven);
+        assert_eq!(
+            p.steps.iter().map(|s| s.cwd.clone()).collect::<Vec<_>>(),
+            [siblings.join("core"), siblings.join("system")]
+        );
+
         let none = tmp.path().join("none");
         std::fs::create_dir_all(&none).unwrap();
         assert!(plan(&none, &BuildModel::default(), BuildKind::Build, None).is_err());
@@ -821,6 +951,142 @@ mod tests {
         }
     }
 
+    fn reactor_model() -> BuildModel {
+        let project = |dir: &str, deps: &[&str]| maven::MavenProject {
+            pom: format!("{dir}/pom.xml"),
+            dir: dir.into(),
+            group_id: "probe".into(),
+            artifact_id: dir.into(),
+            version: "1".into(),
+            aggregated: true,
+            dependencies: deps
+                .iter()
+                .map(|d| maven::MavenDependency {
+                    group_id: "probe".into(),
+                    artifact_id: (*d).into(),
+                    version: Some("1".into()),
+                    scope: "compile".into(),
+                    ..Default::default()
+                })
+                .collect(),
+            ..Default::default()
+        };
+        let mut projects = vec![
+            project("app", &["middle"]),
+            project("middle", &["lib"]),
+            project("lib", &["app"]),
+            project("unrelated", &[]),
+        ];
+        projects.insert(
+            0,
+            maven::MavenProject {
+                pom: "pom.xml".into(),
+                artifact_id: "reactor".into(),
+                command: "mvnw".into(),
+                modules: projects.iter().map(|p| p.pom.clone()).collect(),
+                options: vec!["-s".into(), "settings.xml".into()],
+                env: BTreeMap::from([("JAVA_HOME".into(), "/jdk".into())]),
+                ..Default::default()
+            },
+        );
+        BuildModel { maven: Some(maven::MavenModel { projects, ..Default::default() }), ..Default::default() }
+    }
+
+    #[test]
+    fn mixed_launch_detection_follows_only_reactor_dependencies() {
+        for extension in ["kt", "groovy", "scala"] {
+            let tmp = tempfile::tempdir().unwrap();
+            let root = tmp.path();
+            let mut model = reactor_model();
+            write(root, "app/src/main/java/Application.java", "class Application {}");
+            write(root, &format!("unrelated/src/main/java/Other.{extension}"), "");
+            assert!(!launch_has_non_java_sources(root, &model, &root.join("app"), false));
+            write(root, &format!("lib/src/main/java/Channel.{extension}"), "");
+            assert!(launch_has_non_java_sources(root, &model, &root.join("app"), false));
+            assert_eq!(
+                maven_launch_projects(root, model.maven.as_ref().unwrap(), &root.join("app"), false).len(),
+                3,
+                "cycles terminate"
+            );
+            let m = model.maven.as_mut().unwrap();
+            m.projects[2].dependencies[0].scope = "test".into();
+            assert!(
+                !launch_has_non_java_sources(root, &model, &root.join("app"), true),
+                "upstream test dependencies are not transitive"
+            );
+            let m = model.maven.as_mut().unwrap();
+            m.projects[1].dependencies[0].scope = "test".into();
+            m.projects[2].dependencies[0].scope = "compile".into();
+            assert!(!launch_has_non_java_sources(root, &model, &root.join("app"), false));
+            assert!(launch_has_non_java_sources(root, &model, &root.join("app"), true));
+            model.maven.as_mut().unwrap().projects[2].dependencies[0].version = Some("external".into());
+            assert!(!launch_has_non_java_sources(root, &model, &root.join("app"), true));
+            model.maven.as_mut().unwrap().projects[2].dependencies[0].version = Some("1".into());
+            model.maven.as_mut().unwrap().projects[3].aggregated = false;
+            model.maven.as_mut().unwrap().projects[0].modules.retain(|p| p != "lib/pom.xml");
+            assert!(
+                !launch_has_non_java_sources(root, &model, &root.join("app"), true),
+                "another linked reactor is external"
+            );
+        }
+    }
+
+    #[test]
+    fn maven_launch_steps_use_reactor_settings_and_launch_scope() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        write(root, "app/pom.xml", "<project/>");
+        let model = reactor_model();
+        for (test, goal) in [(false, "compile"), (true, "test-compile")] {
+            let plan = launch_plan(root, &model, &root.join("app"), test).unwrap();
+            let step = &plan.steps[0];
+            assert_eq!(step.cwd, root);
+            assert_eq!(step.program, "mvnw");
+            assert_eq!(step.env["JAVA_HOME"], "/jdk");
+            assert_eq!(
+                step.args,
+                ["-B", "-Dstyle.color=never", "-s", "settings.xml", "-pl", "app", "-am", "clean", goal]
+            );
+        }
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn external_launch_returns_upstream_outputs_and_blocks_failure_or_cancellation() {
+        use std::os::unix::fs::PermissionsExt;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        write(root, "app/pom.xml", "<project/>");
+        write(
+            root,
+            "mvnw",
+            "#!/bin/sh\nmkdir -p app/target/classes middle/target/classes lib/target/classes app/target/test-classes\n",
+        );
+        let wrapper = root.join("mvnw");
+        std::fs::set_permissions(&wrapper, std::fs::Permissions::from_mode(0o755)).unwrap();
+        let mut model = reactor_model();
+        model.maven.as_mut().unwrap().projects[0].command = wrapper.to_string_lossy().into_owned();
+        let dirs = build_for_launch(root, &model, &root.join("app"), true, &CancellationToken::new()).unwrap();
+        assert_eq!(
+            dirs,
+            ["app/target/test-classes", "app/target/classes", "middle/target/classes", "lib/target/classes"]
+                .map(|p| root.join(p))
+        );
+        write(
+            root,
+            "mvnw",
+            "#!/bin/sh\necho '[ERROR] Kotlin compilation failed: unresolved reference broken' >&2\nexit 1\n",
+        );
+        let error = build_for_launch(root, &model, &root.join("app"), false, &CancellationToken::new()).unwrap_err();
+        assert!(error.message.contains("Kotlin compilation failed"), "{}", error.message);
+        let cancel = CancellationToken::new();
+        cancel.cancel();
+        assert_eq!(
+            build_for_launch(root, &model, &root.join("app"), false, &cancel).unwrap_err().kind,
+            ide_core::error::ErrorKind::Cancelled
+        );
+    }
+
     #[test]
     fn non_java_launch_class_dirs() {
         let tmp = tempfile::tempdir().unwrap();

crates/ide-build/src/gradle-model.gradle

@@ -0,0 +1,40 @@
+// OpenIDEA Gradle sync: prints each project as Gradle evaluated it, one JSON line per project.
+// Read by `ide_build::gradle::parse_reported_projects`. Dependencies are not resolved: the
+// Java language server reads the classpath itself, and resolving is the slow part of an import.
+import groovy.json.JsonOutput
+
+def canon = { File f -> f.canonicalPath }
+// Init scripts also run in included builds and buildSrc, whose projects reuse `:`, `:core`…:
+// the identity path (`:lib:core`, `:buildSrc`) tells them apart and addresses their tasks
+// from the root build. Internal API, hence the fallback.
+def identity = { Project p -> try { p.identityPath.toString() } catch (ignored) { p.path } }
+
+def describe = { Project p ->
+    def m = [path: identity(p), dir: canon(p.projectDir), buildDir: canon(p.layout.buildDirectory.get().asFile)]
+    if (p.gradle.parent != null) m.build = identity(p.rootProject)
+    def sets = p.extensions.findByName('sourceSets')
+    if (sets != null) {
+        // Test source sets as IDEA classifies them: `test`, test fixtures, JVM test suites,
+        // and sets whose folders the `idea` plugin lists as test sources.
+        def suites = [] as Set
+        try { p.extensions.findByName('testing')?.suites?.each { suites << it.sources.name } } catch (ignored) {}
+        def ideaTests = [] as Set
+        try { p.extensions.findByName('idea')?.module?.testSources?.files?.each { ideaTests << canon(it) } } catch (ignored) {}
+        m.sourceSets = sets.collect { s ->
+            def res = s.resources.srcDirs.collect(canon)
+            def src = s.allSource.srcDirs.collect(canon) - res
+            def test = s.name == 'test' || s.name == 'testFixtures' || suites.contains(s.name) ||
+                s.name.endsWith('Test') || s.name.endsWith('Tests') ||
+                (!src.isEmpty() && src.every { ideaTests.contains(it) })
+            [name: s.name, test: test, src: src, res: res]
+        }
+    }
+    try {
+        def java = p.extensions.findByName('java')
+        def lv = java?.toolchain?.languageVersion?.getOrNull()
+        m.java = lv != null ? lv.asInt() : (java?.targetCompatibility?.majorVersion as Integer)
+    } catch (ignored) {}
+    println '@openidea-model\t' + JsonOutput.toJson(m)
+}
+
+gradle.projectsEvaluated { g -> g.rootProject.allprojects { describe(it) } }

crates/ide-build/src/gradle.rs

@@ -32,7 +32,8 @@ pub struct GradleModel {
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 pub struct GradleProject {
-    /// Gradle path: `:` for the root project, `:app`, `:libs:core`.
+    /// Gradle path: `:` for the root project, `:app`, `:libs:core`; for a project of a
+    /// nested build its identity path (`:lib:core`), which addresses its tasks from the root.
     pub path: String,
     pub name: String,
     /// Project-relative directory.
@@ -40,6 +41,10 @@ pub struct GradleProject {
     /// Project-relative build script, if any.
     pub build_file: Option<String>,
     pub tasks: Vec<GradleTask>,
+    /// Identity path of the nested build holding the project (`:lib` for `includeBuild`,
+    /// `:buildSrc`); null for the opened build.
+    #[serde(default)]
+    pub build: Option<String>,
 }
 
 #[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
@@ -129,35 +134,88 @@ fn include_args(after: &str) -> Vec<String> {
     out
 }
 
-/// `(root project name, included project paths)` from a settings script.
-pub fn parse_settings(text: &str) -> (Option<String>, Vec<String>) {
+/// What a settings script declares, read statically.
+#[derive(Debug, Default, PartialEq)]
+pub struct Settings {
+    pub name: Option<String>,
+    /// Included project paths (`:app`), in declaration order.
+    pub includes: Vec<String>,
+    /// Project directories that differ from the default `<path>` under the build
+    /// dir, relative to it: `includeFlat` siblings and literal `projectDir = file(..)`.
+    pub dirs: BTreeMap<String, String>,
+}
+
+/// The included projects, root project name and directory overrides of a settings script.
+/// Interpolated (`"$m"`) names and directories cannot be read without Gradle and are skipped.
+pub fn parse_settings(text: &str) -> Settings {
     let text = strip_comments(text);
-    let mut name = None;
-    let mut includes: Vec<String> = Vec::new();
+    let mut s = Settings::default();
     for (i, _) in text.match_indices("rootProject.name") {
         let line = text[i + "rootProject.name".len()..].lines().next().unwrap_or_default();
         if let Some(n) = literals(line).into_iter().next() {
-            name = Some(n);
+            s.name = Some(n);
         }
     }
     let mut from = 0;
     while let Some(i) = text[from..].find("include") {
         let at = from + i;
         from = at + "include".len();
+        let flat = text[from..].starts_with("Flat");
+        if flat {
+            from += "Flat".len();
+        }
         let before_ok = at == 0 || !text[..at].ends_with(|c: char| c.is_alphanumeric() || c == '_' || c == '.');
         let after = &text[from..];
         let after_ok = after.starts_with(|c: char| c == '(' || c.is_whitespace());
         if !before_ok || !after_ok {
             continue;
         }
-        for p in include_args(after) {
+        for p in include_args(after).into_iter().filter(|p| !p.contains('$')) {
             let path = if p.starts_with(':') { p } else { format!(":{p}") };
-            if path.len() > 1 && !includes.contains(&path) {
-                includes.push(path);
+            if path.len() <= 1 {
+                continue;
+            }
+            // `includeFlat 'a'` is the sibling directory `../a` of the root project.
+            if flat {
+                s.dirs.insert(path.clone(), format!("../{}", path.trim_start_matches(':')));
+            }
+            if !s.includes.contains(&path) {
+                s.includes.push(path);
             }
         }
     }
-    (name, includes)
+    // `project(':a').projectDir = file('../a')`; a later assignment wins, as in Gradle.
+    for line in text.lines() {
+        let Some((left, right)) = line.split_once(".projectDir") else { continue };
+        let Some(right) = right.trim_start().strip_prefix('=') else { continue };
+        let Some(arg) = right.trim_start().strip_prefix("file") else { continue };
+        let (Some(path), Some(dir)) = (
+            left.rsplit_once("project").map(|(_, p)| literals(p)).and_then(|l| l.into_iter().next()),
+            literals(arg).into_iter().next(),
+        ) else {
+            continue;
+        };
+        if !path.contains('$') && !dir.contains('$') {
+            let path = if path.starts_with(':') { path } else { format!(":{path}") };
+            s.dirs.insert(path, dir);
+        }
+    }
+    s
+}
+
+/// `a/b/../c` → `a/c`, without touching the filesystem.
+fn normalize(p: &Path) -> PathBuf {
+    let mut out = PathBuf::new();
+    for c in p.components() {
+        match c {
+            std::path::Component::CurDir => {}
+            std::path::Component::ParentDir if out.file_name().is_some() => {
+                out.pop();
+            }
+            c => out.push(c),
+        }
+    }
+    out
 }
 
 /// The directory of the Gradle build under `root`: the root itself, or a direct
@@ -235,31 +293,159 @@ pub fn default_tasks(is_root: bool, script: &str) -> Vec<GradleTask> {
 }
 
 /// Reads the Gradle build under `root` (no Gradle run), or `None` when there is none.
+fn read_first(d: &Path, names: &[&str]) -> Option<(String, String)> {
+    names.iter().find_map(|n| std::fs::read_to_string(d.join(n)).ok().map(|t| (n.to_string(), t)))
+}
+
+/// The project `path` in `pdir`, with the default tasks of its build script.
+/// Outside `root` the directory stays absolute (`rel` falls back).
+fn project_at(root: &Path, path: String, name: String, pdir: &Path) -> GradleProject {
+    let script = read_first(pdir, BUILD_FILES);
+    let tasks = default_tasks(path == ":", script.as_ref().map(|(_, t)| t.as_str()).unwrap_or_default());
+    GradleProject {
+        build_file: script.map(|(n, _)| rel(root, &pdir.join(n))),
+        dir: rel(root, pdir),
+        path,
+        name,
+        tasks,
+        build: None,
+    }
+}
+
+/// A project as Gradle evaluated it (the sync's init script, `gradle-model.gradle`).
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ReportedProject {
+    pub path: String,
+    /// Absolute, canonical.
+    pub dir: String,
+    /// Absolute output folder (`layout.buildDirectory`).
+    #[serde(default)]
+    pub build_dir: Option<String>,
+    #[serde(default)]
+    pub source_sets: Vec<ReportedSourceSet>,
+    /// Toolchain language version, else target compatibility.
+    #[serde(default)]
+    pub java: Option<u32>,
+    /// Identity path of the nested build (included build, buildSrc) reporting the project.
+    #[serde(default)]
+    pub build: Option<String>,
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
+pub struct ReportedSourceSet {
+    pub name: String,
+    pub test: bool,
+    /// Absolute source folders (Java, Kotlin, Groovy, …), which need not exist.
+    #[serde(default)]
+    pub src: Vec<String>,
+    /// Absolute resource folders.
+    #[serde(default)]
+    pub res: Vec<String>,
+}
+
+const MODEL_LINE: &str = "@openidea-model\t";
+
+/// The projects printed by `gradle-model.gradle`; malformed lines are skipped.
+pub fn parse_reported_projects(output: &str) -> Vec<ReportedProject> {
+    output.lines().filter_map(|l| serde_json::from_str(l.trim_end().strip_prefix(MODEL_LINE)?).ok()).collect()
+}
+
+/// Source roots of the reported source sets: `(absolute folder, is test, is resources)`.
+pub fn reported_source_roots(reported: &[ReportedProject]) -> Vec<(PathBuf, ReportedRoot)> {
+    let mut out: Vec<(PathBuf, ReportedRoot)> = Vec::new();
+    for p in reported {
+        for set in &p.source_sets {
+            let (src, res) = if set.test {
+                (ReportedRoot::Test, ReportedRoot::TestResources)
+            } else {
+                (ReportedRoot::Source, ReportedRoot::Resources)
+            };
+            for (dir, kind) in set.src.iter().map(|d| (d, src)).chain(set.res.iter().map(|d| (d, res))) {
+                let dir = PathBuf::from(dir);
+                // A folder shared by `main` and another set is `main`'s, as in IDEA.
+                if !out.iter().any(|(d, _)| *d == dir) {
+                    out.push((dir, kind));
+                }
+            }
+        }
+        // IDEA excludes the build folder of every module.
+        if let Some(b) = &p.build_dir {
+            out.push((PathBuf::from(b), ReportedRoot::Excluded));
+        }
+    }
+    out
+}
+
+/// Role of a folder a Gradle sync reported.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum ReportedRoot {
+    Source,
+    Test,
+    Resources,
+    TestResources,
+    Excluded,
+}
+
+/// Replaces the statically read projects with the ones Gradle reported (root first):
+/// settings scripts may compute their projects, which no static reading sees.
+pub fn merge_reported_projects(root: &Path, model: &mut GradleModel, reported: &[ReportedProject]) {
+    if reported.is_empty() {
+        return;
+    }
+    let root_name = model.projects.iter().find(|p| p.path == ":").map(|p| p.name.clone());
+    model.projects = reported
+        .iter()
+        .map(|p| {
+            let name = match p.path.as_str() {
+                ":" => root_name.clone().unwrap_or_default(),
+                path => path.rsplit(':').next().unwrap_or_default().to_owned(),
+            };
+            let mut project = project_at(root, p.path.clone(), name, Path::new(&p.dir));
+            // buildSrc is built before the build, never addressable as `:buildSrc:<task>`.
+            if p.build.as_deref().is_some_and(|b| b.ends_with(":buildSrc")) {
+                project.tasks.clear();
+            }
+            project.build = p.build.clone();
+            project
+        })
+        .collect();
+    // Each build reports its projects when it is evaluated (nested builds first).
+    model.projects.sort_by(|a, b| a.path.cmp(&b.path));
+    // One JDK runs the whole build: the newest any module needs.
+    if let Some(v) = reported.iter().filter_map(|p| p.java).max() {
+        model.java_version = Some(v);
+    }
+}
+
+/// Project directories outside `root`, outermost only (`../svc`, not also `../svc/sources/app`):
+/// the folders IDEA shows as extra top-level module roots.
+pub fn external_roots<'a>(root: &Path, dirs: impl IntoIterator<Item = &'a str>) -> Vec<PathBuf> {
+    let mut dirs: Vec<PathBuf> = dirs.into_iter().map(|d| root.join(d)).filter(|d| !d.starts_with(root)).collect();
+    dirs.sort();
+    dirs.dedup();
+    let mut out: Vec<PathBuf> = Vec::new();
+    for d in dirs {
+        if !out.iter().any(|o| d.starts_with(o)) {
+            out.push(d);
+        }
+    }
+    out
+}
+
 pub fn load(root: &Path) -> Option<GradleModel> {
     let dir = build_dir(root)?;
-    let read = |d: &Path, names: &[&str]| {
-        names.iter().find_map(|n| std::fs::read_to_string(d.join(n)).ok().map(|t| (n.to_string(), t)))
-    };
-    let (name, includes) = read(&dir, SETTINGS_FILES).map(|(_, t)| parse_settings(&t)).unwrap_or_default();
+    let settings = read_first(&dir, SETTINGS_FILES).map(|(_, t)| parse_settings(&t)).unwrap_or_default();
     let root_name =
-        name.unwrap_or_else(|| dir.file_name().map(|n| n.to_string_lossy().into_owned()).unwrap_or_default());
-    let mut projects = Vec::new();
-    let mut add = |path: String, name: String, pdir: PathBuf| {
-        let script = read(&pdir, BUILD_FILES);
-        let tasks = default_tasks(path == ":", script.as_ref().map(|(_, t)| t.as_str()).unwrap_or_default());
-        projects.push(GradleProject {
-            build_file: script.map(|(n, _)| rel(root, &pdir.join(n))),
-            dir: rel(root, &pdir),
-            path,
-            name,
-            tasks,
-        });
-    };
-    add(":".into(), root_name, dir.clone());
-    for path in includes {
-        let pdir = dir.join(path.trim_start_matches(':').replace(':', "/"));
+        settings.name.unwrap_or_else(|| dir.file_name().map(|n| n.to_string_lossy().into_owned()).unwrap_or_default());
+    let mut projects = vec![project_at(root, ":".into(), root_name, &dir)];
+    for path in settings.includes {
+        let pdir = match settings.dirs.get(&path) {
+            Some(d) => normalize(&dir.join(d)),
+            None => dir.join(path.trim_start_matches(':').replace(':', "/")),
+        };
         let name = path.rsplit(':').next().unwrap_or_default().to_owned();
-        add(path, name, pdir);
+        projects.push(project_at(root, path, name, &pdir));
     }
     let java_version = projects
         .iter()
@@ -358,9 +544,32 @@ pub fn build_files(root: &Path, model: &GradleModel) -> Vec<PathBuf> {
     let dir = root.join(&model.dir);
     let mut out: Vec<PathBuf> = SETTINGS_FILES.iter().map(|f| dir.join(f)).filter(|p| p.is_file()).collect();
     out.extend(model.projects.iter().filter_map(|p| p.build_file.as_ref().map(|f| root.join(f))));
+    // The settings of each nested build (its root project's folder).
+    for p in model.projects.iter().filter(|p| p.build.as_deref() == Some(p.path.as_str())) {
+        let nested = root.join(&p.dir);
+        out.extend(SETTINGS_FILES.iter().map(|f| nested.join(f)).filter(|f| f.is_file()));
+    }
+    // What IDEA's auto-import also watches: properties, the wrapper and version catalogs.
+    let extra = ["gradle.properties", "gradle/wrapper/gradle-wrapper.properties"].map(|f| dir.join(f));
+    out.extend(extra.into_iter().filter(|p| p.is_file()));
+    if let Ok(entries) = std::fs::read_dir(dir.join("gradle")) {
+        let mut catalogs: Vec<PathBuf> = entries
+            .flatten()
+            .map(|e| e.path())
+            .filter(|p| p.to_string_lossy().ends_with(".versions.toml") && p.is_file())
+            .collect();
+        catalogs.sort();
+        out.extend(catalogs);
+    }
     out
 }
 
+/// A build script without comments and with whitespace runs collapsed, so editing a
+/// comment or reformatting does not make a sync stale (IDEA hashes lexer tokens alike).
+pub(crate) fn script_fingerprint(text: &str) -> String {
+    strip_comments(text).split_whitespace().collect::<Vec<_>>().join(" ")
+}
+
 /// `(project path, task)` from `gradle tasks --all` console output; tasks listed as
 /// `app:run` belong to `:app`, unqualified ones to the root project `:`.
 pub fn parse_tasks(output: &str) -> Vec<(String, GradleTask)> {
@@ -451,14 +660,60 @@ dependencies {
             /* include("block") */
             includeBuild("plugins")
         "#;
-        let (name, includes) = parse_settings(kts);
-        assert_eq!(name.as_deref(), Some("gradle-demo"));
-        assert_eq!(includes, [":app", ":lib", ":libs:core"]);
+        let s = parse_settings(kts);
+        assert_eq!(s.name.as_deref(), Some("gradle-demo"));
+        assert_eq!(s.includes, [":app", ":lib", ":libs:core"]);
+        assert!(s.dirs.is_empty());
 
         let groovy = "rootProject.name = 'demo'\ninclude 'a',\n        'b'\ninclude ':c'\nprintln 'x'\n";
-        let (name, includes) = parse_settings(groovy);
-        assert_eq!(name.as_deref(), Some("demo"));
-        assert_eq!(includes, [":a", ":b", ":c"]);
+        let s = parse_settings(groovy);
+        assert_eq!(s.name.as_deref(), Some("demo"));
+        assert_eq!(s.includes, [":a", ":b", ":c"]);
+    }
+
+    #[test]
+    fn settings_include_flat_and_project_dirs() {
+        let groovy = r#"
+            includeFlat 'svc-a'
+            includeFlat 'svc-b', 'svc-c' // trailing comment
+            ['x', 'y'].each { m -> include ":svc-a:$m" }
+            include ':wo'
+            project(':wo').projectDir = file('../svc-a/.worktrees/wo')
+            project(":dyn").projectDir = file("${rootDir}/dyn")
+            includeFlated 'not-a-call'
+        "#;
+        let s = parse_settings(groovy);
+        assert_eq!(s.includes, [":svc-a", ":svc-b", ":svc-c", ":wo"]);
+        assert_eq!(
+            s.dirs.into_iter().collect::<Vec<_>>(),
+            [
+                (":svc-a".into(), "../svc-a".into()),
+                (":svc-b".into(), "../svc-b".into()),
+                (":svc-c".into(), "../svc-c".into()),
+                (":wo".into(), "../svc-a/.worktrees/wo".into()),
+            ]
+        );
+
+        let kts = "includeFlat(\"k\")\nproject(\":k\").projectDir = file(\"../other\")";
+        let s = parse_settings(kts);
+        assert_eq!(s.includes, [":k"]);
+        assert_eq!(s.dirs.get(":k").map(String::as_str), Some("../other"));
+    }
+
+    #[test]
+    fn loads_include_flat_siblings() {
+        let tmp = tempfile::tempdir().unwrap();
+        let ws = tmp.path();
+        std::fs::create_dir_all(ws.join("root")).unwrap();
+        std::fs::create_dir_all(ws.join("svc")).unwrap();
+        std::fs::write(ws.join("root/settings.gradle"), "rootProject.name = 'Root'\nincludeFlat 'svc'").unwrap();
+        std::fs::write(ws.join("svc/build.gradle"), "plugins { id 'java' }").unwrap();
+        let root = ws.join("root");
+        let m = load(&root).unwrap();
+        let svc = m.projects.iter().find(|p| p.path == ":svc").unwrap();
+        assert_eq!(Path::new(&svc.dir), ws.join("svc"));
+        assert_eq!(svc.build_file.as_deref().map(Path::new), Some(ws.join("svc/build.gradle").as_path()));
+        assert!(root.join(svc.build_file.as_ref().unwrap()).is_file());
     }
 
     #[test]
@@ -539,4 +794,52 @@ Pattern: clean<TaskName>: Cleans the output files of a task.
         let none = tempfile::tempdir().unwrap();
         assert!(load(none.path()).is_none());
     }
+
+    #[test]
+    fn merges_included_builds_and_build_src_by_identity_path() {
+        let tmp = tempfile::tempdir().unwrap();
+        let ws = tmp.path();
+        for d in ["shop/app", "shop/buildSrc", "lib/core"] {
+            std::fs::create_dir_all(ws.join(d)).unwrap();
+        }
+        std::fs::write(ws.join("shop/settings.gradle"), "rootProject.name = 'shop'\ninclude 'app'").unwrap();
+        std::fs::write(ws.join("lib/settings.gradle"), "include 'core'").unwrap();
+        let root = ws.join("shop");
+        // In evaluation order, as the init script prints it: nested builds first.
+        let line = |path: &str, d: &str, build: Option<&str>| {
+            let project = ReportedProject {
+                path: path.into(),
+                dir: ws.join(d).to_string_lossy().into_owned(),
+                build: build.map(Into::into),
+                ..ReportedProject::default()
+            };
+            format!("{MODEL_LINE}{}\n", serde_json::to_string(&project).unwrap())
+        };
+        let out = [
+            line(":lib", "lib", Some(":lib")),
+            line(":lib:core", "lib/core", Some(":lib")),
+            line(":buildSrc", "shop/buildSrc", Some(":buildSrc")),
+            line(":", "shop", None),
+            line(":app", "shop/app", None),
+        ]
+        .concat();
+        let mut model = load(&root).unwrap();
+        merge_reported_projects(&root, &mut model, &parse_reported_projects(&out));
+        let projects: Vec<_> =
+            model.projects.iter().map(|p| (p.path.as_str(), p.name.as_str(), p.build.as_deref())).collect();
+        assert_eq!(
+            projects,
+            [
+                (":", "shop", None),
+                (":app", "app", None),
+                (":buildSrc", "buildSrc", Some(":buildSrc")),
+                (":lib", "lib", Some(":lib")),
+                (":lib:core", "core", Some(":lib")),
+            ]
+        );
+        let build_src = &model.projects[2];
+        assert!(build_src.tasks.is_empty(), "buildSrc tasks cannot run from the root build");
+        assert!(!model.projects[4].tasks.is_empty());
+        assert!(build_files(&root, &model).contains(&ws.join("lib/settings.gradle")));
+    }
 }

crates/ide-build/src/kotlin_bridge.rs

@@ -0,0 +1,475 @@
+//! Private Maven builds for JDT's Kotlin binary libraries. Never use launch outputs.
+
+use crate::BuildModel;
+use crate::compile::{self, BuildEvent, BuildKind, BuildMessage};
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use serde::{Deserialize, Serialize};
+use std::collections::BTreeMap;
+use std::path::{Path, PathBuf};
+
+#[derive(Clone, Debug, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct Module {
+    key: String,
+    project_uri: String,
+    output: PathBuf,
+    test_output: Option<PathBuf>,
+    dependencies: Vec<Dependency>,
+    has_kotlin: bool,
+    kotlin_goals: Vec<KotlinGoal>,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+struct KotlinGoal {
+    execution: String,
+    status: String,
+}
+
+#[derive(Clone, Debug, Deserialize)]
+struct Dependency {
+    key: String,
+    scope: String,
+    #[serde(rename = "type")]
+    kind: Option<String>,
+    classifier: Option<String>,
+}
+
+#[derive(Clone, Debug, Serialize, PartialEq, Eq)]
+pub struct Library {
+    pub path: PathBuf,
+    pub test: bool,
+}
+
+#[derive(Clone, Debug, Serialize, PartialEq, Eq)]
+#[serde(rename_all = "camelCase")]
+pub struct ProjectLibraries {
+    pub project_uri: String,
+    pub libraries: Vec<Library>,
+}
+
+pub struct Outcome {
+    pub projects: Vec<ProjectLibraries>,
+    pub messages: Vec<BuildMessage>,
+    pub success: bool,
+}
+
+/// Inspect sources, excluding generated/build/VCS trees and never following symlinks.
+pub fn has_kotlin(root: &Path) -> bool {
+    let Ok(entries) = std::fs::read_dir(root) else { return false };
+    entries.flatten().any(|entry| {
+        let Ok(kind) = entry.file_type() else { return false };
+        if kind.is_file() {
+            entry.path().extension().is_some_and(|e| e == "kt")
+        } else {
+            kind.is_dir()
+                && !matches!(
+                    entry.file_name().to_str(),
+                    Some("target" | "build" | "out" | "bin" | "node_modules" | ".git" | ".openidea")
+                )
+                && has_kotlin(&entry.path())
+        }
+    })
+}
+
+/// Run the project's configured wrapper/settings/JDK and lifecycle, with an output
+/// redirector loaded before Maven calculates its lifecycle execution plans.
+pub fn build(
+    root: &Path,
+    model: &BuildModel,
+    bundle: &Path,
+    generation: &Path,
+    cancel: &CancellationToken,
+) -> IdeResult<Outcome> {
+    std::fs::create_dir_all(generation)?;
+    let mut plan = compile::plan(root, model, BuildKind::Build, None)?;
+    if plan.system != compile::BuildSystem::Maven {
+        return Err(IdeError::invalid("Kotlin bridge requires a Maven build root"));
+    }
+    let mut manifests = Vec::new();
+    for (index, step) in plan.steps.iter_mut().enumerate() {
+        step.args.push("--fail-at-end".into());
+        let directory = generation.join(format!("reactor-{index}"));
+        std::fs::create_dir_all(&directory)?;
+        manifests.push(directory.join("modules.json"));
+        let mut extensions = vec![bundle.to_path_buf()];
+        step.args.retain(|arg| {
+            if let Some(value) = arg.strip_prefix("-Dmaven.ext.class.path=") {
+                extensions.extend(std::env::split_paths(value));
+                false
+            } else {
+                true
+            }
+        });
+        let extension_path = std::env::join_paths(extensions).map_err(|e| IdeError::invalid(e.to_string()))?;
+        step.args.push(format!("-Dmaven.ext.class.path={}", extension_path.to_string_lossy()));
+        step.args.push(format!("-Dopenidea.kotlin.staging={}", directory.join("staging").display()));
+    }
+    let mut messages = Vec::new();
+    // Independent linked reactors must still run after another reactor's javac fails.
+    for step in &plan.steps {
+        let mut reactor = plan.clone();
+        reactor.steps = vec![step.clone()];
+        let result = compile::run(root, &reactor, cancel, &|event| {
+            if let BuildEvent::Output { text, .. } = event {
+                tracing::debug!("kotlin bridge: {}", text.trim_end());
+            }
+        })?;
+        messages.extend(result.messages);
+    }
+    // javac diagnostics belong to JDT, including when a Kotlin target was skipped.
+    messages.retain(|message| {
+        message.path.as_ref().is_some_and(|path| PathBuf::from(path.clone()).extension().is_some_and(|e| e == "kt"))
+    });
+    let mut modules = Vec::new();
+    for manifest in manifests {
+        let parsed: Vec<Module> = serde_json::from_slice(&std::fs::read(manifest)?)
+            .map_err(|e| IdeError::internal(format!("Kotlin module manifest: {e}")))?;
+        modules.extend(parsed);
+    }
+    messages.extend(kotlin_failures(&modules));
+    if messages.iter().any(|message| message.severity == ide_core::Severity::Error) {
+        return Ok(Outcome { projects: Vec::new(), messages, success: false });
+    }
+    let pending = generation.join("libraries.pending");
+    let published = generation.join("libraries");
+    std::fs::create_dir_all(&pending)?;
+    let mut libraries = BTreeMap::new();
+    for (index, module) in modules.iter().enumerate() {
+        let mut outputs = ModuleLibraries::default();
+        for (source, target, name) in [
+            (Some(&module.output), &mut outputs.main, format!("main-{index}")),
+            (module.test_output.as_ref(), &mut outputs.test, format!("test-{index}")),
+        ] {
+            let Some(source) = source else { continue };
+            if !source.starts_with(generation) {
+                return Err(IdeError::internal("Kotlin build output escaped staging"));
+            }
+            if copy_kotlin(source, &pending.join(&name), cancel)? {
+                *target = Some(published.join(name));
+            }
+        }
+        libraries.insert(module.key.clone(), outputs);
+    }
+    publish(&pending, &published, cancel)?;
+    Ok(Outcome { projects: consumers(&modules, &libraries), messages, success: true })
+}
+
+fn kotlin_failures(modules: &[Module]) -> Vec<BuildMessage> {
+    let mut messages = Vec::new();
+    for module in modules {
+        if !module.has_kotlin {
+            continue;
+        }
+        if module.kotlin_goals.is_empty() {
+            messages.push(kotlin_failure(module, "compile target was not executed"));
+        }
+        for goal in &module.kotlin_goals {
+            if goal.status != "success" {
+                messages.push(kotlin_failure(module, &format!("{} {}", goal.execution, goal.status)));
+            }
+        }
+    }
+    messages
+}
+
+fn kotlin_failure(module: &Module, reason: &str) -> BuildMessage {
+    BuildMessage {
+        severity: ide_core::Severity::Error,
+        text: format!("Kotlin compilation for {}: {reason}", module.key),
+        path: None,
+        range: None,
+        code: None,
+    }
+}
+
+fn publish(pending: &Path, published: &Path, cancel: &CancellationToken) -> IdeResult<()> {
+    if cancel.is_cancelled() {
+        return Err(IdeError::cancelled());
+    }
+    std::fs::rename(pending, published)?;
+    Ok(())
+}
+
+#[derive(Default)]
+struct ModuleLibraries {
+    main: Option<PathBuf>,
+    test: Option<PathBuf>,
+}
+
+fn consumers(modules: &[Module], libraries: &BTreeMap<String, ModuleLibraries>) -> Vec<ProjectLibraries> {
+    modules
+        .iter()
+        .map(|consumer| {
+            let mut visible = Vec::<Library>::new();
+            let mut add = |path: &Option<PathBuf>, test: bool| {
+                if let Some(path) = path {
+                    if let Some(previous) = visible.iter_mut().find(|entry| &entry.path == path) {
+                        previous.test &= test;
+                    } else {
+                        visible.push(Library { path: path.clone(), test });
+                    }
+                }
+            };
+            if let Some(own) = libraries.get(&consumer.key) {
+                add(&own.test, true);
+                add(&own.main, false);
+            }
+            // Maven's resolved artifacts already apply exclusions, mediation and optional
+            // propagation. Preserve their classpath order, after the module's own output.
+            for dependency in &consumer.dependencies {
+                let Some(output) = libraries.get(&dependency.key) else { continue };
+                let test = match dependency.scope.as_str() {
+                    "compile" | "provided" | "system" | "" => false,
+                    "test" | "runtime" => true,
+                    _ => continue,
+                };
+                match (dependency.kind.as_deref(), dependency.classifier.as_deref()) {
+                    (Some("test-jar"), None | Some("tests")) | (Some("jar"), Some("tests")) => add(&output.test, test),
+                    (None | Some("jar"), None | Some("")) => add(&output.main, test),
+                    _ => {}
+                }
+            }
+            ProjectLibraries { project_uri: consumer.project_uri.clone(), libraries: visible }
+        })
+        .collect()
+}
+
+fn copy_kotlin(source: &Path, destination: &Path, cancel: &CancellationToken) -> IdeResult<bool> {
+    let Ok(entries) = std::fs::read_dir(source) else { return Ok(false) };
+    let mut found = false;
+    for entry in entries {
+        if cancel.is_cancelled() {
+            return Err(IdeError::cancelled());
+        }
+        let entry = entry?;
+        let kind = entry.file_type()?;
+        let path = entry.path();
+        let output = destination.join(entry.file_name());
+        if kind.is_dir() {
+            found |= copy_kotlin(&path, &output, cancel)?;
+        } else if kind.is_file() {
+            let bytes = std::fs::read(&path)?;
+            let class = path.extension().is_some_and(|e| e == "class");
+            let metadata = path.extension().is_some_and(|e| e == "kotlin_module");
+            if metadata || (class && kotlin_class(&bytes).unwrap_or(false)) {
+                std::fs::create_dir_all(destination)?;
+                std::fs::write(output, bytes)?;
+                found |= class;
+            }
+        }
+    }
+    Ok(found)
+}
+
+/// Read the actual class-level SourceFile attribute, rather than searching strings
+/// (a Java constant containing "Something.kt" must never become a Kotlin library).
+fn kotlin_class(bytes: &[u8]) -> Option<bool> {
+    struct Reader<'a> {
+        bytes: &'a [u8],
+        pos: usize,
+    }
+    impl<'a> Reader<'a> {
+        fn take(&mut self, count: usize) -> Option<&'a [u8]> {
+            let value = self.bytes.get(self.pos..self.pos.checked_add(count)?)?;
+            self.pos += count;
+            Some(value)
+        }
+        fn u2(&mut self) -> Option<usize> {
+            Some(u16::from_be_bytes(self.take(2)?.try_into().ok()?) as usize)
+        }
+        fn u4(&mut self) -> Option<usize> {
+            Some(u32::from_be_bytes(self.take(4)?.try_into().ok()?) as usize)
+        }
+        fn attributes(&mut self) -> Option<()> {
+            for _ in 0..self.u2()? {
+                self.u2()?;
+                let n = self.u4()?;
+                self.take(n)?;
+            }
+            Some(())
+        }
+    }
+    let mut reader = Reader { bytes, pos: 0 };
+    if reader.take(4)? != [0xca, 0xfe, 0xba, 0xbe] {
+        return None;
+    }
+    reader.take(4)?;
+    let count = reader.u2()?;
+    let mut utf8 = BTreeMap::new();
+    let mut index = 1;
+    while index < count {
+        match reader.take(1)?[0] {
+            1 => {
+                let n = reader.u2()?;
+                utf8.insert(index, reader.take(n)?);
+            }
+            3 | 4 | 9..=12 | 17 | 18 => {
+                reader.take(4)?;
+            }
+            5 | 6 => {
+                reader.take(8)?;
+                index += 1;
+            }
+            7 | 8 | 16 | 19 | 20 => {
+                reader.take(2)?;
+            }
+            15 => {
+                reader.take(3)?;
+            }
+            _ => return None,
+        }
+        index += 1;
+    }
+    reader.take(6)?;
+    let interfaces = reader.u2()?;
+    reader.take(interfaces.checked_mul(2)?)?;
+    for _ in 0..2 {
+        for _ in 0..reader.u2()? {
+            reader.take(6)?;
+            reader.attributes()?;
+        }
+    }
+    for _ in 0..reader.u2()? {
+        let name = reader.u2()?;
+        let length = reader.u4()?;
+        if utf8.get(&name).copied() == Some(b"SourceFile".as_slice()) && length == 2 {
+            let source = reader.u2()?;
+            return Some(utf8.get(&source)?.ends_with(b".kt"));
+        }
+        reader.take(length)?;
+    }
+    Some(false)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn every_kotlin_target_must_succeed_even_when_maven_fails_elsewhere() {
+        let mut modules: Vec<Module> = serde_json::from_str(r#"[
+            {"key":"lib","projectUri":"lib","output":"lib","dependencies":[],"hasKotlin":true,
+             "kotlinGoals":[{"execution":"main:compile","status":"success"},{"execution":"test:test-compile","status":"success"}]},
+            {"key":"java","projectUri":"java","output":"java","dependencies":[],"hasKotlin":false,"kotlinGoals":[]}
+        ]"#).unwrap();
+        assert!(kotlin_failures(&modules).is_empty());
+        for status in ["failed", "skipped"] {
+            modules[0].kotlin_goals[1].status = status.into();
+            let failures = kotlin_failures(&modules);
+            assert_eq!(failures.len(), 1);
+            assert!(failures[0].text.contains(&format!("test:test-compile {status}")));
+        }
+        modules[0].kotlin_goals.clear();
+        assert_eq!(kotlin_failures(&modules).len(), 1);
+        modules[0].has_kotlin = false;
+        assert!(kotlin_failures(&modules).is_empty());
+        assert!(
+            serde_json::from_str::<Vec<Module>>(
+                r#"[{"key":"old","projectUri":"old","output":"old","dependencies":[]}]"#
+            )
+            .is_err()
+        );
+    }
+
+    #[test]
+    fn respects_mavens_resolved_closure_and_scopes() {
+        let json = r#"[
+          {"key":"zapp","projectUri":"app","output":"app", "hasKotlin":false,"kotlinGoals":[],"dependencies":[{"key":"mid","scope":"compile","optional":false},{"key":"lib","scope":"compile","optional":false}]},
+          {"key":"mid","projectUri":"mid","output":"mid", "hasKotlin":false,"kotlinGoals":[],"dependencies":[
+            {"key":"lib","scope":"compile","optional":false},
+            {"key":"optional","scope":"compile","optional":true},
+            {"key":"test","scope":"test","optional":false},
+            {"key":"provided","scope":"provided","optional":false}]},
+          {"key":"lib","projectUri":"lib","output":"lib","hasKotlin":false,"kotlinGoals":[],"dependencies":[]}
+        ]"#;
+        let modules: Vec<Module> = serde_json::from_str(json).unwrap();
+        let libraries = ["zapp", "lib", "optional", "test", "provided"]
+            .into_iter()
+            .map(|key| (key.to_owned(), ModuleLibraries { main: Some(PathBuf::from(key)), test: None }))
+            .collect();
+        let result = consumers(&modules, &libraries);
+        assert_eq!(
+            result[0].libraries,
+            vec![Library { path: "zapp".into(), test: false }, Library { path: "lib".into(), test: false },]
+        );
+        assert_eq!(result[1].libraries.len(), 4);
+        assert!(result[1].libraries.iter().find(|l| l.path == Path::new("test")).unwrap().test);
+    }
+
+    #[test]
+    fn test_outputs_are_private_unless_maven_resolves_a_test_jar() {
+        let modules: Vec<Module> = serde_json::from_str(r#"[
+          {"key":"lib","projectUri":"lib","output":"lib","hasKotlin":false,"kotlinGoals":[],"dependencies":[]},
+          {"key":"app","projectUri":"app","output":"app","hasKotlin":false,"kotlinGoals":[],"dependencies":[{"key":"lib","scope":"compile","type":"jar","classifier":null}]},
+          {"key":"test-app","projectUri":"test-app","output":"app","hasKotlin":false,"kotlinGoals":[],"dependencies":[{"key":"lib","scope":"test","type":"test-jar","classifier":"tests"}]}
+        ]"#).unwrap();
+        let libraries =
+            BTreeMap::from([("lib".into(), ModuleLibraries { main: Some("main".into()), test: Some("test".into()) })]);
+        let result = consumers(&modules, &libraries);
+        assert_eq!(
+            result[0].libraries,
+            vec![Library { path: "test".into(), test: true }, Library { path: "main".into(), test: false }]
+        );
+        assert_eq!(result[1].libraries, vec![Library { path: "main".into(), test: false }]);
+        assert_eq!(result[2].libraries, vec![Library { path: "test".into(), test: true }]);
+    }
+
+    #[test]
+    fn publishes_complete_directories_and_cancellation_keeps_them_private() {
+        let directory = tempfile::tempdir().unwrap();
+        let pending = directory.path().join("pending");
+        let final_path = directory.path().join("published");
+        std::fs::create_dir(&pending).unwrap();
+        std::fs::write(pending.join("Channel.class"), "complete").unwrap();
+        let cancelled = CancellationToken::new();
+        cancelled.cancel();
+        assert!(publish(&pending, &final_path, &cancelled).is_err());
+        assert!(!final_path.exists());
+        assert!(pending.exists());
+        publish(&pending, &final_path, &CancellationToken::new()).unwrap();
+        assert!(!pending.exists());
+        assert_eq!(std::fs::read(final_path.join("Channel.class")).unwrap(), b"complete");
+    }
+
+    #[test]
+    fn never_runs_another_build_system_with_maven_output_properties() {
+        let directory = tempfile::tempdir().unwrap();
+        std::fs::write(directory.path().join("Cargo.toml"), "").unwrap();
+        let error = build(
+            directory.path(),
+            &BuildModel::default(),
+            Path::new("unused.jar"),
+            &directory.path().join("private"),
+            &CancellationToken::new(),
+        )
+        .err()
+        .unwrap();
+        assert_eq!(error.message, "Kotlin bridge requires a Maven build root");
+    }
+
+    #[test]
+    fn does_not_find_deleted_sources_in_build_outputs() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::create_dir_all(dir.path().join("target/generated")).unwrap();
+        std::fs::write(dir.path().join("target/generated/Old.kt"), "").unwrap();
+        assert!(!has_kotlin(dir.path()));
+        std::fs::write(dir.path().join("New.kt"), "").unwrap();
+        assert!(has_kotlin(dir.path()));
+    }
+
+    #[test]
+    fn parses_sourcefile_and_rejects_truncated_classes() {
+        let mut class = vec![0xca, 0xfe, 0xba, 0xbe, 0, 0, 0, 52, 0, 3, 1, 0, 10];
+        class.extend_from_slice(b"SourceFile");
+        class.extend_from_slice(&[1, 0, 10]);
+        class.extend_from_slice(b"Channel.kt");
+        class.extend_from_slice(&[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 2, 0, 2]);
+        assert_eq!(kotlin_class(&class), Some(true));
+        for end in 0..class.len() {
+            assert!(kotlin_class(&class[..end]).is_none());
+        }
+        let offset = 26;
+        class[offset..offset + 10].copy_from_slice(b"Other.java");
+        assert_eq!(kotlin_class(&class), Some(false));
+    }
+}

crates/ide-build/src/lib.rs

@@ -5,8 +5,10 @@
 //! and merges what the last sync ([`sync_maven`] / [`sync_gradle`], which run
 //! Maven / Gradle in the background) cached for the project.
 
+pub mod application_update;
 pub mod compile;
 pub mod gradle;
+pub mod kotlin_bridge;
 pub mod maven;
 pub mod pom_edit;
 mod process;
@@ -16,7 +18,7 @@ mod xml;
 
 pub use gradle::{GradleModel, GradleProject, GradleTask};
 pub use maven::{MavenDependency, MavenModel, MavenPlugin, MavenProfile, MavenProject, Omission};
-pub use sync::{SyncOptions, SyncProgress, sync_gradle, sync_maven};
+pub use sync::{SyncOptions, SyncProgress, maven_profiles, save_maven_profiles, sync_gradle, sync_maven};
 
 use serde::{Deserialize, Serialize};
 use specta::Type;
@@ -63,6 +65,18 @@ pub fn load_linked(
     BuildModel { maven, gradle }
 }
 
+/// Gradle project folders outside `root` as of the last sync (`includeFlat` siblings):
+/// extra content roots, as IDEA lists module roots beside the project folder.
+/// Reads only the sync's cached projects (no build script), so it is cheap enough for hot paths.
+pub fn gradle_external_roots(root: &Path, cache_dir: &Path) -> Vec<PathBuf> {
+    gradle::external_roots(root, sync::reported_gradle_projects(cache_dir).iter().map(|p| p.dir.as_str()))
+}
+
+/// Source, resource and build folders of the last Gradle sync, absolute.
+pub fn gradle_source_roots(cache_dir: &Path) -> Vec<(PathBuf, gradle::ReportedRoot)> {
+    gradle::reported_source_roots(&sync::reported_gradle_projects(cache_dir))
+}
+
 /// A library the project depends on, as `groupId:artifactId:version`.
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct DependencyCoordinate {

crates/ide-build/src/maven.rs

@@ -11,7 +11,9 @@ use crate::xml::{self, Element};
 use serde::{Deserialize, Serialize};
 use specta::Type;
 use std::collections::{BTreeMap, HashMap, HashSet};
+use std::io::Read;
 use std::path::{Path, PathBuf};
+use std::sync::{Mutex, OnceLock};
 
 /// Phases shown under "Lifecycle" (IDEA's default list).
 pub const LIFECYCLE: &[&str] =
@@ -243,7 +245,8 @@ struct RawPom {
     plugins: Vec<RawPlugin>,
     managed_plugins: Vec<RawPlugin>,
     profiles: Vec<RawProfile>,
-    /// `<build><plugins>` `maven-compiler-plugin` `<release>` / `<source>`.
+    /// `maven-compiler-plugin` `<release>` / `<source>` of `<build><plugins>`, else of
+    /// `<pluginManagement>`.
     compiler_release: Option<String>,
 }
 
@@ -285,11 +288,29 @@ fn texts(e: &Element, path: &str, item: &str) -> Vec<String> {
     e.list(path, item).iter().map(|m| m.text.trim().to_owned()).filter(|m| !m.is_empty()).collect()
 }
 
+/// Child modules of a project or profile: `<modules>` (model 4.0.0) plus `<subprojects>`,
+/// which Maven 4 (model 4.1.0) uses instead.
+fn module_names(e: &Element) -> Vec<String> {
+    let mut names = texts(e, "modules", "module");
+    names.extend(texts(e, "subprojects", "subproject"));
+    names
+}
+
 fn read_build(e: &Element, plugins: &mut Vec<RawPlugin>, managed: &mut Vec<RawPlugin>) {
     plugins.extend(e.list("build/plugins", "plugin").into_iter().filter_map(read_plugin));
     managed.extend(e.list("build/pluginManagement/plugins", "plugin").into_iter().filter_map(read_plugin));
 }
 
+/// `maven-compiler-plugin` `<release>` / `<source>` among the plugins at `path`.
+fn compiler_level(project: &Element, path: &str) -> Option<String> {
+    project
+        .list(path, "plugin")
+        .into_iter()
+        .find(|p| p.text_of("artifactId").as_deref() == Some("maven-compiler-plugin"))
+        .and_then(|p| p.child("configuration"))
+        .and_then(|c| c.text_of("release").or_else(|| c.text_of("source")))
+}
+
 fn read_raw(project: &Element) -> RawPom {
     let parent = project.child("parent").and_then(|p| {
         Some(ParentRef {
@@ -308,7 +329,7 @@ fn read_raw(project: &Element) -> RawPom {
         name: project.text_of("name"),
         parent,
         properties: read_properties(project.child("properties")),
-        modules: texts(project, "modules", "module"),
+        modules: module_names(project),
         deps: project.list("dependencies", "dependency").into_iter().filter_map(read_dep).collect(),
         managed: project
             .list("dependencyManagement/dependencies", "dependency")
@@ -318,18 +339,13 @@ fn read_raw(project: &Element) -> RawPom {
         ..RawPom::default()
     };
     read_build(project, &mut pom.plugins, &mut pom.managed_plugins);
-    if let Some(c) = pom.plugins.iter().position(|p| p.artifact_id == "maven-compiler-plugin") {
-        let plugin =
-            project.list("build/plugins", "plugin").into_iter().filter(|p| p.text_of("artifactId").is_some()).nth(c);
-        if let Some(cfg) = plugin.and_then(|p| p.child("configuration")) {
-            pom.compiler_release = cfg.text_of("release").or_else(|| cfg.text_of("source"));
-        }
-    }
+    pom.compiler_release =
+        compiler_level(project, "build/plugins").or_else(|| compiler_level(project, "build/pluginManagement/plugins"));
     for p in project.list("profiles", "profile") {
         let mut profile = RawProfile {
             id: p.text_of("id").unwrap_or_else(|| "default".into()),
             active_by_default: p.at("activation/activeByDefault").is_some_and(|a| a.text.trim() == "true"),
-            modules: texts(p, "modules", "module"),
+            modules: module_names(p),
             properties: read_properties(p.child("properties")),
             deps: p.list("dependencies", "dependency").into_iter().filter_map(read_dep).collect(),
             ..RawProfile::default()
@@ -401,6 +417,9 @@ struct Inherited {
     managed: Vec<RawDep>,
     plugins: Vec<RawPlugin>,
     managed_plugins: Vec<RawPlugin>,
+    /// The nearest `maven-compiler-plugin` `<release>` / `<source>`: a module usually
+    /// inherits its compiler level from the parent's (managed) plugin configuration.
+    compiler_release: Option<String>,
     /// `<id>`, `activeByDefault`: profiles of the POM and its ancestors —
     /// Maven lets a child enable a parent's profiles with `-P`.
     profiles: Vec<(String, bool)>,
@@ -448,13 +467,20 @@ struct Resolver {
 /// `~/.m2/repository`, or `<localRepository>` from `~/.m2/settings.xml`.
 pub(crate) fn default_local_repo() -> Option<PathBuf> {
     let m2 = dirs::home_dir()?.join(".m2");
-    if let Some(settings) = std::fs::read_to_string(m2.join("settings.xml")).ok().and_then(|t| xml::parse(&t))
-        && let Some(repo) = settings.text_of("localRepository")
-    {
-        let home = dirs::home_dir().map(|h| h.to_string_lossy().into_owned()).unwrap_or_default();
-        return Some(PathBuf::from(repo.replace("${user.home}", &home)));
+    local_repository_of(&m2.join("settings.xml")).or(Some(m2.join("repository")))
+}
+
+/// `<localRepository>` of a settings file, when it names one: the repository a build
+/// with `-s <file>` resolves into, which is not necessarily the user's default.
+pub fn local_repository_of(settings: &Path) -> Option<PathBuf> {
+    let text = std::fs::read_to_string(settings).ok()?;
+    let root = xml::parse(&text)?;
+    let repo = root.text_of("localRepository")?.trim().to_owned();
+    if repo.is_empty() {
+        return None;
     }
-    Some(m2.join("repository"))
+    let home = dirs::home_dir().map(|h| h.to_string_lossy().into_owned()).unwrap_or_default();
+    Some(PathBuf::from(repo.replace("${user.home}", &home)))
 }
 
 impl Resolver {
@@ -521,6 +547,9 @@ impl Resolver {
         merge_by(&mut ctx.deps, &pom.deps, RawDep::key);
         merge_plugins(&mut ctx.plugins, &pom.plugins);
         merge_plugins(&mut ctx.managed_plugins, &pom.managed_plugins);
+        if pom.compiler_release.is_some() {
+            ctx.compiler_release = pom.compiler_release.clone();
+        }
         for p in pom.profiles.iter().filter(|p| p.active_by_default) {
             merge_by(&mut ctx.properties, &p.properties, |(k, _)| k.clone());
             merge_by(&mut ctx.deps, &p.deps, RawDep::key);
@@ -601,6 +630,72 @@ impl Resolver {
     }
 }
 
+/// Files and source/resource trees consumed by a launch build. Unresolved custom
+/// roots disable reuse rather than silently omitting an input.
+pub(crate) fn launch_inputs(
+    root: &Path,
+    projects: &[&MavenProject],
+    local_repo: Option<PathBuf>,
+) -> Option<Vec<PathBuf>> {
+    fn roots(el: &Element, parent: &str, dir: &Path, out: &mut Vec<PathBuf>) -> Option<()> {
+        let input =
+            matches!(el.name.as_str(), "sourceDirectory" | "testSourceDirectory" | "sourceDir" | "testSourceDir")
+                || (matches!(parent, "sources" | "sourceDirs" | "testSources" | "testSourceDirs")
+                    && matches!(el.name.as_str(), "source" | "sourceDir" | "testSourceDir"))
+                || (matches!(parent, "resource" | "testResource" | "source" | "testSource") && el.name == "directory")
+                || (parent == "filters" && el.name == "filter");
+        // Profile activation may depend on the presence of an otherwise unrelated file.
+        let activation = parent == "file" && matches!(el.name.as_str(), "exists" | "missing");
+        if input || activation {
+            // Other properties can be overridden by -D, profiles or settings.
+            // Without Maven's effective roots, conservatively disable reuse for them.
+            let value = el
+                .text
+                .trim()
+                .replace("${project.basedir}", &dir.to_string_lossy())
+                .replace("${basedir}", &dir.to_string_lossy());
+            if value.contains("${") {
+                return None;
+            }
+            if !value.is_empty() {
+                out.push(dir.join(value));
+            }
+        }
+        for child in &el.children {
+            roots(child, &el.name, dir, out)?;
+        }
+        Some(())
+    }
+    let mut resolver = Resolver::new(local_repo.or_else(default_local_repo));
+    let mut out = Vec::new();
+    for project in projects {
+        let dir = root.join(&project.dir);
+        // Include all conventional language/resource roots, including nonstandard files under src.
+        out.push(dir.join("src"));
+        let pom = root.join(&project.pom);
+        resolver.context(&pom, 0);
+        let mut path = pom;
+        let mut seen = HashSet::new();
+        loop {
+            let canonical = dunce::canonicalize(&path).ok()?;
+            if !seen.insert(canonical) || seen.len() > MAX_PARENT_DEPTH {
+                return None;
+            }
+            out.push(path.clone());
+            let text = std::fs::read_to_string(&path).ok()?;
+            roots(&xml::parse(&text)?, "", &dir, &mut out)?;
+            let raw = resolver.pom(&path)?;
+            let Some(parent) = raw.parent else { break };
+            path = resolver.parent_path(path.parent()?, &parent)?;
+        }
+    }
+    // Also track imported BOMs read while resolving inheritance.
+    out.extend(resolver.poms.into_keys());
+    out.sort();
+    out.dedup();
+    Some(out)
+}
+
 // ---------------------------------------------------------------- plugins
 
 /// `maven-clean-plugin` → `clean`, `spring-boot-maven-plugin` → `spring-boot`.
@@ -614,7 +709,76 @@ pub fn goal_prefix(artifact_id: &str) -> String {
     artifact_id.strip_suffix("-plugin").unwrap_or(artifact_id).to_owned()
 }
 
-/// Goals of well-known plugins (their plugin descriptors are not read).
+/// Goals of every plugin jar read so far, by the path of that jar.
+static DESCRIPTOR: OnceLock<Mutex<HashMap<String, Vec<String>>>> = OnceLock::new();
+
+/// `<goal>` names of the plugin descriptor inside its jar (`META-INF/maven/plugin.xml`),
+/// which is where Maven itself takes the list `plugin:help` prints. Empty when the jar
+/// is not in the local repository yet.
+fn descriptor_goals(repo: &Path, group_id: &str, artifact_id: &str, version: &str) -> Vec<String> {
+    // Keyed by the jar itself, not by its coordinates: a repository can be replaced
+    // between runs, and a test's empty repository must not answer for another's.
+    // One `push` per group segment: the layout is `<repo>/<group as directories>/…` on
+    // every platform, Windows' separator included.
+    let mut dir = repo.to_path_buf();
+    dir.extend(group_id.split('.'));
+    dir.push(artifact_id);
+    dir.push(version);
+    let Some(jar) = plugin_jar(&dir, artifact_id, version) else { return Vec::new() };
+    let key = jar.to_string_lossy().into_owned();
+    let cache = DESCRIPTOR.get_or_init(|| Mutex::new(HashMap::new()));
+    if let Some(cached) = cache.lock().unwrap_or_else(|e| e.into_inner()).get(&key) {
+        return cached.clone();
+    }
+    // A failed read is not remembered: the jar may be half written by Maven right now.
+    let Some(goals) = read_descriptor(&jar) else { return Vec::new() };
+    cache.lock().unwrap_or_else(|e| e.into_inner()).insert(key, goals.clone());
+    goals
+}
+
+/// The plugin's jar in its version directory: `<artifactId>-<version>.jar`, or — for a
+/// SNAPSHOT installed from a repository, whose file name carries a timestamp — the newest
+/// `<artifactId>-*.jar` that is neither sources nor javadoc.
+fn plugin_jar(dir: &Path, artifact_id: &str, version: &str) -> Option<PathBuf> {
+    let exact = dir.join(format!("{artifact_id}-{version}.jar"));
+    if exact.is_file() {
+        return Some(exact);
+    }
+    let prefix = format!("{artifact_id}-");
+    let mut best: Option<(std::time::SystemTime, PathBuf)> = None;
+    for entry in std::fs::read_dir(dir).ok()?.flatten() {
+        let path = entry.path();
+        let Some(name) = path.file_name().and_then(|n| n.to_str()) else { continue };
+        if !name.starts_with(&prefix) || !name.ends_with(".jar") || name.ends_with("-sources.jar") {
+            continue;
+        }
+        if name.ends_with("-javadoc.jar") {
+            continue;
+        }
+        let Ok(modified) = entry.metadata().and_then(|m| m.modified()) else { continue };
+        if best.as_ref().is_none_or(|(at, _)| modified > *at) {
+            best = Some((modified, path));
+        }
+    }
+    best.map(|(_, p)| p)
+}
+
+fn read_descriptor(jar: &Path) -> Option<Vec<String>> {
+    let file = std::fs::File::open(jar).ok()?;
+    let mut archive = zip::ZipArchive::new(file).ok()?;
+    let mut entry = archive.by_name("META-INF/maven/plugin.xml").ok()?;
+    let mut text = String::new();
+    entry.read_to_string(&mut text).ok()?;
+    let root = xml::parse(&text)?;
+    let mut goals: Vec<String> =
+        root.list("mojos", "mojo").iter().filter_map(|m| m.text_of("goal")).map(|g| g.trim().to_owned()).collect();
+    goals.retain(|g| !g.is_empty());
+    goals.sort();
+    goals.dedup();
+    Some(goals)
+}
+
+/// Goals of well-known plugins, for a jar that is not in the local repository yet.
 fn known_goals(artifact_id: &str) -> &'static [&'static str] {
     match artifact_id {
         "maven-clean-plugin" => &["clean", "help"],
@@ -766,9 +930,27 @@ fn lifecycle_plugins(packaging: &str) -> &'static [&'static str] {
     }
 }
 
-/// A plugin as shown in the tree: execution goals plus the plugin's known goals, sorted.
-pub(crate) fn plugin(group_id: &str, artifact_id: &str, version: Option<String>, goals: &[String]) -> MavenPlugin {
+/// A plugin as shown in the tree: the goals its jar declares, the ones known by name for
+/// the common plugins, and the ones the project binds in `<executions>`, sorted. IDEA lists
+/// a plugin's goals the same way, which is why a plugin outside the table (checkstyle, say)
+/// still shows every goal it offers instead of only the bound one.
+pub(crate) fn plugin(
+    group_id: &str,
+    artifact_id: &str,
+    version: Option<String>,
+    goals: &[String],
+    local_repo: Option<&Path>,
+) -> MavenPlugin {
     let mut all: Vec<String> = known_goals(artifact_id).iter().map(|g| (*g).to_owned()).collect();
+    let repo = local_repo.map(Path::to_path_buf).or_else(default_local_repo);
+    // An unresolved `${…}` version names no jar: the table and the bound goals stand in.
+    if let (Some(repo), Some(version)) = (repo.as_deref(), version.as_deref().filter(|v| !v.contains("${"))) {
+        for g in descriptor_goals(repo, group_id, artifact_id, version) {
+            if !all.contains(&g) {
+                all.push(g);
+            }
+        }
+    }
     for g in goals {
         if !all.contains(g) {
             all.push(g.clone());
@@ -796,13 +978,19 @@ fn rel_path(root: &Path, p: &Path) -> String {
 }
 
 /// The POMs that are not modules of another one: the root `pom.xml`, else the
-/// shallowest `pom.xml` of each branch (a folder holding several builds).
+/// shallowest `pom.xml` of each branch (a folder holding several builds). An
+/// aggregate POM directly inside `src/` counts too (issue #1001: `src/pom.xml`
+/// with its modules beside it, `src/app/pom.xml` and so on).
 fn top_level_poms(root: &Path) -> Vec<PathBuf> {
     let top = root.join("pom.xml");
     if top.is_file() {
         return vec![top];
     }
     let mut out = Vec::new();
+    let src_pom = root.join("src").join("pom.xml");
+    if src_pom.is_file() {
+        out.push(src_pom);
+    }
     let mut queue: Vec<(PathBuf, usize)> = vec![(root.to_path_buf(), 0)];
     while let Some((dir, depth)) = queue.pop() {
         let Ok(entries) = std::fs::read_dir(&dir) else { continue };
@@ -816,9 +1004,16 @@ fn top_level_poms(root: &Path) -> Vec<PathBuf> {
         }
         dirs.sort();
         for d in dirs.into_iter().rev() {
-            if d.join("pom.xml").is_file() {
-                out.push(d.join("pom.xml"));
-            } else if depth + 1 < POM_SEARCH_DEPTH {
+            let pom = d.join("pom.xml");
+            if pom.is_file() {
+                out.push(pom);
+                continue;
+            }
+            let src_pom = d.join("src").join("pom.xml");
+            if src_pom.is_file() {
+                out.push(src_pom);
+            }
+            if depth + 1 < POM_SEARCH_DEPTH {
                 queue.push((d, depth + 1));
             }
         }
@@ -933,14 +1128,14 @@ pub(crate) fn load_with_repo(root: &Path, local_repo: Option<PathBuf>) -> MavenM
                     .or_else(|| ctx.managed_plugins.iter().find(|m| m.key() == p.key()).and_then(|m| m.version.clone()))
                     .map(|v| i(&v))
                     .filter(|v| !v.contains("${"));
-                plugin(&i(&p.group_id), &i(&p.artifact_id), version, &p.goals)
+                plugin(&i(&p.group_id), &i(&p.artifact_id), version, &p.goals, resolver.local_repo.as_deref())
             })
             .collect();
 
         let jv = ["maven.compiler.release", "java.version", "maven.compiler.source", "maven.compiler.target"]
             .iter()
             .find_map(|k| props.get(*k).map(|v| i(v)))
-            .or_else(|| pom.compiler_release.as_deref().map(i))
+            .or_else(|| ctx.compiler_release.as_deref().map(i))
             .and_then(|v| java_version(&v));
 
         // The project can activate the profiles of its own POM and its ancestors'.
@@ -1013,6 +1208,40 @@ impl UnlinkedProjects {
         self.poms.iter().map(String::as_str)
     }
 
+    /// The POMs the Java language server should import when an unlinked POM is a module of a
+    /// linked reactor, else `None` (excluding the unlinked directories is enough then).
+    ///
+    /// jdtls imports an aggregator together with all of its modules, whatever its import
+    /// exclusions say, so a reactor keeping an unlinked module is left out; its other linked
+    /// modules are listed on their own. Such an aggregator (`pom` packaging) has no sources.
+    pub fn import_poms(&self, model: &MavenModel) -> Option<Vec<String>> {
+        let linked: Vec<&MavenProject> = model.projects.iter().filter(|p| !self.contains(&p.pom)).collect();
+        if !linked.iter().any(|p| p.modules.iter().any(|m| self.contains(m))) {
+            return None;
+        }
+        let by_pom: std::collections::HashMap<String, &MavenProject> =
+            model.projects.iter().map(|p| (normalized_pom(&p.pom), p)).collect();
+        // Whether `pom`'s module tree reaches an unlinked POM.
+        let reaches_unlinked = |pom: &str| {
+            let mut seen = std::collections::HashSet::new();
+            let mut pending = vec![normalized_pom(pom)];
+            while let Some(pom) = pending.pop() {
+                if !seen.insert(pom.clone()) {
+                    continue;
+                }
+                let Some(project) = by_pom.get(&pom) else { continue };
+                for module in &project.modules {
+                    if self.contains(module) {
+                        return true;
+                    }
+                    pending.push(normalized_pom(module));
+                }
+            }
+            false
+        };
+        Some(linked.into_iter().filter(|p| !reaches_unlinked(&p.pom)).map(|p| normalized_pom(&p.pom)).collect())
+    }
+
     pub fn filter(&self, model: &mut MavenModel) {
         model.projects.retain(|p| !self.contains(&p.pom));
         for project in &mut model.projects {
@@ -1045,6 +1274,16 @@ pub fn build_files(root: &Path, model: &MavenModel) -> Vec<PathBuf> {
 /// Projects and their plugins / dependencies from `mvn help:effective-pom` output
 /// (`<project>` or `<projects>`), keyed `groupId:artifactId`.
 pub fn parse_effective_pom(text: &str) -> Vec<(String, Vec<MavenPlugin>, Vec<MavenDependency>)> {
+    parse_effective_pom_in(text, None)
+}
+
+/// The same, with the local repository the project actually builds against (a
+/// `-Dmaven.repo.local` of the build, say): the plugin goals come from jars there,
+/// rather than from the user's default one.
+pub fn parse_effective_pom_in(
+    text: &str,
+    local_repo: Option<&Path>,
+) -> Vec<(String, Vec<MavenPlugin>, Vec<MavenDependency>)> {
     let Some(root) = xml::parse(text) else { return Vec::new() };
     let projects: Vec<&Element> =
         if root.name == "projects" { root.children_named("project").collect() } else { vec![&root] };
@@ -1056,7 +1295,7 @@ pub fn parse_effective_pom(text: &str) -> Vec<(String, Vec<MavenPlugin>, Vec<Mav
             let plugins = raw
                 .plugins
                 .iter()
-                .map(|pl| plugin(&pl.group_id, &pl.artifact_id, pl.version.clone(), &pl.goals))
+                .map(|pl| plugin(&pl.group_id, &pl.artifact_id, pl.version.clone(), &pl.goals, local_repo))
                 .collect();
             let deps = raw
                 .deps
@@ -1187,6 +1426,107 @@ pub fn parse_dependency_tree(output: &str) -> Vec<(String, Vec<MavenDependency>)
 mod tests {
     use super::*;
 
+    /// A plugin jar in `repo` whose descriptor declares `goals`.
+    fn write_plugin_jar(repo: &Path, group: &str, artifact: &str, version: &str, goals: &[&str]) {
+        let dir = repo.join(group.replace('.', "/")).join(artifact).join(version);
+        std::fs::create_dir_all(&dir).unwrap();
+        let mojos: String = goals.iter().map(|g| format!("<mojo><goal>{g}</goal></mojo>")).collect();
+        let descriptor = format!("<plugin><mojos>{mojos}</mojos></plugin>");
+        let file = std::fs::File::create(dir.join(format!("{artifact}-{version}.jar"))).unwrap();
+        let mut zip = zip::ZipWriter::new(file);
+        zip.start_file("META-INF/maven/plugin.xml", zip::write::SimpleFileOptions::default()).unwrap();
+        std::io::Write::write_all(&mut zip, descriptor.as_bytes()).unwrap();
+        zip.finish().unwrap();
+    }
+
+    #[test]
+    fn a_plugin_lists_the_goals_its_jar_declares() {
+        let tmp = tempfile::tempdir().unwrap();
+        let repo = tmp.path();
+        write_plugin_jar(
+            repo,
+            "org.apache.maven.plugins",
+            "maven-checkstyle-plugin",
+            "3.3.1",
+            &["checkstyle", "checkstyle-aggregate", "help", "check"],
+        );
+        let p = plugin(
+            "org.apache.maven.plugins",
+            "maven-checkstyle-plugin",
+            Some("3.3.1".into()),
+            &["check".to_owned()],
+            Some(repo),
+        );
+        assert_eq!(p.goals, ["check", "checkstyle", "checkstyle-aggregate", "help"], "every goal the plugin offers");
+        assert_eq!(p.prefix, "checkstyle");
+    }
+
+    #[test]
+    fn a_settings_file_names_the_repository_to_read_goals_from() {
+        let tmp = tempfile::tempdir().unwrap();
+        let settings = tmp.path().join("settings.xml");
+        std::fs::write(
+            &settings,
+            "<settings><localRepository>${user.home}/repo-from-settings</localRepository></settings>",
+        )
+        .unwrap();
+        let repo = local_repository_of(&settings).unwrap();
+        assert!(repo.ends_with("repo-from-settings"), "{}", repo.display());
+        assert!(!repo.to_string_lossy().contains("${user.home}"));
+        // A settings file that names none leaves Maven's default alone.
+        let plain = tmp.path().join("plain.xml");
+        std::fs::write(&plain, "<settings><offline>true</offline></settings>").unwrap();
+        assert!(local_repository_of(&plain).is_none());
+        assert!(local_repository_of(&tmp.path().join("missing.xml")).is_none());
+    }
+
+    #[test]
+    fn effective_pom_goals_come_from_the_local_repository_it_is_given() {
+        let tmp = tempfile::tempdir().unwrap();
+        write_plugin_jar(tmp.path(), "org.apache.maven.plugins", "maven-demo-plugin", "1.0", &["run", "help"]);
+        let text = "<project><groupId>g</groupId><artifactId>a</artifactId><build><plugins>\
+            <plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-demo-plugin</artifactId>\
+            <version>1.0</version><executions><execution><goals><goal>run</goal></goals></execution></executions>\
+            </plugin></plugins></build></project>";
+        let with_repo = parse_effective_pom_in(text, Some(tmp.path()));
+        assert_eq!(with_repo[0].1[0].goals, ["help", "run"], "the jar's own goals come first");
+        // Without that repository the plugin is unknown: only what the project binds.
+        assert_eq!(parse_effective_pom(text)[0].1[0].goals, ["run"]);
+    }
+
+    #[test]
+    fn a_snapshot_plugin_is_found_by_its_timestamped_jar() {
+        let tmp = tempfile::tempdir().unwrap();
+        let dir = tmp.path().join("g/p/maven-demo-plugin/1.0-SNAPSHOT");
+        std::fs::create_dir_all(&dir).unwrap();
+        let descriptor = "<plugin><mojos><mojo><goal>run</goal></mojo></mojos></plugin>";
+        let file = std::fs::File::create(dir.join("maven-demo-plugin-1.0-20240101.120000-3.jar")).unwrap();
+        let mut zip = zip::ZipWriter::new(file);
+        zip.start_file("META-INF/maven/plugin.xml", zip::write::SimpleFileOptions::default()).unwrap();
+        std::io::Write::write_all(&mut zip, descriptor.as_bytes()).unwrap();
+        zip.finish().unwrap();
+        // A sibling sources jar must not win.
+        std::fs::File::create(dir.join("maven-demo-plugin-1.0-20240101.120000-3-sources.jar")).unwrap();
+        let p = plugin("g.p", "maven-demo-plugin", Some("1.0-SNAPSHOT".into()), &[], Some(tmp.path()));
+        assert_eq!(p.goals, ["run"]);
+    }
+
+    #[test]
+    fn a_plugin_without_its_jar_keeps_the_table_and_the_bound_goals() {
+        let tmp = tempfile::tempdir().unwrap();
+        let p = plugin(
+            "org.apache.maven.plugins",
+            "maven-checkstyle-plugin",
+            Some("3.3.1".into()),
+            &["check".to_owned()],
+            Some(tmp.path()),
+        );
+        assert_eq!(p.goals, ["check"], "nothing beyond what the project binds");
+        let known =
+            plugin("org.apache.maven.plugins", "maven-compiler-plugin", Some("3.13.0".into()), &[], Some(tmp.path()));
+        assert_eq!(known.goals, ["compile", "help", "testCompile"], "the common plugins keep their table");
+    }
+
     fn write(dir: &Path, rel: &str, text: &str) {
         let p = dir.join(rel);
         std::fs::create_dir_all(p.parent().unwrap()).unwrap();
@@ -1210,6 +1550,72 @@ mod tests {
       </profiles>
     </project>"#;
 
+    #[test]
+    fn maven_4_subprojects_are_modules() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        write(
+            root,
+            "pom.xml",
+            r#"<project xmlns="http://maven.apache.org/POM/4.1.0"><modelVersion>4.1.0</modelVersion>
+              <groupId>demo</groupId><artifactId>parent</artifactId><version>1.0</version><packaging>pom</packaging>
+              <subprojects><subproject>core</subproject></subprojects>
+              <profiles><profile><id>extra</id><subprojects><subproject>extra</subproject></subprojects></profile></profiles>
+            </project>"#,
+        );
+        write(root, "core/pom.xml", "<project><artifactId>core</artifactId></project>");
+        write(root, "extra/pom.xml", "<project><artifactId>extra</artifactId></project>");
+        let model = load_with_repo(root, None);
+        assert_eq!(model.projects[0].modules, ["core/pom.xml"]);
+        assert!(model.projects.iter().any(|p| p.pom == "core/pom.xml" && p.aggregated));
+    }
+
+    #[test]
+    fn modules_inherit_the_compiler_level_of_the_parent_plugin_configuration() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let parent = |build: &str| {
+            format!(
+                r#"<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1.0</version><packaging>pom</packaging>
+                  <modules><module>core</module><module>app</module></modules>
+                  <properties><jdk>17</jdk></properties>{build}</project>"#
+            )
+        };
+        let child = |name: &str, build: &str| {
+            format!(
+                r#"<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1.0</version></parent>
+                  <artifactId>{name}</artifactId>{build}</project>"#
+            )
+        };
+        let compiler = |level: &str| {
+            format!(
+                "<plugin><artifactId>maven-compiler-plugin</artifactId><configuration><source>{level}</source></configuration></plugin>"
+            )
+        };
+        let versions = |model: &MavenModel| -> Vec<(String, Option<u32>)> {
+            model.projects.iter().map(|p| (p.pom.clone(), p.java_version)).collect()
+        };
+        let app_build = format!("<build><plugins>{}</plugins></build>", compiler("21"));
+        write(root, "core/pom.xml", &child("core", ""));
+        write(root, "app/pom.xml", &child("app", &app_build));
+        for build in [
+            format!("<build><pluginManagement><plugins>{}</plugins></pluginManagement></build>", compiler("${jdk}")),
+            format!("<build><plugins>{}</plugins></build>", compiler("1.8")),
+        ] {
+            write(root, "pom.xml", &parent(&build));
+            let expected = if build.contains("1.8") { 8 } else { 17 };
+            assert_eq!(
+                versions(&load_with_repo(root, None)),
+                [
+                    ("pom.xml".to_owned(), Some(expected)),
+                    ("core/pom.xml".to_owned(), Some(expected)),
+                    ("app/pom.xml".to_owned(), Some(21)),
+                ],
+                "{build}"
+            );
+        }
+    }
+
     #[test]
     fn multi_module_parent_properties_and_managed_versions() {
         let tmp = tempfile::tempdir().unwrap();
@@ -1405,6 +1811,25 @@ mod tests {
         assert!(!is_maven_project(&root.join("c")));
     }
 
+    #[test]
+    fn aggregate_pom_in_src_is_a_build() {
+        // Issue #1001: `src/pom.xml` aggregating modules under `src/` is recognized,
+        // with its modules loaded — while `src` stays unsearched otherwise.
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        write(
+            root,
+            "src/pom.xml",
+            "<project><groupId>g</groupId><artifactId>parent</artifactId><packaging>pom</packaging>\
+             <modules><module>app</module></modules></project>",
+        );
+        write(root, "src/app/pom.xml", "<project><groupId>g</groupId><artifactId>app</artifactId></project>");
+        let model = load_with_repo(root, None);
+        let names: Vec<&str> = model.projects.iter().map(|p| p.artifact_id.as_str()).collect();
+        assert_eq!(names, ["parent", "app"]);
+        assert!(is_maven_project(root));
+    }
+
     #[test]
     fn property_interpolation() {
         let props: HashMap<String, String> =
@@ -1602,4 +2027,51 @@ mod linkage_tests {
         UnlinkedProjects::from_model(&original, &MavenSettings::default()).filter(&mut restored);
         assert_eq!(restored, original);
     }
+
+    #[test]
+    fn language_server_imports_reactor_modules_individually_once_one_is_unlinked() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        // r ─┬─ x
+        //    ├─ y ─┬─ y/y1
+        //    │     └─ y/y2
+        //    └─ z          other/ is a separate root.
+        for (dir, modules) in [
+            ("r", "<modules><module>x</module><module>y</module><module>z</module></modules>"),
+            ("r/x", ""),
+            ("r/y", "<modules><module>y1</module><module>y2</module></modules>"),
+            ("r/y/y1", ""),
+            ("r/y/y2", ""),
+            ("r/z", ""),
+            ("other", ""),
+        ] {
+            std::fs::create_dir_all(root.join(dir)).unwrap();
+            std::fs::write(
+                root.join(dir).join("pom.xml"),
+                format!("<project><artifactId>{dir}</artifactId>{modules}</project>"),
+            )
+            .unwrap();
+        }
+        let model = load_with_repo(root, None);
+        let cases: [(&[&str], Option<&[&str]>); 5] = [
+            // Nothing unlinked, or whole roots: the import exclusions do it.
+            (&[], None),
+            (&["other/pom.xml"], None),
+            (&["r/pom.xml"], None),
+            // A module of a linked reactor: every other linked POM, minus the aggregators above it.
+            (&["r/y/y1/pom.xml"], Some(&["other/pom.xml", "r/x/pom.xml", "r/y/y2/pom.xml", "r/z/pom.xml"])),
+            (&["./r/y/pom.xml"], Some(&["other/pom.xml", "r/x/pom.xml", "r/z/pom.xml"])),
+        ];
+        for (unlinked, expected) in cases {
+            let settings = MavenSettings {
+                unlinked_projects: unlinked.iter().map(|s| s.to_string()).collect(),
+                ..Default::default()
+            };
+            let mut poms = UnlinkedProjects::from_model(&model, &settings).import_poms(&model);
+            if let Some(poms) = &mut poms {
+                poms.sort();
+            }
+            assert_eq!(poms, expected.map(|e| e.iter().map(|s| s.to_string()).collect::<Vec<_>>()), "{unlinked:?}");
+        }
+    }
 }

crates/ide-build/src/process.rs

@@ -2,11 +2,12 @@
 //! line to a callback, and cancellation kills the whole process group (the
 //! `mvnw` / `gradlew` wrapper scripts start the JVM as a child).
 
+use ide_core::process::kill_tree;
 use ide_core::{CancellationToken, IdeError, IdeResult};
 use std::collections::BTreeMap;
 use std::io::{BufRead, BufReader, Read};
 use std::path::Path;
-use std::process::{Child, Command, Stdio};
+use std::process::{Command, Stdio};
 use std::sync::mpsc;
 use std::time::Duration;
 
@@ -22,22 +23,10 @@ pub(crate) struct Output {
     pub text: String,
 }
 
-fn kill_tree(child: &mut Child) {
-    #[cfg(unix)]
-    if let Ok(pid) = i32::try_from(child.id()) {
-        // SAFETY: plain syscall; the group was created by `process_group(0)` at spawn.
-        unsafe {
-            libc::kill(-pid, libc::SIGKILL);
-        }
-    }
-    let _ = child.kill();
-    let _ = child.wait();
-}
-
 /// `program` as spawnable: a bare name (`mvn`, `mvn.cmd`) resolves on the IDE's
 /// search path — the login shell's `PATH` plus version-manager shims — since the
 /// app's own `PATH` can be minimal and `Command` would not see `mvn` there.
-fn program_path(program: &str, env: &BTreeMap<String, String>) -> std::path::PathBuf {
+pub(crate) fn program_path(program: &str, env: &BTreeMap<String, String>) -> std::path::PathBuf {
     let path = std::path::Path::new(program);
     if !path.is_relative() || path.components().count() > 1 {
         return path.to_path_buf();
@@ -58,6 +47,18 @@ pub(crate) fn run(
     cwd: &Path,
     env: &BTreeMap<String, String>,
     cancel: &CancellationToken,
+    on_line: impl FnMut(Stream, &str),
+) -> IdeResult<Output> {
+    run_with_env(program, args, cwd, env, false, cancel, on_line)
+}
+
+pub(crate) fn run_with_env(
+    program: &str,
+    args: &[String],
+    cwd: &Path,
+    env: &BTreeMap<String, String>,
+    clear_env: bool,
+    cancel: &CancellationToken,
     mut on_line: impl FnMut(Stream, &str),
 ) -> IdeResult<Output> {
     tracing::info!("build: {program} {} (in {})", args.join(" "), cwd.display());
@@ -66,14 +67,13 @@ pub(crate) fn run(
         ide_core::output_encoding::fix(program, args, env, |k| std::env::var(k).ok(), "UTF-8", cfg!(windows));
     let program = program_path(program, env);
     let mut command = Command::new(&program);
-    command.args(args).current_dir(cwd).envs(env).envs(encoding.env).stdin(Stdio::null());
+    command.args(args).current_dir(cwd).envs(env).envs(encoding.env.iter().map(|(k, v)| (k, v))).stdin(Stdio::null());
     command.stdout(Stdio::piped()).stderr(Stdio::piped());
-    #[cfg(unix)]
-    {
-        use std::os::unix::process::CommandExt;
-        command.process_group(0);
+    // Its own group: `mvnw` / `gradlew` start the JVM as a child, and cancelling kills both.
+    ide_core::process::prepare(ide_core::process::own_group(&mut command));
+    if clear_env {
+        command.env_clear().envs(env).envs(encoding.env);
     }
-    ide_core::process::prepare(&mut command);
     let mut child =
         command.spawn().map_err(|e| IdeError::unavailable(format!("cannot start {}: {e}", program.display())))?;
     let (tx, rx) = mpsc::channel::<(Stream, String)>();

crates/ide-build/src/sync.rs

@@ -4,14 +4,16 @@
 //! per project (`maven.json`, `gradle.json` in the cache directory) and merged
 //! into the static model by [`crate::load`]; a changed build file marks them stale.
 
-use crate::gradle::{self, GradleModel, GradleTask};
+use crate::gradle::{self, GradleModel, GradleTask, ReportedProject, parse_reported_projects};
 use crate::maven::{self, MavenDependency, MavenModel, MavenPlugin};
 use crate::process::{self, Output};
 use ide_core::{CancellationToken, IdeError, IdeResult};
 use serde::{Deserialize, Serialize, de::DeserializeOwned};
 use specta::Type;
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, HashMap};
 use std::path::{Path, PathBuf};
+use std::sync::{Arc, LazyLock, Mutex};
+use std::time::SystemTime;
 
 #[derive(Clone, Debug, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
@@ -48,6 +50,11 @@ struct CachedMavenProject {
 
 #[derive(Clone, Debug, Default, Serialize, Deserialize)]
 struct MavenCache {
+    /// Bumped whenever what the cache holds stops matching what the model would be
+    /// built as now (plugin goals read from a descriptor, say): an older cache is
+    /// dropped instead of shadowing the model.
+    #[serde(default)]
+    version: u32,
     hash: String,
     at_ms: f64,
     error: Option<String>,
@@ -63,9 +70,16 @@ struct GradleCache {
     at_ms: f64,
     error: Option<String>,
     tasks: Vec<(String, GradleTask)>,
+    /// The projects as Gradle evaluated them; empty in caches from before they were read.
+    #[serde(default)]
+    projects: Vec<ReportedProject>,
 }
 
+/// Init script printing every project, its source sets and Java version once configured.
+const MODEL_INIT_SCRIPT: &str = include_str!("gradle-model.gradle");
+
 const MAVEN_CACHE: &str = "maven.json";
+const MAVEN_CACHE_VERSION: u32 = 1;
 
 /// `dependency:tree` of a plugin version whose `-Dverbose` lists the occurrences Maven
 /// omitted (conflicts, duplicates): verbose output was dropped in 3.0 and is back since 3.2.
@@ -82,6 +96,24 @@ fn maven_sync_goals(effective: &Path, offline: bool) -> Vec<String> {
     ]
 }
 const GRADLE_CACHE: &str = "gradle.json";
+const MAVEN_PROFILES: &str = "maven-profiles.json";
+
+/// The Maven profiles (`-P` entries, `!id` deactivates) the project was last synced
+/// with: what the IDE resolves it with besides `mvn` (the Java language server, Build Project).
+pub fn maven_profiles(cache_dir: &Path) -> Vec<String> {
+    read_cache(cache_dir, MAVEN_PROFILES).unwrap_or_default()
+}
+
+/// Records the profiles of a sync for [`maven_profiles`]; `true` when they changed.
+pub fn save_maven_profiles(cache_dir: &Path, profiles: &[String]) -> IdeResult<bool> {
+    if maven_profiles(cache_dir) == profiles {
+        return Ok(false);
+    }
+    std::fs::create_dir_all(cache_dir)?;
+    let json = serde_json::to_vec(profiles).map_err(|e| IdeError::internal(e.to_string()))?;
+    std::fs::write(cache_dir.join(MAVEN_PROFILES), json)?;
+    Ok(true)
+}
 
 fn read_cache<T: DeserializeOwned>(dir: &Path, name: &str) -> Option<T> {
     serde_json::from_slice(&std::fs::read(dir.join(name)).ok()?).ok()
@@ -98,6 +130,20 @@ fn write_cache<T: Serialize>(dir: &Path, name: &str, value: &T) -> IdeResult<()>
 
 /// FNV-1a over the paths and contents of `files` (missing files count as empty).
 fn hash_files(files: &[PathBuf]) -> String {
+    hash_contents(files, |f| std::fs::read(f).unwrap_or_default())
+}
+
+/// Like IDEA's auto-import CRC: editing a comment or reformatting a build script
+/// does not make the last sync stale.
+fn hash_gradle_files(files: &[PathBuf]) -> String {
+    hash_contents(files, |f| {
+        let text = std::fs::read_to_string(f).unwrap_or_default();
+        let script = f.extension().is_some_and(|e| e == "gradle" || e == "kts");
+        if script { gradle::script_fingerprint(&text) } else { text }.into_bytes()
+    })
+}
+
+fn hash_contents(files: &[PathBuf], read: impl Fn(&Path) -> Vec<u8>) -> String {
     let mut h: u64 = 0xcbf29ce484222325;
     let mut feed = |bytes: &[u8]| {
         for b in bytes {
@@ -108,7 +154,7 @@ fn hash_files(files: &[PathBuf]) -> String {
     for f in files {
         feed(f.to_string_lossy().as_bytes());
         feed(&[0]);
-        feed(&std::fs::read(f).unwrap_or_default());
+        feed(&read(f));
         feed(&[0]);
     }
     format!("{h:016x}")
@@ -121,6 +167,9 @@ fn now_ms() -> f64 {
 /// Merges the cached effective build into `model`.
 pub fn apply_maven_cache(root: &Path, cache_dir: &Path, model: &mut MavenModel) {
     let Some(cache) = read_cache::<MavenCache>(cache_dir, MAVEN_CACHE) else { return };
+    if cache.version != MAVEN_CACHE_VERSION {
+        return; // built by an older IDE: what it holds no longer matches the model
+    }
     model.synced_at = Some(cache.at_ms);
     model.sync_error = cache.error;
     let changed = cache.hash != hash_files(&maven::build_files(root, model));
@@ -141,9 +190,33 @@ pub fn apply_maven_cache(root: &Path, cache_dir: &Path, model: &mut MavenModel)
     }
 }
 
+/// The projects of the last successful Gradle sync.
+/// Parsed once per change of the cache file (modification time and size): content and source
+/// roots are read on hot paths (every references search, Find in Files, repository scans).
+pub fn reported_gradle_projects(cache_dir: &Path) -> Arc<Vec<ReportedProject>> {
+    type Memo = HashMap<PathBuf, (Option<SystemTime>, u64, Arc<Vec<ReportedProject>>)>;
+    static MEMO: LazyLock<Mutex<Memo>> = LazyLock::new(Default::default);
+    let path = cache_dir.join(GRADLE_CACHE);
+    let Ok(meta) = std::fs::metadata(&path) else {
+        MEMO.lock().unwrap_or_else(|e| e.into_inner()).remove(&path);
+        return Arc::default();
+    };
+    let stamp = (meta.modified().ok(), meta.len());
+    let mut memo = MEMO.lock().unwrap_or_else(|e| e.into_inner());
+    if let Some((modified, len, projects)) = memo.get(&path)
+        && (*modified, *len) == stamp
+    {
+        return projects.clone();
+    }
+    let projects = Arc::new(read_cache::<GradleCache>(cache_dir, GRADLE_CACHE).map(|c| c.projects).unwrap_or_default());
+    memo.insert(path, (stamp.0, stamp.1, projects.clone()));
+    projects
+}
+
 /// Merges the cached task list into `model`.
 pub fn apply_gradle_cache(root: &Path, cache_dir: &Path, model: &mut GradleModel) {
     let Some(cache) = read_cache::<GradleCache>(cache_dir, GRADLE_CACHE) else { return };
+    gradle::merge_reported_projects(root, model, &cache.projects);
     if !cache.tasks.is_empty() {
         for p in &mut model.projects {
             let tasks: Vec<GradleTask> =
@@ -153,9 +226,11 @@ pub fn apply_gradle_cache(root: &Path, cache_dir: &Path, model: &mut GradleModel
             }
         }
     }
+    // A successful sync from before projects were cached has not seen computed includes.
+    let without_projects = cache.error.is_none() && cache.projects.is_empty();
     model.synced_at = Some(cache.at_ms);
     model.sync_error = cache.error;
-    model.stale = cache.hash != hash_files(&gradle::build_files(root, model));
+    model.stale = without_projects || cache.hash != hash_gradle_files(&gradle::build_files(root, model));
 }
 
 // ---------------------------------------------------------------- processes
@@ -211,8 +286,31 @@ pub fn sync_maven(
     let mut model = maven::load(root);
     maven::UnlinkedProjects::from_model(&model, &options.maven_settings).filter(&mut model);
     std::fs::create_dir_all(cache_dir)?;
-    let mut cache =
-        MavenCache { hash: hash_files(&maven::build_files(root, &model)), verbose: true, ..MavenCache::default() };
+    let mut cache = MavenCache {
+        version: MAVEN_CACHE_VERSION,
+        hash: hash_files(&maven::build_files(root, &model)),
+        verbose: true,
+        ..MavenCache::default()
+    };
+    // Where the build resolves its jars, and therefore where the plugin goals are read
+    // from: `-Dmaven.repo.local=` first, then `<localRepository>` of the `-s` settings,
+    // then the user's default repository (which `plugin()` resolves itself).
+    let local_repo: Option<PathBuf> =
+        options.maven_options.iter().find_map(|a| a.strip_prefix("-Dmaven.repo.local=")).map(PathBuf::from).or_else(
+            || {
+                let mut args = options.maven_options.iter();
+                while let Some(arg) = args.next() {
+                    let path = match arg.as_str() {
+                        "-s" | "--settings" => args.next().map(String::as_str),
+                        _ => arg.strip_prefix("-s=").or_else(|| arg.strip_prefix("--settings=")),
+                    };
+                    if let Some(path) = path {
+                        return maven::local_repository_of(Path::new(path));
+                    }
+                }
+                None
+            },
+        );
     let mut errors: Vec<String> = Vec::new();
     for (n, top) in model.projects.iter().filter(|p| !p.aggregated).enumerate() {
         let effective = cache_dir.join(format!("effective-pom-{n}.xml"));
@@ -241,8 +339,9 @@ pub fn sync_maven(
                 });
             }
         })?;
-        let effective_projects =
-            std::fs::read_to_string(&effective).map(|t| maven::parse_effective_pom(&t)).unwrap_or_default();
+        let effective_projects = std::fs::read_to_string(&effective)
+            .map(|t| maven::parse_effective_pom_in(&t, local_repo.as_deref()))
+            .unwrap_or_default();
         let trees = maven::parse_dependency_tree(&out.text);
         for (key, plugins, deps) in effective_projects {
             let dependencies = trees.iter().find(|(k, _)| *k == key).map(|(_, t)| t.clone()).unwrap_or(deps);
@@ -271,8 +370,18 @@ pub fn sync_gradle(
     cancel: &CancellationToken,
     progress: &dyn Fn(SyncProgress),
 ) -> IdeResult<()> {
-    let model = gradle::load(root).ok_or_else(|| IdeError::not_found("no Gradle build in this project"))?;
-    let mut args: Vec<String> = vec!["--console=plain".into(), "-q".into(), "tasks".into(), "--all".into()];
+    let mut model = gradle::load(root).ok_or_else(|| IdeError::not_found("no Gradle build in this project"))?;
+    std::fs::create_dir_all(cache_dir)?;
+    let init_script = cache_dir.join("openidea-model.gradle");
+    std::fs::write(&init_script, MODEL_INIT_SCRIPT)?;
+    let mut args: Vec<String> = vec![
+        "--console=plain".into(),
+        "-q".into(),
+        "--init-script".into(),
+        init_script.to_string_lossy().into_owned(),
+        "tasks".into(),
+        "--all".into(),
+    ];
     if options.offline {
         args.push("--offline".into());
     }
@@ -285,11 +394,15 @@ pub fn sync_gradle(
         cancel,
         |_| {},
     )?;
+    let projects = if out.success { parse_reported_projects(&out.text) } else { Vec::new() };
+    // Hash the build files of the reported projects, or the model is stale right after the sync.
+    gradle::merge_reported_projects(root, &mut model, &projects);
     let cache = GradleCache {
-        hash: hash_files(&gradle::build_files(root, &model)),
+        hash: hash_gradle_files(&gradle::build_files(root, &model)),
         at_ms: now_ms(),
         error: (!out.success).then(|| error_summary(&out.text)),
         tasks: if out.success { gradle::parse_tasks(&out.text) } else { Vec::new() },
+        projects,
     };
     write_cache(cache_dir, GRADLE_CACHE, &cache)
 }
@@ -332,6 +445,7 @@ mod tests {
         let mut model = maven::load_with_repo(&root, None);
         assert!(model.synced_at.is_none());
         let cache = MavenCache {
+            version: MAVEN_CACHE_VERSION,
             hash: hash_files(&maven::build_files(&root, &model)),
             at_ms: 5.0,
             error: None,
@@ -343,6 +457,7 @@ mod tests {
                     "maven-clean-plugin",
                     Some("3.2.0".into()),
                     &[],
+                    None,
                 )],
                 dependencies: vec![MavenDependency { artifact_id: "dep".into(), ..MavenDependency::default() }],
             }],
@@ -368,6 +483,128 @@ mod tests {
         assert_eq!(model.projects[0].dependencies[0].artifact_id, "fresh");
     }
 
+    #[test]
+    fn a_cache_from_an_older_ide_is_ignored() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path().join("p");
+        let cache_dir = tmp.path().join("cache");
+        std::fs::create_dir_all(&root).unwrap();
+        std::fs::write(root.join("pom.xml"), "<project><groupId>g</groupId><artifactId>a</artifactId></project>")
+            .unwrap();
+        let mut model = maven::load_with_repo(&root, None);
+        let cache = MavenCache {
+            // What an older build wrote: no plugin descriptors were read back then, so
+            // its goal lists would shadow the ones the model now knows.
+            version: 0,
+            hash: hash_files(&maven::build_files(&root, &model)),
+            at_ms: 5.0,
+            error: None,
+            verbose: true,
+            projects: vec![CachedMavenProject {
+                key: "g:a".into(),
+                plugins: vec![maven::plugin(
+                    "org.apache.maven.plugins",
+                    "maven-clean-plugin",
+                    Some("3.2.0".into()),
+                    &[],
+                    None,
+                )],
+                dependencies: vec![MavenDependency { artifact_id: "cached".into(), ..MavenDependency::default() }],
+            }],
+        };
+        write_cache(&cache_dir, MAVEN_CACHE, &cache).unwrap();
+        apply_maven_cache(&root, &cache_dir, &mut model);
+        assert!(model.synced_at.is_none(), "the cache is dropped, the model stays unsynced");
+        assert!(model.projects[0].dependencies.iter().all(|d| d.artifact_id != "cached"));
+    }
+
+    #[test]
+    fn gradle_reported_projects_replace_static_ones() {
+        let tmp = tempfile::tempdir().unwrap();
+        let ws = dunce::canonicalize(tmp.path()).unwrap();
+        let root = ws.join("app");
+        let billing = ws.join("billing");
+        std::fs::create_dir_all(root.join("shared")).unwrap();
+        std::fs::create_dir_all(billing.join("modules/core")).unwrap();
+        // Computed includes: nothing a static reading can see.
+        std::fs::write(root.join("settings.gradle"), "rootProject.name = 'Shop'\n['billing'].each { includeFlat it }")
+            .unwrap();
+        std::fs::write(billing.join("modules/core/build.gradle"), "apply plugin: 'java'").unwrap();
+        // Built with serde: a Windows path holds backslashes, which raw JSON text would leave unescaped.
+        let line = |p: ReportedProject| format!("@openidea-model\t{}\n", serde_json::to_string(&p).unwrap());
+        let (r, b) = (root.display().to_string(), billing.display().to_string());
+        let core_src = |p: &str| format!("{b}/modules/core/src/{p}");
+        let set = |name: &str, test: bool, src: &[&str], res: &[&str]| gradle::ReportedSourceSet {
+            name: name.into(),
+            test,
+            src: src.iter().map(|p| core_src(p)).collect(),
+            res: res.iter().map(|p| core_src(p)).collect(),
+        };
+        // A settings script's own println comes first; task listing lines follow.
+        let out = format!(
+            "configuring billing\n{}{}{}@openidea-model\t{{broken\n\nOther tasks\n-----------\nbilling:core:jar\n",
+            line(ReportedProject { path: ":".into(), dir: r.clone(), ..ReportedProject::default() }),
+            line(ReportedProject {
+                path: ":billing".into(),
+                dir: b.clone(),
+                java: Some(17),
+                ..ReportedProject::default()
+            }),
+            line(ReportedProject {
+                path: ":billing:core".into(),
+                dir: format!("{b}/modules/core"),
+                java: Some(21),
+                source_sets: vec![
+                    set("main", false, &["main/java"], &["main/resources"]),
+                    set("test", true, &["main/java", "test/java"], &[]),
+                ],
+                ..ReportedProject::default()
+            }),
+        );
+        let projects = parse_reported_projects(&out);
+        assert_eq!(projects.len(), 3, "the malformed line is skipped");
+        let src = |p: &str| PathBuf::from(core_src(p));
+        assert_eq!(
+            gradle::reported_source_roots(&projects),
+            [
+                (src("main/java"), gradle::ReportedRoot::Source),
+                (src("main/resources"), gradle::ReportedRoot::Resources),
+                (src("test/java"), gradle::ReportedRoot::Test),
+            ]
+        );
+        let mut model = gradle::load(&root).unwrap();
+        assert_eq!(model.projects.len(), 1);
+        gradle::merge_reported_projects(&root, &mut model, &projects);
+        let paths: Vec<_> = model.projects.iter().map(|p| (p.path.as_str(), p.name.as_str())).collect();
+        assert_eq!(paths, [(":", "Shop"), (":billing", "billing"), (":billing:core", "core")]);
+        assert_eq!(model.projects[0].dir, "");
+        assert!(root.join(model.projects[2].build_file.as_ref().unwrap()).is_file());
+        assert_eq!(
+            gradle::external_roots(&root, model.projects.iter().map(|p| p.dir.as_str())),
+            std::slice::from_ref(&billing)
+        );
+        assert_eq!(model.java_version, Some(21), "the newest version any module needs");
+        assert_eq!(
+            gradle::parse_tasks(&out),
+            [(":billing:core".into(), GradleTask { name: "jar".into(), group: "other".into(), description: None })]
+        );
+
+        // The cached projects are parsed once per change of the cache file.
+        let cache_dir = ws.join("cache");
+        let write = |projects: &[ReportedProject]| {
+            let cache = GradleCache { projects: projects.to_vec(), ..GradleCache::default() };
+            write_cache(&cache_dir, GRADLE_CACHE, &cache).unwrap();
+        };
+        write(&projects);
+        let first = reported_gradle_projects(&cache_dir);
+        assert!(Arc::ptr_eq(&first, &reported_gradle_projects(&cache_dir)), "unchanged: not parsed again");
+        assert_eq!(crate::gradle_external_roots(&root, &cache_dir), [billing]);
+        write(&projects[..1]);
+        assert_eq!(reported_gradle_projects(&cache_dir).len(), 1, "a new sync is read");
+        std::fs::remove_file(cache_dir.join(GRADLE_CACHE)).unwrap();
+        assert!(reported_gradle_projects(&cache_dir).is_empty());
+    }
+
     #[test]
     fn gradle_cache_replaces_tasks_per_project() {
         let tmp = tempfile::tempdir().unwrap();
@@ -378,16 +615,39 @@ mod tests {
         std::fs::write(root.join("app/build.gradle"), "apply plugin: 'java'").unwrap();
         let mut model = gradle::load(&root).unwrap();
         let cache = GradleCache {
-            hash: hash_files(&gradle::build_files(&root, &model)),
+            hash: hash_gradle_files(&gradle::build_files(&root, &model)),
             at_ms: 1.0,
             error: None,
             tasks: vec![(":app".into(), GradleTask { name: "hello".into(), group: "demo".into(), description: None })],
+            projects: [":", ":app"]
+                .iter()
+                .zip([root.clone(), root.join("app")])
+                .map(|(path, dir)| ReportedProject {
+                    path: (*path).into(),
+                    dir: dir.to_string_lossy().into_owned(),
+                    ..Default::default()
+                })
+                .collect(),
         };
         write_cache(&cache_dir, GRADLE_CACHE, &cache).unwrap();
         apply_gradle_cache(&root, &cache_dir, &mut model);
         assert_eq!(model.projects[1].tasks.len(), 1);
         assert!(model.projects[0].tasks.iter().any(|t| t.name == "wrapper"), "root keeps its defaults");
         assert!(!model.stale);
+
+        let stale_after = |script: &str| {
+            std::fs::write(root.join("app/build.gradle"), script).unwrap();
+            let mut m = gradle::load(&root).unwrap();
+            apply_gradle_cache(&root, &cache_dir, &mut m);
+            m.stale
+        };
+        assert!(!stale_after("// a note\napply   plugin: 'java'\n"), "comments and spacing don't count");
+        assert!(stale_after("apply plugin: 'groovy'"));
+        std::fs::write(root.join("app/build.gradle"), "apply plugin: 'java'").unwrap();
+        std::fs::write(root.join("gradle.properties"), "org.gradle.jvmargs=-Xmx2g").unwrap();
+        let mut m = gradle::load(&root).unwrap();
+        apply_gradle_cache(&root, &cache_dir, &mut m);
+        assert!(m.stale, "gradle.properties is watched");
     }
 
     #[test]

crates/ide-build/src/web.rs

@@ -1,6 +1,6 @@
 //! WAR modules and build-tool-owned archive resolution (including custom output names).
 use crate::BuildModel;
-use ide_core::{IdeError, IdeResult};
+use ide_core::{CancellationToken, IdeError, IdeResult};
 use serde::{Deserialize, Serialize};
 use specta::Type;
 use std::{collections::BTreeMap, fs, path::Path};
@@ -47,6 +47,50 @@ pub struct WebBuild {
     pub args: Vec<String>,
     pub cwd: String,
     pub env: BTreeMap<String, String>,
+    maven_project: Option<(Vec<String>, std::path::PathBuf)>,
+}
+
+impl WebBuild {
+    /// Resolve the selected module's effective identity using the build's options and environment.
+    /// Runs off the UI thread, before launching the reactor build.
+    pub fn resolve_project(
+        &mut self,
+        root: &Path,
+        env: &BTreeMap<String, String>,
+        cancel: &CancellationToken,
+    ) -> IdeResult<()> {
+        let Some((args, output)) = &self.maven_project else {
+            return Ok(());
+        };
+        if output.exists() {
+            fs::remove_file(output)?;
+        }
+        let cwd = root.join(&self.cwd).canonicalize()?;
+        let mut env = env.clone();
+        if !env.iter().any(|(k, v)| k.eq_ignore_ascii_case("MAVEN_BASEDIR") && !v.is_empty()) {
+            // -f changes Maven's .mvn search origin; keep the reactor's launcher settings.
+            let base = cwd.ancestors().find(|p| p.join(".mvn").is_dir()).unwrap_or(&cwd);
+            env.retain(|k, _| !k.eq_ignore_ascii_case("MAVEN_BASEDIR"));
+            env.insert("MAVEN_BASEDIR".into(), base.to_string_lossy().into_owned());
+        }
+        let result = crate::process::run_with_env(&self.command, args, &cwd, &env, true, cancel, |_, _| {})?;
+        if !result.success {
+            return Err(IdeError::invalid(format!("Cannot resolve Maven WAR artifact: {}", result.text.trim())));
+        }
+        let id = fs::read_to_string(output)?;
+        let parts: Vec<_> = id.trim().split(':').collect();
+        if parts.len() != 4 || parts[2] != "war" || parts.iter().any(|s| s.is_empty()) {
+            return Err(IdeError::invalid(format!("Cannot resolve Maven WAR artifact: {}", id.trim())));
+        }
+        let project = format!("{}:{}:{}", parts[0], parts[1], parts[3]);
+        self.args.push(format!("-Dexpression=session.projectMap({project}).artifact.file"));
+        self.maven_project = None;
+        Ok(())
+    }
+}
+
+fn groovy_literal(s: &str) -> String {
+    format!("'{}'", s.replace('\\', "\\\\").replace('\'', "\\'"))
 }
 
 pub fn build(root: &Path, model: &BuildModel, id: &str, cache: &Path) -> IdeResult<WebBuild> {
@@ -81,21 +125,36 @@ pub fn build(root: &Path, model: &BuildModel, id: &str, cache: &Path) -> IdeResu
                 .replace('\\', "/");
             args.extend(["-pl".into(), module, "-am".into()]);
         }
+        // help:evaluate runs once, in the reactor's first project. Query the selected
+        // POM's effective identity first; profiles and -D options can change its GAV.
+        let output = cache.join("artifact-project.txt");
+        let mut probe = top.options.clone();
+        probe.extend([
+            "-f".into(),
+            root.join(&p.pom).to_string_lossy().into_owned(),
+            "help:evaluate".into(),
+            "-Dexpression=project.id".into(),
+            format!("-Doutput={}", output.display()),
+        ]);
         args.extend([
             "-DskipTests".into(),
             "package".into(),
             "help:evaluate".into(),
-            "-Dexpression=project.artifact.file".into(),
             format!("-Doutput={}", manifest.display()),
         ]);
-        return Ok(WebBuild { command: top.command.clone(), args, cwd: top.dir.clone(), env: p.env.clone() });
+        return Ok(WebBuild {
+            command: top.command.clone(),
+            args,
+            cwd: top.dir.clone(),
+            env: p.env.clone(),
+            maven_project: Some((probe, output)),
+        });
     }
     if let Some(path) = id.strip_prefix("gradle:") {
         let g = model.gradle.as_ref().ok_or_else(|| IdeError::invalid("Choose a Gradle WAR module"))?;
         if !artifacts(root, model).iter().any(|a| a.id == id) {
             return Err(IdeError::invalid("Choose a Gradle WAR module"));
         }
-        let literal = |s: &str| format!("'{}'", s.replace('\\', "\\\\").replace('\'', "\\'"));
         let script = cache.join("war.init.gradle");
         fs::write(
             &script,
@@ -105,12 +164,12 @@ pub fn build(root: &Path, model: &BuildModel, id: &str, cache: &Path) -> IdeResu
     def warTask = p.tasks.named('war')
     p.tasks.register('openideaTomcatArtifact') {{
         dependsOn warTask
-        doLast {{ new File({}).text = warTask.get().archiveFile.get().asFile.absolutePath }}
+        doLast {{ new File({}).setText(warTask.get().archiveFile.get().asFile.absolutePath, 'UTF-8') }}
     }}
 }}
 "#,
-                literal(path),
-                literal(&manifest.to_string_lossy())
+                groovy_literal(path),
+                groovy_literal(&manifest.to_string_lossy())
             ),
         )?;
         let task = format!("{}:openideaTomcatArtifact", path.trim_end_matches(':'));
@@ -119,6 +178,7 @@ pub fn build(root: &Path, model: &BuildModel, id: &str, cache: &Path) -> IdeResu
             args: vec!["--init-script".into(), script.to_string_lossy().into_owned(), task],
             cwd: g.dir.clone(),
             env: g.env.clone(),
+            maven_project: None,
         });
     }
     Err(IdeError::invalid("Choose a WAR artifact"))
@@ -136,7 +196,9 @@ mod tests {
         assert_eq!(a.len(), 1);
         assert_eq!(a[0].name, "web");
         let plan = build(tmp.path(), &model, &a[0].id, &tmp.path().join("base with spaces")).unwrap();
-        assert!(plan.args.contains(&"-Dexpression=project.artifact.file".into()));
+        let (probe, _) = plan.maven_project.as_ref().unwrap();
+        assert!(probe.contains(&"-Dexpression=project.id".into()));
+        assert!(probe.contains(&tmp.path().join("pom.xml").to_string_lossy().into_owned()));
         assert!(
             plan.args.iter().any(|a| a.ends_with("base with spaces/artifact-path.txt")
                 || a.ends_with("base with spaces\\artifact-path.txt"))
@@ -152,6 +214,13 @@ mod tests {
         let plan = build(tmp.path(), &model, "maven:web/pom.xml", &tmp.path().join("base")).unwrap();
         assert_eq!(plan.cwd, "");
         assert_eq!(&plan.args[..3], &["-pl", "web", "-am"]);
+        assert!(
+            plan.maven_project
+                .as_ref()
+                .unwrap()
+                .0
+                .contains(&tmp.path().join("web/pom.xml").to_string_lossy().into_owned())
+        );
     }
     #[test]
     fn gradle_war_uses_archive_provider_and_ignores_comments() {
@@ -169,4 +238,31 @@ mod tests {
         assert!(fs::read_to_string(tmp.path().join("base/war.init.gradle")).unwrap().contains("archiveFile.get()"));
         assert!(!crate::gradle::has_war_plugin("// plugins { war }"));
     }
+
+    #[test]
+    fn gradle_manifest_paths_preserve_windows_characters() {
+        for path in [r"C:\工作 区\Tomcat's cache\artifact-path.txt", r"\\server\share\artifact-path.txt"] {
+            let literal = groovy_literal(path);
+            assert_eq!(literal[1..literal.len() - 1].replace("\\'", "'").replace("\\\\", "\\"), path);
+        }
+    }
+
+    #[test]
+    fn gradle_root_and_nested_modules_write_utf8_archive_paths() {
+        for module in [":", ":apps:timesheet"] {
+            let tmp = tempfile::tempdir().unwrap();
+            let dir = if module == ":" { "" } else { "apps/timesheet" };
+            fs::create_dir_all(tmp.path().join(dir)).unwrap();
+            fs::write(tmp.path().join("settings.gradle"), "rootProject.name = 'timesheet'\ninclude 'apps:timesheet'")
+                .unwrap();
+            fs::write(tmp.path().join(dir).join("build.gradle"), "plugins { id 'war' }").unwrap();
+            let model = crate::load(tmp.path(), &tmp.path().join("cache"), None);
+            let cache = tmp.path().join("工作 cache");
+            let plan = build(tmp.path(), &model, &format!("gradle:{module}"), &cache).unwrap();
+            assert!(plan.args.contains(&format!("{}:openideaTomcatArtifact", module.trim_end_matches(':'))));
+            let script = fs::read_to_string(cache.join("war.init.gradle")).unwrap();
+            assert!(script.contains(&format!("rootProject.project('{}')", module)));
+            assert!(script.contains("archiveFile.get().asFile.absolutePath, 'UTF-8'"));
+        }
+    }
 }

crates/ide-clipboard/src/lib.rs

@@ -1,6 +1,8 @@
 //! The file list on the OS clipboard: what Explorer copies when the user
 //! copies files, so the project view can paste them, and what the project view
-//! writes so Explorer can paste the files it copied (IDEA does both).
+//! writes so Explorer can paste the files it copied (IDEA does both). The
+//! written list comes with the paths as text, so a paste into an editor
+//! inserts them instead of doing nothing.
 //!
 //! Windows keeps it as `CF_HDROP`: a `DROPFILES` header and a double-NUL
 //! terminated list of absolute paths, wide when `fWide` is set. The data is set
@@ -10,6 +12,9 @@
 //! macOS keeps one `public.file-url` item per file on the general
 //! `NSPasteboard`; `NSURL` reads and writes them, so Finder's copies paste here
 //! and ours paste in Finder.
+//! On macOS, [`files`], [`has_files`] and [`set_files`] must run on the main
+//! thread: AppKit and WebKit also access the general pasteboard there, and its
+//! mutable type cache cannot be protected by a mutex in this crate.
 //!
 //! Other platforms (`text/uri-list` on X11) are not wired up: [`files`] is
 //! empty and [`set_files`] fails there.
@@ -20,7 +25,8 @@ use std::path::PathBuf;
 const HEADER: usize = 20;
 
 /// The absolute paths on the clipboard, empty when it holds no file list.
-pub fn files() -> Vec<PathBuf> {
+/// Read failures remain errors so callers can retain an internal copy.
+pub fn files() -> std::io::Result<Vec<PathBuf>> {
     imp::files()
 }
 
@@ -29,9 +35,8 @@ pub fn has_files() -> bool {
     imp::has_files()
 }
 
-/// Replaces the clipboard with `paths`. False when it is busy or holds nothing
-/// to write; the clipboard is a shared resource, so callers treat this as
-/// best-effort.
+/// Replaces the clipboard with `paths`. True only when the file list was
+/// accepted; writing just the accompanying text is not a successful hand-off.
 pub fn set_files(paths: &[PathBuf]) -> bool {
     if paths.is_empty() {
         return false;
@@ -111,6 +116,8 @@ mod imp {
 
     /// `CF_HDROP`, the clipboard format holding a file list.
     const CF_HDROP: u32 = 15;
+    /// `CF_UNICODETEXT`, so an editor paste of copied files inserts the paths.
+    const CF_UNICODETEXT: u32 = 13;
 
     /// An `HGLOBAL` or a `HANDLE`: both are opaque pointers here.
     type Handle = *mut c_void;
@@ -156,25 +163,29 @@ mod imp {
         (unsafe { IsClipboardFormatAvailable(CF_HDROP) }) != 0
     }
 
-    pub fn files() -> Vec<PathBuf> {
-        if !has_files() || !open() {
-            return Vec::new();
+    pub fn files() -> std::io::Result<Vec<PathBuf>> {
+        if !open() {
+            return Err(std::io::Error::last_os_error());
+        }
+        if !has_files() {
+            unsafe { CloseClipboard() };
+            return Ok(Vec::new());
         }
         let memory = unsafe { GetClipboardData(CF_HDROP) };
         let paths = if memory.is_null() {
-            Vec::new()
+            Err(std::io::Error::last_os_error())
         } else {
             // SAFETY: the clipboard keeps the block alive while it is open, and
             // `GlobalSize` bounds the bytes read from it.
             unsafe {
                 let data = GlobalLock(memory);
                 if data.is_null() {
-                    Vec::new()
+                    Err(std::io::Error::last_os_error())
                 } else {
                     let bytes = std::slice::from_raw_parts(data as *const u8, GlobalSize(memory));
                     let paths = decode(bytes);
                     GlobalUnlock(memory);
-                    paths
+                    Ok(paths)
                 }
             }
         };
@@ -182,12 +193,37 @@ mod imp {
         paths
     }
 
+    /// An `HGLOBAL` holding `text` as UTF-16 with a terminating NUL, and its
+    /// byte size. Null when the allocation failed.
+    fn global_text(text: &str) -> (Handle, usize) {
+        let mut units: Vec<u16> = text.encode_utf16().collect();
+        units.push(0);
+        let bytes = units.len() * 2;
+        unsafe {
+            let memory = GlobalAlloc(GMEM_MOVEABLE, bytes);
+            if memory.is_null() {
+                return (ptr::null_mut(), 0);
+            }
+            let data = GlobalLock(memory);
+            if data.is_null() {
+                GlobalFree(memory);
+                return (ptr::null_mut(), 0);
+            }
+            ptr::copy_nonoverlapping(units.as_ptr() as *const u8, data as *mut u8, bytes);
+            GlobalUnlock(memory);
+            (memory, bytes)
+        }
+    }
+
     pub fn set_files(paths: &[PathBuf]) -> bool {
         let bytes = encode(paths);
         if bytes.len() <= HEADER {
             return false;
         }
-        // SAFETY: the block is allocated, filled, handed to the clipboard and
+        // The paths as text, newline-separated, so pasting into an editor
+        // inserts them (IDEA writes the list and the text together).
+        let text = paths.iter().map(|p| p.to_string_lossy().into_owned()).collect::<Vec<_>>().join("\r\n");
+        // SAFETY: the blocks are allocated, filled, handed to the clipboard and
         // freed only on the paths where the clipboard did not take ownership.
         unsafe {
             let memory = GlobalAlloc(GMEM_MOVEABLE, bytes.len());
@@ -205,17 +241,26 @@ mod imp {
                 GlobalFree(memory);
                 return false;
             }
-            // Replacing the list also drops the text the user copied before.
+            // Replacing the list also drops the text the user copied before;
+            // the paths' own text is set back with it.
             if EmptyClipboard() == 0 {
                 CloseClipboard();
                 GlobalFree(memory);
                 return false;
             }
             let taken = !SetClipboardData(CF_HDROP, memory).is_null();
-            CloseClipboard();
             if !taken {
                 GlobalFree(memory);
             }
+            let (text_memory, _) = global_text(&text);
+            if !text_memory.is_null() {
+                // The text alone still pastes somewhere useful.
+                let text_taken = !SetClipboardData(CF_UNICODETEXT, text_memory).is_null();
+                if !text_taken {
+                    GlobalFree(text_memory);
+                }
+            }
+            CloseClipboard();
             taken
         }
     }
@@ -223,13 +268,14 @@ mod imp {
 
 #[cfg(target_os = "macos")]
 mod imp {
-    use objc2::ClassType;
     use objc2::rc::{Retained, autoreleasepool};
     use objc2::runtime::{AnyClass, AnyObject, ProtocolObject};
+    use objc2::{ClassType, MainThreadMarker};
     use objc2_app_kit::{
-        NSPasteboard, NSPasteboardReadingOptionKey, NSPasteboardURLReadingFileURLsOnlyKey, NSPasteboardWriting,
+        NSPasteboard, NSPasteboardReadingOptionKey, NSPasteboardTypeString, NSPasteboardURLReadingFileURLsOnlyKey,
+        NSPasteboardWriting,
     };
-    use objc2_foundation::{NSArray, NSDictionary, NSNumber, NSURL};
+    use objc2_foundation::{NSArray, NSDictionary, NSNumber, NSString, NSURL};
     use std::path::PathBuf;
 
     /// `NSURL` as the one class to read, limited to file URLs: a web link the
@@ -237,6 +283,7 @@ mod imp {
     fn read_file_urls<R>(
         f: impl FnOnce(&NSPasteboard, &NSArray<AnyClass>, &NSDictionary<NSPasteboardReadingOptionKey, AnyObject>) -> R,
     ) -> R {
+        debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
         autoreleasepool(|_| {
             let board = NSPasteboard::generalPasteboard();
             let classes = NSArray::from_slice(&[NSURL::class()]);
@@ -256,23 +303,28 @@ mod imp {
         })
     }
 
-    pub fn files() -> Vec<PathBuf> {
+    pub fn files() -> std::io::Result<Vec<PathBuf>> {
         read_file_urls(|board, classes, options| {
             // SAFETY: as in `has_files`; every object read for `NSURL` is one.
             let Some(objects) = (unsafe { board.readObjectsForClasses_options(classes, Some(options)) }) else {
-                return Vec::new();
+                return if unsafe { board.canReadObjectForClasses_options(classes, Some(options)) } {
+                    Err(std::io::Error::other("Cannot read clipboard files"))
+                } else {
+                    Ok(Vec::new())
+                };
             };
-            objects
+            Ok(objects
                 .iter()
                 .filter_map(|object| object.downcast::<NSURL>().ok())
                 .filter_map(|url| url.to_file_path())
                 // Finder ends a folder's URL in `/`; the project view names it without.
                 .map(|path| path.components().collect())
-                .collect()
+                .collect())
         })
     }
 
     pub fn set_files(paths: &[PathBuf]) -> bool {
+        debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
         autoreleasepool(|_| {
             // Folders get a directory URL (ending in `/`), as Finder writes them.
             let urls: Vec<Retained<NSURL>> = paths
@@ -285,9 +337,16 @@ mod imp {
             let writers: Vec<&ProtocolObject<dyn NSPasteboardWriting>> =
                 urls.iter().map(|url| ProtocolObject::from_ref(&**url)).collect();
             let board = NSPasteboard::generalPasteboard();
-            // Replacing the list also drops the text the user copied before.
+            // Replacing the list also drops the text the user copied before;
+            // the paths' own text is set back with it, so an editor paste
+            // inserts them (IDEA writes the list and the text together).
             board.clearContents();
-            board.writeObjects(&NSArray::from_slice(&writers))
+            let written = board.writeObjects(&NSArray::from_slice(&writers));
+            let text = NSString::from_str(
+                &paths.iter().map(|p| p.to_string_lossy().into_owned()).collect::<Vec<_>>().join("\n"),
+            );
+            board.setString_forType(&text, unsafe { NSPasteboardTypeString });
+            written
         })
     }
 }
@@ -300,8 +359,8 @@ mod imp {
         false
     }
 
-    pub fn files() -> Vec<PathBuf> {
-        Vec::new()
+    pub fn files() -> std::io::Result<Vec<PathBuf>> {
+        Ok(Vec::new())
     }
 
     pub fn set_files(_paths: &[PathBuf]) -> bool {

crates/ide-core/Cargo.toml

@@ -18,5 +18,8 @@ tokio-util.workspace = true
 [dev-dependencies]
 tempfile.workspace = true
 
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
 [target.'cfg(windows)'.dependencies]
-windows-sys = { version = "0.61", features = ["Win32_Globalization"] }
+windows-sys = { version = "0.61", features = ["Win32_Globalization", "Win32_Security", "Win32_System_Registry", "Win32_Foundation"] }

crates/ide-core/src/editor_settings.rs

@@ -12,6 +12,8 @@ use std::collections::BTreeMap;
 pub struct EditorGeneralSettings {
     /// Change font size with ⌘ + mouse wheel.
     pub wheel_zoom: bool,
+    pub markdown_image_folder: String,
+    pub markdown_image_name_pattern: String,
     /// Drag-and-drop of selected text inside the editor.
     pub drag_and_drop: bool,
     /// When the caret moves out of view: `minimize` scrolling | `center` the caret line.
@@ -35,6 +37,8 @@ impl Default for EditorGeneralSettings {
     fn default() -> Self {
         Self {
             wheel_zoom: false,
+            markdown_image_folder: "assets".into(),
+            markdown_image_name_pattern: "image-{timestamp}".into(),
             drag_and_drop: true,
             caret_scroll: "minimize".into(),
             soft_wrap_files: "*.md; *.txt; *.rst; *.adoc".into(),
@@ -367,6 +371,12 @@ pub struct TextAttributesOverride {
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct LanguageCodeStyle {
+    /// Java formatter: `default` | `intellij` | `custom` (other languages ignore it).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub formatter: Option<String>,
+    /// Eclipse formatter XML; relative paths start at the project root.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub formatter_path: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub use_tab: Option<bool>,
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -434,6 +444,8 @@ pub struct EncodingSettings {
     pub project: String,
     /// Fallback for `.properties` files.
     pub properties: String,
+    /// Display properties Unicode escapes as characters and save non-ASCII as escapes.
+    pub native_to_ascii: bool,
     /// Create UTF-8 files: `never` (no BOM) | `always` (with BOM) | `windows` (with BOM on Windows).
     pub utf8_bom: String,
 }
@@ -444,6 +456,7 @@ impl Default for EncodingSettings {
             global: "utf-8".into(),
             project: "utf-8".into(),
             properties: "iso-8859-1".into(),
+            native_to_ascii: false,
             utf8_bom: "never".into(),
         }
     }

crates/ide-core/src/error.rs

@@ -12,6 +12,15 @@ pub type IdeResult<T> = Result<T, IdeError>;
 pub struct IdeError {
     pub kind: ErrorKind,
     pub message: String,
+    /// Structured detail for errors the UI acts on; `null` for plain errors.
+    #[specta(optional)]
+    pub data: Option<ErrorData>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(tag = "type", rename_all = "camelCase")]
+pub enum ErrorData {
+    Tool { tool: String, missing: bool },
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
@@ -24,6 +33,7 @@ pub enum ErrorKind {
     /// Document version mismatch; the UI must resync the full text.
     OutOfSync,
     Cancelled,
+    TimedOut,
     /// A required external tool (language server, git, debugger) is unavailable.
     Unavailable,
     Io,
@@ -33,7 +43,21 @@ pub enum ErrorKind {
 
 impl IdeError {
     pub fn new(kind: ErrorKind, message: impl Into<String>) -> Self {
-        Self { kind, message: message.into() }
+        Self { kind, message: message.into(), data: None }
+    }
+    pub fn with_tool(mut self, tool: impl Into<String>) -> Self {
+        if self.data.is_none() {
+            self.data = Some(ErrorData::Tool { tool: tool.into(), missing: false });
+        }
+        self
+    }
+    pub fn missing_tool(tool: impl Into<String>) -> Self {
+        let tool = tool.into();
+        Self {
+            kind: ErrorKind::NotFound,
+            message: format!("{tool} is not installed"),
+            data: Some(ErrorData::Tool { tool, missing: true }),
+        }
     }
     pub fn not_found(m: impl Into<String>) -> Self {
         Self::new(ErrorKind::NotFound, m)
@@ -65,3 +89,30 @@ impl From<std::io::Error> for IdeError {
         Self::new(kind, e.to_string())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn tool_errors_round_trip_without_changing_diagnostics() {
+        let message = "[error] file.css: Unexpected token\n  1 | }\n";
+        let error = IdeError::invalid(message).with_tool("prettier");
+        let decoded: IdeError = serde_json::from_str(&serde_json::to_string(&error).unwrap()).unwrap();
+        assert_eq!(decoded.message, message);
+        assert_eq!(decoded.data, Some(ErrorData::Tool { tool: "prettier".into(), missing: false }));
+        let missing = IdeError::missing_tool("prettier").with_tool("prettier");
+        assert_eq!(missing.kind, ErrorKind::NotFound);
+        assert_eq!(missing.data, Some(ErrorData::Tool { tool: "prettier".into(), missing: true }));
+    }
+
+    #[test]
+    fn legacy_errors_need_no_data() {
+        let error: IdeError = serde_json::from_str(r#"{"kind":"unavailable","message":"no server"}"#).unwrap();
+        assert!(error.data.is_none());
+        assert_eq!(
+            serde_json::to_value(error).unwrap(),
+            serde_json::json!({"kind":"unavailable","message":"no server","data":null})
+        );
+    }
+}

crates/ide-core/src/event.rs

@@ -15,12 +15,20 @@ use std::sync::Arc;
 pub enum IdeEvent {
     /// Project window membership or selection changed.
     WindowGroupsChanged,
+    ProjectTrustChanged {
+        root: crate::IpcPath,
+        trusted: bool,
+    },
     /// Files or directories changed on disk (after debouncing, ignore rules applied).
     FsChanged {
         created: Vec<crate::IpcPath>,
         modified: Vec<crate::IpcPath>,
         removed: Vec<crate::IpcPath>,
     },
+    /// Excluded or ignored folders whose contents changed; they stay out of `FsChanged`.
+    ExcludedDirsChanged {
+        dirs: Vec<crate::IpcPath>,
+    },
     /// The backend changed a document (reload from disk, formatting, refactoring).
     /// The UI applies `changes` on top of `base_version`, yielding `version`.
     DocPatched {
@@ -28,12 +36,21 @@ pub enum IdeEvent {
         base_version: u32,
         version: u32,
         changes: Vec<TextChange>,
+        /// Part of a grouped transaction; the editor must not record a file-local undo.
+        #[serde(default)]
+        #[specta(optional)]
+        workspace_edit: bool,
     },
     /// A document's dirty flag changed (saved / modified externally).
     DocDirty {
         doc: DocId,
         dirty: bool,
     },
+    /// A complete workspace edit can be undone as one operation.
+    WorkspaceEditApplied {
+        id: u32,
+        paths: Vec<crate::IpcPath>,
+    },
     /// An open document's language changed (Settings › File Types, Override File
     /// Type), or its UI mode (a framework's root marker appeared or went).
     DocLanguage {
@@ -74,6 +91,12 @@ pub enum IdeEvent {
         status: ServerStatus,
         message: Option<String>,
     },
+    /// A running server lacks a capability; the UI offers the managed tool as a replacement.
+    LanguageServerWarning {
+        name: String,
+        message: String,
+        install_tool: String,
+    },
     /// A stopped language server left the project's list (disabled in settings, or a
     /// fallback that a preferred server took over from again).
     LanguageServerRemoved {

crates/ide-core/src/java_runtime.rs

@@ -0,0 +1,25 @@
+//! Capabilities needed by the JVM hosting Java language-server bundles.
+
+use std::path::Path;
+
+/// jdtls' javac bundle, java-debug / hot code replace, and Lombok / Gradle tooling.
+const BUNDLE_MODULES: &[&str] = &["jdk.compiler", "jdk.jdi", "jdk.unsupported"];
+
+/// Require a full JDK, including the modules used by jdtls and its bundles.
+/// Temurin JREs can list the build JDK's modules in `release` even when the runtime
+/// image omits them, so module metadata alone does not establish suitability.
+pub fn supports_java_bundles(home: &Path) -> bool {
+    let Ok(release) = std::fs::read_to_string(home.join("release")) else { return false };
+    let property =
+        |key: &str| release.lines().find_map(|line| line.trim().strip_prefix(key)).map(|v| v.trim().trim_matches('"'));
+    let javac = if cfg!(windows) { "javac.exe" } else { "javac" };
+    if property("IMAGE_TYPE=").is_some_and(|image| image.eq_ignore_ascii_case("jre"))
+        || !home.join("bin").join(javac).is_file()
+    {
+        return false;
+    }
+    match property("MODULES=") {
+        Some(modules) => BUNDLE_MODULES.iter().all(|required| modules.split_whitespace().any(|m| m == *required)),
+        None => BUNDLE_MODULES.iter().all(|m| home.join("jmods").join(format!("{m}.jmod")).is_file()),
+    }
+}

crates/ide-core/src/lib.rs

@@ -11,6 +11,7 @@ pub mod ids;
 pub mod ignored;
 pub mod inspection_settings;
 pub mod ipc_path;
+pub mod java_runtime;
 pub mod jsonc;
 pub mod output_encoding;
 pub mod process;

crates/ide-core/src/output_encoding.rs

@@ -13,7 +13,10 @@
 //!   they fork get them too (`spring-boot:run`, Surefire, `bootRun`, test workers).
 //!   Each JVM then reports "Picked up JAVA_TOOL_OPTIONS: …" on stderr (which a build tool
 //!   may copy to its stdout); that line is hidden again ([`NoticeFilter`]). `file.encoding` is left alone there: it would change
-//!   how a build reads sources that declare no encoding.
+//!   how a build reads sources that declare no encoding. The application JVMs a build
+//!   forks get `file.encoding=UTF-8` for a UTF-8 console instead, through the build's own
+//!   options: `-Dspring-boot.run.jvmArguments` for Maven `spring-boot:run`, an init script
+//!   ([`GRADLE_FILE_ENCODING_SCRIPT`]) for Gradle `JavaExec` tasks (`bootRun`, `run`).
 //! - Python: `PYTHONIOENCODING`.
 
 use std::collections::BTreeMap;
@@ -75,16 +78,34 @@ fn encoding_for_code_page(cp: u32) -> Option<&'static encoding_rs::Encoding> {
 const STD_PROPERTIES: &[&str] = &["stdout.encoding", "stderr.encoding", "sun.stdout.encoding", "sun.stderr.encoding"];
 const FILE_ENCODING: &str = "file.encoding";
 const TOOL_OPTIONS: &str = "JAVA_TOOL_OPTIONS";
+const SPRING_BOOT_JVM_ARGS: &str = "-Dspring-boot.run.jvmArguments=";
 
 /// Build tools and launcher scripts that run on (and may fork) JVMs.
-const JVM_TOOLS: &[&str] =
-    &["mvn", "mvnw", "mvnd", "gradle", "gradlew", "sbt", "ant", "kotlin", "kotlinc", "groovy", "scala", "jbang"];
+const JVM_TOOLS: &[&str] = &["sbt", "ant", "kotlin", "kotlinc", "groovy", "scala", "jbang"];
+const MAVEN: &[&str] = &["mvn", "mvnw", "mvnd"];
+const GRADLE: &[&str] = &["gradle", "gradlew"];
+
+/// Gradle init script giving the `JavaExec` tasks (`bootRun`, `run`, custom ones) a UTF-8
+/// default charset before the build configures them, so the build can override it.
+/// Gradle's own JVM and the compiler's source encoding are untouched.
+pub const GRADLE_FILE_ENCODING_SCRIPT: &str = "\
+// Written by OpenIDEA: a UTF-8 default charset for applications run by Gradle, as the Run console decodes UTF-8.
+allprojects {
+    tasks.withType(JavaExec).configureEach {
+        defaultCharacterEncoding = 'UTF-8'
+    }
+}
+";
 
 /// What a launch needs: `-D` options to put first on a `java` command line,
 /// environment variables to set, and the notice line its JVMs print because of them.
 #[derive(Debug, Default, PartialEq, Eq)]
 pub struct EncodingFix {
     pub java_args: Vec<String>,
+    /// The build tool's arguments, rewritten to pass options to the JVM it forks.
+    pub args: Option<Vec<String>>,
+    /// Gradle: pass [`GRADLE_FILE_ENCODING_SCRIPT`] with `--init-script`.
+    pub gradle_init_script: bool,
     pub env: Vec<(String, String)>,
     /// "Picked up JAVA_TOOL_OPTIONS: …" for a variable set here alone, to drop from the output.
     pub notice: Option<String>,
@@ -116,6 +137,8 @@ fn options(properties: &[&str], encoding: &str) -> Vec<String> {
 #[derive(Clone, Copy, PartialEq, Eq)]
 enum Kind {
     Java,
+    Maven,
+    Gradle,
     JvmTool,
     Python,
     Other,
@@ -125,6 +148,10 @@ fn kind(program: &str) -> Kind {
     let name = program_name(program);
     if name == "java" || name == "javaw" {
         Kind::Java
+    } else if MAVEN.contains(&name.as_str()) {
+        Kind::Maven
+    } else if GRADLE.contains(&name.as_str()) {
+        Kind::Gradle
     } else if JVM_TOOLS.contains(&name.as_str()) {
         Kind::JvmTool
     } else if is_python(&name) {
@@ -193,7 +220,17 @@ fn fix_kind(
                 out.java_args.push(format!("-D{FILE_ENCODING}=UTF-8"));
             }
         }
-        (Kind::Java | Kind::JvmTool, _) => {
+        (Kind::Java | Kind::Maven | Kind::Gradle | Kind::JvmTool, _) => {
+            if let Some(args) = args
+                && is_utf8(encoding)
+                && !sets(&tool_options, &[FILE_ENCODING])
+            {
+                match kind {
+                    Kind::Maven => out.args = spring_boot_file_encoding(args),
+                    Kind::Gradle => out.gradle_init_script = true,
+                    _ => {}
+                }
+            }
             if !sets(&tool_options, STD_PROPERTIES) {
                 let added = options(STD_PROPERTIES, encoding).join(" ");
                 let value = match tool_options.trim() {
@@ -214,14 +251,42 @@ fn fix_kind(
     out
 }
 
-/// `vmArgs` of a launch by java-debug, which decodes the JVM's output as `encoding`
-/// (its launch attribute, UTF-8 when unset) and sets `file.encoding` itself.
-pub fn java_debug_vm_args(vm_args: &str, encoding: Option<&str>, windows: bool) -> Option<String> {
-    let encoding = encoding.map(str::trim).filter(|e| !e.is_empty()).unwrap_or("UTF-8");
-    if (!windows && is_utf8(encoding)) || sets(vm_args, STD_PROPERTIES) {
+fn spring_boot_file_encoding(args: &[String]) -> Option<Vec<String>> {
+    if !args.iter().any(|a| a == "spring-boot:run" || (a.contains(":spring-boot-maven-plugin:") && a.ends_with(":run")))
+    {
         return None;
     }
-    let added = options(STD_PROPERTIES, encoding).join(" ");
+    let option = format!("-D{FILE_ENCODING}=UTF-8");
+    let mut out = args.to_vec();
+    match out.iter_mut().rfind(|a| a.starts_with(SPRING_BOOT_JVM_ARGS)) {
+        Some(own) if sets(own, &[FILE_ENCODING]) => return None,
+        Some(own) => {
+            if own.len() > SPRING_BOOT_JVM_ARGS.len() {
+                own.push(' ');
+            }
+            own.push_str(&option);
+        }
+        None => out.push(format!("{SPRING_BOOT_JVM_ARGS}{option}")),
+    }
+    Some(out)
+}
+
+/// `vmArgs` of a launch by java-debug, which decodes the JVM's output as `encoding`
+/// (its launch attribute, UTF-8 when unset). java-debug sets `file.encoding` only
+/// when that attribute is nonblank; use the same defaults and user overrides as [`fix`].
+pub fn java_debug_vm_args(
+    vm_args: &str,
+    vars: &BTreeMap<String, String>,
+    inherited: impl Fn(&str) -> Option<String>,
+    encoding: Option<&str>,
+    windows: bool,
+) -> Option<String> {
+    let encoding = encoding.map(str::trim).filter(|e| !e.is_empty()).unwrap_or("UTF-8");
+    let added = fix_kind(Kind::Java, Some(&[vm_args.to_owned()]), vars, inherited, encoding, windows).java_args;
+    if added.is_empty() {
+        return None;
+    }
+    let added = added.join(" ");
     Some(match vm_args.trim() {
         "" => added,
         own => format!("{own} {added}"),
@@ -427,6 +492,64 @@ mod tests {
         assert_eq!(run("python3", &[], &[], "GBK", false).env, [("PYTHONIOENCODING".to_owned(), "GBK".to_owned())]);
     }
 
+    #[test]
+    fn spring_boot_run_forks_get_a_utf8_default_charset() {
+        let boot = |args: &[&str], env: &[(&str, &str)]| run("mvn.cmd", args, env, "UTF-8", true).args;
+        let utf8 = "-Dspring-boot.run.jvmArguments=-Dfile.encoding=UTF-8";
+        assert_eq!(boot(&["spring-boot:run"], &[]).unwrap(), ["spring-boot:run", utf8]);
+        let plugin = "org.springframework.boot:spring-boot-maven-plugin:3.2.0:run";
+        assert_eq!(boot(&["-pl", "app", plugin], &[]).unwrap(), ["-pl", "app", plugin, utf8]);
+        // The user's VM options are kept; their own `file.encoding` wins.
+        assert_eq!(
+            boot(&["spring-boot:run", "-Dspring-boot.run.jvmArguments=-Xmx1g \"-Da=b c\""], &[]).unwrap(),
+            ["spring-boot:run", "-Dspring-boot.run.jvmArguments=-Xmx1g \"-Da=b c\" -Dfile.encoding=UTF-8"]
+        );
+        assert_eq!(boot(&["spring-boot:run", "-Dspring-boot.run.jvmArguments="], &[]).unwrap()[1], utf8);
+        assert!(boot(&["spring-boot:run", "-Dspring-boot.run.jvmArguments=-Dfile.encoding=GBK"], &[]).is_none());
+        assert!(boot(&["spring-boot:run"], &[(TOOL_OPTIONS, "-Dfile.encoding=GBK")]).is_none());
+        // Other goals and tools, other consoles, and other platforms are left alone.
+        assert!(boot(&["package"], &[]).is_none());
+        assert!(run("mvn", &["spring-boot:run"], &[], "GBK", true).args.is_none());
+        assert!(run("mvn", &["spring-boot:run"], &[], "UTF-8", false).args.is_none());
+    }
+
+    #[test]
+    fn forked_application_jvms_get_a_utf8_default_charset() {
+        // Reported: a Spring Boot app run by the build on Chinese Windows (JDK 8–17, GBK default).
+        for (tool, args) in [
+            ("C:\\p\\gradlew.bat", &["bootRun"][..]),
+            ("gradle", &[":app:run"]),
+            ("mvnw.cmd", &["spring-boot:run"]),
+            ("mvnd", &["org.springframework.boot:spring-boot-maven-plugin:2.7.18:run"]),
+        ] {
+            let f = run(tool, args, &[], "UTF-8", true);
+            let gradle = tool.contains("gradle");
+            assert_eq!(f.gradle_init_script, gradle, "{tool}");
+            assert_eq!(f.args.is_some(), !gradle, "{tool}");
+            // The build tool's own JVM keeps its default charset.
+            assert!(!tool_env(&f).unwrap().contains("file.encoding"), "{tool}");
+            // The user's choice, a GBK console and other platforms are left alone.
+            let own = run(tool, args, &[(TOOL_OPTIONS, "-Dfile.encoding=GBK")], "UTF-8", true);
+            assert!(!own.gradle_init_script && own.args.is_none(), "{tool}");
+            let gbk = run(tool, args, &[], "GBK", true);
+            assert!(!gbk.gradle_init_script && gbk.args.is_none(), "{tool}");
+            assert_eq!(run(tool, args, &[], "UTF-8", false), EncodingFix::default(), "{tool}");
+        }
+        // Shell command lines can't take arguments; other JVM tools fork no application.
+        assert!(!fix_command_line("gradlew bootRun", &BTreeMap::new(), |_| None, "UTF-8", true).gradle_init_script);
+        let sbt = run("sbt", &["run"], &[], "UTF-8", true);
+        assert!(!sbt.gradle_init_script && sbt.args.is_none());
+    }
+
+    #[test]
+    fn gradle_script_respects_the_builds_own_file_encoding() {
+        let s = GRADLE_FILE_ENCODING_SCRIPT;
+        assert!(s.contains("tasks.withType(JavaExec).configureEach"), "{s}");
+        assert!(s.contains("defaultCharacterEncoding = 'UTF-8'"), "{s}");
+        assert!(!s.contains("doFirst"), "the build must be able to override the default: {s}");
+        assert!(!s.contains("withType(Test)") && !s.contains("JavaCompile"), "{s}");
+    }
+
     #[test]
     fn shell_command_lines_get_variables_from_their_first_word() {
         let line = |l: &str| fix_command_line(l, &BTreeMap::new(), |_| None, "UTF-8", true);
@@ -446,12 +569,53 @@ mod tests {
 
     #[test]
     fn java_debug_launches_write_what_java_debug_decodes() {
-        assert_eq!(java_debug_vm_args("", None, true).as_deref(), Some(TOOL_UTF8));
-        assert_eq!(java_debug_vm_args("-Xmx1g", Some(""), true), Some(format!("-Xmx1g {TOOL_UTF8}")));
-        assert_eq!(java_debug_vm_args("", Some("GBK"), true).unwrap().split(' ').next(), Some("-Dstdout.encoding=GBK"));
-        assert_eq!(java_debug_vm_args("-Dstdout.encoding=GBK", None, true), None);
-        assert_eq!(java_debug_vm_args("-Xmx1g", None, false), None);
-        assert!(java_debug_vm_args("", Some("GBK"), false).is_some());
+        let debug =
+            |args: &str, encoding, windows| java_debug_vm_args(args, &BTreeMap::new(), |_| None, encoding, windows);
+        for encoding in [None, Some(""), Some("  "), Some("UTF-8"), Some("utf8")] {
+            let streams = encoding.filter(|e| !e.trim().is_empty()).unwrap_or("UTF-8");
+            let utf8 = format!("{} -Dfile.encoding=UTF-8", options(STD_PROPERTIES, streams).join(" "));
+            assert_eq!(debug("", encoding, true), Some(utf8.clone()));
+            assert_eq!(debug("-Xmx1g", encoding, true), Some(format!("-Xmx1g {utf8}")));
+            assert_eq!(debug("-Xmx1g", encoding, false), None);
+        }
+        for windows in [true, false] {
+            assert_eq!(debug("", Some("GBK"), windows), Some(options(STD_PROPERTIES, "GBK").join(" ")));
+        }
+    }
+
+    #[test]
+    fn java_debug_preserves_user_options_independently() {
+        let debug = |args: &str| java_debug_vm_args(args, &BTreeMap::new(), |_| None, None, true);
+        assert_eq!(debug("-Dfile.encoding=GBK"), Some(format!("-Dfile.encoding=GBK {TOOL_UTF8}")));
+        for property in STD_PROPERTIES {
+            let args = format!("-D{property}=GBK");
+            assert_eq!(debug(&args), Some(format!("{args} -Dfile.encoding=UTF-8")));
+            assert_eq!(debug(&format!("{args} -Dfile.encoding=GBK")), None);
+        }
+        for key in ["JDK_JAVA_OPTIONS", TOOL_OPTIONS] {
+            for (own, expected) in [
+                ("-Dfile.encoding=GBK", Some(TOOL_UTF8.to_owned())),
+                ("-Dstdout.encoding=GBK", Some("-Dfile.encoding=UTF-8".to_owned())),
+                ("-Dstdout.encoding=GBK -Dfile.encoding=GBK", None),
+            ] {
+                assert_eq!(java_debug_vm_args("", &vars(&[(key, own)]), |_| None, None, true), expected);
+                assert_eq!(
+                    java_debug_vm_args("", &BTreeMap::new(), |k| (k == key).then(|| own.to_owned()), None, true),
+                    expected
+                );
+            }
+            // A launch environment value overrides the inherited one, as in Run.
+            assert_eq!(
+                java_debug_vm_args(
+                    "",
+                    &vars(&[(key, "")]),
+                    |k| (k == key).then(|| "-Dfile.encoding=GBK".into()),
+                    None,
+                    true
+                ),
+                Some(format!("{TOOL_UTF8} -Dfile.encoding=UTF-8"))
+            );
+        }
     }
 
     fn filtered(chunks: &[&str]) -> String {

crates/ide-core/src/process.rs

@@ -1,8 +1,11 @@
 //! Child-process helpers shared by every crate that spawns tools.
 
 use std::ffi::{OsStr, OsString};
-use std::process::Command;
+#[cfg(windows)]
+use std::process::Stdio;
+use std::process::{Child, Command};
 use std::sync::{Arc, RwLock};
+use std::time::Duration;
 
 /// Windows `CREATE_NO_WINDOW` creation flag, for call sites that combine it
 /// with other flags (and then call [`host_env`] themselves). Prefer [`prepare`] otherwise.
@@ -25,6 +28,95 @@ pub fn prepare(cmd: &mut Command) -> &mut Command {
     host_env(cmd)
 }
 
+/// Starts the child as the leader of its own process group on Unix, so [`kill_tree`] and
+/// [`terminate_tree`] reach what it starts in turn (`gh` → `git`, `npm` → `node`, `mvnw` →
+/// the JVM). A no-op elsewhere: on Windows the tree is found from the child's process id.
+pub fn own_group(cmd: &mut Command) -> &mut Command {
+    #[cfg(unix)]
+    {
+        use std::os::unix::process::CommandExt;
+        cmd.process_group(0);
+    }
+    cmd
+}
+
+/// Kills the child and everything it started, then reaps it.
+///
+/// - Unix: `SIGKILL` to its process group, so spawn it with [`own_group`].
+/// - Windows: `taskkill /T /F`, which walks the tree from the child's process id.
+pub fn kill_tree(child: &mut Child) {
+    #[cfg(unix)]
+    signal_group(child, libc::SIGKILL);
+    #[cfg(windows)]
+    taskkill_tree(child);
+    let _ = child.kill();
+    let _ = child.wait();
+}
+
+/// [`kill_tree`] for a child known by its process id (a `tokio` child): `SIGKILL` to its
+/// process group (spawn it with [`own_group`]) or `taskkill /T /F`. Call it before the child
+/// is reaped, so the id still names it. The child itself is left to its owner to kill and reap.
+pub fn kill_tree_of(pid: u32) {
+    #[cfg(unix)]
+    if let Ok(pid) = libc::pid_t::try_from(pid) {
+        // SAFETY: plain syscall; see `signal_group`.
+        unsafe {
+            libc::kill(-pid, libc::SIGKILL);
+        }
+    }
+    #[cfg(windows)]
+    {
+        let mut taskkill = Command::new("taskkill");
+        prepare(&mut taskkill)
+            .args(["/T", "/F", "/PID", &pid.to_string()])
+            .stdin(Stdio::null())
+            .stdout(Stdio::null())
+            .stderr(Stdio::null());
+        let _ = taskkill.status();
+    }
+    #[cfg(not(any(unix, windows)))]
+    let _ = pid;
+}
+
+/// [`kill_tree`] that first asks the group to exit: `SIGTERM`, then `grace`, then `SIGKILL`.
+/// Git removes its `index.lock` on `SIGTERM`, where `SIGKILL` leaves it behind and the next
+/// git command fails. Windows has no such signal to send from outside the child's console,
+/// so there it is [`kill_tree`].
+pub fn terminate_tree(child: &mut Child, grace: Duration) {
+    #[cfg(unix)]
+    {
+        signal_group(child, libc::SIGTERM);
+        // Sleep rather than `try_wait`: the child stays unreaped, so its process id (and the
+        // group id) cannot be reused before the `SIGKILL` below.
+        std::thread::sleep(grace);
+    }
+    #[cfg(not(unix))]
+    let _ = grace;
+    kill_tree(child);
+}
+
+#[cfg(unix)]
+fn signal_group(child: &Child, signal: libc::c_int) {
+    if let Ok(pid) = libc::pid_t::try_from(child.id()) {
+        // SAFETY: plain syscall. The child is not reaped yet, so `-pid` is still its group (or
+        // no group at all when it was not spawned with `own_group`, and the call fails).
+        unsafe {
+            libc::kill(-pid, signal);
+        }
+    }
+}
+
+#[cfg(windows)]
+fn taskkill_tree(child: &Child) {
+    let mut taskkill = Command::new("taskkill");
+    prepare(&mut taskkill)
+        .args(["/T", "/F", "/PID", &child.id().to_string()])
+        .stdin(Stdio::null())
+        .stdout(Stdio::null())
+        .stderr(Stdio::null());
+    let _ = taskkill.status();
+}
+
 /// Gives `cmd` the host's environment back when the IDE runs from an AppImage. `AppRun` and
 /// its hooks point `LD_LIBRARY_PATH`, `PATH`, `XDG_DATA_DIRS`, `GIO_MODULE_DIR`, `GTK_PATH`,
 /// `GST_PLUGIN_*`, ... into the mounted image for the IDE itself; a host program that
@@ -237,10 +329,227 @@ pub fn find_executable(name: &str, search: &OsStr) -> Option<std::path::PathBuf>
     find_executable_in(name, search, cfg!(windows), pathext.as_deref().and_then(|p| p.to_str()))
 }
 
+/// The user's own `PATH` entries on Windows (`HKCU\Environment`), the part of the
+/// merged `PATH` a process may not inherit — an IDE started before the variable was
+/// edited, or as a different user, sees only the machine entries. `%VAR%` references
+/// (`REG_EXPAND_SZ`) are expanded against the current environment. `None` elsewhere:
+/// there a login shell already supplies the user's whole `PATH`.
+#[cfg(windows)]
+pub fn user_path() -> Option<OsString> {
+    use windows_sys::Win32::Foundation::ERROR_SUCCESS;
+    use windows_sys::Win32::System::Registry::{HKEY, HKEY_CURRENT_USER, KEY_READ, RegCloseKey, RegOpenKeyExW};
+
+    fn wide(s: &str) -> Vec<u16> {
+        s.encode_utf16().chain(std::iter::once(0)).collect()
+    }
+
+    unsafe {
+        let mut key: HKEY = std::ptr::null_mut();
+        if RegOpenKeyExW(HKEY_CURRENT_USER, wide("Environment").as_ptr(), 0, KEY_READ, &mut key) != ERROR_SUCCESS {
+            return None;
+        }
+        let value = read_registry_string(key, &wide("Path"));
+        RegCloseKey(key);
+        value.filter(|v| !v.trim().is_empty()).map(OsString::from)
+    }
+}
+
+/// The string of value `name` under open `key`: `REG_SZ` as-is, `REG_EXPAND_SZ` expanded
+/// against the current environment. `None` when the value is missing or unreadable.
+///
+/// A `REG_EXPAND_SZ` value's first size query reports the unexpanded size, so a value
+/// that grows when expanded is re-read at the size the failed call reports. And the
+/// terminating NUL can leak into the read buffer with a stray UTF-16 unit behind it —
+/// seen with a `REG_EXPAND_SZ` user `Path`, where it made `env::set_var("PATH", …)`
+/// panic with "strings passed to WinAPI cannot contain NULs" — so the text is cut at
+/// the first NUL, not just stripped of trailing ones.
+#[cfg(windows)]
+fn read_registry_string(key: windows_sys::Win32::System::Registry::HKEY, name: &[u16]) -> Option<String> {
+    use windows_sys::Win32::Foundation::{ERROR_MORE_DATA, ERROR_SUCCESS};
+    use windows_sys::Win32::System::Registry::{RRF_RT_REG_EXPAND_SZ, RRF_RT_REG_SZ, RegGetValueW};
+
+    const FLAGS: u32 = RRF_RT_REG_SZ | RRF_RT_REG_EXPAND_SZ;
+    let mut kind = 0u32;
+    let mut len = 0u32;
+    // SAFETY: `name` is NUL-terminated and the size query writes only `kind` and `len`.
+    let status =
+        unsafe { RegGetValueW(key, std::ptr::null(), name.as_ptr(), FLAGS, &mut kind, std::ptr::null_mut(), &mut len) };
+    if status != ERROR_SUCCESS || len == 0 {
+        return None;
+    }
+    let buf = loop {
+        let mut buf = vec![0u16; len as usize / 2 + 1];
+        // SAFETY: as above; the buffer holds at least the `len` bytes the call may write.
+        let status = unsafe {
+            RegGetValueW(key, std::ptr::null(), name.as_ptr(), FLAGS, &mut kind, buf.as_mut_ptr() as *mut _, &mut len)
+        };
+        if status == ERROR_SUCCESS {
+            break buf;
+        }
+        if status != ERROR_MORE_DATA || len == 0 {
+            return None;
+        }
+    };
+    let text = String::from_utf16_lossy(&buf);
+    let end = text.find('\0').unwrap_or(text.len());
+    Some(text[..end].to_owned())
+}
+
+/// The user's own `PATH` entries; `None` outside Windows (see the Windows impl).
+#[cfg(not(windows))]
+pub fn user_path() -> Option<OsString> {
+    None
+}
+
+/// `path` followed by the [`user_path`] entries it lacks.
+pub fn with_user_path(path: &OsStr) -> OsString {
+    user_path().map_or_else(|| path.to_owned(), |user| append_path_entries(path, &user))
+}
+
+fn append_path_entries(path: &OsStr, extra: &OsStr) -> OsString {
+    let mut dirs: Vec<std::path::PathBuf> = std::env::split_paths(path).filter(|d| !d.as_os_str().is_empty()).collect();
+    for dir in std::env::split_paths(extra).filter(|d| !d.as_os_str().is_empty()) {
+        if !dirs.contains(&dir) {
+            dirs.push(dir);
+        }
+    }
+    std::env::join_paths(dirs).unwrap_or_else(|_| path.to_owned())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
 
+    #[cfg(unix)]
+    #[test]
+    fn kill_tree_of_reaches_what_the_child_started() {
+        use std::io::BufRead;
+        let mut cmd = Command::new("sh");
+        own_group(&mut cmd).args(["-c", "sleep 30 & echo $!; wait"]).stdout(std::process::Stdio::piped());
+        let mut child = cmd.spawn().unwrap();
+        let mut line = String::new();
+        std::io::BufReader::new(child.stdout.take().unwrap()).read_line(&mut line).unwrap();
+        let grandchild: libc::pid_t = line.trim().parse().unwrap();
+        let alive = |pid: libc::pid_t| unsafe { libc::kill(pid, 0) } == 0;
+        assert!(alive(grandchild));
+        kill_tree_of(child.id());
+        let _ = child.wait();
+        // Reparented to init once its parent is gone, which reaps it.
+        let gone = (0..100).any(|_| {
+            std::thread::sleep(Duration::from_millis(20));
+            !alive(grandchild)
+        });
+        assert!(gone, "the grandchild {grandchild} survived");
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn user_path_reads_the_current_users_path() {
+        // This host has a user `Path` only when the test account set one; either way the call
+        // must not fail, and a present value is a non-empty `;`-joined list of directories.
+        if let Some(path) = user_path() {
+            let dirs: Vec<_> = std::env::split_paths(&path).collect();
+            assert!(!dirs.is_empty(), "user PATH should hold at least one directory");
+        }
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn registry_strings_expand_and_stay_terminator_free() {
+        use windows_sys::Win32::Foundation::ERROR_SUCCESS;
+        use windows_sys::Win32::System::Registry::{
+            HKEY, HKEY_CURRENT_USER, KEY_READ, KEY_WRITE, REG_EXPAND_SZ, REG_SZ, RegCloseKey, RegCreateKeyExW,
+            RegDeleteTreeW, RegSetValueExW,
+        };
+
+        fn wide(s: &str) -> Vec<u16> {
+            s.encode_utf16().chain(std::iter::once(0)).collect()
+        }
+
+        struct TestState {
+            key: HKEY,
+            name: String,
+            variable: String,
+            previous: Option<OsString>,
+        }
+        impl Drop for TestState {
+            fn drop(&mut self) {
+                // SAFETY: the key belongs to this test; Windows environment mutation is safe.
+                unsafe {
+                    RegCloseKey(self.key);
+                    RegDeleteTreeW(HKEY_CURRENT_USER, wide(&self.name).as_ptr());
+                    match &self.previous {
+                        Some(value) => std::env::set_var(&self.variable, value),
+                        None => std::env::remove_var(&self.variable),
+                    }
+                }
+            }
+        }
+        let name = format!("Software\\ai.l0ng.openidea.registry-read-test-{}", std::process::id());
+        let variable = format!("OPENIDEA_TEST_REGVAR_{}", std::process::id());
+        let long = "x".repeat(600);
+        let mut key: HKEY = std::ptr::null_mut();
+        let opened = unsafe {
+            RegCreateKeyExW(
+                HKEY_CURRENT_USER,
+                wide(&name).as_ptr(),
+                0,
+                std::ptr::null(),
+                0,
+                KEY_READ | KEY_WRITE,
+                std::ptr::null(),
+                &mut key,
+                std::ptr::null_mut(),
+            )
+        };
+        assert_eq!(opened, ERROR_SUCCESS, "the test key must be creatable under HKCU\\Software");
+        let _cleanup = TestState { key, name, previous: std::env::var_os(&variable), variable: variable.clone() };
+        // SAFETY: Windows permits environment mutation. No other test uses this process-specific name.
+        unsafe { std::env::set_var(&variable, &long) };
+        let set = |value: &str, kind: u32, data: &[u16]| {
+            // SAFETY: `key` is open for writing and `data` holds `data.len() * 2` bytes.
+            assert_eq!(
+                unsafe {
+                    RegSetValueExW(
+                        key,
+                        wide(value).as_ptr(),
+                        0,
+                        kind,
+                        data.as_ptr() as *const _,
+                        (data.len() * 2) as u32,
+                    )
+                },
+                ERROR_SUCCESS
+            );
+        };
+        let read = |value: &str| read_registry_string(key, &wide(value));
+        set("Plain", REG_SZ, &wide("plain"));
+        set("Expand", REG_EXPAND_SZ, &wide(&format!("%{variable}%\\bin")));
+        set("ExpandLong", REG_EXPAND_SZ, &wide(&format!("%{variable}%")));
+        // Reproduce the reported interior terminator followed by a stale UTF-16 unit.
+        set("TrailingGarbage", REG_SZ, &wide("C:\\Zed\\bin\0n"));
+        set("ExpandTrailingGarbage", REG_EXPAND_SZ, &wide(&format!("%{variable}%\\bin\0n")));
+        set("Empty", REG_SZ, &wide(""));
+        let plain = read("Plain");
+        let expand = read("Expand");
+        let expand_long = read("ExpandLong");
+        assert_eq!(plain.as_deref(), Some("plain"));
+        assert_eq!(expand.as_deref(), Some(format!("{long}\\bin")).as_deref());
+        // Longer than its unexpanded form: needs the re-read at the expanded size.
+        assert_eq!(expand_long.as_deref(), Some(long.as_str()));
+        assert_eq!(read("TrailingGarbage").as_deref(), Some("C:\\Zed\\bin"));
+        assert_eq!(read("ExpandTrailingGarbage").as_deref(), Some(format!("{long}\\bin")).as_deref());
+        assert_eq!(read("Empty").as_deref(), Some(""));
+        assert_eq!(read("Missing"), None);
+    }
+
+    #[test]
+    fn append_path_entries_keeps_the_order_and_adds_what_is_missing() {
+        let join = |dirs: &[&str]| std::env::join_paths(dirs).unwrap();
+        assert_eq!(append_path_entries(&join(&["a", "b"]), &join(&["b", "c"])), join(&["a", "b", "c"]));
+        assert_eq!(append_path_entries(OsStr::new(""), &join(&["c"])), join(&["c"]));
+    }
+
     #[test]
     fn shell_env_adds_only_what_the_process_lacks_and_the_overlay_wins() {
         set_shell_env(vec![("OPENIDEA_SHELL_ONLY_VAR".into(), "1".into()), ("PATH".into(), "/from/shell".into())]);
@@ -402,3 +711,71 @@ mod tests {
         assert_eq!(find_executable("nope", &search), None);
     }
 }
+
+#[cfg(all(test, unix))]
+mod kill_tests {
+    use super::*;
+    use std::path::Path;
+    use std::time::Instant;
+
+    /// Runs `script` in `sh` as its own group's leader and waits for it to write `ready`.
+    fn start(script: &str, ready: &Path) -> Child {
+        let mut cmd = Command::new("sh");
+        cmd.arg("-c").arg(script);
+        let child = own_group(&mut cmd).spawn().unwrap();
+        let deadline = Instant::now() + Duration::from_secs(5);
+        while !ready.exists() {
+            assert!(Instant::now() < deadline, "the script never got ready");
+            std::thread::sleep(Duration::from_millis(10));
+        }
+        child
+    }
+
+    fn assert_gone(pid: libc::pid_t) {
+        let deadline = Instant::now() + Duration::from_secs(5);
+        // SAFETY: signal 0 only checks that the process exists.
+        while unsafe { libc::kill(pid, 0) } == 0 {
+            assert!(Instant::now() < deadline, "process {pid} survived");
+            std::thread::sleep(Duration::from_millis(20));
+        }
+    }
+
+    #[test]
+    fn kill_tree_kills_what_the_child_started() {
+        let dir = tempfile::tempdir().unwrap();
+        let pid_file = dir.path().join("pid");
+        let script = format!("sleep 30 & echo $! > '{0}.tmp' && mv '{0}.tmp' '{0}'; wait", pid_file.display());
+        let mut child = start(&script, &pid_file);
+        let grandchild: libc::pid_t = std::fs::read_to_string(&pid_file).unwrap().trim().parse().unwrap();
+        kill_tree(&mut child);
+        assert!(child.try_wait().unwrap().is_some(), "the child is reaped");
+        assert_gone(grandchild);
+    }
+
+    #[test]
+    fn terminate_tree_lets_the_child_clean_up() {
+        let dir = tempfile::tempdir().unwrap();
+        let (ready, cleaned) = (dir.path().join("ready"), dir.path().join("cleaned"));
+        let script = format!(
+            "trap 'touch \"{}\"; exit 0' TERM; touch \"{}\"; sleep 30 & wait",
+            cleaned.display(),
+            ready.display()
+        );
+        let mut child = start(&script, &ready);
+        terminate_tree(&mut child, Duration::from_millis(500));
+        assert!(cleaned.exists(), "the SIGTERM handler ran before the SIGKILL");
+        assert!(child.try_wait().unwrap().is_some(), "the child is reaped");
+    }
+
+    #[test]
+    fn terminate_tree_still_kills_a_child_that_ignores_sigterm() {
+        let dir = tempfile::tempdir().unwrap();
+        let ready = dir.path().join("ready");
+        let script = format!("trap '' TERM; touch \"{}\"; while :; do sleep 1; done", ready.display());
+        let mut child = start(&script, &ready);
+        let started = Instant::now();
+        terminate_tree(&mut child, Duration::from_millis(50));
+        assert!(child.try_wait().unwrap().is_some(), "the child is reaped");
+        assert!(started.elapsed() < Duration::from_secs(5));
+    }
+}

crates/ide-core/src/proxy_settings.rs

@@ -207,6 +207,58 @@ impl ProxySettings {
         env.push((OsString::from("no_proxy"), Some(OsString::from(no_proxy))));
         env
     }
+
+    /// System properties that make a JVM follow this configuration. A JVM reads none of
+    /// [`Self::child_env`]: a Java tool (jetty, Maven's resolver, a language server's own
+    /// HTTP client) goes direct without these, and a repository its proxy answers in
+    /// milliseconds can then hang it instead.
+    pub fn jvm_args(&self) -> Vec<String> {
+        match self.mode {
+            // macOS and Windows JVMs read the system proxy with this one.
+            ProxyMode::Auto => vec!["-Djava.net.useSystemProxies=true".into()],
+            ProxyMode::None => Vec::new(),
+            ProxyMode::Manual if self.manual() => self.manual_jvm_args(),
+            ProxyMode::Manual => Vec::new(),
+        }
+    }
+
+    fn manual_jvm_args(&self) -> Vec<String> {
+        let (host, port) = (self.host.trim(), self.port);
+        match self.kind {
+            ProxyKind::Http => {
+                // HTTPS hosts read `https.proxyHost`, plain ones `http.proxyHost`.
+                let mut args = vec![
+                    format!("-Dhttp.proxyHost={host}"),
+                    format!("-Dhttp.proxyPort={port}"),
+                    format!("-Dhttps.proxyHost={host}"),
+                    format!("-Dhttps.proxyPort={port}"),
+                ];
+                let hosts = self.non_proxy_hosts();
+                if !hosts.is_empty() {
+                    args.push(format!("-Dhttp.nonProxyHosts={}", hosts.join("|")));
+                }
+                args
+            }
+            // SOCKS proxies every TCP connection, so there is one property pair.
+            ProxyKind::Socks => vec![
+                format!("-DsocksProxyHost={host}"),
+                format!("-DsocksProxyPort={port}"),
+                "-Djava.net.useSystemProxies=false".into(),
+            ],
+        }
+    }
+
+    /// [`Self::no_proxy`] in the JVM's `http.nonProxyHosts` format: `|` between host
+    /// globs. CIDR ranges and IPv6 literals have no equivalent there and are dropped.
+    fn non_proxy_hosts(&self) -> Vec<String> {
+        let mut hosts: Vec<String> = LOOPBACK.iter().filter(|h| !h.contains(':')).map(|h| (*h).to_owned()).collect();
+        for entry in self.no_proxy_entries() {
+            if !entry.contains(['/', ':', '[', ']']) && !hosts.contains(&entry) {
+                hosts.push(entry);
+            }
+        }
+        hosts
+    }
 }
 
 /// Case-insensitive host glob (`pattern` is lowercase): `*` matches any run of characters.
@@ -292,6 +344,34 @@ mod tests {
         assert!(p.child_env().is_empty());
     }
 
+    #[test]
+    fn jvm_args_carry_the_proxy_as_system_properties() {
+        // A JVM reads none of `child_env`: a Java language server needs these to not go
+        // direct while curl, git and Node follow the environment.
+        assert_eq!(ProxySettings::default().jvm_args(), ["-Djava.net.useSystemProxies=true"]);
+        assert!(ProxySettings { mode: ProxyMode::None, ..manual("proxy", 3128) }.jvm_args().is_empty());
+        assert_eq!(
+            manual("proxy.corp", 3128).jvm_args(),
+            [
+                "-Dhttp.proxyHost=proxy.corp",
+                "-Dhttp.proxyPort=3128",
+                "-Dhttps.proxyHost=proxy.corp",
+                "-Dhttps.proxyPort=3128",
+                "-Dhttp.nonProxyHosts=localhost|127.0.0.1",
+            ]
+        );
+        let socks = ProxySettings { kind: ProxyKind::Socks, ..manual("10.0.0.1", 1080) };
+        assert_eq!(socks.jvm_args()[..2], ["-DsocksProxyHost=10.0.0.1", "-DsocksProxyPort=1080"]);
+        // `http.nonProxyHosts` takes host globs: CIDR ranges and IPv6 literals drop out.
+        let p = ProxySettings {
+            no_proxy: "*.corp.com, 172.0.0.0/8, [::1], ::1, localhost".into(),
+            ..manual("proxy.corp", 3128)
+        };
+        assert_eq!(p.jvm_args().last().unwrap(), "-Dhttp.nonProxyHosts=localhost|127.0.0.1|*.corp.com");
+        // A manual proxy without a host connects directly, and so does its JVM.
+        assert!(manual(" ", 80).jvm_args().is_empty());
+    }
+
     #[test]
     fn manual_http_and_socks_urls() {
         let p = manual("proxy.corp", 3128);

crates/ide-core/src/remote_settings.rs

@@ -103,10 +103,19 @@ impl Default for DeploymentSettings {
     }
 }
 
-/// An SFTP server and how project folders map onto it.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum DeploymentType {
+    #[default]
+    Sftp,
+    Local,
+}
+
+/// A deployment filesystem and how project folders map onto it.
 #[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct DeploymentServer {
+    pub kind: DeploymentType,
     pub id: String,
     pub name: String,
     /// [`SshConfiguration::id`].
@@ -123,7 +132,7 @@ pub struct DeploymentServer {
 #[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct DeploymentMapping {
-    /// Project-relative folder; empty = the project root.
+    /// Project-relative folder, or absolute inside the project; empty = the project root.
     pub local: String,
     /// Remote folder, relative to the server root (a leading `/` is the root too).
     pub deployment: String,
@@ -148,3 +157,23 @@ pub struct RunTarget {
     pub node: String,
     pub java: String,
 }
+
+#[cfg(test)]
+mod deployment_tests {
+    use super::*;
+
+    #[test]
+    fn deployment_type_defaults_and_round_trips() {
+        let legacy: DeploymentServer =
+            serde_json::from_str(r#"{"id":"existing","sshConfig":"ssh","rootPath":"/srv"}"#).unwrap();
+        assert_eq!(legacy.kind, DeploymentType::Sftp);
+        assert_eq!(legacy.ssh_config, "ssh");
+        for kind in [DeploymentType::Sftp, DeploymentType::Local] {
+            let server = DeploymentServer { kind, ..legacy.clone() };
+            assert_eq!(
+                serde_json::from_str::<DeploymentServer>(&serde_json::to_string(&server).unwrap()).unwrap(),
+                server
+            );
+        }
+    }
+}

crates/ide-core/src/settings.rs

@@ -58,6 +58,68 @@ pub struct Settings {
     pub deployment: DeploymentSettings,
     /// Build, Execution, Deployment › Run Targets.
     pub run_targets: Vec<RunTarget>,
+    pub cmake: CMakeSettings,
+    /// Tools › Agents › Chat.
+    pub agents: AgentSettings,
+    /// 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>>,
+}
+
+/// What the meters in an agent task's header show.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct AgentSettings {
+    /// Context window use.
+    pub show_context_usage: bool,
+    /// Time the agent spent on the task.
+    pub show_work_time: bool,
+    /// The account's usage-limit windows (Claude's 5-hour and weekly limits).
+    pub show_usage_limits: bool,
+    /// What the session has cost so far, as the agent reports it.
+    pub show_cost: bool,
+}
+
+impl Default for AgentSettings {
+    fn default() -> Self {
+        Self { show_context_usage: true, show_work_time: true, show_usage_limits: true, show_cost: false }
+    }
+}
+
+/// Absent profiles retain automatic discovery for existing projects.
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct CMakeSettings {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[specta(optional)]
+    pub profiles: Option<Vec<CMakeProfile>>,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct CMakeProfile {
+    pub name: String,
+    pub build_type: String,
+    pub generator: String,
+    pub cmake_args: Vec<String>,
+    /// Empty uses cmake-build-<lowercase build type>.
+    pub build_dir: String,
+    pub build_args: Vec<String>,
+    pub env: BTreeMap<String, String>,
+}
+
+impl Default for CMakeProfile {
+    fn default() -> Self {
+        Self {
+            name: "Debug".into(),
+            build_type: "Debug".into(),
+            generator: String::new(),
+            cmake_args: Vec::new(),
+            build_dir: String::new(),
+            build_args: Vec::new(),
+            env: BTreeMap::new(),
+        }
+    }
 }
 
 #[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
@@ -154,6 +216,9 @@ impl Default for Settings {
             ssh: SshSettings::default(),
             deployment: DeploymentSettings::default(),
             run_targets: Vec::new(),
+            cmake: CMakeSettings::default(),
+            agents: AgentSettings::default(),
+            plugins: BTreeMap::new(),
         }
     }
 }
@@ -197,7 +262,7 @@ impl Default for GeneralSettings {
     fn default() -> Self {
         Self {
             reopen_last_project: true,
-            confirm_exit: false,
+            confirm_exit: true,
             open_project_in: "ask".into(),
             default_project_directory: String::new(),
             save_on_idle: false,
@@ -262,7 +327,8 @@ impl Default for NotificationGroupSettings {
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct AppearanceSettings {
-    /// `dark` | `light` | `system` | `dark-hc` (high-contrast dark)
+    /// A built-in theme id (`light`, `dark`, `dark-hc`, …), `system` (legacy
+    /// "Sync with OS"), or a plugin's theme: `plugin:<plugin-id>/<theme-id>`.
     pub theme: String,
     pub accent: String,
     pub ui_font_size: f32,
@@ -271,11 +337,15 @@ pub struct AppearanceSettings {
     pub sync_with_os: bool,
     pub preferred_light_theme: String,
     pub preferred_dark_theme: String,
+    /// A plugin's file icon theme (`<plugin-id>/<theme-id>`); empty = the built-in icons.
+    pub file_icon_theme: String,
     /// IDE zoom in percent (50–300).
     pub zoom: u32,
     /// Apply `ui_font_family` / `ui_font_size` (otherwise the theme's).
     pub use_custom_font: bool,
     pub ui_font_family: String,
+    /// Font tried when `ui_font_family` lacks a glyph; empty = none.
+    pub ui_font_fallback: String,
     pub contrast_scrollbars: bool,
     /// Adjust colours for red-green vision deficiency.
     pub red_green_vision: bool,
@@ -285,11 +355,14 @@ pub struct AppearanceSettings {
     pub project_colors_in_toolbar: bool,
     pub dnd_with_alt_only: bool,
     pub menu_icons: bool,
+    /// `hamburger` | `merged`: main menu presentation in the frameless title bar.
+    pub main_menu_style: String,
     /// `subpixel` | `greyscale` | `none`
     pub ide_antialiasing: String,
     pub editor_antialiasing: String,
     pub show_tool_window_bars: bool,
     pub show_tool_window_names: bool,
+    pub show_tool_window_badges: bool,
     pub widescreen_tool_windows: bool,
     /// Status bar widgets shown (`true`) or hidden (`false`) by the user
     /// (status bar context menu); widgets not listed use their default.
@@ -320,9 +393,11 @@ impl Default for AppearanceSettings {
             sync_with_os: false,
             preferred_light_theme: "light".into(),
             preferred_dark_theme: "dark".into(),
+            file_icon_theme: String::new(),
             zoom: 100,
             use_custom_font: false,
             ui_font_family: "Inter".into(),
+            ui_font_fallback: String::new(),
             contrast_scrollbars: false,
             red_green_vision: false,
             different_tool_window_background: false,
@@ -331,10 +406,12 @@ impl Default for AppearanceSettings {
             project_colors_in_toolbar: true,
             dnd_with_alt_only: false,
             menu_icons: true,
+            main_menu_style: "hamburger".into(),
             ide_antialiasing: "greyscale".into(),
             editor_antialiasing: "greyscale".into(),
             show_tool_window_bars: true,
             show_tool_window_names: false,
+            show_tool_window_badges: true,
             widescreen_tool_windows: false,
             status_bar_widgets: BTreeMap::new(),
             main_toolbar: None,
@@ -342,6 +419,15 @@ impl Default for AppearanceSettings {
     }
 }
 
+/// Imported editor colour scheme on top of a built-in base.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct CustomColorScheme {
+    pub name: String,
+    pub parent: String,
+    pub attributes: BTreeMap<String, TextAttributesOverride>,
+}
+
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct EditorSettings {
@@ -357,6 +443,8 @@ pub struct EditorSettings {
     pub format_on_save: bool,
     /// Editor colour scheme id; `theme-default` follows the IDE theme.
     pub color_scheme: String,
+    /// Imported editor schemes, stored in user settings.
+    pub custom_schemes: BTreeMap<String, CustomColorScheme>,
     /// Color Scheme edits: scheme id → attribute id → override.
     pub color_overrides: BTreeMap<String, BTreeMap<String, TextAttributesOverride>>,
     /// Color Scheme › Language Defaults › Semantic highlighting: local variables and
@@ -404,6 +492,7 @@ impl Default for EditorSettings {
             format_on_save: false,
             color_scheme: "theme-default".into(),
             color_overrides: BTreeMap::new(),
+            custom_schemes: BTreeMap::new(),
             semantic_highlighting: false,
             rainbow_brackets: false,
             ligatures: false,
@@ -434,6 +523,8 @@ impl Default for EditorSettings {
 pub struct FileSettings {
     /// Save on focus loss / tab switch, like IDEA.
     pub auto_save: bool,
+    /// Re-check open files against disk when the IDE window gains focus.
+    pub sync_on_focus: bool,
     pub exclude: Vec<String>,
     /// Ignored Files and Folders: name patterns hidden everywhere; see [`crate::ignored`].
     pub ignored_names: Vec<String>,
@@ -465,6 +556,7 @@ impl Default for FileSettings {
     fn default() -> Self {
         Self {
             auto_save: true,
+            sync_on_focus: true,
             exclude: vec!["**/.git".into(), "**/node_modules".into(), "**/target".into()],
             ignored_names: crate::ignored::DEFAULT_IGNORED_NAMES.iter().map(|s| (*s).into()).collect(),
             trim_trailing_whitespace: true,
@@ -482,10 +574,91 @@ impl Default for FileSettings {
 pub struct LanguagesSettings {
     pub python: PythonSettings,
     pub node: NodeSettings,
+    pub php: PhpSettings,
     pub rust: RustSettings,
     pub go: GoSettings,
     pub typescript: TypeScriptSettings,
+    pub prettier: ExternalFormatterSettings,
+    pub oxfmt: ExternalFormatterSettings,
     pub java: JavaSettings,
+    pub ruby: RubySettings,
+    pub markdown: MarkdownSettings,
+}
+
+/// Languages & Frameworks › Markdown. Like IDEA's, it is application-level only.
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct MarkdownSettings {
+    /// Preview (and notebook Markdown cell) font size in px; unset follows the editor font size.
+    pub preview_font_size: Option<u32>,
+}
+
+impl LanguagesSettings {
+    pub fn formatter(&self, tool: ExternalFormatter) -> &ExternalFormatterSettings {
+        match tool {
+            ExternalFormatter::Prettier => &self.prettier,
+            ExternalFormatter::Oxfmt => &self.oxfmt,
+        }
+    }
+}
+
+/// A formatter that runs outside the language servers, with its own settings group.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "lowercase")]
+pub enum ExternalFormatter {
+    Prettier,
+    Oxfmt,
+}
+
+impl ExternalFormatter {
+    /// The name of the tool in the tool registry.
+    pub fn name(self) -> &'static str {
+        match self {
+            Self::Prettier => "prettier",
+            Self::Oxfmt => "oxfmt",
+        }
+    }
+}
+
+/// An external formatter (Prettier, oxfmt) and the languages it formats.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct ExternalFormatterSettings {
+    /// Empty path: project node_modules, managed installation, then PATH.
+    pub path: String,
+    pub languages: Vec<String>,
+    /// Prefer this formatter even when a language server offers formatting.
+    pub prefer: bool,
+    pub run_on_save: bool,
+}
+
+impl Default for ExternalFormatterSettings {
+    fn default() -> Self {
+        Self {
+            path: String::new(),
+            languages: [
+                "markdown",
+                "yaml",
+                "css",
+                "scss",
+                "less",
+                "html",
+                "graphql",
+                "javascript",
+                "javascriptreact",
+                "typescript",
+                "typescriptreact",
+                "json",
+                "jsonc",
+                "vue",
+            ]
+            .into_iter()
+            .map(String::from)
+            .collect(),
+            prefer: false,
+            run_on_save: false,
+        }
+    }
 }
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
@@ -503,6 +676,20 @@ impl Default for PythonSettings {
     }
 }
 
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct PhpSettings {
+    /// `php` CLI executable; empty = the one on `PATH`.
+    pub interpreter: String,
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct RubySettings {
+    /// Project interpreter executable; empty = auto-detect (`.ruby-version`, mise / asdf, else `ruby` on PATH).
+    pub interpreter: String,
+}
+
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct NodeSettings {
@@ -546,6 +733,35 @@ pub struct GoSettings {
     pub goroot: String,
     /// Empty = `go env GOPATH`.
     pub gopath: String,
+    pub build_tags: GoBuildTags,
+    pub modules: GoModules,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct GoModules {
+    pub env: BTreeMap<String, String>,
+    pub auto_vendor: bool,
+}
+
+impl Default for GoModules {
+    fn default() -> Self {
+        Self { env: BTreeMap::new(), auto_vendor: true }
+    }
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct GoBuildTags {
+    /// Empty values inherit the selected toolchain's defaults.
+    pub os: String,
+    pub arch: String,
+    pub version: String,
+    pub compiler: String,
+    /// Empty = automatic, "1" = enabled, "0" = disabled.
+    pub cgo: String,
+    pub custom: String,
+    pub experiments: String,
 }
 
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
@@ -578,6 +794,19 @@ pub struct GradleSettings {
     pub home: String,
     /// Empty = Gradle's default user home.
     pub user_home: String,
+    /// IDEA's "Build and run using": who builds and launches an Application main.
+    pub run_using: GradleRunUsing,
+}
+
+/// IDEA's "Build and run using" for Gradle builds; IDEA defaults to Gradle.
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum GradleRunUsing {
+    /// A `JavaExec` task on the source set's runtime classpath (`gradleRun.gradle`).
+    #[default]
+    Gradle,
+    /// The Java language server's classpath, launched by OpenIDEA.
+    Ide,
 }
 
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
@@ -672,6 +901,76 @@ impl Settings {
 mod tests {
     use super::*;
 
+    #[test]
+    fn cmake_profile_argument_arrays_round_trip() {
+        let mut settings = Settings::default();
+        assert!(settings.cmake.profiles.is_none());
+        assert!(CMakeProfile::default().cmake_args.is_empty());
+        assert!(CMakeProfile::default().build_args.is_empty());
+        let profile = CMakeProfile {
+            cmake_args: ["-DMESSAGE=two words", "-DQUOTE=\"hello\"", ""].map(String::from).into(),
+            build_args: ["-j", "8", "--", "LABEL=it's a build"].map(String::from).into(),
+            ..Default::default()
+        };
+        settings.cmake.profiles = Some(vec![profile.clone()]);
+        let value = serde_json::to_value(&settings).unwrap();
+        assert_eq!(value["cmake"]["profiles"][0]["cmakeArgs"], serde_json::json!(profile.cmake_args));
+        assert_eq!(value["cmake"]["profiles"][0]["buildArgs"], serde_json::json!(profile.build_args));
+        assert_eq!(serde_json::from_value::<Settings>(value).unwrap(), settings);
+    }
+
+    #[test]
+    fn ui_font_fallback_defaults_empty_and_round_trips() {
+        let old: Settings = serde_json::from_str(r#"{"appearance":{"useCustomFont":true}}"#).unwrap();
+        assert!(old.appearance.ui_font_fallback.is_empty());
+        for family in ["", "Songti SC", "Maple Mono NF CN"] {
+            let mut settings = Settings::default();
+            settings.appearance.ui_font_fallback = family.into();
+            let json = serde_json::to_value(&settings).unwrap();
+            assert_eq!(json["appearance"]["uiFontFallback"], family);
+            let restored: Settings = serde_json::from_value(json).unwrap();
+            assert_eq!(restored.appearance.ui_font_fallback, family);
+        }
+    }
+
+    #[test]
+    fn tool_window_badges_default_on_and_round_trip() {
+        let old: Settings = serde_json::from_str(r#"{"appearance":{"showToolWindowNames":true}}"#).unwrap();
+        assert!(old.appearance.show_tool_window_badges);
+        assert!(Settings::default().appearance.show_tool_window_badges);
+        for enabled in [false, true] {
+            let mut settings = Settings::default();
+            settings.appearance.show_tool_window_badges = enabled;
+            let json = serde_json::to_value(&settings).unwrap();
+            assert_eq!(json["appearance"]["showToolWindowBadges"], enabled);
+            let restored: Settings = serde_json::from_value(json).unwrap();
+            assert_eq!(restored.appearance.show_tool_window_badges, enabled);
+        }
+    }
+
+    #[test]
+    fn agent_meters_default_and_round_trip() {
+        let old: Settings = serde_json::from_str(r#"{"agents":{"showCost":true}}"#).unwrap();
+        assert!(old.agents.show_cost);
+        assert!(old.agents.show_context_usage && old.agents.show_work_time && old.agents.show_usage_limits);
+        assert!(!Settings::default().agents.show_cost);
+        let mut settings = Settings::default();
+        settings.agents.show_usage_limits = false;
+        let json = serde_json::to_value(&settings).unwrap();
+        assert_eq!(json["agents"]["showUsageLimits"], false);
+        let restored: Settings = serde_json::from_value(json).unwrap();
+        assert_eq!(restored.agents, settings.agents);
+    }
+
+    #[test]
+    fn main_menu_style_defaults_and_round_trips() {
+        let old: Settings = serde_json::from_str(r#"{"appearance":{"compactMode":true}}"#).unwrap();
+        assert_eq!(old.appearance.main_menu_style, "hamburger");
+        let merged: Settings = serde_json::from_str(r#"{"appearance":{"mainMenuStyle":"merged"}}"#).unwrap();
+        assert_eq!(merged.appearance.main_menu_style, "merged");
+        assert_eq!(serde_json::to_value(merged).unwrap()["appearance"]["mainMenuStyle"], "merged");
+    }
+
     #[test]
     fn editor_font_weights_default_to_regular_and_bold() {
         let json = serde_json::to_value(Settings::default()).unwrap();
@@ -748,9 +1047,26 @@ mod gradle_settings_tests {
                 distribution,
                 home: "/gradle".into(),
                 user_home: "/cache/gradle".into(),
+                run_using: GradleRunUsing::Ide,
             };
             let restored: Settings = serde_json::from_str(&serde_json::to_string(&settings).unwrap()).unwrap();
             assert_eq!(restored.languages.java.gradle, settings.languages.java.gradle);
         }
     }
 }
+
+#[cfg(test)]
+mod go_module_tests {
+    use super::*;
+    #[test]
+    fn old_go_settings_inherit_module_defaults() {
+        let old: GoSettings = serde_json::from_str(r#"{"goroot":"/go"}"#).unwrap();
+        assert!(old.modules.auto_vendor);
+        assert!(old.modules.env.is_empty());
+        let configured: GoSettings =
+            serde_json::from_str(r#"{"modules":{"autoVendor":false,"env":{"GOPRIVATE":"example.com/private"}}}"#)
+                .unwrap();
+        assert!(!configured.modules.auto_vendor);
+        assert_eq!(configured.modules.env["GOPRIVATE"], "example.com/private");
+    }
+}

crates/ide-core/src/task.rs

@@ -44,6 +44,39 @@ pub fn cancel(id: TaskId) -> bool {
     }
 }
 
+/// A progress title a tool reported, made readable: a leading absolute executable path
+/// (rust-analyzer reports `/…/bin/cargo check`) shows as its program name (`cargo check`).
+pub fn display_title(title: &str) -> String {
+    let is_sep = |c: char| c == '/' || c == '\\';
+    let b = title.as_bytes();
+    let absolute = title.starts_with(is_sep)
+        || (b.len() > 2 && b[0].is_ascii_alphabetic() && b[1] == b':' && is_sep(b[2] as char));
+    if !absolute {
+        return title.to_owned();
+    }
+    // The path runs on through spaces (`Application Support/…`) while the next word still
+    // continues it; the first word without a separator, an option or a new path ends it.
+    let mut end = title.find(' ').unwrap_or(title.len());
+    while end < title.len() {
+        let rest = &title[end + 1..];
+        let word = rest.split(' ').next().unwrap_or_default();
+        if word.is_empty() || !word.contains(is_sep) || word.starts_with(is_sep) || word.starts_with('-') {
+            break;
+        }
+        end += 1 + word.len();
+    }
+    let (path, rest) = title.split_at(end);
+    let name = path.rsplit(is_sep).next().unwrap_or(path);
+    let name = [".exe", ".cmd", ".bat"]
+        .iter()
+        .find_map(|ext| {
+            let cut = name.len().checked_sub(ext.len())?;
+            (name.is_char_boundary(cut) && name[cut..].eq_ignore_ascii_case(ext)).then(|| &name[..cut])
+        })
+        .unwrap_or(name);
+    if name.is_empty() { title.to_owned() } else { format!("{name}{rest}") }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -71,4 +104,28 @@ mod tests {
         assert!(!cancel(other), "an ended task is not cancelled");
         assert_eq!(hits.load(Ordering::SeqCst), 1);
     }
+
+    #[test]
+    fn display_title_shows_a_leading_executable_path_as_its_name() {
+        for (title, shown) in [
+            ("/Users/thomas/Library/Application Support/mbx/bin/cargo check", "cargo check"),
+            ("/home/me/.cargo/bin/cargo clippy (#2)", "cargo clippy (#2)"),
+            (
+                "/opt/my tools/bin/cargo check --manifest-path /x/Cargo.toml",
+                "cargo check --manifest-path /x/Cargo.toml",
+            ),
+            (r"C:\Users\me\.cargo\bin\cargo.exe check", "cargo check"),
+            (r"C:\Program Files\Rust\bin\cargo.EXE check", "cargo check"),
+            (r"\\server\share\tools\x.cmd build", "x build"),
+            ("/usr/bin/make", "make"),
+            ("cargo check", "cargo check"),
+            ("Indexing", "Indexing"),
+            ("Building compile-time-deps", "Building compile-time-deps"),
+            ("Loading /src/app (2/3)", "Loading /src/app (2/3)"),
+            ("/", "/"),
+            ("", ""),
+        ] {
+            assert_eq!(display_title(title), shown, "{title:?}");
+        }
+    }
 }

crates/ide-core/src/text.rs

@@ -97,15 +97,88 @@ pub struct TextEdit {
 #[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
 pub struct WorkspaceEdit {
     pub files: Vec<FileEdit>,
+    /// Content fingerprints captured before presenting an edit for confirmation.
+    #[serde(default)]
+    #[specta(optional)]
+    pub preconditions: Vec<WorkspaceEditPrecondition>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+pub struct WorkspaceEditPrecondition {
+    pub path: crate::IpcPath,
+    pub hash: String,
+}
+
+impl WorkspaceEdit {
+    /// Coalesces aliases of the same file before applying edits against its original text.
+    /// Resource operations separate batches because later edits may use the new contents.
+    pub fn deduplicate(&mut self) {
+        let mut files = Vec::new();
+        let mut batch = std::collections::HashMap::<std::path::PathBuf, usize>::new();
+        let mut resolve_aliases = true;
+        for file in std::mem::take(&mut self.files) {
+            match file {
+                FileEdit::Edit { path, edits, version } => {
+                    let path = if resolve_aliases {
+                        dunce::canonicalize(&path).unwrap_or_else(|_| path.to_path_buf())
+                    } else {
+                        path.to_path_buf()
+                    };
+                    let index = *batch.entry(path.clone()).or_insert_with(|| {
+                        files.push(FileEdit::Edit { path: path.clone().into(), edits: Vec::new(), version });
+                        files.len() - 1
+                    });
+                    let FileEdit::Edit { edits: own, version: expected, .. } = &mut files[index] else {
+                        unreachable!()
+                    };
+                    if expected.is_some() && version.is_some() && *expected != version {
+                        // Keep incompatible constraints so application rejects them
+                        // before changing any file instead of silently losing one.
+                        files.push(FileEdit::Edit { path: path.into(), edits, version });
+                        continue;
+                    }
+                    *expected = expected.or(version);
+                    for edit in edits {
+                        if !own.contains(&edit) {
+                            own.push(edit);
+                        }
+                    }
+                }
+                op => {
+                    batch.clear();
+                    // Later paths refer to a filesystem state the resource operation has yet to create.
+                    resolve_aliases = false;
+                    files.push(op);
+                }
+            }
+        }
+        self.files = files;
+    }
 }
 
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(tag = "kind", rename_all = "camelCase")]
 pub enum FileEdit {
-    Edit { path: crate::IpcPath, edits: Vec<TextEdit> },
-    Create { path: crate::IpcPath, overwrite: bool },
-    Rename { from: crate::IpcPath, to: crate::IpcPath },
-    Delete { path: crate::IpcPath, recursive: bool },
+    Edit {
+        path: crate::IpcPath,
+        edits: Vec<TextEdit>,
+        /// LSP TextDocumentEdit version; null/unversioned edits use content preconditions.
+        #[serde(default)]
+        #[specta(optional)]
+        version: Option<i32>,
+    },
+    Create {
+        path: crate::IpcPath,
+        overwrite: bool,
+    },
+    Rename {
+        from: crate::IpcPath,
+        to: crate::IpcPath,
+    },
+    Delete {
+        path: crate::IpcPath,
+        recursive: bool,
+    },
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize, Type)]
@@ -203,3 +276,35 @@ pub struct OutlineItem {
 
 /// Fuzzy-match highlight: indices (in chars of the displayed string) that matched.
 pub type MatchIndices = Vec<u32>;
+
+#[cfg(all(test, unix))]
+mod workspace_edit_tests {
+    use super::*;
+
+    #[test]
+    fn aliases_are_one_edit_but_resource_operations_preserve_order() {
+        let dir = tempfile::tempdir().unwrap();
+        let real = dir.path().join("main.cpp");
+        let alias = dir.path().join("alias.cpp");
+        std::fs::write(&real, "add()").unwrap();
+        std::os::unix::fs::symlink(&real, &alias).unwrap();
+        let change = TextEdit { range: Range::new(Pos::new(0, 0), Pos::new(0, 3)), new_text: "sum_values".into() };
+        let edit = |path: PathBuf| FileEdit::Edit { path: path.into(), edits: vec![change.clone()], version: None };
+        let mut workspace = WorkspaceEdit {
+            files: vec![
+                edit(real.clone()),
+                edit(alias),
+                FileEdit::Create { path: dir.path().join("other").into(), overwrite: false },
+                edit(real),
+            ],
+            ..Default::default()
+        };
+        workspace.deduplicate();
+        assert_eq!(workspace.files.len(), 3);
+        let FileEdit::Edit { edits, .. } = &workspace.files[0] else { panic!() };
+        assert_eq!(edits, &[change]);
+        let once = workspace.clone();
+        workspace.deduplicate();
+        assert_eq!(workspace, once);
+    }
+}

crates/ide-core/src/tool_path.rs

@@ -17,7 +17,16 @@ pub fn search_path() -> OsString {
     let home = std::env::var_os("HOME").or_else(|| std::env::var_os("USERPROFILE")).map(PathBuf::from);
     let shell_path = login_env().and_then(|env| env.iter().find(|(k, _)| k == "PATH").map(|(_, v)| v.clone()));
     let shims: Vec<PathBuf> = version_managers::managers().iter().map(|m| m.shims()).collect();
-    let dirs = search_dirs(host_var_os("PATH").as_deref(), shell_path.as_deref(), home.as_deref(), &shims);
+    // The Windows user `PATH` may not reach a process started before it was set; append its
+    // entries after the inherited ones so missing user tools still resolve.
+    let user_path = crate::process::user_path();
+    let dirs = search_dirs(
+        host_var_os("PATH").as_deref(),
+        shell_path.as_deref(),
+        user_path.as_deref(),
+        home.as_deref(),
+        &shims,
+    );
     std::env::join_paths(dirs).unwrap_or_default()
 }
 
@@ -56,10 +65,12 @@ fn is_executable(path: &Path) -> bool {
 fn search_dirs(
     process_path: Option<&OsStr>,
     shell_path: Option<&OsStr>,
+    user_path: Option<&OsStr>,
     home: Option<&Path>,
     shims: &[PathBuf],
 ) -> Vec<PathBuf> {
-    let mut dirs: Vec<PathBuf> = process_path.into_iter().chain(shell_path).flat_map(std::env::split_paths).collect();
+    let mut dirs: Vec<PathBuf> =
+        process_path.into_iter().chain(shell_path).chain(user_path).flat_map(std::env::split_paths).collect();
     if let Some(home) = home {
         dirs.extend(USER_DIRS.iter().map(|d| home.join(d)));
         dirs.extend(nvm_bins(&home.join(".nvm/versions/node")));
@@ -80,6 +91,8 @@ const USER_DIRS: &[&str] = &[
     ".cargo/bin",
     ".local/bin",
     "go/bin",
+    // `dotnet tool install --global` puts fsautocomplete, csharp-ls and friends here.
+    ".dotnet/tools",
     ".bun/bin",
     ".deno/bin",
     ".npm-global/bin",
@@ -96,6 +109,12 @@ const USER_DIRS: &[&str] = &[
 
 const SYSTEM_DIRS: &[&str] = &["/opt/homebrew/bin", "/usr/local/go/bin", "/usr/local/bin", "/usr/bin", "/bin"];
 
+/// Whether `dir` is one of the system's own bin directories, which [`search_path`] adds
+/// whatever `PATH` holds.
+pub fn is_system_dir(dir: &Path) -> bool {
+    SYSTEM_DIRS.iter().any(|d| Path::new(d) == dir)
+}
+
 /// The `bin` directories of nvm's Node versions in `dir`, newest first.
 fn nvm_bins(dir: &Path) -> Vec<PathBuf> {
     let mut versions: Vec<(Vec<u64>, PathBuf)> = std::fs::read_dir(dir)
@@ -164,21 +183,42 @@ mod tests {
             Some(OsStr::new("/usr/bin:.:node_modules/.bin:/opt/tools")),
             // nushell prints `$PATH` as is.
             Some(OsStr::new("$PATH:/opt/tools:/home/me/.asdf/shims")),
+            None,
             Some(Path::new("/home/me")),
             &shims,
         );
         let at = |d: &str| dirs.iter().position(|p| p == Path::new(d)).unwrap();
         assert_eq!(dirs[..3], [PathBuf::from("/usr/bin"), "/opt/tools".into(), "/home/me/.asdf/shims".into()]);
         assert!(at("/home/me/.npm-global/bin") < at("/home/me/.pyenv/shims"));
+        // Global .NET tools (fsautocomplete, csharp-ls) install here, off PATH.
+        assert!(at("/home/me/.dotnet/tools") < at("/usr/local/bin"));
         assert!(at("/home/me/.local/share/mise/shims") < at("/usr/local/bin"));
         assert!(dirs.iter().all(|d| d.is_absolute()));
         let unique: HashSet<&PathBuf> = dirs.iter().collect();
         assert_eq!(unique.len(), dirs.len());
         // A `:` can't be in a `PATH` entry: those below such a home are left out.
-        let dirs = search_dirs(Some(OsStr::new("/usr/bin")), None, Some(Path::new("/home/a:b")), &[]);
+        let dirs = search_dirs(Some(OsStr::new("/usr/bin")), None, None, Some(Path::new("/home/a:b")), &[]);
         assert!(dirs.contains(&PathBuf::from("/usr/bin")) && !dirs.iter().any(|d| d.starts_with("/home")));
     }
 
+    #[test]
+    fn search_dirs_append_user_path_entries_once_after_the_inherited_path() {
+        let (system, dup, usertool) =
+            if cfg!(windows) { ("C:/system", "C:/dup", "C:/usertool") } else { ("/system", "/dup", "/usertool") };
+        let home = Path::new(if cfg!(windows) { "C:/home/me" } else { "/home/me" });
+        let join = |dirs: &[&str]| std::env::join_paths(dirs.iter().map(PathBuf::from)).unwrap();
+        let inherited = join(&[system, dup]);
+        let user = join(&[dup, usertool]);
+        let dirs = search_dirs(Some(inherited.as_os_str()), None, Some(user.as_os_str()), Some(home), &[]);
+        let at = |d: &str| dirs.iter().position(|p| p == Path::new(d)).unwrap();
+        // User entries follow the inherited PATH, de-duplicated, ahead of the fallbacks.
+        assert_eq!(dirs.iter().filter(|d| *d == Path::new(dup)).count(), 1);
+        assert!(at(dup) < at(usertool));
+        // And before this platform's home/system fallbacks.
+        let fallback = dirs.iter().position(|d| d == &home.join(USER_DIRS[0])).unwrap();
+        assert!(at(usertool) < fallback);
+    }
+
     #[test]
     fn nvm_versions_newest_first() {
         let dir = std::env::temp_dir().join(format!("openidea-nvm-{}", std::process::id()));

crates/ide-core/src/version_managers.rs

@@ -18,6 +18,7 @@ pub enum Tool {
     Go,
     Maven,
     Gradle,
+    Ruby,
 }
 
 impl Tool {
@@ -30,6 +31,7 @@ impl Tool {
             Tool::Go => &["go", "golang"],
             Tool::Maven => &["maven"],
             Tool::Gradle => &["gradle"],
+            Tool::Ruby => &["ruby"],
         }
     }
 }

crates/ide-core/src/workflow_settings.rs

@@ -41,6 +41,8 @@ impl Default for VcsSettings {
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct GitSettings {
+    /// Show blame after the current editor line.
+    pub inline_blame: bool,
     /// Path to the git executable; empty = auto-detect.
     pub executable: String,
     /// Default of Update Project: `merge` | `rebase`.
@@ -71,6 +73,7 @@ pub struct GitSettings {
 impl Default for GitSettings {
     fn default() -> Self {
         Self {
+            inline_blame: false,
             executable: String::new(),
             update_method: "merge".into(),
             auto_update_on_push_rejected: false,

crates/ide-dap/src/adapter.rs

@@ -8,7 +8,7 @@
 
 use ide_core::process::executable_names;
 use ide_core::{IdeError, IdeResult};
-use ide_language::{DebuggerConfig, LanguageRegistry};
+use ide_language::{DebuggerConfig, LanguageRegistry, ProgramPin};
 use std::future::Future;
 use std::path::{Path, PathBuf};
 use std::pin::Pin;
@@ -44,6 +44,8 @@ pub struct AdapterSpec {
     /// `host:port` of an adapter inside another program (the Godot editor): connected to
     /// when it accepts, else `command` is started.
     pub connect: Option<String>,
+    /// A plugin language's adapter: start exactly this approved program.
+    pub pinned: Option<ProgramPin>,
 }
 
 /// Built-in adapters used when no language definition names `adapter`.
@@ -55,6 +57,7 @@ fn builtin(adapter: &str) -> Option<DebuggerConfig> {
         transport: transport.to_owned(),
         connect: None,
         install_hint: Some(hint.to_owned()),
+        pinned: None,
     };
     Some(match adapter {
         "codelldb" => cfg(
@@ -133,6 +136,7 @@ pub fn resolve(config: &DebuggerConfig, cwd: PathBuf) -> AdapterSpec {
         env: Vec::new(),
         server_host: None,
         connect: config.connect.clone(),
+        pinned: config.pinned.clone(),
     }
 }
 
@@ -348,8 +352,17 @@ pub struct AdapterIo {
     pub port: Option<u16>,
     /// Recent stderr lines of the adapter process, for error messages.
     pub stderr: Arc<parking_lot::Mutex<Vec<String>>>,
+    /// (category, line) printed by the debuggee when it shares the adapter's stdio.
+    pub program_output: Option<ProgramOutput>,
 }
 
+pub type ProgramOutput = tokio::sync::mpsc::UnboundedReceiver<(&'static str, String)>;
+type ProgramSink = tokio::sync::mpsc::UnboundedSender<(&'static str, String)>;
+
+/// Delve's debuggee inherits its stdio; no DAP output event carries what the program prints.
+const SHARES_STDIO: &str = "delve";
+const DELVE_BANNER: &str = "DAP server listening at:";
+
 pub type LaunchFuture = Pin<Box<dyn Future<Output = IdeResult<AdapterIo>> + Send>>;
 
 /// Starts adapters. Tests substitute in-memory adapters.
@@ -385,6 +398,7 @@ impl AdapterLauncher for ProcessLauncher {
                     child: None,
                     port: Some(port),
                     stderr,
+                    program_output: None,
                 });
             }
             let embedded = match spec.connect.as_deref().filter(|_| spec.transport == Transport::Tcp) {
@@ -407,6 +421,7 @@ impl AdapterLauncher for ProcessLauncher {
                     child: None,
                     port: Some(*port),
                     stderr,
+                    program_output: None,
                 });
             }
             if spec.adapter == DEBUGPY_TOOL {
@@ -415,12 +430,20 @@ impl AdapterLauncher for ProcessLauncher {
             if is_plugin_bundle(&spec.command) {
                 return Err(not_standalone(&spec));
             }
-            let (command, cwd) = (spec.command.clone(), spec.cwd.clone());
-            let binary = tokio::task::spawn_blocking(move || resolve_binary(&command, &cwd))
-                .await
-                .ok()
-                .flatten()
-                .ok_or_else(|| missing(&spec))?;
+            let binary = match spec.pinned.clone() {
+                Some(pin) => tokio::task::spawn_blocking(move || pin.verify().map(Path::to_path_buf))
+                    .await
+                    .map_err(|e| IdeError::internal(e.to_string()))?
+                    .map_err(|e| IdeError::new(ide_core::error::ErrorKind::PermissionDenied, e))?,
+                None => {
+                    let (command, cwd) = (spec.command.clone(), spec.cwd.clone());
+                    tokio::task::spawn_blocking(move || resolve_binary(&command, &cwd))
+                        .await
+                        .ok()
+                        .flatten()
+                        .ok_or_else(|| missing(&spec))?
+                }
+            };
             let port = match spec.transport {
                 // An embedded adapter started without `${port}` listens on its usual address.
                 Transport::Tcp => match &embedded {
@@ -445,8 +468,14 @@ impl AdapterLauncher for ProcessLauncher {
                 .kill_on_drop(true);
             let mut child =
                 cmd.spawn().map_err(|e| IdeError::unavailable(format!("failed to start {}: {e}", binary.display())))?;
+            let (program_sink, program_output) = if spec.adapter == SHARES_STDIO {
+                let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
+                (Some(tx), Some(rx))
+            } else {
+                (None, None)
+            };
             if let Some(err) = child.stderr.take() {
-                pump_lines(err, spec.adapter.clone(), stderr.clone());
+                pump_lines(err, spec.adapter.clone(), stderr.clone(), program_sink.clone().map(|tx| (tx, "stderr")));
             }
             match port {
                 None => {
@@ -458,11 +487,12 @@ impl AdapterLauncher for ProcessLauncher {
                         child: Some(child),
                         port: None,
                         stderr,
+                        program_output,
                     })
                 }
                 Some(port) => {
                     if let Some(out) = child.stdout.take() {
-                        pump_lines(out, spec.adapter.clone(), stderr.clone());
+                        pump_lines(out, spec.adapter.clone(), stderr.clone(), program_sink.map(|tx| (tx, "stdout")));
                     }
                     let timeout = if embedded.is_some() { EMBEDDED_START_TIMEOUT } else { CONNECT_TIMEOUT };
                     let stream = match connect_with_retries(LOOPBACK, port, Some(&mut child), timeout).await {
@@ -484,6 +514,7 @@ impl AdapterLauncher for ProcessLauncher {
                         child: Some(child),
                         port: Some(port),
                         stderr,
+                        program_output,
                     })
                 }
             }
@@ -495,9 +526,15 @@ fn pump_lines<R: AsyncRead + Unpin + Send + 'static>(
     stream: R,
     name: String,
     sink: Arc<parking_lot::Mutex<Vec<String>>>,
+    program: Option<(ProgramSink, &'static str)>,
 ) {
     tokio::spawn(ide_jsonrpc::output::read_lines(stream, move |line| {
         tracing::debug!(target: "ide_dap::adapter", "[{name}] {line}");
+        if let Some((tx, category)) = &program
+            && !line.starts_with(DELVE_BANNER)
+        {
+            let _ = tx.send((category, format!("{line}\n")));
+        }
         push_line(&sink, line);
     }));
 }
@@ -549,6 +586,18 @@ async fn connect_with_retries(
 mod tests {
     use super::*;
 
+    #[tokio::test]
+    async fn program_output_is_forwarded_without_the_adapter_banner() {
+        let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel();
+        let sink = Arc::default();
+        let text: &[u8] = b"DAP server listening at: 127.0.0.1:1\n[hello two words]\nno newline";
+        pump_lines(text, "delve".into(), Arc::clone(&sink), Some((tx, "stdout")));
+        assert_eq!(rx.recv().await, Some(("stdout", "[hello two words]\n".into())));
+        assert_eq!(rx.recv().await, Some(("stdout", "no newline\n".into())));
+        assert_eq!(rx.recv().await, None);
+        assert_eq!(sink.lock().len(), 3);
+    }
+
     /// Managed tools win over `PATH`, and debugpy falls back to the private copy.
     #[cfg(unix)]
     #[tokio::test]

crates/ide-dap/src/lib.rs

@@ -697,6 +697,14 @@ impl DebugManager {
         };
         let session =
             Arc::new(Session::new(id, owner, name, adapter_name, parent, request, conn, spec, io.port, io.child));
+        if let Some(mut output) = io.program_output {
+            let session = session.clone();
+            tokio::spawn(async move {
+                while let Some((category, output)) = output.recv().await {
+                    session.emit(ide_core::event::DebugEvent::Output { category: category.into(), output });
+                }
+            });
+        }
         self.sessions.lock().insert(id, session.clone());
         self.order.lock().push(id);
         // Announced before the event loop runs, so it precedes every adapter event.
@@ -1381,6 +1389,16 @@ impl DebugManager {
         })
     }
 
+    /// Stops every session `key` started: the window that opened the project is closing.
+    pub async fn stop_key(&self, key: &str) {
+        let ids: Vec<DebugSessionId> = self.sessions(Some(key)).into_iter().map(|s| s.id).collect();
+        for id in ids {
+            if let Err(e) = self.stop(id).await {
+                tracing::debug!("debug session {id:?} did not stop: {e}");
+            }
+        }
+    }
+
     /// Stops a session and its child sessions.
     pub async fn stop(&self, s: DebugSessionId) -> IdeResult<()> {
         let session = self.session(s)?;

crates/ide-dap/src/session.rs

@@ -405,7 +405,7 @@ async fn on_event(mgr: &Arc<DebugManager>, s: &Arc<Session>, event: &str, mut bo
                 let mut progress = s.progress.lock();
                 let id =
                     if done { progress.remove(&pid) } else { Some(*progress.entry(pid).or_insert_with(TaskId::next)) };
-                (id, str_("title").unwrap_or_else(|| s.name.clone()))
+                (id, str_("title").map(|t| ide_core::task::display_title(&t)).unwrap_or_else(|| s.name.clone()))
             };
             let Some(id) = id else { return };
             s.owner.sink.emit(IdeEvent::Task {

crates/ide-dap/src/tests.rs

@@ -32,7 +32,14 @@ impl AdapterLauncher for FakeLauncher {
         tokio::spawn(fake_adapter(server, log, script));
         let (r, w) = tokio::io::split(client);
         Box::pin(async move {
-            Ok(AdapterIo { reader: Box::new(r), writer: Box::new(w), child: None, port: None, stderr: Arc::default() })
+            Ok(AdapterIo {
+                reader: Box::new(r),
+                writer: Box::new(w),
+                child: None,
+                port: None,
+                stderr: Arc::default(),
+                program_output: None,
+            })
         })
     }
 }
@@ -898,6 +905,7 @@ fn godot_registry(port: u16, command: &str, args: &[&str]) -> Arc<LanguageRegist
         indent: None,
         ui_mode: None,
         framework_ui_modes: Vec::new(),
+        formatter: None,
         tree_sitter: None,
         language_servers: vec![],
         debugger: Some(ide_language::DebuggerConfig {
@@ -907,6 +915,7 @@ fn godot_registry(port: u16, command: &str, args: &[&str]) -> Arc<LanguageRegist
             transport: "tcp".into(),
             connect: Some(format!("127.0.0.1:{port}")),
             install_hint: Some("Open the project in the Godot editor".into()),
+            pinned: None,
         }),
     };
     Arc::new(LanguageRegistry::from_configs(vec![lang]))
@@ -1139,3 +1148,58 @@ async fn java_stack_frames_without_breakpoints_normalize_windows_paths() {
         h.manager.stop(id).await.unwrap();
     }
 }
+
+/// A built-in language definition (GDScript) shipped by a plugin
+/// instead: its debugger starts the program approved for the plugin's
+/// `process:godot` grant, and refuses once that file changed.
+#[cfg(unix)]
+#[tokio::test]
+async fn a_plugin_language_runs_its_debug_adapter_from_the_approved_program() {
+    use ide_language::ProgramPin;
+    use ide_language::plugin_point::{PluginLanguages, parse_definition};
+    use std::os::unix::fs::PermissionsExt;
+
+    let dir = std::env::temp_dir().join(format!("openidea-plugin-dap-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    // Stands in for `godot --headless --editor …`.
+    let program = dir.join("godot");
+    std::fs::write(&program, "#!/bin/sh\nexec sleep 30\n").unwrap();
+    std::fs::set_permissions(&program, std::fs::Permissions::from_mode(0o755)).unwrap();
+
+    let port = std::net::TcpListener::bind(("127.0.0.1", 0)).unwrap().local_addr().unwrap().port();
+    let mut gdscript = parse_definition(include_str!("../../../languages/gdscript.toml")).unwrap();
+    let debugger = gdscript.debugger.as_mut().unwrap();
+    debugger.args.clear();
+    debugger.connect = Some(format!("127.0.0.1:{port}"));
+
+    // No built-in GDScript: it comes from the plugin.
+    let registry = Arc::new(LanguageRegistry::from_configs(Vec::new()));
+    let store = PluginLanguages::new();
+    registry.attach_plugins(store.clone());
+    let pin = ProgramPin::approve(&program).unwrap();
+    store.set_process_policy(Arc::new(move |plugin, cap| {
+        (plugin == "acme.godot" && cap.to_string() == "process:godot").then(|| pin.clone())
+    }));
+    let _language = store.add("acme.godot".into(), gdscript);
+
+    let log: Log = Arc::default();
+    let server_log = log.clone();
+    tokio::spawn(async move {
+        tokio::time::sleep(std::time::Duration::from_millis(300)).await;
+        let listener = tokio::net::TcpListener::bind(("127.0.0.1", port)).await.unwrap();
+        let (stream, _) = listener.accept().await.unwrap();
+        fake_adapter(stream, server_log, Script::default()).await;
+    });
+    let (owner, _events) = recording_owner("main");
+    let manager = DebugManager::new(registry.clone());
+    let id = manager.start(godot_launch(&dir), owner).await.unwrap();
+    assert!(log.lock().iter().any(|m| m["command"] == "launch"));
+    manager.stop(id).await.unwrap();
+
+    // Replaced after approval: refused before anything starts.
+    std::fs::write(&program, "#!/bin/sh\nexec sleep 31\n").unwrap();
+    let (owner, _events) = recording_owner("main");
+    let err = manager.start(godot_launch(&dir), owner).await.unwrap_err();
+    assert_eq!(err.kind, ide_core::error::ErrorKind::PermissionDenied, "{}", err.message);
+    let _ = std::fs::remove_dir_all(&dir);
+}

crates/ide-docker/Cargo.toml

@@ -13,8 +13,5 @@ specta.workspace = true
 tracing.workspace = true
 which = "8"
 
-[target.'cfg(unix)'.dependencies]
-libc = "0.2"
-
 [dev-dependencies]
 tempfile.workspace = true

crates/ide-docker/src/process.rs

@@ -1,11 +1,16 @@
 //! Child processes of the docker CLI: bounded runs and cancellable line streams.
 
+use ide_core::process::terminate_tree;
 use ide_core::{CancellationToken, IdeError, IdeResult};
 use std::io::Read;
 use std::process::{Child, Command, Stdio};
 use std::sync::mpsc;
 use std::time::{Duration, Instant};
 
+/// How long a cancelled or timed-out child's process group (CLI plugins such as compose)
+/// gets to exit on `SIGTERM`, and clean up, before `SIGKILL`.
+const KILL_GRACE: Duration = Duration::from_millis(20);
+
 pub(crate) struct Output {
     pub stdout: String,
     pub stderr: String,
@@ -20,36 +25,13 @@ pub(crate) enum Stream {
 
 fn prepare(cmd: &mut Command) {
     cmd.stdin(Stdio::null()).stdout(Stdio::piped()).stderr(Stdio::piped());
-    #[cfg(unix)]
-    {
-        use std::os::unix::process::CommandExt;
-        cmd.process_group(0);
-    }
-    ide_core::process::prepare(cmd);
+    ide_core::process::prepare(ide_core::process::own_group(cmd));
 }
 
 fn spawn(cmd: &mut Command) -> IdeResult<Child> {
     cmd.spawn().map_err(|e| IdeError::unavailable(format!("could not run docker: {e}")))
 }
 
-/// Kills the child and, on Unix, its whole process group (CLI plugins such as compose).
-pub(crate) fn kill(child: &mut Child) {
-    #[cfg(unix)]
-    {
-        let pid = child.id() as libc::pid_t;
-        // SAFETY: plain syscall; the child leads its own process group (`prepare`).
-        unsafe {
-            libc::kill(-pid, libc::SIGTERM);
-        }
-        std::thread::sleep(Duration::from_millis(20));
-        unsafe {
-            libc::kill(-pid, libc::SIGKILL);
-        }
-    }
-    let _ = child.kill();
-    let _ = child.wait();
-}
-
 fn read_all(mut pipe: impl Read + Send + 'static) -> std::thread::JoinHandle<String> {
     std::thread::spawn(move || {
         let mut buf = Vec::new();
@@ -88,11 +70,11 @@ pub(crate) fn run_with_input(
             break status;
         }
         if cancel.is_some_and(CancellationToken::is_cancelled) {
-            kill(&mut child);
+            terminate_tree(&mut child, KILL_GRACE);
             return Err(IdeError::cancelled());
         }
         if Instant::now() >= deadline {
-            kill(&mut child);
+            terminate_tree(&mut child, KILL_GRACE);
             return Err(IdeError::unavailable("docker did not respond in time"));
         }
         std::thread::sleep(Duration::from_millis(10));
@@ -166,7 +148,7 @@ pub(crate) fn stream(
     let mut stderr_tail: Vec<String> = Vec::new();
     while open > 0 {
         if cancel.is_cancelled() {
-            kill(&mut child);
+            terminate_tree(&mut child, KILL_GRACE);
             return Err(IdeError::cancelled());
         }
         match rx.recv_timeout(Duration::from_millis(50)) {
@@ -189,7 +171,7 @@ pub(crate) fn stream(
             break status;
         }
         if cancel.is_cancelled() {
-            kill(&mut child);
+            terminate_tree(&mut child, KILL_GRACE);
             return Err(IdeError::cancelled());
         }
         std::thread::sleep(Duration::from_millis(10));

crates/ide-extension/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "ide-extension"
+description = "Plugin manifest, extension points, contribution registry and capability model (no Wasm runtime)"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+ide-core.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+specta.workspace = true
+specta-typescript.workspace = true
+toml.workspace = true
+tracing.workspace = true
+parking_lot.workspace = true
+semver = "1"
+blake3.workspace = true
+zip.workspace = true
+base64.workspace = true
+ed25519-dalek = "3"
+
+[dev-dependencies]
+tempfile.workspace = true

crates/ide-extension/src/capability.rs

@@ -0,0 +1,277 @@
+//! What a plugin may do beyond pure computation, and how risky each grant is.
+//!
+//! Capabilities are written as strings in the manifest (`project.read`,
+//! `net:crates.io`, `process:cargo`) and stored the same way in the grant
+//! ledger. The 0.1 permission names (`project-read`, …) parse as their 0.2
+//! equivalents.
+
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+use specta::Type;
+use std::fmt;
+use std::str::FromStr;
+
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum Capability {
+    /// Read files inside the project root; the project root itself.
+    ProjectRead,
+    /// The focused editor's file, selection and text.
+    EditorRead,
+    /// Edit the focused editor (versioned edits).
+    EditorWrite,
+    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.
+    Events,
+    /// Keystrokes and editor input events.
+    InputEvents,
+    /// The system clipboard, from the plugin's web views.
+    Clipboard,
+    /// HTTP(S) to one host (`*.example.com` matches subdomains).
+    Net(String),
+    /// Run one external program. Full code execution: never fine-grained.
+    Process(String),
+    /// Read files outside the project under one path.
+    FsRead(String),
+}
+
+/// How a grant is presented (plan 4.2).
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum Risk {
+    /// Listed on the install page, one confirmation.
+    Low,
+    /// Listed separately with its purpose.
+    Medium,
+    /// Separate dialog: "equivalent to running arbitrary code on this machine".
+    High,
+}
+
+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,
+        }
+    }
+
+    /// Low-risk capabilities that the one-time migration of the 0.1 "declared
+    /// means granted" behaviour may grant automatically (plan 4.6).
+    pub fn auto_migrates(&self) -> bool {
+        self.risk() == Risk::Low
+    }
+
+    /// Short user-facing description for install and grant pages.
+    pub fn describe(&self) -> String {
+        match self {
+            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::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::InputEvents => "Observe keystrokes and editor input".into(),
+            Self::Clipboard => "Read and write the clipboard from its web views".into(),
+            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"),
+        }
+    }
+
+    /// Whether `self`, granted, also covers `wanted` (`net:*.x.com` covers `net:a.x.com`).
+    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)) => {
+                std::path::Path::new(path).starts_with(std::path::Path::new(base))
+            }
+            _ => self == wanted,
+        }
+    }
+}
+
+/// `example.com` matches exactly; `*.example.com` matches any subdomain (not the apex).
+pub fn host_matches(pattern: &str, host: &str) -> bool {
+    let host = host.trim_end_matches('.').to_ascii_lowercase();
+    let pattern = pattern.to_ascii_lowercase();
+    match pattern.strip_prefix("*.") {
+        Some(suffix) => host.len() > suffix.len() + 1 && host.ends_with(&format!(".{suffix}")),
+        None => host == pattern,
+    }
+}
+
+impl fmt::Display for Capability {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::ProjectRead => f.write_str("project.read"),
+            Self::EditorRead => f.write_str("editor.read"),
+            Self::EditorWrite => f.write_str("editor.write"),
+            Self::VcsRead => f.write_str("vcs.read"),
+            Self::VcsWrite => f.write_str("vcs.write"),
+            Self::Storage => f.write_str("storage"),
+            Self::Secrets => f.write_str("secrets"),
+            Self::Events => f.write_str("events"),
+            Self::InputEvents => f.write_str("events.input"),
+            Self::Clipboard => f.write_str("clipboard"),
+            Self::Net(h) => write!(f, "net:{h}"),
+            Self::Process(b) => write!(f, "process:{b}"),
+            Self::FsRead(p) => write!(f, "fs.read:{p}"),
+        }
+    }
+}
+
+impl FromStr for Capability {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, String> {
+        let s = s.trim();
+        if let Some((kind, arg)) = s.split_once(':') {
+            let arg = arg.trim();
+            if arg.is_empty() {
+                return Err(format!("capability {s:?} needs a value after ':'"));
+            }
+            return match kind {
+                "net" => {
+                    let host = arg.strip_prefix("*.").unwrap_or(arg);
+                    let valid = !host.is_empty()
+                        && host.len() <= 253
+                        && host.split('.').all(|label| {
+                            !label.is_empty()
+                                && label.len() <= 63
+                                && label.bytes().all(|b| b.is_ascii_alphanumeric() || b == b'-')
+                        });
+                    if valid { Ok(Self::Net(arg.to_ascii_lowercase())) } else { Err(format!("invalid host in {s:?}")) }
+                }
+                "process" => {
+                    if arg.contains(['/', '\\']) && !std::path::Path::new(arg).is_absolute() {
+                        return Err(format!("{s:?}: use a program name or an absolute path"));
+                    }
+                    Ok(Self::Process(arg.to_owned()))
+                }
+                "fs.read" => {
+                    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()))
+                }
+                _ => Err(format!("unknown capability {s:?}")),
+            };
+        }
+        Ok(match s {
+            "project.read" | "project-read" => Self::ProjectRead,
+            "editor.read" | "editor-read" => Self::EditorRead,
+            "editor.write" | "editor-write" => Self::EditorWrite,
+            "vcs.read" => Self::VcsRead,
+            "vcs.write" => Self::VcsWrite,
+            "storage" => Self::Storage,
+            "secrets" => Self::Secrets,
+            "events" => Self::Events,
+            "events.input" => Self::InputEvents,
+            "clipboard" => Self::Clipboard,
+            _ => return Err(format!("unknown capability {s:?}")),
+        })
+    }
+}
+
+impl Serialize for Capability {
+    fn serialize<S: Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
+        s.collect_str(self)
+    }
+}
+
+impl<'de> Deserialize<'de> for Capability {
+    fn deserialize<D: Deserializer<'de>>(d: D) -> Result<Self, D::Error> {
+        String::deserialize(d)?.parse().map_err(serde::de::Error::custom)
+    }
+}
+
+/// A capability as the UI shows it.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct CapabilityInfo {
+    /// `project.read`, `net:crates.io`, …
+    pub id: String,
+    pub risk: Risk,
+    pub description: String,
+    /// Declared under `optional`: the plugin runs without it.
+    pub optional: bool,
+    /// Currently granted.
+    pub granted: bool,
+}
+
+impl CapabilityInfo {
+    pub fn new(cap: &Capability, optional: bool, granted: bool) -> Self {
+        Self { id: cap.to_string(), risk: cap.risk(), description: cap.describe(), optional, granted }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parses_and_prints() {
+        for s in [
+            "project.read",
+            "editor.write",
+            "vcs.write",
+            "storage",
+            "secrets",
+            "events",
+            "events.input",
+            "net:crates.io",
+            "net:*.github.com",
+            "process:cargo",
+        ] {
+            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")
+        } else {
+            ("process:/usr/bin/git", "fs.read:/etc")
+        };
+        for s in [git, etc] {
+            assert_eq!(s.parse::<Capability>().unwrap().to_string(), s);
+        }
+        assert_eq!("project-read".parse::<Capability>().unwrap(), Capability::ProjectRead);
+        assert!("net:".parse::<Capability>().is_err());
+        assert!("net:a b".parse::<Capability>().is_err());
+        assert!("process:./evil".parse::<Capability>().is_err());
+        assert!("fs.read:rel".parse::<Capability>().is_err());
+        assert!("network".parse::<Capability>().is_err());
+    }
+
+    #[test]
+    fn risk_levels() {
+        assert_eq!(Capability::ProjectRead.risk(), Risk::Low);
+        assert_eq!(Capability::Net("x".into()).risk(), Risk::Medium);
+        assert_eq!(Capability::InputEvents.risk(), Risk::Medium);
+        assert_eq!("clipboard".parse::<Capability>().unwrap(), Capability::Clipboard);
+        assert_eq!(Capability::Clipboard.risk(), Risk::Medium);
+        assert_eq!(Capability::Process("cargo".into()).risk(), Risk::High);
+        assert!(Capability::Storage.auto_migrates() && !Capability::EditorWrite.auto_migrates());
+    }
+
+    #[test]
+    fn host_patterns() {
+        assert!(host_matches("crates.io", "crates.io"));
+        assert!(host_matches("crates.io", "CRATES.IO."));
+        assert!(!host_matches("crates.io", "static.crates.io"));
+        assert!(host_matches("*.github.com", "api.github.com"));
+        assert!(!host_matches("*.github.com", "github.com"));
+        assert!(!host_matches("*.github.com", "evilgithub.com"));
+        let any_gh: Capability = "net:*.github.com".parse().unwrap();
+        assert!(any_gh.covers(&"net:api.github.com".parse().unwrap()));
+        assert!(Capability::FsRead("/etc".into()).covers(&Capability::FsRead("/etc/hosts".into())));
+        assert!(!Capability::FsRead("/etc".into()).covers(&Capability::FsRead("/etcx".into())));
+    }
+}

crates/ide-extension/src/index.rs

@@ -0,0 +1,104 @@
+//! The contribution index: validated UI
+//! declarations of installed packages, kept on disk so start-up does not
+//! validate them again (sanitising thousands of icon SVGs, say).
+//!
+//! Only packages with a [`Package::digest`] are indexed: installed copies,
+//! which the host never modifies after install. An entry is keyed by that
+//! digest, the extension point, the declaration and a salt naming the
+//! validation logic (the IDE version), so a new package version, a changed
+//! declaration or an IDE upgrade simply misses. A miss or an unreadable entry
+//! only costs the validation.
+
+use crate::point::Package;
+use crate::ui::UiDecl;
+use std::collections::BTreeSet;
+use std::path::PathBuf;
+
+/// Bumped when [`UiDecl`]'s serialized shape changes.
+const FORMAT: u32 = 1;
+
+pub struct ContributionIndex {
+    dir: PathBuf,
+    salt: String,
+}
+
+impl ContributionIndex {
+    /// `salt` names the validators' version (the IDE version).
+    pub fn new(dir: PathBuf, salt: &str) -> Self {
+        Self { dir, salt: format!("{FORMAT}:{salt}") }
+    }
+
+    /// Entries start with a prefix of the package digest, for pruning.
+    fn file(&self, digest: &str, point: &str, decl: &toml::Value) -> PathBuf {
+        let mut h = blake3::Hasher::new();
+        for part in [self.salt.as_str(), digest, point, &decl.to_string()] {
+            h.update(part.as_bytes());
+            h.update(&[0]);
+        }
+        let key = h.finalize().to_hex();
+        self.dir.join(format!("{}-{}.json", prefix(digest), &key[..32]))
+    }
+
+    pub fn get(&self, pkg: &Package, point: &str, decl: &toml::Value) -> Option<UiDecl> {
+        let digest = pkg.digest.as_deref()?;
+        let bytes = std::fs::read(self.file(digest, point, decl)).ok()?;
+        serde_json::from_slice(&bytes).ok()
+    }
+
+    pub fn put(&self, pkg: &Package, point: &str, decl: &toml::Value, ui: &UiDecl) {
+        let Some(digest) = pkg.digest.as_deref() else { return };
+        let Ok(bytes) = serde_json::to_vec(ui) else { return };
+        let file = self.file(digest, point, decl);
+        let _ = std::fs::create_dir_all(&self.dir);
+        let tmp = file.with_extension(format!("tmp{}", std::process::id()));
+        if std::fs::write(&tmp, bytes).and_then(|()| std::fs::rename(&tmp, &file)).is_err() {
+            let _ = std::fs::remove_file(&tmp);
+        }
+    }
+
+    /// Removes entries of packages other than `live` (digests).
+    pub fn prune<'a>(&self, live: impl IntoIterator<Item = &'a str>) {
+        let keep: BTreeSet<String> = live.into_iter().map(|d| prefix(d).to_owned()).collect();
+        let Ok(entries) = std::fs::read_dir(&self.dir) else { return };
+        for e in entries.flatten() {
+            let name = e.file_name().to_string_lossy().into_owned();
+            if !name.split_once('-').is_some_and(|(p, _)| keep.contains(p)) {
+                let _ = std::fs::remove_file(e.path());
+            }
+        }
+    }
+}
+
+fn prefix(digest: &str) -> &str {
+    let d = digest.strip_prefix("blake3:").unwrap_or(digest);
+    let end = d.char_indices().nth(16).map_or(d.len(), |(i, _)| i);
+    &d[..end]
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::manifest::Manifest;
+
+    #[test]
+    fn hits_only_the_same_package_point_declaration_and_salt() {
+        let tmp = tempfile::tempdir().unwrap();
+        let index = ContributionIndex::new(tmp.path().join("idx"), "1.0");
+        let manifest =
+            Manifest::parse("id = \"p\"\nname = \"P\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.0\"\n").unwrap();
+        let pkg = Package::new(manifest, tmp.path().to_path_buf()).with_digest("blake3:00aa11bb22cc33dd44ee");
+        let decl: toml::Value = toml::from_str("id = \"x\"").unwrap();
+        let ui = UiDecl::new("x", "X", serde_json::json!({ "id": "x" }));
+        assert!(index.get(&pkg, "pt", &decl).is_none());
+        index.put(&pkg, "pt", &decl, &ui);
+        assert_eq!(index.get(&pkg, "pt", &decl).unwrap().label, "X");
+        assert!(index.get(&pkg, "other", &decl).is_none());
+        assert!(index.get(&pkg, "pt", &toml::from_str("id = \"y\"").unwrap()).is_none());
+        assert!(ContributionIndex::new(tmp.path().join("idx"), "1.1").get(&pkg, "pt", &decl).is_none());
+        let unhashed = Package { digest: None, ..pkg.clone() };
+        assert!(index.get(&unhashed, "pt", &decl).is_none(), "not an installed copy");
+
+        index.prune(["blake3:ffff"]);
+        assert!(index.get(&pkg, "pt", &decl).is_none());
+    }
+}

crates/ide-extension/src/ledger.rs

@@ -0,0 +1,483 @@
+//! The grant ledger (plan 4.6): which capabilities the user granted to which
+//! plugin, saved as `grants.json` next to the installed plugins.
+//!
+//! - Installed plugins are keyed by id and remember the version and package
+//!   hash they were confirmed for. An update that needs no new capability is
+//!   accepted silently; one that does must be confirmed again.
+//! - Linked development plugins and project plugins (`.openidea/plugins/*`)
+//!   are keyed by their directory, not by hash, so rebuilding does not ask
+//!   again; new capabilities still do.
+//! - `process:<program>` grants record the program's absolute path and file
+//!   hash at grant time. Calls use that path, never a `PATH` lookup, and fail
+//!   when the file changed (re-confirmation needed).
+
+use crate::capability::{Capability, Risk};
+use serde::{Deserialize, Serialize};
+use std::collections::{BTreeMap, BTreeSet};
+use std::ffi::OsStr;
+use std::path::{Path, PathBuf};
+
+pub const LEDGER_FILE: &str = "grants.json";
+const FORMAT: u32 = 1;
+
+/// Whose grant an entry is.
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
+#[serde(tag = "kind", content = "value", rename_all = "camelCase")]
+pub enum Subject {
+    /// Installed under the plugins directory, by plugin id.
+    Installed(String),
+    /// A linked development plugin or a project plugin, by package directory.
+    Path(PathBuf),
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct BinaryGrant {
+    pub path: PathBuf,
+    /// blake3 of the file when granted.
+    pub hash: String,
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Grant {
+    pub plugin_id: String,
+    /// The version and package hash the user confirmed (installed plugins).
+    #[serde(default)]
+    pub version: String,
+    #[serde(default)]
+    pub package_hash: String,
+    /// The user confirmed the plugin (the install page or the project-plugin prompt).
+    #[serde(default)]
+    pub confirmed: bool,
+    /// Granted capabilities (`project.read`, `net:x`, …).
+    #[serde(default)]
+    pub granted: BTreeSet<String>,
+    /// Optional capabilities the user declined (not asked again until re-confirmed).
+    #[serde(default)]
+    pub declined: BTreeSet<String>,
+    /// `process:<program>` → the program confirmed for it.
+    #[serde(default)]
+    pub binaries: BTreeMap<String, BinaryGrant>,
+    /// Migrated from 0.1: capabilities not granted yet are asked for on first
+    /// use instead of blocking the plugin from loading.
+    #[serde(default)]
+    pub ask_on_use: bool,
+}
+
+impl Grant {
+    pub fn has(&self, cap: &Capability) -> bool {
+        self.granted.iter().filter_map(|s| s.parse::<Capability>().ok()).any(|g| g.covers(cap))
+    }
+}
+
+/// What a plugin (in its current form) needs, to compare with its grant.
+#[derive(Clone, Debug)]
+pub struct Request<'a> {
+    pub subject: Subject,
+    pub plugin_id: &'a str,
+    pub version: &'a str,
+    pub package_hash: &'a str,
+    pub required: Vec<Capability>,
+    pub optional: Vec<Capability>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum Decision {
+    /// Load with these capabilities. `pending` required ones are asked for when
+    /// the plugin is first used (plugins migrated from 0.1 only).
+    Allowed { granted: Vec<Capability>, pending: Vec<Capability> },
+    /// Ask the user first. `new` lists what was never granted (all of it on first use).
+    NeedsConfirmation { new: Vec<Capability>, first_time: bool },
+}
+
+#[derive(Debug, Default, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct File {
+    #[serde(default)]
+    format: u32,
+    /// The one-time migration from 0.1 ("declared means granted") ran.
+    #[serde(default)]
+    migrated: bool,
+    #[serde(default)]
+    grants: Vec<(Subject, Grant)>,
+}
+
+/// The ledger, loaded into memory; [`Ledger::save`] writes it atomically.
+#[derive(Debug, Default)]
+pub struct Ledger {
+    path: Option<PathBuf>,
+    migrated: bool,
+    grants: BTreeMap<Subject, Grant>,
+}
+
+impl Ledger {
+    /// Loads `<dir>/grants.json`; a missing or unreadable file gives an empty
+    /// ledger with `needs_migration()` true.
+    pub fn load(dir: &Path) -> Self {
+        let path = dir.join(LEDGER_FILE);
+        let file: Option<File> = std::fs::read_to_string(&path).ok().and_then(|s| match serde_json::from_str(&s) {
+            Ok(f) => Some(f),
+            Err(e) => {
+                tracing::warn!("{}: {e}; starting with an empty grant ledger", path.display());
+                None
+            }
+        });
+        let existed = file.is_some();
+        let file = file.unwrap_or_default();
+        Self { path: Some(path), migrated: file.migrated || existed, grants: file.grants.into_iter().collect() }
+    }
+
+    pub fn in_memory() -> Self {
+        Self { path: None, migrated: true, grants: BTreeMap::new() }
+    }
+
+    pub fn save(&self) -> std::io::Result<()> {
+        let Some(path) = &self.path else { return Ok(()) };
+        let file = File {
+            format: FORMAT,
+            migrated: self.migrated,
+            grants: self.grants.iter().map(|(s, g)| (s.clone(), g.clone())).collect(),
+        };
+        let json = serde_json::to_string_pretty(&file).map_err(std::io::Error::other)?;
+        let tmp = path.with_extension("json.tmp");
+        std::fs::write(&tmp, json)?;
+        std::fs::rename(&tmp, path)
+    }
+
+    pub fn get(&self, subject: &Subject) -> Option<&Grant> {
+        self.grants.get(subject)
+    }
+
+    pub fn remove(&mut self, subject: &Subject) -> Option<Grant> {
+        self.grants.remove(subject)
+    }
+
+    /// Puts back an earlier state of `subject`'s grant (`None`: none), e.g.
+    /// after rolling back an update.
+    pub fn restore(&mut self, subject: &Subject, grant: Option<Grant>) {
+        match grant {
+            Some(g) => {
+                self.grants.insert(subject.clone(), g);
+            }
+            None => {
+                self.grants.remove(subject);
+            }
+        }
+    }
+
+    /// The one-time migration of 0.1's "declared means granted" has not run yet.
+    pub fn needs_migration(&self) -> bool {
+        !self.migrated
+    }
+
+    /// Migrates plugins installed before the ledger existed: low-risk
+    /// capabilities are granted, the rest are asked on first use.
+    pub fn migrate(&mut self, installed: &[Request<'_>]) {
+        for req in installed {
+            let granted: BTreeSet<String> =
+                req.required.iter().chain(&req.optional).filter(|c| c.auto_migrates()).map(|c| c.to_string()).collect();
+            self.grants.entry(req.subject.clone()).or_insert_with(|| Grant {
+                plugin_id: req.plugin_id.to_owned(),
+                version: req.version.to_owned(),
+                package_hash: req.package_hash.to_owned(),
+                confirmed: true,
+                granted,
+                ask_on_use: true,
+                ..Grant::default()
+            });
+        }
+        self.migrated = true;
+    }
+
+    /// Compares what the plugin needs with what was granted.
+    pub fn decide(&mut self, req: &Request<'_>) -> Decision {
+        let Some(grant) = self.grants.get_mut(&req.subject) else {
+            return Decision::NeedsConfirmation { new: req.required.clone(), first_time: true };
+        };
+        if !grant.confirmed {
+            return Decision::NeedsConfirmation { new: req.required.clone(), first_time: true };
+        }
+        let new: Vec<Capability> = req.required.iter().filter(|c| !grant.has(c)).cloned().collect();
+        if !new.is_empty() && !grant.ask_on_use {
+            return Decision::NeedsConfirmation { new, first_time: false };
+        }
+        // Same or fewer needs: accept an update silently (plan 4.6).
+        if grant.version != req.version || grant.package_hash != req.package_hash {
+            grant.version = req.version.to_owned();
+            grant.package_hash = req.package_hash.to_owned();
+        }
+        let granted = req.required.iter().chain(&req.optional).filter(|c| grant.has(c)).cloned().collect();
+        Decision::Allowed { granted, pending: new }
+    }
+
+    /// Records the user's confirmation: `required` plus the accepted optional capabilities.
+    pub fn confirm(
+        &mut self,
+        req: &Request<'_>,
+        accepted_optional: &[Capability],
+        binaries: BTreeMap<String, BinaryGrant>,
+    ) {
+        let grant = self.grants.entry(req.subject.clone()).or_default();
+        grant.plugin_id = req.plugin_id.to_owned();
+        grant.version = req.version.to_owned();
+        grant.package_hash = req.package_hash.to_owned();
+        grant.confirmed = true;
+        grant.ask_on_use = false;
+        for cap in req.required.iter().chain(accepted_optional) {
+            grant.granted.insert(cap.to_string());
+        }
+        for cap in &req.optional {
+            let s = cap.to_string();
+            if accepted_optional.contains(cap) {
+                grant.declined.remove(&s);
+            } else if !grant.granted.contains(&s) {
+                grant.declined.insert(s);
+            }
+        }
+        grant.binaries.extend(binaries);
+    }
+
+    /// Grants or revokes one capability (Settings › Plugins › permissions).
+    pub fn set(&mut self, subject: &Subject, cap: &Capability, granted: bool) -> bool {
+        let Some(grant) = self.grants.get_mut(subject) else { return false };
+        let s = cap.to_string();
+        if granted {
+            grant.declined.remove(&s);
+            grant.granted.insert(s)
+        } else {
+            if let Capability::Process(_) = cap {
+                grant.binaries.remove(&s);
+            }
+            grant.granted.remove(&s)
+        }
+    }
+
+    /// Records the program approved for a `process:` grant.
+    pub fn set_binary(&mut self, subject: &Subject, cap: &Capability, binary: BinaryGrant) {
+        if let Some(grant) = self.grants.get_mut(subject) {
+            grant.binaries.insert(cap.to_string(), binary);
+        }
+    }
+
+    /// Checks a `process:` grant at call time: the program confirmed for it,
+    /// unchanged since. Errors name what to do.
+    pub fn check_binary(&self, subject: &Subject, cap: &Capability) -> Result<PathBuf, String> {
+        let Capability::Process(name) = cap else { return Err(format!("{cap} is not a process capability")) };
+        let grant = self.grants.get(subject).ok_or_else(|| format!("{cap} was not granted"))?;
+        let key = cap.to_string();
+        if !grant.granted.contains(&key) {
+            return Err(format!("{cap} was not granted"));
+        }
+        let bin = grant.binaries.get(&key).ok_or_else(|| format!("{cap}: no program was confirmed for {name}"))?;
+        match file_hash(&bin.path) {
+            Ok(hash) if hash == bin.hash => Ok(bin.path.clone()),
+            Ok(_) => Err(format!(
+                "{} changed since it was approved for {cap}; confirm the plugin's permissions again",
+                bin.path.display()
+            )),
+            Err(e) => Err(format!("{}: {e}; confirm the plugin's permissions again", bin.path.display())),
+        }
+    }
+
+    /// The program approved for a granted `process:` capability, without
+    /// checking the file: whoever starts it verifies the hash then
+    /// ([`check_binary`](Self::check_binary) or the pin's own check).
+    pub fn pinned_binary(&self, subject: &Subject, cap: &Capability) -> Option<BinaryGrant> {
+        let grant = self.grants.get(subject)?;
+        let key = cap.to_string();
+        if !grant.granted.contains(&key) {
+            return None;
+        }
+        grant.binaries.get(&key).cloned()
+    }
+
+    pub fn subjects(&self) -> impl Iterator<Item = (&Subject, &Grant)> {
+        self.grants.iter()
+    }
+}
+
+/// What a confirmation page shows: every capability with its risk, high risk first.
+pub fn by_risk(caps: &[Capability]) -> Vec<(Risk, Vec<Capability>)> {
+    let mut groups: BTreeMap<std::cmp::Reverse<Risk>, Vec<Capability>> = BTreeMap::new();
+    for c in caps {
+        groups.entry(std::cmp::Reverse(c.risk())).or_default().push(c.clone());
+    }
+    groups.into_iter().map(|(r, v)| (r.0, v)).collect()
+}
+
+/// 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`.
+pub fn resolve_program(name: &str, path_var: Option<&OsStr>) -> Result<PathBuf, String> {
+    let candidate = Path::new(name);
+    if candidate.is_absolute() {
+        return if candidate.is_file() { Ok(candidate.to_path_buf()) } else { Err(format!("{name}: no such program")) };
+    }
+    let exts: Vec<String> = if cfg!(windows) {
+        std::env::var("PATHEXT").unwrap_or_else(|_| ".EXE;.CMD;.BAT".into()).split(';').map(str::to_owned).collect()
+    } else {
+        vec![String::new()]
+    };
+    for dir in std::env::split_paths(path_var.unwrap_or_default()) {
+        if !dir.is_absolute() {
+            continue; // `.` or relative entries could point into the project
+        }
+        for ext in &exts {
+            let p = dir.join(format!("{name}{ext}"));
+            if is_executable(&p) {
+                return Ok(dunce_canonical(&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())
+}
+
+fn is_executable(p: &Path) -> bool {
+    let Ok(meta) = std::fs::metadata(p) else { return false };
+    if !meta.is_file() {
+        return false;
+    }
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        meta.permissions().mode() & 0o111 != 0
+    }
+    #[cfg(not(unix))]
+    true
+}
+
+/// blake3 of a file, hex.
+pub fn file_hash(path: &Path) -> std::io::Result<String> {
+    let mut hasher = blake3::Hasher::new();
+    hasher.update_reader(std::fs::File::open(path)?)?;
+    Ok(hasher.finalize().to_hex().to_string())
+}
+
+/// blake3 over a package's files (sorted relative paths and contents).
+pub fn package_hash(dir: &Path, files: &[PathBuf]) -> std::io::Result<String> {
+    let mut sorted: Vec<&PathBuf> = files.iter().collect();
+    sorted.sort();
+    sorted.dedup();
+    let mut hasher = blake3::Hasher::new();
+    for rel in sorted {
+        hasher.update(rel.to_string_lossy().as_bytes());
+        hasher.update(&[0]);
+        hasher.update_reader(std::fs::File::open(dir.join(rel))?)?;
+        hasher.update(&[0]);
+    }
+    Ok(hasher.finalize().to_hex().to_string())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn caps(list: &[&str]) -> Vec<Capability> {
+        list.iter().map(|s| s.parse().unwrap()).collect()
+    }
+
+    fn req<'a>(version: &'a str, hash: &'a str, required: &[&str], optional: &[&str]) -> Request<'a> {
+        Request {
+            subject: Subject::Installed("p".into()),
+            plugin_id: "p",
+            version,
+            package_hash: hash,
+            required: caps(required),
+            optional: caps(optional),
+        }
+    }
+
+    #[test]
+    fn confirmation_then_silent_update_then_reconfirm_on_new_capability() {
+        let mut l = Ledger::in_memory();
+        let r1 = req("1.0.0", "h1", &["project.read"], &["net:crates.io"]);
+        assert_eq!(l.decide(&r1), Decision::NeedsConfirmation { new: caps(&["project.read"]), first_time: true });
+        l.confirm(&r1, &[], BTreeMap::new());
+        assert_eq!(
+            l.decide(&r1),
+            Decision::Allowed { granted: caps(&["project.read"]), pending: vec![] },
+            "declined optional"
+        );
+        assert!(l.get(&r1.subject).unwrap().declined.contains("net:crates.io"));
+
+        // Same needs, new version: silent.
+        let r2 = req("1.1.0", "h2", &["project.read"], &["net:crates.io"]);
+        assert!(matches!(l.decide(&r2), Decision::Allowed { .. }));
+        assert_eq!(l.get(&r2.subject).unwrap().version, "1.1.0");
+
+        // A new required capability: ask again, only for it.
+        let r3 = req("1.2.0", "h3", &["project.read", "editor.write"], &[]);
+        assert_eq!(l.decide(&r3), Decision::NeedsConfirmation { new: caps(&["editor.write"]), first_time: false });
+        l.confirm(&r3, &[], BTreeMap::new());
+        assert!(matches!(l.decide(&r3), Decision::Allowed { .. }));
+
+        // Revoking a required capability blocks loading again.
+        assert!(l.set(&r3.subject, &Capability::EditorWrite, false));
+        assert!(matches!(l.decide(&r3), Decision::NeedsConfirmation { .. }));
+    }
+
+    #[test]
+    fn migration_grants_low_risk_only() {
+        let tmp = tempfile::tempdir().unwrap();
+        let mut l = Ledger::load(tmp.path());
+        assert!(l.needs_migration());
+        let r = req("0.1.0", "h", &["project.read", "editor.write"], &[]);
+        l.migrate(std::slice::from_ref(&r));
+        // Loads with the low-risk part; the rest is asked for on first use.
+        assert_eq!(
+            l.decide(&r),
+            Decision::Allowed { granted: caps(&["project.read"]), pending: caps(&["editor.write"]) }
+        );
+        l.confirm(&r, &[], BTreeMap::new());
+        assert_eq!(
+            l.decide(&r),
+            Decision::Allowed { granted: caps(&["project.read", "editor.write"]), pending: vec![] }
+        );
+        l.save().unwrap();
+        let again = Ledger::load(tmp.path());
+        assert!(!again.needs_migration());
+        assert!(again.get(&r.subject).unwrap().has(&Capability::ProjectRead));
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn binaries_are_pinned_by_path_and_hash() {
+        use std::os::unix::fs::PermissionsExt;
+        let tmp = tempfile::tempdir().unwrap();
+        let bin_dir = tmp.path().join("bin");
+        std::fs::create_dir(&bin_dir).unwrap();
+        let tool = bin_dir.join("tool");
+        std::fs::write(&tool, "#!/bin/sh\necho v1\n").unwrap();
+        std::fs::set_permissions(&tool, std::fs::Permissions::from_mode(0o755)).unwrap();
+        let path_var = std::env::join_paths([PathBuf::from("relative"), bin_dir.clone()]).unwrap();
+        let resolved = resolve_program("tool", Some(&path_var)).unwrap();
+        assert!(resolved.is_absolute());
+        assert!(resolve_program("missing", Some(&path_var)).is_err());
+
+        let mut l = Ledger::in_memory();
+        let r = req("1.0.0", "h", &["process:tool"], &[]);
+        let cap: Capability = "process:tool".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(&tool, "#!/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();
+        std::fs::write(tmp.path().join("a"), "1").unwrap();
+        std::fs::write(tmp.path().join("b"), "2").unwrap();
+        let h1 = package_hash(tmp.path(), &["a".into(), "b".into()]).unwrap();
+        assert_eq!(h1, package_hash(tmp.path(), &["b".into(), "a".into()]).unwrap());
+        std::fs::write(tmp.path().join("b"), "3").unwrap();
+        assert_ne!(h1, package_hash(tmp.path(), &["a".into(), "b".into()]).unwrap());
+        let groups = by_risk(&caps(&["storage", "process:git", "net:x.io"]));
+        assert_eq!(groups.iter().map(|g| g.0).collect::<Vec<_>>(), [Risk::High, Risk::Medium, Risk::Low]);
+    }
+}

crates/ide-extension/src/lib.rs

@@ -0,0 +1,36 @@
+//! The plugin system's kernel, independent of the Wasm runtime:
+//!
+//! - [`Manifest`]: `plugin.toml` (0.2 format; 0.1 still parses);
+//! - [`Capability`]: what a plugin may do, with its [`Risk`] level;
+//! - [`ExtensionPoint`]: one kind of contribution, implemented by the crate that
+//!   owns the feature; [`ExtensionRegistry`] validates a package's declarations
+//!   ([`ExtensionRegistry::prepare`], no side effects), makes them take effect
+//!   all or nothing ([`ExtensionRegistry::commit`]) and withdraws them per plugin;
+//! - [`UiStore`] / [`UiPoint`]: UI contributions, validated here and projected
+//!   by the client without the possibility to fail;
+//! - [`ledger`]: which capabilities the user granted to which plugin;
+//! - [`package`]: the package file, its signature and the marketplace index.
+//!
+//! Dependency direction: `ide-core` ← `ide-extension` ← feature crates (their
+//! extension points) and `ide-plugin` (Wasm) ← `ide-host` (assembly).
+
+mod capability;
+mod index;
+pub mod ledger;
+mod manifest;
+pub mod package;
+mod point;
+mod registry;
+mod ui;
+mod when;
+
+pub use capability::{Capability, CapabilityInfo, Risk, host_matches};
+pub use index::ContributionIndex;
+pub use manifest::{
+    ActivationEvent, Capabilities, ENGINE_VERSION, EVENT_KINDS, LEGACY_API, MANIFEST_FILE, 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 ui::{UiContribution, UiDecl, UiPoint, UiStore, to_json};
+pub use when::validate_when;

crates/ide-extension/src/manifest.rs

@@ -0,0 +1,501 @@
+//! `plugin.toml`, the package manifest (plan 4.4).
+//!
+//! ```toml
+//! id = "acme.rust-tools"          # optional publisher namespace before the first '.'
+//! name = "Rust Tools"
+//! version = "1.2.0"
+//! engines.openidea = "^1.0"
+//! wasm = "plugin.wasm"
+//! activation = ["on-language:rust", "on-command:check"]
+//!
+//! [capabilities]
+//! required = ["project.read", "editor.write"]
+//! optional = ["net:crates.io", "process:cargo"]
+//!
+//! [[contributes.commands]]
+//! id = "check"
+//! title = "Check"
+//! ```
+//!
+//! `contributes` is kept as raw TOML: each `contributes.<point>` is parsed and
+//! validated by the extension point registered under that id
+//! ([`crate::ExtensionRegistry`]), so new contribution types need no change here.
+//!
+//! Manifests in the 0.1 format (`openidea-api = "0.1"`, `permissions = [...]`)
+//! still parse: permissions become required capabilities and the plugin is
+//! activated at start-up, as before.
+
+use crate::capability::Capability;
+use serde::Deserialize;
+use std::collections::BTreeSet;
+use std::path::{Component, Path, PathBuf};
+
+pub const MANIFEST_FILE: &str = "plugin.toml";
+/// The plugin API (engine) version this host implements.
+pub const ENGINE_VERSION: &str = "1.0.0";
+/// The 0.1 API, still accepted for contribution-only packages and 0.1 components.
+pub const LEGACY_API: &str = "0.1";
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct Manifest {
+    pub id: String,
+    pub name: String,
+    pub version: String,
+    pub description: String,
+    pub authors: Vec<String>,
+    pub homepage: Option<String>,
+    pub license: Option<String>,
+    /// Release notes of this version (Settings › Plugins › What's New).
+    pub change_notes: Option<String>,
+    /// `engines.openidea` (a semver requirement), or the legacy `openidea-api`.
+    pub engine: String,
+    /// Written in the 0.1 format.
+    pub legacy: bool,
+    /// Component file relative to the package directory.
+    pub wasm: Option<PathBuf>,
+    pub activation: Vec<ActivationEvent>,
+    pub capabilities: Capabilities,
+    /// `contributes.<point>` → its declarations, validated by the extension points.
+    pub contributes: toml::Table,
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct Capabilities {
+    pub required: Vec<Capability>,
+    pub optional: Vec<Capability>,
+}
+
+impl Capabilities {
+    pub fn all(&self) -> impl Iterator<Item = &Capability> {
+        self.required.iter().chain(&self.optional)
+    }
+
+    pub fn is_optional(&self, cap: &Capability) -> bool {
+        self.optional.contains(cap) && !self.required.contains(cap)
+    }
+}
+
+/// When a plugin's code is instantiated (plan 4.4). Contributions are live
+/// without it; code only runs once one of these fires.
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum ActivationEvent {
+    /// One of the plugin's commands is run (`on-command:<id>`; `*` = any).
+    Command(String),
+    /// A file of this language is opened.
+    Language(String),
+    /// A file matching this glob (project-relative) is opened.
+    File(String),
+    /// One of the plugin's views is shown.
+    View(String),
+    /// Periodically: `on-schedule:<seconds>`. Does not keep the plugin alive.
+    Schedule(u32),
+    /// A workbench event of this kind (`on-event:file-saved`): the plugin is
+    /// subscribed from the start, and activated to receive it.
+    Event(String),
+    /// Shortly after the workbench is ready.
+    StartupFinished,
+}
+
+impl ActivationEvent {
+    pub fn parse(s: &str) -> Result<Self, String> {
+        let s = s.trim();
+        if s == "on-startup-finished" {
+            return Ok(Self::StartupFinished);
+        }
+        let (kind, arg) = s.split_once(':').ok_or_else(|| format!("unknown activation event {s:?}"))?;
+        let arg = arg.trim();
+        if arg.is_empty() {
+            return Err(format!("activation event {s:?} needs a value"));
+        }
+        Ok(match kind {
+            "on-command" => Self::Command(arg.into()),
+            "on-language" => Self::Language(arg.into()),
+            "on-file" => Self::File(arg.into()),
+            "on-view" => Self::View(arg.into()),
+            "on-schedule" => {
+                let secs: u32 =
+                    arg.trim_end_matches('s').parse().map_err(|_| format!("{s:?}: expected seconds, e.g. 300"))?;
+                if secs < 60 {
+                    return Err(format!("{s:?}: the shortest schedule is 60 seconds"));
+                }
+                Self::Schedule(secs)
+            }
+            "on-event" => {
+                if !EVENT_KINDS.contains(&arg) {
+                    return Err(format!("{s:?}: unknown event kind (one of {})", EVENT_KINDS.join(", ")));
+                }
+                Self::Event(arg.into())
+            }
+            _ => return Err(format!("unknown activation event {s:?}")),
+        })
+    }
+}
+
+/// 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"];
+
+impl std::fmt::Display for ActivationEvent {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Command(c) => write!(f, "on-command:{c}"),
+            Self::Language(l) => write!(f, "on-language:{l}"),
+            Self::File(g) => write!(f, "on-file:{g}"),
+            Self::View(v) => write!(f, "on-view:{v}"),
+            Self::Schedule(s) => write!(f, "on-schedule:{s}"),
+            Self::Event(k) => write!(f, "on-event:{k}"),
+            Self::StartupFinished => f.write_str("on-startup-finished"),
+        }
+    }
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "kebab-case", deny_unknown_fields)]
+struct Raw {
+    id: String,
+    name: String,
+    version: String,
+    #[serde(default)]
+    description: String,
+    #[serde(default)]
+    authors: Vec<String>,
+    #[serde(default)]
+    homepage: Option<String>,
+    #[serde(default)]
+    license: Option<String>,
+    #[serde(default)]
+    change_notes: Option<String>,
+    #[serde(default)]
+    engines: Option<Engines>,
+    /// 0.1 format.
+    #[serde(default)]
+    openidea_api: Option<String>,
+    #[serde(default)]
+    wasm: Option<PathBuf>,
+    #[serde(default)]
+    activation: Option<Vec<String>>,
+    #[serde(default)]
+    capabilities: Option<RawCapabilities>,
+    /// 0.1 format.
+    #[serde(default)]
+    permissions: Option<Vec<String>>,
+    #[serde(default)]
+    contributes: toml::Table,
+}
+
+#[derive(Deserialize)]
+#[serde(deny_unknown_fields)]
+struct Engines {
+    openidea: String,
+}
+
+#[derive(Deserialize)]
+#[serde(deny_unknown_fields)]
+struct RawCapabilities {
+    #[serde(default)]
+    required: Vec<String>,
+    #[serde(default)]
+    optional: Vec<String>,
+}
+
+impl Manifest {
+    pub fn parse(src: &str) -> Result<Self, String> {
+        let raw: Raw = toml::from_str(src).map_err(|e| e.to_string())?;
+        let (engine, legacy) = match (raw.engines, raw.openidea_api) {
+            (Some(e), None) => (e.openidea, false),
+            (None, Some(api)) => (api, true),
+            (Some(_), Some(_)) => return Err("use `engines.openidea`, not `openidea-api`".into()),
+            (None, None) => return Err("missing `engines.openidea` (e.g. \"^1.0\")".into()),
+        };
+        if legacy && raw.capabilities.is_some() {
+            return Err("`capabilities` requires `engines.openidea`; 0.1 manifests use `permissions`".into());
+        }
+        if !legacy && raw.permissions.is_some() {
+            return Err("`permissions` is the 0.1 format; use `[capabilities] required = [...]`".into());
+        }
+        let parse_caps = |list: Vec<String>| -> Result<Vec<Capability>, String> {
+            let mut out: Vec<Capability> = Vec::new();
+            for s in list {
+                let cap: Capability = s.parse()?;
+                if !out.contains(&cap) {
+                    out.push(cap);
+                }
+            }
+            Ok(out)
+        };
+        let capabilities = match (raw.capabilities, raw.permissions) {
+            (Some(c), _) => Capabilities { required: parse_caps(c.required)?, optional: parse_caps(c.optional)? },
+            (None, Some(p)) => Capabilities { required: parse_caps(p)?, optional: Vec::new() },
+            (None, None) => Capabilities::default(),
+        };
+        let activation = match raw.activation {
+            Some(list) => list.iter().map(|s| ActivationEvent::parse(s)).collect::<Result<Vec<_>, _>>()?,
+            // 0.1 plugins were activated at start-up; keep that until they move to 1.0.
+            None if legacy && raw.wasm.is_some() => vec![ActivationEvent::StartupFinished],
+            None => Vec::new(),
+        };
+        let m = Manifest {
+            id: raw.id,
+            name: raw.name,
+            version: raw.version,
+            description: raw.description,
+            authors: raw.authors,
+            homepage: raw.homepage,
+            license: raw.license,
+            change_notes: raw.change_notes,
+            engine,
+            legacy,
+            wasm: raw.wasm,
+            activation,
+            capabilities,
+            contributes: raw.contributes,
+        };
+        m.validate()?;
+        Ok(m)
+    }
+
+    pub fn load(dir: &Path) -> Result<Self, String> {
+        let path = dir.join(MANIFEST_FILE);
+        let src = std::fs::read_to_string(&path).map_err(|e| format!("{}: {e}", path.display()))?;
+        Self::parse(&src).map_err(|e| format!("{}: {e}", path.display()))
+    }
+
+    fn validate(&self) -> Result<(), String> {
+        validate_plugin_id(&self.id)?;
+        if self.name.trim().is_empty() {
+            return Err("`name` must not be empty".into());
+        }
+        if semver::Version::parse(&self.version).is_err() {
+            return Err(format!("`version` must be a semantic version like 1.2.3, got {:?}", self.version));
+        }
+        if !engine_compatible(&self.engine, self.legacy) {
+            return Err(if self.legacy {
+                format!(
+                    "unsupported openidea-api {:?} (this IDE implements {LEGACY_API} and {ENGINE_VERSION})",
+                    self.engine
+                )
+            } else {
+                format!("engines.openidea {:?} does not match this IDE's plugin API {ENGINE_VERSION}", self.engine)
+            });
+        }
+        if let Some(wasm) = &self.wasm {
+            check_relative(wasm, "wasm")?;
+        }
+        if self.wasm.is_none() && !self.activation.is_empty() {
+            return Err("`activation` needs `wasm`: there is no code to activate".into());
+        }
+        let mut seen = BTreeSet::new();
+        for event in &self.activation {
+            if !seen.insert(event) {
+                return Err(format!("duplicate activation event {event}"));
+            }
+        }
+        for (point, decls) in &self.contributes {
+            validate_point_id(point)?;
+            if !matches!(decls, toml::Value::Array(_) | toml::Value::Table(_)) {
+                return Err(format!("`contributes.{point}` must be a table or an array of tables"));
+            }
+        }
+        Ok(())
+    }
+
+    /// The declarations of one extension point: `[[contributes.x]]` gives
+    /// several, `[contributes.x]` one.
+    pub fn declarations(&self, point: &str) -> Vec<toml::Value> {
+        match self.contributes.get(point) {
+            Some(toml::Value::Array(items)) => items.clone(),
+            Some(single @ toml::Value::Table(_)) => vec![single.clone()],
+            _ => Vec::new(),
+        }
+    }
+
+    /// Number of declarations per extension point (for listings before loading).
+    pub fn declaration_counts(&self) -> Vec<(String, u32)> {
+        self.contributes.keys().map(|p| (p.clone(), self.declarations(p).len() as u32)).collect()
+    }
+
+    /// Publisher namespace: the id's part before the first `.` (`acme` in `acme.tools`).
+    pub fn publisher(&self) -> Option<&str> {
+        self.id.split_once('.').map(|(p, _)| p)
+    }
+
+    /// Whether `cap` is declared (required or optional).
+    pub fn declares(&self, cap: &Capability) -> bool {
+        self.capabilities.all().any(|c| c.covers(cap))
+    }
+}
+
+/// Whether this host can load a plugin written for `engine`.
+pub fn engine_compatible(engine: &str, legacy: bool) -> bool {
+    if legacy {
+        return engine == LEGACY_API || engine.strip_prefix(LEGACY_API).is_some_and(|rest| rest.starts_with('.'));
+    }
+    let Ok(req) = semver::VersionReq::parse(engine) else { return false };
+    let host = semver::Version::parse(ENGINE_VERSION).expect("valid engine version");
+    req.matches(&host)
+}
+
+/// Segments of `[a-z0-9][a-z0-9_-]*` joined by `.` (an optional publisher
+/// namespace first), at most 64 chars.
+pub fn validate_plugin_id(id: &str) -> Result<(), String> {
+    let ok = id.len() <= 64 && !id.is_empty() && id.split('.').all(segment_ok);
+    if ok {
+        Ok(())
+    } else {
+        Err(format!(
+            "invalid plugin id {id:?}: use a-z, 0-9, '-', '_' in '.'-separated parts (e.g. acme.tools), max 64"
+        ))
+    }
+}
+
+/// `[a-z0-9][a-z0-9._-]*`, at most 64 chars (commands, themes, views…).
+pub fn validate_item_id(id: &str, what: &str) -> Result<(), String> {
+    let ok_first = id.chars().next().is_some_and(|c| c.is_ascii_lowercase() || c.is_ascii_digit());
+    let ok_rest = id.chars().all(|c| c.is_ascii_lowercase() || c.is_ascii_digit() || matches!(c, '-' | '_' | '.'));
+    if ok_first && ok_rest && id.len() <= 64 {
+        Ok(())
+    } else {
+        Err(format!("invalid {what} {id:?}: use a-z, 0-9, '.', '-', '_', starting with a letter or digit (max 64)"))
+    }
+}
+
+/// Extension point ids: `camelCase` or `kebab-case` words, dots allowed (`iconThemes`, `menus`).
+pub fn validate_point_id(id: &str) -> Result<(), String> {
+    let ok = !id.is_empty()
+        && id.len() <= 64
+        && id.starts_with(|c: char| c.is_ascii_lowercase())
+        && id.chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '-' | '.'));
+    if ok { Ok(()) } else { Err(format!("invalid contribution point {id:?}")) }
+}
+
+fn segment_ok(s: &str) -> bool {
+    s.chars().next().is_some_and(|c| c.is_ascii_lowercase() || c.is_ascii_digit())
+        && s.chars().all(|c| c.is_ascii_lowercase() || c.is_ascii_digit() || c == '-' || c == '_')
+}
+
+/// Package paths must stay inside the package directory.
+pub fn check_relative(path: &Path, what: &str) -> Result<(), String> {
+    let ok = !path.as_os_str().is_empty() && path.components().all(|c| matches!(c, Component::Normal(_)));
+    if ok { Ok(()) } else { Err(format!("{what} {:?} must be a relative path inside the plugin", path.display())) }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const FULL: &str = r#"
+        id = "acme.rust-tools"
+        name = "Rust Tools"
+        version = "1.2.0"
+        engines.openidea = "^1.0"
+        wasm = "plugin.wasm"
+        activation = ["on-language:rust", "on-command:check", "on-schedule:300"]
+
+        [capabilities]
+        required = ["project.read", "editor.write"]
+        optional = ["net:crates.io", "process:cargo"]
+
+        [[contributes.commands]]
+        id = "check"
+        title = "%check.title%"
+
+        [[contributes.menus]]
+        menu = "editor.context"
+        command = "check"
+        when = "editorLang == rust"
+
+        [contributes.settings]
+        schema = "settings.schema.json"
+    "#;
+
+    #[test]
+    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");
+        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");
+    }
+
+    #[test]
+    fn parses_the_02_format() {
+        let m = Manifest::parse(FULL).unwrap();
+        assert_eq!(m.publisher(), Some("acme"));
+        assert!(!m.legacy);
+        assert_eq!(m.activation.len(), 3);
+        assert_eq!(m.activation[2], ActivationEvent::Schedule(300));
+        assert_eq!(m.capabilities.required, vec![Capability::ProjectRead, Capability::EditorWrite]);
+        assert!(m.capabilities.is_optional(&Capability::Process("cargo".into())));
+        assert_eq!(m.declarations("commands").len(), 1);
+        assert_eq!(m.declarations("settings").len(), 1, "a single table is one declaration");
+        assert!(m.declarations("nope").is_empty());
+        let counts: Vec<_> = m.declaration_counts();
+        assert!(counts.contains(&("menus".into(), 1)));
+    }
+
+    #[test]
+    fn parses_the_01_format() {
+        let m = Manifest::parse(
+            "id = \"hello\"\nname = \"Hello\"\nversion = \"0.1.0\"\nopenidea-api = \"0.1\"\nwasm = \"dist/plugin.wasm\"\n\
+             permissions = [\"project-read\", \"editor-write\"]\n[[contributes.commands]]\nid = \"x\"\ntitle = \"X\"",
+        )
+        .unwrap();
+        assert!(m.legacy);
+        assert_eq!(m.capabilities.required, vec![Capability::ProjectRead, Capability::EditorWrite]);
+        assert_eq!(m.activation, vec![ActivationEvent::StartupFinished]);
+        assert_eq!(m.publisher(), None);
+    }
+
+    fn err(src: &str) -> String {
+        Manifest::parse(src).unwrap_err()
+    }
+
+    #[test]
+    fn rejects_invalid_manifests() {
+        let base = |extra: &str| format!("id = \"ok\"\nname = \"N\"\nversion = \"1.0.0\"\n{extra}");
+        assert!(err(&base("")).contains("engines.openidea"));
+        assert!(err(&base("engines.openidea = \"^0.3\"")).contains("does not match"));
+        assert!(err(&base("engines.openidea = \"^2\"")).contains("does not match"));
+        assert!(err(&base("engines.openidea = \"^0.2\"")).contains("does not match"));
+        assert!(err(&base("openidea-api = \"0.2\"")).contains("unsupported"));
+        assert!(err(&base("engines.openidea = \"^1.0\"\npermissions = [\"project-read\"]")).contains("0.1 format"));
+        assert!(
+            err(&base("engines.openidea = \"^1.0\"\n[capabilities]\nrequired = [\"network\"]")).contains("unknown")
+        );
+        assert!(err(&base("engines.openidea = \"^1.0\"\nwasm = \"../x.wasm\"")).contains("relative path"));
+        assert!(err(&base("engines.openidea = \"^1.0\"\nactivation = [\"on-command:x\"]")).contains("needs `wasm`"));
+        assert!(
+            err(&base("engines.openidea = \"^1.0\"\nwasm = \"p.wasm\"\nactivation = [\"on-boot\"]"))
+                .contains("unknown")
+        );
+        assert!(
+            err(&base("engines.openidea = \"^1.0\"\nwasm = \"p.wasm\"\nactivation = [\"on-schedule:5\"]"))
+                .contains("60 seconds")
+        );
+        assert!(err(&base("engines.openidea = \"^1.0\"\nbogus = 1")).contains("unknown field"));
+        assert!(err(&base("engines.openidea = \"^1.0\"\ncontributes.commands = 3")).contains("table"));
+        assert!(
+            err("id = \"Bad\"\nname = \"N\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.0\"").contains("plugin id")
+        );
+        assert!(
+            err("id = \"a..b\"\nname = \"N\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.0\"").contains("plugin id")
+        );
+        assert!(err("id = \"ok\"\nname = \"N\"\nversion = \"1.0\"\nengines.openidea = \"^1.0\"").contains("version"));
+    }
+
+    #[test]
+    fn ids() {
+        assert!(validate_plugin_id("openidea.material-icons").is_ok());
+        assert!(validate_plugin_id("hello_2").is_ok());
+        assert!(validate_plugin_id(".x").is_err());
+        assert!(validate_item_id("word-count.v2_x", "command id").is_ok());
+        assert!(validate_item_id("-x", "command id").is_err());
+        assert!(validate_point_id("iconThemes").is_ok());
+        assert!(validate_point_id("Icon").is_err());
+        assert!(engine_compatible("1.0", false));
+        assert!(engine_compatible(">=1.0, <2", false));
+        assert!(!engine_compatible("^0.2", false), "0.x components don't run on 1.0");
+        assert!(engine_compatible("0.1.3", true));
+        assert!(!engine_compatible("0.10", true));
+    }
+}

crates/ide-extension/src/package.rs

@@ -0,0 +1,465 @@
+//! Plugin distribution: the package file, its
+//! signature, and the static marketplace index.
+//!
+//! - **Package** (`<id>-<version>.oiplugin`): a zip of the manifest, the files
+//!   its declarations reference, the component and licence files, plus
+//!   [`SIGNATURE_FILE`] when signed.
+//! - **Signature**: Ed25519 over `openidea-plugin/1\n<id>\n<version>\n<digest>`,
+//!   `digest` being [`package_digest`] of the unpacked files. A signature
+//!   proves who published the bytes; whether to trust that publisher is the
+//!   index's call.
+//! - **Index** (`index.json`): the publishers and their keys (the trust root),
+//!   the published plugins, and revocations. A publisher owns the id prefix
+//!   `<publisher>.`; a revoked key invalidates everything it signed, a
+//!   revoked plugin version is disabled where it is installed.
+
+use crate::MANIFEST_FILE;
+use base64::Engine as _;
+use ed25519_dalek::{Signature, Signer, SigningKey, VerifyingKey};
+use serde::{Deserialize, Serialize};
+use std::io::{Read, Write};
+use std::path::{Component, Path, PathBuf};
+
+pub const SIGNATURE_FILE: &str = "SIGNATURE.json";
+pub const PACKAGE_EXTENSION: &str = "oiplugin";
+pub const INDEX_FORMAT: u32 = 1;
+/// Limits when unpacking an untrusted package.
+const MAX_ENTRIES: usize = 10_000;
+const MAX_TOTAL: u64 = 512 << 20;
+
+const B64: base64::engine::GeneralPurpose = base64::engine::general_purpose::STANDARD;
+
+/// Content digest of a package: the manifest plus `files` (relative paths).
+pub fn package_digest(dir: &Path, files: &[PathBuf]) -> std::io::Result<String> {
+    let mut all = files.to_vec();
+    all.push(PathBuf::from(MANIFEST_FILE));
+    crate::ledger::package_hash(dir, &all)
+}
+
+fn signed_message(id: &str, version: &str, digest: &str) -> Vec<u8> {
+    format!("openidea-plugin/1\n{id}\n{version}\n{digest}").into_bytes()
+}
+
+/// `SIGNATURE.json` of a signed package.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct PackageSignature {
+    pub publisher: String,
+    /// Ed25519 public key, base64.
+    pub key: String,
+    /// Ed25519 signature, base64.
+    pub signature: String,
+}
+
+/// A publisher's key pair (the 32-byte seed, base64, in a file only the publisher has).
+pub struct PublisherKey(SigningKey);
+
+impl PublisherKey {
+    pub fn from_seed(seed: [u8; 32]) -> Self {
+        Self(SigningKey::from_bytes(&seed))
+    }
+
+    /// The seed as written by `openidea-plugin keygen`.
+    pub fn from_base64(text: &str) -> Result<Self, String> {
+        let bytes = B64.decode(text.trim()).map_err(|e| format!("key file: {e}"))?;
+        let seed: [u8; 32] = bytes.try_into().map_err(|_| "key file: expected a 32-byte key".to_owned())?;
+        Ok(Self::from_seed(seed))
+    }
+
+    pub fn seed_base64(&self) -> String {
+        B64.encode(self.0.to_bytes())
+    }
+
+    pub fn public_base64(&self) -> String {
+        B64.encode(self.0.verifying_key().to_bytes())
+    }
+
+    pub fn sign(&self, publisher: &str, id: &str, version: &str, digest: &str) -> PackageSignature {
+        let sig = self.0.sign(&signed_message(id, version, digest));
+        PackageSignature {
+            publisher: publisher.into(),
+            key: self.public_base64(),
+            signature: B64.encode(sig.to_bytes()),
+        }
+    }
+}
+
+impl PackageSignature {
+    /// Whether the signature is valid for `id`, `version` and `digest` (the
+    /// key's validity is checked against an [`Index`]).
+    pub fn check(&self, id: &str, version: &str, digest: &str) -> Result<(), String> {
+        let key: [u8; 32] = B64
+            .decode(&self.key)
+            .ok()
+            .and_then(|b| b.try_into().ok())
+            .ok_or_else(|| "signature: malformed public key".to_owned())?;
+        let key = VerifyingKey::from_bytes(&key).map_err(|_| "signature: invalid public key".to_owned())?;
+        let sig: [u8; 64] = B64
+            .decode(&self.signature)
+            .ok()
+            .and_then(|b| b.try_into().ok())
+            .ok_or_else(|| "signature: malformed".to_owned())?;
+        key.verify_strict(&signed_message(id, version, digest), &Signature::from_bytes(&sig))
+            .map_err(|_| "the signature does not match the package (it was changed after signing)".to_owned())
+    }
+}
+
+/// Writes the package `out` from `dir`: the manifest, `files`, and the signature if any.
+pub fn pack(dir: &Path, files: &[PathBuf], out: &Path, signature: Option<&PackageSignature>) -> Result<(), String> {
+    let io = |e: std::io::Error| e.to_string();
+    let file = std::fs::File::create(out).map_err(io)?;
+    let mut zip = zip::ZipWriter::new(file);
+    let options = zip::write::SimpleFileOptions::default().compression_method(zip::CompressionMethod::Deflated);
+    let mut names: Vec<PathBuf> = std::iter::once(PathBuf::from(MANIFEST_FILE)).chain(files.iter().cloned()).collect();
+    names.sort();
+    names.dedup();
+    for rel in names {
+        let name = rel.to_str().ok_or("non UTF-8 file name")?.replace('\\', "/");
+        zip.start_file(name, options).map_err(|e| e.to_string())?;
+        let bytes = std::fs::read(dir.join(&rel)).map_err(|e| format!("{}: {e}", rel.display()))?;
+        zip.write_all(&bytes).map_err(io)?;
+    }
+    if let Some(sig) = signature {
+        zip.start_file(SIGNATURE_FILE, options).map_err(|e| e.to_string())?;
+        zip.write_all(serde_json::to_string_pretty(sig).map_err(|e| e.to_string())?.as_bytes()).map_err(io)?;
+    }
+    zip.finish().map_err(|e| e.to_string())?;
+    Ok(())
+}
+
+/// What [`unpack`] wrote.
+#[derive(Debug)]
+pub struct Unpacked {
+    /// Every file but the manifest and the signature, relative.
+    pub files: Vec<PathBuf>,
+    pub signature: Option<PackageSignature>,
+}
+
+/// `name` as a relative path that stays inside the package.
+fn safe_path(name: &str) -> Option<PathBuf> {
+    let p = Path::new(name);
+    (!name.is_empty() && p.components().all(|c| matches!(c, Component::Normal(_)))).then(|| p.to_path_buf())
+}
+
+/// Archiver metadata at the top of an archive, not part of a package
+/// (`__MACOSX/…`, `.DS_Store`, AppleDouble `._…` files).
+fn archiver_metadata(name: &str) -> bool {
+    let top = name.split('/').next().unwrap_or_default();
+    top == "__MACOSX" || top == ".DS_Store" || (top.starts_with("._") && top.len() > 2)
+}
+
+/// Where the package is inside an archive: at its root (`.oiplugin`, or a zip
+/// of the package's contents) or in its only folder (a zip of the package
+/// folder). `None` when neither holds a manifest.
+fn package_prefix(names: &[String]) -> Option<String> {
+    if names.iter().any(|n| n == MANIFEST_FILE) {
+        return Some(String::new());
+    }
+    let mut tops = names.iter().filter(|n| !archiver_metadata(n)).map(|n| n.split('/').next().unwrap_or_default());
+    let top = tops.next()?;
+    if tops.any(|t| t != top) {
+        return None;
+    }
+    let prefix = format!("{top}/");
+    names.iter().any(|n| *n == format!("{prefix}{MANIFEST_FILE}")).then_some(prefix)
+}
+
+/// Extracts the package `archive` (an `.oiplugin`, or a `.zip` of a package
+/// folder or of its contents) into the empty directory `dest`, refusing
+/// paths leaving it, links, and oversized contents.
+pub fn unpack(archive: &Path, dest: &Path) -> Result<Unpacked, String> {
+    let file = std::fs::File::open(archive).map_err(|e| format!("{}: {e}", archive.display()))?;
+    let mut zip =
+        zip::ZipArchive::new(file).map_err(|e| format!("{}: not a plugin package ({e})", archive.display()))?;
+    if zip.len() > MAX_ENTRIES {
+        return Err(format!("more than {MAX_ENTRIES} files"));
+    }
+    let mut names = Vec::with_capacity(zip.len());
+    for i in 0..zip.len() {
+        let entry = zip.by_index(i).map_err(|e| e.to_string())?;
+        if !entry.is_dir() {
+            names.push(entry.name().map_err(|e| e.to_string())?.into_owned());
+        }
+    }
+    // An IntelliJ plugin or any other zip: say what is missing rather than fail later.
+    let prefix = package_prefix(&names).ok_or_else(|| {
+        format!("{} is not an OpenIDEA plugin: no {MANIFEST_FILE} at its root or in its only folder", archive.display())
+    })?;
+    std::fs::create_dir_all(dest).map_err(|e| e.to_string())?;
+    let (mut files, mut signature, mut total, mut manifest) = (Vec::new(), None, 0u64, false);
+    for i in 0..zip.len() {
+        let mut entry = zip.by_index(i).map_err(|e| e.to_string())?;
+        if entry.is_dir() {
+            continue;
+        }
+        let full = entry.name().map_err(|e| e.to_string())?.into_owned();
+        // Outside the package folder there is only archiver metadata (`package_prefix` checked).
+        let Some(name) = full.strip_prefix(&prefix).map(str::to_owned) else { continue };
+        if archiver_metadata(&name) {
+            continue;
+        }
+        if entry.is_symlink() {
+            return Err(format!("{full}: links are not allowed in packages"));
+        }
+        let rel = safe_path(&name).ok_or_else(|| format!("invalid path {full:?} in package"))?;
+        let mut bytes = Vec::new();
+        entry.by_ref().take(MAX_TOTAL - total + 1).read_to_end(&mut bytes).map_err(|e| e.to_string())?;
+        total += bytes.len() as u64;
+        if total > MAX_TOTAL {
+            return Err(format!("the package unpacks to more than {} MiB", MAX_TOTAL >> 20));
+        }
+        if rel == Path::new(SIGNATURE_FILE) {
+            signature = Some(serde_json::from_slice(&bytes).map_err(|e| format!("{SIGNATURE_FILE}: {e}"))?);
+            continue;
+        }
+        let to = dest.join(&rel);
+        if let Some(parent) = to.parent() {
+            std::fs::create_dir_all(parent).map_err(|e| e.to_string())?;
+        }
+        std::fs::write(&to, bytes).map_err(|e| e.to_string())?;
+        if rel == Path::new(MANIFEST_FILE) {
+            manifest = true;
+        } else {
+            files.push(rel);
+        }
+    }
+    if !manifest {
+        return Err(format!("the package has no {MANIFEST_FILE}"));
+    }
+    files.sort();
+    Ok(Unpacked { files, signature })
+}
+
+// ---- index -------------------------------------------------------------------
+
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, specta::Type)]
+#[serde(rename_all = "camelCase")]
+pub struct Index {
+    pub format: u32,
+    #[serde(default)]
+    pub publishers: Vec<Publisher>,
+    #[serde(default)]
+    pub plugins: Vec<IndexEntry>,
+    #[serde(default)]
+    pub revoked: Vec<Revocation>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, specta::Type)]
+#[serde(rename_all = "camelCase")]
+pub struct Publisher {
+    /// Owns plugin ids `<id>.…`.
+    pub id: String,
+    pub name: String,
+    pub keys: Vec<KeyEntry>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, specta::Type)]
+#[serde(rename_all = "camelCase")]
+pub struct KeyEntry {
+    /// Ed25519 public key, base64.
+    pub key: String,
+    /// Packages signed with it are no longer trusted.
+    #[serde(default)]
+    pub revoked: bool,
+}
+
+/// A published plugin version.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, specta::Type)]
+#[serde(rename_all = "camelCase")]
+pub struct IndexEntry {
+    pub id: String,
+    pub name: String,
+    pub version: String,
+    #[serde(default)]
+    pub description: String,
+    #[serde(default)]
+    pub authors: Vec<String>,
+    pub publisher: String,
+    /// The package, relative to the index (or an absolute URL).
+    pub download: String,
+    /// [`package_digest`] of its contents.
+    pub digest: String,
+    #[serde(default)]
+    pub capabilities: Vec<String>,
+}
+
+/// A plugin (all versions when `versions` is empty) that must not run.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, specta::Type)]
+#[serde(rename_all = "camelCase")]
+pub struct Revocation {
+    pub id: String,
+    #[serde(default)]
+    pub versions: Vec<String>,
+    pub reason: String,
+}
+
+impl Index {
+    pub fn parse(text: &str) -> Result<Self, String> {
+        let index: Index = serde_json::from_str(text).map_err(|e| format!("index: {e}"))?;
+        if index.format != INDEX_FORMAT {
+            return Err(format!("index format {} is not supported (this IDE reads {INDEX_FORMAT})", index.format));
+        }
+        Ok(index)
+    }
+
+    /// The revocation that applies to `id` at `version`.
+    pub fn revocation(&self, id: &str, version: &str) -> Option<&Revocation> {
+        self.revoked.iter().find(|r| r.id == id && (r.versions.is_empty() || r.versions.iter().any(|v| v == version)))
+    }
+
+    /// Whether `key` (base64) belongs to a publisher and was revoked.
+    pub fn key_revoked(&self, key: &str) -> bool {
+        self.publishers.iter().flat_map(|p| &p.keys).any(|k| k.key == key && k.revoked)
+    }
+
+    /// The trusted publisher of a signed package: the signature is valid, its
+    /// key is one of the publisher's and not revoked, and the publisher owns
+    /// the plugin's id prefix.
+    pub fn verify(&self, sig: &PackageSignature, id: &str, version: &str, digest: &str) -> Result<String, String> {
+        let publisher = self
+            .publishers
+            .iter()
+            .find(|p| p.id == sig.publisher)
+            .ok_or_else(|| format!("unknown publisher {:?}", sig.publisher))?;
+        let key = publisher
+            .keys
+            .iter()
+            .find(|k| k.key == sig.key)
+            .ok_or_else(|| format!("the key is not one of {}'s", publisher.name))?;
+        if key.revoked {
+            return Err(format!("{}'s signing key was revoked", publisher.name));
+        }
+        if !id.starts_with(&format!("{}.", publisher.id)) {
+            return Err(format!("{} may only publish plugins named {}.*", publisher.name, publisher.id));
+        }
+        sig.check(id, version, digest)?;
+        Ok(publisher.id.clone())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn package(dir: &Path) -> Vec<PathBuf> {
+        std::fs::create_dir_all(dir.join("dist")).unwrap();
+        std::fs::write(dir.join(MANIFEST_FILE), "id = \"acme.tools\"\nversion = \"1.0.0\"").unwrap();
+        std::fs::write(dir.join("dist/plugin.wasm"), b"\0asm").unwrap();
+        vec![PathBuf::from("dist/plugin.wasm")]
+    }
+
+    fn index(key: &PublisherKey) -> Index {
+        Index {
+            format: INDEX_FORMAT,
+            publishers: vec![Publisher {
+                id: "acme".into(),
+                name: "ACME".into(),
+                keys: vec![KeyEntry { key: key.public_base64(), revoked: false }],
+            }],
+            plugins: Vec::new(),
+            revoked: vec![Revocation {
+                id: "acme.bad".into(),
+                versions: vec!["1.0.0".into()],
+                reason: "malware".into(),
+            }],
+        }
+    }
+
+    #[test]
+    fn signed_packages_round_trip_and_tampering_is_caught() {
+        let tmp = tempfile::tempdir().unwrap();
+        let src = tmp.path().join("src");
+        let files = package(&src);
+        let digest = package_digest(&src, &files).unwrap();
+        let key = PublisherKey::from_seed([7; 32]);
+        let sig = key.sign("acme", "acme.tools", "1.0.0", &digest);
+        let out = tmp.path().join("acme.tools-1.0.0.oiplugin");
+        pack(&src, &files, &out, Some(&sig)).unwrap();
+
+        let dest = tmp.path().join("dest");
+        let unpacked = unpack(&out, &dest).unwrap();
+        assert_eq!(unpacked.files, files);
+        assert_eq!(package_digest(&dest, &unpacked.files).unwrap(), digest);
+        let index = index(&key);
+        assert_eq!(index.verify(unpacked.signature.as_ref().unwrap(), "acme.tools", "1.0.0", &digest).unwrap(), "acme");
+
+        // Changed bytes, another id, someone else's prefix, a revoked key.
+        assert!(index.verify(&sig, "acme.tools", "1.0.0", "0000").is_err());
+        assert!(index.verify(&sig, "acme.tools", "1.0.1", &digest).is_err());
+        let other = PublisherKey::from_seed([9; 32]).sign("acme", "acme.tools", "1.0.0", &digest);
+        assert!(index.verify(&other, "acme.tools", "1.0.0", &digest).unwrap_err().contains("not one of"));
+        let foreign = key.sign("acme", "evil.tools", "1.0.0", &digest);
+        assert!(index.verify(&foreign, "evil.tools", "1.0.0", &digest).unwrap_err().contains("acme.*"));
+        let mut revoked = index.clone();
+        revoked.publishers[0].keys[0].revoked = true;
+        assert!(revoked.verify(&sig, "acme.tools", "1.0.0", &digest).unwrap_err().contains("revoked"));
+        assert!(revoked.key_revoked(&sig.key));
+        assert_eq!(index.revocation("acme.bad", "1.0.0").unwrap().reason, "malware");
+        assert!(index.revocation("acme.bad", "1.0.1").is_none());
+        assert_eq!(PublisherKey::from_base64(&key.seed_base64()).unwrap().public_base64(), key.public_base64());
+    }
+
+    #[test]
+    fn unpacking_refuses_paths_leaving_the_package() {
+        let tmp = tempfile::tempdir().unwrap();
+        let out = tmp.path().join("evil.oiplugin");
+        let mut zip = zip::ZipWriter::new(std::fs::File::create(&out).unwrap());
+        let o = zip::write::SimpleFileOptions::default();
+        zip.start_file(MANIFEST_FILE, o).unwrap();
+        zip.write_all(b"id = \"x\"").unwrap();
+        zip.start_file("../outside.txt", o).unwrap();
+        zip.write_all(b"x").unwrap();
+        zip.finish().unwrap();
+        let err = unpack(&out, &tmp.path().join("dest")).unwrap_err();
+        assert!(err.contains("invalid path"), "{err}");
+        assert!(!tmp.path().join("outside.txt").exists());
+        assert!(Index::parse(r#"{"format": 2}"#).is_err());
+    }
+
+    fn zip_of(path: &Path, entries: &[(&str, &str)]) {
+        let mut zip = zip::ZipWriter::new(std::fs::File::create(path).unwrap());
+        for (name, body) in entries {
+            zip.start_file(*name, zip::write::SimpleFileOptions::default()).unwrap();
+            zip.write_all(body.as_bytes()).unwrap();
+        }
+        zip.finish().unwrap();
+    }
+
+    #[test]
+    fn a_zip_holds_the_package_at_its_root_or_in_its_only_folder() {
+        let tmp = tempfile::tempdir().unwrap();
+        let manifest = "id = \"acme.tools\"";
+        let at_root = tmp.path().join("root.zip");
+        zip_of(&at_root, &[(MANIFEST_FILE, manifest), ("dist/plugin.wasm", "w"), (".DS_Store", "x")]);
+        let got = unpack(&at_root, &tmp.path().join("a")).unwrap();
+        assert_eq!(got.files, [PathBuf::from("dist/plugin.wasm")]);
+
+        // What zipping the folder in Finder makes: the folder plus `__MACOSX`.
+        let folder = tmp.path().join("folder.zip");
+        zip_of(
+            &folder,
+            &[
+                ("acme-tools/plugin.toml", manifest),
+                ("acme-tools/dist/plugin.wasm", "w"),
+                ("__MACOSX/acme-tools/._plugin.toml", "x"),
+            ],
+        );
+        let dest = tmp.path().join("b");
+        let got = unpack(&folder, &dest).unwrap();
+        assert_eq!(got.files, [PathBuf::from("dist/plugin.wasm")]);
+        assert!(dest.join(MANIFEST_FILE).is_file());
+        assert!(!dest.join("__MACOSX").exists() && !dest.join("acme-tools").exists());
+
+        // Two folders, a manifest one level too deep, or none (an IntelliJ plugin): not a package.
+        for (name, entries) in [
+            ("two.zip", &[("a/plugin.toml", manifest), ("b/x.txt", "x")][..]),
+            ("deep.zip", &[("a/b/plugin.toml", manifest)][..]),
+            ("intellij.zip", &[("my-plugin/lib/my-plugin.jar", "jar")][..]),
+        ] {
+            let path = tmp.path().join(name);
+            zip_of(&path, entries);
+            let err = unpack(&path, &tmp.path().join(name).with_extension("out")).unwrap_err();
+            assert!(err.contains("is not an OpenIDEA plugin"), "{name}: {err}");
+        }
+    }
+}

crates/ide-extension/src/point.rs

@@ -0,0 +1,175 @@
+//! The extension point contract (plan 4.1).
+
+use crate::capability::Capability;
+use crate::manifest::{Manifest, check_relative};
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+/// Where a contribution takes effect (plan 3, placement rules).
+#[derive(Clone, Copy, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize, specta::Type)]
+#[serde(rename_all = "camelCase")]
+pub enum Placement {
+    /// Projected to the client (menus, keybindings, themes, icons).
+    Ui,
+    /// Takes effect on the machine the project is on (languages, LSP, run configurations).
+    Workspace,
+}
+
+/// The package a declaration comes from, as extension points see it.
+#[derive(Clone, Debug)]
+pub struct Package {
+    pub manifest: Arc<Manifest>,
+    /// Package directory.
+    pub dir: PathBuf,
+    /// Hash of the package's files when they never change (an installed
+    /// copy): validated declarations are then reused from the
+    /// [`ContributionIndex`](crate::ContributionIndex).
+    pub digest: Option<Arc<str>>,
+}
+
+/// Largest single package file an extension point reads.
+pub const MAX_PACKAGE_FILE: u64 = 8 << 20;
+
+impl Package {
+    pub fn new(manifest: Manifest, dir: PathBuf) -> Self {
+        Self { manifest: Arc::new(manifest), dir, digest: None }
+    }
+
+    pub fn with_digest(mut self, digest: &str) -> Self {
+        self.digest = Some(digest.into());
+        self
+    }
+
+    pub fn id(&self) -> &str {
+        &self.manifest.id
+    }
+
+    /// Resolves a package-relative path, refusing anything that leaves the
+    /// package (`..`, absolute paths, symlinks pointing outside).
+    pub fn resolve(&self, rel: &Path) -> Result<PathBuf, String> {
+        check_relative(rel, "path")?;
+        let joined = self.dir.join(rel);
+        let real = joined.canonicalize().map_err(|_| format!("{}: no such file in the plugin", rel.display()))?;
+        let root = self.dir.canonicalize().map_err(|e| format!("plugin directory: {e}"))?;
+        if !real.starts_with(&root) {
+            return Err(format!("{}: points outside the plugin", rel.display()));
+        }
+        Ok(real)
+    }
+
+    pub fn read_bytes(&self, rel: &Path) -> Result<Vec<u8>, String> {
+        let real = self.resolve(rel)?;
+        let meta = std::fs::metadata(&real).map_err(|e| format!("{}: {e}", rel.display()))?;
+        if !meta.is_file() {
+            return Err(format!("{}: not a file", rel.display()));
+        }
+        if meta.len() > MAX_PACKAGE_FILE {
+            return Err(format!("{}: larger than {} MiB", rel.display(), MAX_PACKAGE_FILE >> 20));
+        }
+        std::fs::read(&real).map_err(|e| format!("{}: {e}", rel.display()))
+    }
+
+    pub fn read_text(&self, rel: &Path) -> Result<String, String> {
+        String::from_utf8(self.read_bytes(rel)?).map_err(|_| format!("{}: not UTF-8 text", rel.display()))
+    }
+}
+
+/// Undoes one committed contribution. Dropping without [`dispose`](Self::dispose) also disposes.
+#[must_use = "dropping a Disposable undoes the contribution"]
+pub struct Disposable(Option<Box<dyn FnOnce() + Send>>);
+
+impl Disposable {
+    pub fn new(f: impl FnOnce() + Send + 'static) -> Self {
+        Self(Some(Box::new(f)))
+    }
+
+    /// A contribution with nothing to undo.
+    pub fn noop() -> Self {
+        Self(None)
+    }
+
+    pub fn dispose(mut self) {
+        if let Some(f) = self.0.take() {
+            f();
+        }
+    }
+}
+
+impl Drop for Disposable {
+    fn drop(&mut self) {
+        if let Some(f) = self.0.take() {
+            f();
+        }
+    }
+}
+
+impl std::fmt::Debug for Disposable {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("Disposable")
+    }
+}
+
+pub type Commit = Box<dyn FnOnce() -> Result<Disposable, String> + Send>;
+
+/// A validated declaration, ready to take effect.
+pub struct Prepared {
+    /// Capabilities this declaration needs (a language with an LSP → `process:<binary>`).
+    pub capabilities: Vec<Capability>,
+    /// Package files the declaration references (copied on install).
+    pub files: Vec<PathBuf>,
+    /// Identity within the point: a later declaration with the same key replaces
+    /// the earlier one of the same plugin (re-registering a command).
+    pub key: Option<String>,
+    /// User-facing one-liner for the plugin details page ("Insert Date").
+    pub label: String,
+    /// Makes it take effect. Must not fail for reasons `prepare` could have checked.
+    pub commit: Commit,
+}
+
+impl Prepared {
+    pub fn new(label: impl Into<String>, commit: impl FnOnce() -> Result<Disposable, String> + Send + 'static) -> Self {
+        Self { capabilities: Vec::new(), files: Vec::new(), key: None, label: label.into(), commit: Box::new(commit) }
+    }
+
+    pub fn key(mut self, key: impl Into<String>) -> Self {
+        self.key = Some(key.into());
+        self
+    }
+
+    pub fn file(mut self, path: impl Into<PathBuf>) -> Self {
+        self.files.push(path.into());
+        self
+    }
+
+    pub fn capability(mut self, cap: Capability) -> Self {
+        if !self.capabilities.contains(&cap) {
+            self.capabilities.push(cap);
+        }
+        self
+    }
+}
+
+impl std::fmt::Debug for Prepared {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Prepared").field("key", &self.key).field("label", &self.label).finish_non_exhaustive()
+    }
+}
+
+/// A kind of contribution (`contributes.<id>` in the manifest). Implemented by
+/// the crate that owns the feature; registered once in an [`crate::ExtensionRegistry`].
+pub trait ExtensionPoint: Send + Sync {
+    /// `"languages"`, `"iconThemes"`, …
+    fn id(&self) -> &'static str;
+
+    fn placement(&self) -> Placement;
+
+    /// Parses and validates one declaration without side effects, and works
+    /// out the capabilities it needs. `Ui` points validate completely here: the
+    /// client's projection is not allowed to fail.
+    fn prepare(&self, pkg: &Package, decl: toml::Value) -> Result<Prepared, String>;
+}
+
+/// Deserializes a declaration with serde, prefixing errors with the point id.
+pub fn decode<T: serde::de::DeserializeOwned>(point: &str, decl: toml::Value) -> Result<T, String> {
+    decl.try_into().map_err(|e: toml::de::Error| format!("contributes.{point}: {}", e.message()))
+}

crates/ide-extension/src/registry.rs

@@ -0,0 +1,305 @@
+//! Extension points plus the contributions committed to them, accounted per plugin.
+
+use crate::capability::Capability;
+use crate::point::{Disposable, ExtensionPoint, Package, Placement, Prepared};
+use parking_lot::{Mutex, RwLock};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::collections::BTreeMap;
+use std::path::PathBuf;
+use std::sync::Arc;
+
+/// A contribution as the plugin details page lists it.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct ContributionInfo {
+    pub point: String,
+    pub label: String,
+}
+
+struct Entry {
+    point: &'static str,
+    key: Option<String>,
+    label: String,
+    disposable: Disposable,
+}
+
+/// Every declaration of a package, validated; nothing has taken effect yet.
+pub struct PreparedSet {
+    pub plugin: String,
+    /// Union of what the declarations need (beyond the manifest's own list).
+    pub capabilities: Vec<Capability>,
+    /// Package files the declarations reference.
+    pub files: Vec<PathBuf>,
+    /// Declarations for extension points this host does not know (skipped).
+    pub warnings: Vec<String>,
+    items: Vec<(&'static str, Prepared)>,
+}
+
+impl PreparedSet {
+    pub fn is_empty(&self) -> bool {
+        self.items.is_empty()
+    }
+
+    pub fn len(&self) -> usize {
+        self.items.len()
+    }
+}
+
+impl std::fmt::Debug for PreparedSet {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("PreparedSet")
+            .field("plugin", &self.plugin)
+            .field("items", &self.items.len())
+            .field("warnings", &self.warnings)
+            .finish()
+    }
+}
+
+#[derive(Default)]
+pub struct ExtensionRegistry {
+    points: RwLock<BTreeMap<&'static str, Arc<dyn ExtensionPoint>>>,
+    /// plugin id → its contributions in commit order.
+    entries: Mutex<BTreeMap<String, Vec<Entry>>>,
+}
+
+impl ExtensionRegistry {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Adds an extension point. Ids are unique.
+    pub fn register(&self, point: Arc<dyn ExtensionPoint>) -> Result<(), String> {
+        let id = point.id();
+        crate::manifest::validate_point_id(id)?;
+        let mut points = self.points.write();
+        if points.contains_key(id) {
+            return Err(format!("extension point {id:?} is already registered"));
+        }
+        points.insert(id, point);
+        Ok(())
+    }
+
+    pub fn point_ids(&self) -> Vec<&'static str> {
+        self.points.read().keys().copied().collect()
+    }
+
+    pub fn placement(&self, point: &str) -> Option<Placement> {
+        self.points.read().get(point).map(|p| p.placement())
+    }
+
+    fn point(&self, id: &str) -> Option<Arc<dyn ExtensionPoint>> {
+        self.points.read().get(id).cloned()
+    }
+
+    /// Validates every `contributes.<point>` declaration of `pkg`. Fails as a
+    /// whole on the first invalid declaration; unknown points are skipped with
+    /// a warning (forward compatibility).
+    pub fn prepare(&self, pkg: &Package) -> Result<PreparedSet, String> {
+        let mut set = PreparedSet {
+            plugin: pkg.id().to_owned(),
+            capabilities: Vec::new(),
+            files: Vec::new(),
+            warnings: Vec::new(),
+            items: Vec::new(),
+        };
+        for point_id in pkg.manifest.contributes.keys() {
+            let Some(point) = self.point(point_id) else {
+                let msg = format!("contributes.{point_id}: not supported by this version of the IDE; skipped");
+                tracing::warn!(plugin = %pkg.id(), "{msg}");
+                set.warnings.push(msg);
+                continue;
+            };
+            for (i, decl) in pkg.manifest.declarations(point_id).into_iter().enumerate() {
+                let prepared = point
+                    .prepare(pkg, decl)
+                    .map_err(|e| format!("contributes.{point_id}[{i}]: {}", strip_prefix(&e, point_id)))?;
+                for cap in &prepared.capabilities {
+                    if !set.capabilities.contains(cap) {
+                        set.capabilities.push(cap.clone());
+                    }
+                }
+                for f in &prepared.files {
+                    if !set.files.contains(f) {
+                        set.files.push(f.clone());
+                    }
+                }
+                set.items.push((point.id(), prepared));
+            }
+        }
+        Ok(set)
+    }
+
+    /// Makes a prepared set take effect, all or nothing: if one commit fails,
+    /// the ones before it are disposed in reverse order.
+    pub fn commit(&self, set: PreparedSet) -> Result<(), String> {
+        let mut committed: Vec<Entry> = Vec::with_capacity(set.items.len());
+        for (point, prepared) in set.items {
+            let Prepared { key, label, commit, .. } = prepared;
+            match commit() {
+                Ok(disposable) => committed.push(Entry { point, key, label, disposable }),
+                Err(e) => {
+                    tracing::error!(plugin = %set.plugin, "contributes.{point}: commit failed: {e}");
+                    while let Some(entry) = committed.pop() {
+                        entry.disposable.dispose();
+                    }
+                    return Err(format!("contributes.{point}: {e}"));
+                }
+            }
+        }
+        let replaced = {
+            let mut entries = self.entries.lock();
+            let list = entries.entry(set.plugin).or_default();
+            let mut replaced = Vec::new();
+            for new in &committed {
+                if let Some(key) = &new.key
+                    && let Some(pos) = list.iter().position(|e| e.point == new.point && e.key.as_ref() == Some(key))
+                {
+                    replaced.push(list.remove(pos));
+                }
+            }
+            list.extend(committed);
+            replaced
+        };
+        for old in replaced.into_iter().rev() {
+            old.disposable.dispose();
+        }
+        Ok(())
+    }
+
+    /// Withdraws everything `plugin` contributed, newest first.
+    pub fn dispose_plugin(&self, plugin: &str) -> bool {
+        let list = self.entries.lock().remove(plugin).unwrap_or_default();
+        let any = !list.is_empty();
+        for entry in list.into_iter().rev() {
+            entry.disposable.dispose();
+        }
+        any
+    }
+
+    pub fn contributions(&self, plugin: &str) -> Vec<ContributionInfo> {
+        self.entries
+            .lock()
+            .get(plugin)
+            .map(|list| {
+                list.iter().map(|e| ContributionInfo { point: e.point.into(), label: e.label.clone() }).collect()
+            })
+            .unwrap_or_default()
+    }
+
+    /// How many contributions `plugin` has at `point`.
+    pub fn count(&self, plugin: &str, point: &str) -> usize {
+        self.entries.lock().get(plugin).map_or(0, |list| list.iter().filter(|e| e.point == point).count())
+    }
+
+    /// Plugins with at least one contribution.
+    pub fn plugins(&self) -> Vec<String> {
+        self.entries.lock().iter().filter(|(_, l)| !l.is_empty()).map(|(id, _)| id.clone()).collect()
+    }
+}
+
+fn strip_prefix<'a>(e: &'a str, point: &str) -> &'a str {
+    e.strip_prefix(&format!("contributes.{point}: ")).unwrap_or(e)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::manifest::Manifest;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+
+    /// Records live items in a shared list; `fail = true` makes commit fail.
+    struct Recording {
+        id: &'static str,
+        live: Arc<Mutex<Vec<String>>>,
+        commits: Arc<AtomicUsize>,
+    }
+
+    impl ExtensionPoint for Recording {
+        fn id(&self) -> &'static str {
+            self.id
+        }
+        fn placement(&self) -> Placement {
+            Placement::Ui
+        }
+        fn prepare(&self, _pkg: &Package, decl: toml::Value) -> Result<Prepared, String> {
+            let name = decl.get("name").and_then(|v| v.as_str()).ok_or("missing name")?.to_owned();
+            let fail = decl.get("fail").and_then(|v| v.as_bool()).unwrap_or(false);
+            let (live, commits) = (self.live.clone(), self.commits.clone());
+            let label = name.clone();
+            let mut p = Prepared::new(label, move || {
+                commits.fetch_add(1, Ordering::SeqCst);
+                if fail {
+                    return Err("boom".into());
+                }
+                live.lock().push(name.clone());
+                Ok(Disposable::new(move || live.lock().retain(|n| *n != name)))
+            });
+            if let Some(f) = decl.get("file").and_then(|v| v.as_str()) {
+                p = p.file(f);
+            }
+            if decl.get("key").and_then(|v| v.as_bool()).unwrap_or(false) {
+                p = p.key("k");
+            }
+            Ok(p)
+        }
+    }
+
+    fn setup() -> (ExtensionRegistry, Arc<Mutex<Vec<String>>>) {
+        let reg = ExtensionRegistry::new();
+        let live = Arc::new(Mutex::new(Vec::new()));
+        let commits = Arc::new(AtomicUsize::new(0));
+        reg.register(Arc::new(Recording { id: "things", live: live.clone(), commits: commits.clone() })).unwrap();
+        reg.register(Arc::new(Recording { id: "others", live: live.clone(), commits })).unwrap();
+        (reg, live)
+    }
+
+    fn pkg(contributes: &str) -> Package {
+        let src = format!("id = \"p\"\nname = \"P\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.0\"\n{contributes}");
+        Package::new(Manifest::parse(&src).unwrap(), PathBuf::from("/nonexistent"))
+    }
+
+    #[test]
+    fn commits_and_disposes_per_plugin() {
+        let (reg, live) = setup();
+        assert!(
+            reg.register(Arc::new(Recording { id: "things", live: live.clone(), commits: Default::default() }))
+                .is_err()
+        );
+        let p = pkg(
+            "[[contributes.things]]\nname = \"a\"\nfile = \"x.json\"\n[[contributes.things]]\nname = \"b\"\n[contributes.others]\nname = \"c\"",
+        );
+        let set = reg.prepare(&p).unwrap();
+        assert_eq!(set.len(), 3);
+        assert_eq!(set.files, [PathBuf::from("x.json")]);
+        assert!(live.lock().is_empty(), "prepare has no side effects");
+        reg.commit(set).unwrap();
+        assert_eq!(*live.lock(), ["c", "a", "b"]);
+        assert_eq!(reg.count("p", "things"), 2);
+        assert_eq!(reg.contributions("p").len(), 3);
+        assert!(reg.dispose_plugin("p"));
+        assert!(live.lock().is_empty());
+    }
+
+    #[test]
+    fn a_failed_commit_rolls_back() {
+        let (reg, live) = setup();
+        let p = pkg("[[contributes.things]]\nname = \"a\"\n[[contributes.things]]\nname = \"b\"\nfail = true");
+        let err = reg.commit(reg.prepare(&p).unwrap()).unwrap_err();
+        assert!(err.contains("boom"));
+        assert!(live.lock().is_empty(), "a was undone");
+        assert!(reg.contributions("p").is_empty());
+    }
+
+    #[test]
+    fn invalid_declarations_fail_prepare_and_unknown_points_warn() {
+        let (reg, _) = setup();
+        let err = reg.prepare(&pkg("[[contributes.things]]\nnope = 1")).unwrap_err();
+        assert_eq!(err, "contributes.things[0]: missing name");
+        let set =
+            reg.prepare(&pkg("[[contributes.futureThing]]\nx = 1\n[[contributes.things]]\nname = \"a\"")).unwrap();
+        assert_eq!(set.len(), 1);
+        assert_eq!(set.warnings.len(), 1);
+        assert!(set.warnings[0].contains("futureThing"));
+    }
+}

crates/ide-extension/src/ui.rs

@@ -0,0 +1,247 @@
+//! UI contributions: validated declarations projected to the client.
+//!
+//! A `Ui` extension point validates a declaration completely in Rust and
+//! commits it as JSON into the [`UiStore`]; the client receives the store's
+//! snapshot and projects each item onto an existing `register*` function
+//! (`defineUiPoint` in `src/features/plugins/projection.ts`). Large payloads
+//! (icon SVGs) go into the store's assets and are fetched on demand.
+
+use crate::index::ContributionIndex;
+use crate::point::{Disposable, ExtensionPoint, Package, Placement, Prepared};
+use parking_lot::RwLock;
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::collections::BTreeMap;
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicU64, Ordering};
+
+/// One projected declaration.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct UiContribution {
+    pub plugin_id: String,
+    /// Extension point id (`commands`, `iconThemes`, …).
+    pub point: String,
+    /// Stable within (plugin, point): the client keys its registrations on it.
+    pub key: String,
+    /// The validated declaration, shaped by the point.
+    #[specta(type = specta_typescript::Unknown)]
+    pub decl: serde_json::Value,
+}
+
+struct Item {
+    seq: u64,
+    contribution: UiContribution,
+}
+
+/// Committed UI contributions of all plugins.
+#[derive(Default)]
+pub struct UiStore {
+    items: RwLock<Vec<Item>>,
+    /// (plugin, asset id) → content.
+    assets: RwLock<BTreeMap<(String, String), Arc<str>>>,
+    seq: AtomicU64,
+    revision: AtomicU64,
+    index: RwLock<Option<Arc<ContributionIndex>>>,
+}
+
+impl UiStore {
+    pub fn new() -> Arc<Self> {
+        Arc::new(Self::default())
+    }
+
+    /// Adds an item; the returned disposable removes it.
+    pub fn insert(self: &Arc<Self>, contribution: UiContribution) -> Disposable {
+        let seq = self.seq.fetch_add(1, Ordering::Relaxed);
+        self.items.write().push(Item { seq, contribution });
+        self.revision.fetch_add(1, Ordering::Release);
+        let store = Arc::downgrade(self);
+        Disposable::new(move || {
+            if let Some(store) = store.upgrade() {
+                store.items.write().retain(|i| i.seq != seq);
+                store.revision.fetch_add(1, Ordering::Release);
+            }
+        })
+    }
+
+    /// Stores assets of a plugin (ids are unique per plugin; later ones replace).
+    pub fn insert_assets(self: &Arc<Self>, plugin: &str, assets: Vec<(String, String)>) -> Disposable {
+        let keys: Vec<(String, String)> = assets.iter().map(|(id, _)| (plugin.to_owned(), id.clone())).collect();
+        {
+            let mut map = self.assets.write();
+            for (id, content) in assets {
+                map.insert((plugin.to_owned(), id), Arc::from(content));
+            }
+        }
+        let store = Arc::downgrade(self);
+        Disposable::new(move || {
+            if let Some(store) = store.upgrade() {
+                let mut map = store.assets.write();
+                for k in keys {
+                    map.remove(&k);
+                }
+            }
+        })
+    }
+
+    pub fn asset(&self, plugin: &str, id: &str) -> Option<Arc<str>> {
+        self.assets.read().get(&(plugin.to_owned(), id.to_owned())).cloned()
+    }
+
+    /// Assets of `plugin` whose id starts with `prefix`.
+    pub fn assets_with_prefix(&self, plugin: &str, prefix: &str) -> Vec<(String, Arc<str>)> {
+        self.assets
+            .read()
+            .range((plugin.to_owned(), prefix.to_owned())..)
+            .take_while(|((p, id), _)| p == plugin && id.starts_with(prefix))
+            .map(|((_, id), v)| (id.clone(), v.clone()))
+            .collect()
+    }
+
+    /// Where [`UiPoint`]s keep validated declarations of installed packages.
+    pub fn set_index(&self, index: Option<Arc<ContributionIndex>>) {
+        *self.index.write() = index;
+    }
+
+    /// Bumped on every change: clients compare it to skip re-projection.
+    pub fn revision(&self) -> u64 {
+        self.revision.load(Ordering::Acquire)
+    }
+
+    pub fn snapshot(&self) -> Vec<UiContribution> {
+        self.items.read().iter().map(|i| i.contribution.clone()).collect()
+    }
+
+    /// Items of one point, optionally of one plugin.
+    pub fn items(&self, point: &str, plugin: Option<&str>) -> Vec<UiContribution> {
+        self.items
+            .read()
+            .iter()
+            .filter(|i| i.contribution.point == point && plugin.is_none_or(|p| i.contribution.plugin_id == p))
+            .map(|i| i.contribution.clone())
+            .collect()
+    }
+}
+
+/// What a [`UiPoint`]'s validator produces for one declaration.
+#[derive(Debug, Serialize, Deserialize)]
+pub struct UiDecl {
+    pub key: String,
+    pub label: String,
+    pub json: serde_json::Value,
+    /// Package files referenced (copied on install).
+    pub files: Vec<PathBuf>,
+    /// Large validated payloads fetched separately by the client.
+    pub assets: Vec<(String, String)>,
+}
+
+impl UiDecl {
+    pub fn new(key: impl Into<String>, label: impl Into<String>, json: serde_json::Value) -> Self {
+        Self { key: key.into(), label: label.into(), json, files: Vec::new(), assets: Vec::new() }
+    }
+}
+
+type Validate = dyn Fn(&Package, toml::Value) -> Result<UiDecl, String> + Send + Sync;
+
+/// A `Ui` extension point defined by a validator: committing stores the
+/// validated JSON (and assets) in the [`UiStore`]. Most UI contribution types
+/// (menus, keybindings, status bar items, icon themes) are one of these.
+pub struct UiPoint {
+    id: &'static str,
+    store: Arc<UiStore>,
+    validate: Box<Validate>,
+}
+
+impl UiPoint {
+    pub fn new(
+        id: &'static str,
+        store: Arc<UiStore>,
+        validate: impl Fn(&Package, toml::Value) -> Result<UiDecl, String> + Send + Sync + 'static,
+    ) -> Self {
+        Self { id, store, validate: Box::new(validate) }
+    }
+}
+
+impl ExtensionPoint for UiPoint {
+    fn id(&self) -> &'static str {
+        self.id
+    }
+
+    fn placement(&self) -> Placement {
+        Placement::Ui
+    }
+
+    fn prepare(&self, pkg: &Package, decl: toml::Value) -> Result<Prepared, String> {
+        let index = pkg.digest.as_ref().and_then(|_| self.store.index.read().clone());
+        let ui = match index.as_ref().and_then(|i| i.get(pkg, self.id, &decl)) {
+            Some(ui) => ui,
+            None => match &index {
+                Some(i) => {
+                    let ui = (self.validate)(pkg, decl.clone())?;
+                    i.put(pkg, self.id, &decl, &ui);
+                    ui
+                }
+                None => (self.validate)(pkg, decl)?,
+            },
+        };
+        let UiDecl { key, label, json, files, assets } = ui;
+        let store = self.store.clone();
+        let contribution =
+            UiContribution { plugin_id: pkg.id().to_owned(), point: self.id.to_owned(), key: key.clone(), decl: json };
+        let plugin = pkg.id().to_owned();
+        let mut prepared = Prepared::new(label, move || {
+            let item = store.insert(contribution);
+            if assets.is_empty() {
+                return Ok(item);
+            }
+            let assets = store.insert_assets(&plugin, assets);
+            Ok(Disposable::new(move || {
+                item.dispose();
+                assets.dispose();
+            }))
+        })
+        .key(key);
+        prepared.files = files;
+        Ok(prepared)
+    }
+}
+
+/// TOML declaration → JSON for the client.
+pub fn to_json(v: &toml::Value) -> serde_json::Value {
+    serde_json::to_value(v).unwrap_or(serde_json::Value::Null)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::manifest::Manifest;
+    use crate::registry::ExtensionRegistry;
+
+    #[test]
+    fn ui_point_projects_into_the_store() {
+        let store = UiStore::new();
+        let reg = ExtensionRegistry::new();
+        reg.register(Arc::new(UiPoint::new("badges", store.clone(), |_pkg, decl| {
+            let text = decl.get("text").and_then(|v| v.as_str()).ok_or("missing text")?.to_owned();
+            let mut d = UiDecl::new(text.clone(), text.clone(), serde_json::json!({ "text": text }));
+            d.assets.push((format!("badge/{text}"), "<svg/>".into()));
+            Ok(d)
+        })))
+        .unwrap();
+        let src = "id = \"p\"\nname = \"P\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.0\"\n\
+                   [[contributes.badges]]\ntext = \"hi\"";
+        let pkg = Package::new(Manifest::parse(src).unwrap(), PathBuf::from("/x"));
+        let rev = store.revision();
+        reg.commit(reg.prepare(&pkg).unwrap()).unwrap();
+        assert!(store.revision() > rev);
+        let items = store.items("badges", Some("p"));
+        assert_eq!(items.len(), 1);
+        assert_eq!(items[0].decl["text"], "hi");
+        assert_eq!(store.asset("p", "badge/hi").as_deref(), Some("<svg/>"));
+        assert_eq!(store.assets_with_prefix("p", "badge/").len(), 1);
+        reg.dispose_plugin("p");
+        assert!(store.snapshot().is_empty());
+        assert!(store.asset("p", "badge/hi").is_none());
+    }
+}

crates/ide-extension/src/when.rs

@@ -0,0 +1,136 @@
+//! Syntax check for `when` clauses in UI declarations. The client evaluates
+//! them (`src/platform/context.ts`); validating here keeps the client's
+//! projection from failing. Grammar (same as the client):
+//!
+//! ```text
+//! expr := or ; or := and ("||" and)* ; and := unary ("&&" unary)*
+//! unary := "!" unary | "(" expr ")" | cmp ; cmp := key (("==" | "!=") value)?
+//! ```
+
+const MAX_LEN: usize = 512;
+
+#[derive(Debug, PartialEq)]
+enum Tok<'a> {
+    Id(&'a str),
+    Str,
+    Op(&'a str),
+}
+
+fn tokenize(src: &str) -> Result<Vec<Tok<'_>>, String> {
+    let mut out = Vec::new();
+    let b = src.as_bytes();
+    let mut i = 0;
+    while i < b.len() {
+        let c = b[i] as char;
+        if c.is_whitespace() {
+            i += 1;
+        } else if ["&&", "||", "==", "!="].iter().any(|op| src[i..].starts_with(op)) {
+            out.push(Tok::Op(&src[i..i + 2]));
+            i += 2;
+        } else if matches!(c, '!' | '(' | ')') {
+            out.push(Tok::Op(&src[i..i + 1]));
+            i += 1;
+        } else if c == '\'' || c == '"' {
+            let end = src[i + 1..].find(c).ok_or_else(|| format!("unterminated string in when clause: {src}"))?;
+            out.push(Tok::Str);
+            i += end + 2;
+        } else {
+            let len = src[i..]
+                .find(|ch: char| !(ch.is_alphanumeric() || matches!(ch, '_' | '.' | '-' | ':' | '/')))
+                .unwrap_or(src.len() - i);
+            if len == 0 {
+                return Err(format!("unexpected '{c}' in when clause: {src}"));
+            }
+            out.push(Tok::Id(&src[i..i + len]));
+            i += len;
+        }
+    }
+    Ok(out)
+}
+
+/// Checks a `when` clause; empty means "always".
+pub fn validate_when(src: &str) -> Result<(), String> {
+    if src.len() > MAX_LEN {
+        return Err(format!("when clause longer than {MAX_LEN} bytes"));
+    }
+    if src.trim().is_empty() {
+        return Ok(());
+    }
+    let toks = tokenize(src)?;
+    let mut p = 0;
+    parse_or(&toks, &mut p, src)?;
+    if p != toks.len() {
+        return Err(format!("unexpected token in when clause: {src}"));
+    }
+    Ok(())
+}
+
+fn parse_or(t: &[Tok], p: &mut usize, src: &str) -> Result<(), String> {
+    parse_and(t, p, src)?;
+    while t.get(*p) == Some(&Tok::Op("||")) {
+        *p += 1;
+        parse_and(t, p, src)?;
+    }
+    Ok(())
+}
+
+fn parse_and(t: &[Tok], p: &mut usize, src: &str) -> Result<(), String> {
+    parse_unary(t, p, src)?;
+    while t.get(*p) == Some(&Tok::Op("&&")) {
+        *p += 1;
+        parse_unary(t, p, src)?;
+    }
+    Ok(())
+}
+
+fn parse_unary(t: &[Tok], p: &mut usize, src: &str) -> Result<(), String> {
+    match t.get(*p) {
+        Some(Tok::Op("!")) => {
+            *p += 1;
+            parse_unary(t, p, src)
+        }
+        Some(Tok::Op("(")) => {
+            *p += 1;
+            parse_or(t, p, src)?;
+            if t.get(*p) != Some(&Tok::Op(")")) {
+                return Err(format!("missing ')' in when clause: {src}"));
+            }
+            *p += 1;
+            Ok(())
+        }
+        Some(Tok::Id(_)) => {
+            *p += 1;
+            if matches!(t.get(*p), Some(Tok::Op("==" | "!="))) {
+                *p += 1;
+                match t.get(*p) {
+                    Some(Tok::Id(_) | Tok::Str) => *p += 1,
+                    _ => return Err(format!("missing value after comparison in when clause: {src}")),
+                }
+            }
+            Ok(())
+        }
+        _ => Err(format!("expected a context key in when clause: {src}")),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::validate_when;
+
+    #[test]
+    fn accepts_the_client_grammar() {
+        for ok in [
+            "",
+            "editorFocus",
+            "editorLang == rust",
+            "editorLang != 'rust' && !readOnly",
+            "(a || b) && toolWindow.project.active",
+            "resourceScheme == file:/x",
+        ] {
+            assert!(validate_when(ok).is_ok(), "{ok}");
+        }
+        for bad in ["a &&", "(a", "a == ", "== a", "a b", "a $ b", "'x", "!()"] {
+            assert!(validate_when(bad).is_err(), "{bad}");
+        }
+    }
+}

crates/ide-fonts/Cargo.toml

@@ -7,10 +7,11 @@ license.workspace = true
 
 [dependencies]
 serde.workspace = true
+serde_json.workspace = true
 specta.workspace = true
 
 [target.'cfg(target_os = "macos")'.dependencies]
-objc2-core-foundation = { version = "0.3", default-features = false, features = ["std", "CFArray", "CFDictionary", "CFNumber", "CFString"] }
+objc2-core-foundation = { version = "0.3", default-features = false, features = ["std", "CFArray", "CFDictionary", "CFNumber", "CFString", "CFURL"] }
 objc2-core-text = { version = "0.3", default-features = false, features = ["std", "CTFontCollection", "CTFontDescriptor", "CTFontTraits"] }
 
 [target.'cfg(windows)'.dependencies]

crates/ide-fonts/src/lib.rs

@@ -1,8 +1,7 @@
 //! The font families installed on this machine, for the font pickers in
 //! Settings (editor, typography fallback, terminal, UI font).
 //!
-//! Each platform asks the font system the WebView itself resolves CSS
-//! `font-family` names against, so every listed name renders: CoreText on
+//! Each platform asks the native font system for installed families: CoreText on
 //! macOS, DirectWrite on Windows, fontconfig (`fc-list`) on Linux and the BSDs.
 //! The list is read on first use and cached until explicitly refreshed; the
 //! query can take a few hundred milliseconds, so callers run it off the UI and
@@ -84,14 +83,164 @@ pub fn parse_fc_list(output: &str) -> Vec<(String, bool)> {
         .collect()
 }
 
+/// Binary font bundle: little-endian u32 JSON-header length, a face metadata
+/// array, then raw font bytes. Paths never cross IPC; only CoreText-enumerated
+/// files under user font directories can be read, selected by family name.
+/// Includes only the nearest regular/bold faces and their optional italics.
+pub fn user_font_data(family: &str) -> std::io::Result<Vec<u8>> {
+    #[cfg(target_os = "macos")]
+    {
+        let entries = imp::user_faces();
+        bundle_family(family, &entries)
+    }
+    #[cfg(not(target_os = "macos"))]
+    {
+        let _ = family;
+        Err(std::io::Error::new(std::io::ErrorKind::Unsupported, "User font loading is macOS only"))
+    }
+}
+
+#[cfg(any(target_os = "macos", test))]
+#[derive(Debug)]
+struct UserFace {
+    family: String,
+    path: std::path::PathBuf,
+    weight: u16,
+    italic: bool,
+}
+
+#[cfg(any(target_os = "macos", test))]
+fn user_font_path(path: &std::path::Path, roots: &[std::path::PathBuf]) -> Option<std::path::PathBuf> {
+    let path = path.canonicalize().ok()?;
+    roots.iter().any(|root| path.starts_with(root)).then_some(path)
+}
+
+#[cfg(any(target_os = "macos", test))]
+fn family_faces<'a>(family: &str, entries: &'a [UserFace]) -> Vec<&'a UserFace> {
+    let mut selected: Vec<&UserFace> = Vec::new();
+    for italic in [false, true] {
+        for weight in [400u16, 700] {
+            let closest = entries
+                .iter()
+                .filter(|e| e.family.eq_ignore_ascii_case(family.trim()) && e.italic == italic)
+                .min_by_key(|e| (e.weight.abs_diff(weight), e.weight, &e.path));
+            if let Some(face) = closest
+                && !selected.iter().any(|f| std::ptr::eq(*f, face))
+            {
+                selected.push(face);
+            }
+        }
+    }
+    selected
+}
+
+#[cfg(any(target_os = "macos", test))]
+fn bundle_family(family: &str, entries: &[UserFace]) -> std::io::Result<Vec<u8>> {
+    #[derive(Serialize)]
+    struct Face {
+        weight: u16,
+        style: &'static str,
+        offset: usize,
+        length: usize,
+    }
+    let mut faces = Vec::new();
+    let mut data = Vec::new();
+    let mut files = BTreeMap::new();
+    // Bound large CJK families to regular/bold and their nearest italic faces.
+    for entry in family_faces(family, entries) {
+        // Reject a file replaced by a symlink after enumeration.
+        if entry.path.canonicalize()? != entry.path {
+            return Err(std::io::Error::new(std::io::ErrorKind::PermissionDenied, "Font file changed"));
+        }
+        let (offset, length) = if let Some(range) = files.get(&entry.path) {
+            *range
+        } else {
+            let bytes = std::fs::read(&entry.path)?;
+            let range = (data.len(), bytes.len());
+            data.extend(bytes);
+            files.insert(entry.path.clone(), range);
+            range
+        };
+        faces.push(Face {
+            weight: entry.weight,
+            style: if entry.italic { "italic" } else { "normal" },
+            offset,
+            length,
+        });
+    }
+    if faces.is_empty() {
+        return Err(std::io::Error::new(std::io::ErrorKind::NotFound, "No installed user font family"));
+    }
+    let header = serde_json::to_vec(&faces)?;
+    let mut out = (header.len() as u32).to_le_bytes().to_vec();
+    out.extend(header);
+    out.extend(data);
+    Ok(out)
+}
+
 #[cfg(target_os = "macos")]
 mod imp {
-    use objc2_core_foundation::{CFArray, CFDictionary, CFNumber, CFString, CFType};
+    use objc2_core_foundation::{CFArray, CFDictionary, CFNumber, CFString, CFType, CFURL};
     use objc2_core_text::{
         CTFontCollection, CTFontDescriptor, CTFontSymbolicTraits, kCTFontFamilyNameAttribute, kCTFontSymbolicTrait,
-        kCTFontTraitsAttribute,
+        kCTFontTraitsAttribute, kCTFontURLAttribute, kCTFontWeightTrait,
     };
 
+    pub(crate) fn user_faces() -> Vec<super::UserFace> {
+        let mut roots = vec![std::path::PathBuf::from("/Library/Fonts")];
+        if let Some(home) = std::env::var_os("HOME") {
+            roots.push(std::path::PathBuf::from(home).join("Library/Fonts"));
+        }
+        let roots: Vec<_> = roots.into_iter().filter_map(|r| r.canonicalize().ok()).collect();
+        // SAFETY: CoreText descriptors carry documented CFString, CFURL and trait dictionary values.
+        unsafe {
+            let collection = CTFontCollection::from_available_fonts(None);
+            let Some(descriptors) = collection.matching_font_descriptors() else { return Vec::new() };
+            let mut seen = std::collections::BTreeSet::new();
+            descriptors
+                .cast_unchecked::<CTFontDescriptor>()
+                .iter()
+                .filter_map(|d| {
+                    let family = d.attribute(kCTFontFamilyNameAttribute)?.downcast::<CFString>().ok()?.to_string();
+                    let path = d.attribute(kCTFontURLAttribute)?.downcast::<CFURL>().ok()?.to_file_path()?;
+                    let path = super::user_font_path(&path, &roots)?;
+                    let traits = d.attribute(kCTFontTraitsAttribute)?.downcast::<CFDictionary>().ok()?;
+                    let traits = traits.cast_unchecked::<CFString, CFType>();
+                    let symbolic = traits
+                        .get(kCTFontSymbolicTrait)
+                        .and_then(|n| n.downcast::<CFNumber>().ok())
+                        .and_then(|n| n.as_i64())
+                        .unwrap_or(0) as u32;
+                    let weight = traits
+                        .get(kCTFontWeightTrait)
+                        .and_then(|n| n.downcast::<CFNumber>().ok())
+                        .and_then(|n| n.as_f64())
+                        .unwrap_or(0.0);
+                    // CoreText's normalized weight values corresponding to CSS's nine standard weights.
+                    let weight = [
+                        (-0.8, 100),
+                        (-0.6, 200),
+                        (-0.4, 300),
+                        (0.0, 400),
+                        (0.23, 500),
+                        (0.3, 600),
+                        (0.4, 700),
+                        (0.56, 800),
+                        (0.62, 900),
+                    ]
+                    .into_iter()
+                    .min_by(|(a, _), (b, _)| (weight - a).abs().total_cmp(&(weight - b).abs()))?
+                    .1;
+                    let italic = symbolic & CTFontSymbolicTraits::TraitItalic.0 != 0;
+                    if !seen.insert((family.clone(), path.clone(), weight, italic)) {
+                        return None;
+                    }
+                    Some(super::UserFace { family, path, weight, italic })
+                })
+                .collect()
+        }
+    }
+
     /// Every face CoreText makes available to this process, as (family, fixed pitch).
     pub(crate) fn list(_refresh: bool) -> Vec<(String, bool)> {
         // SAFETY: CoreText's documented types: the matching descriptors array
@@ -210,6 +359,92 @@ mod tests {
     use super::*;
     use std::sync::atomic::{AtomicUsize, Ordering};
 
+    #[test]
+    fn selects_only_regular_bold_and_matching_italics_from_dense_families() {
+        let entries: Vec<_> = [false, true]
+            .into_iter()
+            .flat_map(|italic| {
+                (100..=900).step_by(100).map(move |weight| UserFace {
+                    family: "CJK".into(),
+                    path: format!("{weight}-{italic}.ttf").into(),
+                    weight,
+                    italic,
+                })
+            })
+            .collect();
+        let selected = family_faces(" cjk ", &entries);
+        assert_eq!(
+            selected.iter().map(|f| (f.weight, f.italic)).collect::<Vec<_>>(),
+            [(400, false), (700, false), (400, true), (700, true),]
+        );
+        assert!(family_faces("unknown", &entries).is_empty());
+    }
+
+    #[test]
+    fn selects_nearest_available_weights_once_with_optional_italics() {
+        let entries: Vec<_> = [(300, false), (500, false), (800, false), (500, true)]
+            .into_iter()
+            .map(|(weight, italic)| UserFace {
+                family: "Sparse".into(),
+                path: format!("{weight}-{italic}.ttf").into(),
+                weight,
+                italic,
+            })
+            .collect();
+        let selected = family_faces("Sparse", &entries);
+        assert_eq!(
+            selected.iter().map(|f| (f.weight, f.italic)).collect::<Vec<_>>(),
+            [(300, false), (800, false), (500, true),]
+        );
+        assert_eq!(family_faces("Sparse", &entries[..1]).len(), 1);
+    }
+
+    #[test]
+    fn bundle_only_reads_enumerated_family_faces() {
+        let root = std::env::current_dir().unwrap().join(format!("../../.font-bundle-test-{}", std::process::id()));
+        std::fs::create_dir_all(&root).unwrap();
+        let root = root.canonicalize().unwrap();
+        let regular = root.join("regular.ttf");
+        let bold = root.join("bold.ttf");
+        std::fs::write(&regular, [1, 2, 3]).unwrap();
+        std::fs::write(&bold, [4, 5]).unwrap();
+        let entries = [
+            UserFace { family: "Test Nerd Font".into(), path: regular.clone(), weight: 400, italic: false },
+            UserFace { family: "Test Nerd Font".into(), path: bold, weight: 700, italic: false },
+            // A non-selected face is never opened, even if its file has disappeared.
+            UserFace { family: "Test Nerd Font".into(), path: root.join("thin.ttf"), weight: 100, italic: false },
+        ];
+        let result = bundle_family("test nerd font", &entries).unwrap();
+        let len = u32::from_le_bytes(result[..4].try_into().unwrap()) as usize;
+        let faces: serde_json::Value = serde_json::from_slice(&result[4..4 + len]).unwrap();
+        assert_eq!(faces[0]["weight"], 400);
+        assert_eq!(faces[1]["weight"], 700);
+        assert_eq!(faces.as_array().unwrap().len(), 2);
+        assert_eq!(&result[4 + len..], &[1, 2, 3, 4, 5]);
+        // Existing files are not inputs: neither paths nor unenumerated families grant access.
+        assert!(bundle_family(regular.to_str().unwrap(), &entries).is_err());
+        assert!(bundle_family("Unenumerated", &entries).is_err());
+        assert!(user_font_path(&regular, &[]).is_none());
+        assert!(user_font_path(&regular, std::slice::from_ref(&root)).is_some());
+        // Multiple selected descriptors in a collection still transfer the file only once.
+        let shared = [
+            UserFace { family: "Collection".into(), path: regular.clone(), weight: 400, italic: false },
+            UserFace { family: "Collection".into(), path: regular, weight: 700, italic: false },
+        ];
+        let result = bundle_family("Collection", &shared).unwrap();
+        let len = u32::from_le_bytes(result[..4].try_into().unwrap()) as usize;
+        let faces: serde_json::Value = serde_json::from_slice(&result[4..4 + len]).unwrap();
+        assert_eq!(faces[0]["offset"], faces[1]["offset"]);
+        assert_eq!(&result[4 + len..], &[1, 2, 3]);
+        #[cfg(unix)]
+        {
+            let link = root.join("outside.ttf");
+            std::os::unix::fs::symlink(std::env::current_exe().unwrap(), &link).unwrap();
+            assert!(user_font_path(&link, std::slice::from_ref(&root)).is_none());
+        }
+        std::fs::remove_dir_all(root).unwrap();
+    }
+
     fn fam(name: &str, monospaced: bool) -> FontFamily {
         FontFamily { name: name.into(), monospaced }
     }

crates/ide-github/Cargo.toml

@@ -13,6 +13,3 @@ serde_json.workspace = true
 specta.workspace = true
 tracing.workspace = true
 which = "8"
-
-[target.'cfg(unix)'.dependencies]
-libc = "0.2"

crates/ide-github/src/lib.rs

@@ -107,7 +107,7 @@ pub fn availability(root: &Path) -> GhAvailability {
     }
     let (repo, login) = std::thread::scope(|s| {
         let repo = s.spawn(|| {
-            let cmd = command(root, &["repo", "view", "--json", "nameWithOwner,url,defaultBranchRef"])?;
+            let cmd = command(root, &["repo", "view", "--json", REPO_FIELDS])?;
             process::run(cmd, QUICK, None)
         });
         let login = s.spawn(|| run(root, &["api", "user", "--jq", ".login"]));
@@ -278,6 +278,53 @@ pub fn add_comment(root: &Path, number: u32, body: &str) -> IdeResult<()> {
     run(root, &["pr", "comment", &n, "--body", body]).map(drop)
 }
 
+/// A GitHub API call through `gh api`: GraphQL (`endpoint` `graphql`, `body`
+/// `{"query", "variables"}`) or REST (`repos/{owner}/{repo}/…`, gh fills in the
+/// placeholders from the project's remote).
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct GhApiRequest {
+    /// `GET`, `POST`, `PATCH`, `PUT`, `DELETE`.
+    pub method: String,
+    pub endpoint: String,
+    /// JSON request body, sent on stdin.
+    pub body: Option<String>,
+    /// Follow REST `Link` pages; the result is the array of all pages (`--slurp`).
+    pub paginate: bool,
+}
+
+const METHODS: &[&str] = &["GET", "POST", "PATCH", "PUT", "DELETE"];
+
+/// `gh api` arguments for `req`.
+pub fn api_args(req: &GhApiRequest) -> IdeResult<Vec<String>> {
+    let method = req.method.to_ascii_uppercase();
+    if !METHODS.contains(&method.as_str()) {
+        return Err(IdeError::invalid(format!("unsupported HTTP method {}", req.method)));
+    }
+    let endpoint = req.endpoint.trim();
+    if endpoint.is_empty() || endpoint.starts_with('-') || endpoint.contains("://") {
+        return Err(IdeError::invalid(format!("not a GitHub API endpoint: {endpoint}")));
+    }
+    let mut args: Vec<String> = vec!["api".into(), "--method".into(), method, endpoint.into()];
+    if req.body.is_some() {
+        args.push("--input".into());
+        args.push("-".into());
+    }
+    if req.paginate {
+        args.push("--paginate".into());
+        args.push("--slurp".into());
+    }
+    Ok(args)
+}
+
+/// Runs `req`; returns the response body (JSON text, empty for `204 No Content`).
+pub fn api(root: &Path, req: &GhApiRequest) -> IdeResult<String> {
+    let args = api_args(req)?;
+    let refs: Vec<&str> = args.iter().map(String::as_str).collect();
+    let out = process::run_with_input(command(root, &refs)?, req.body.as_deref(), QUICK, None)?;
+    if out.success { Ok(out.stdout) } else { Err(failure(&out.stderr, &out.stdout)) }
+}
+
 /// Revisions to diff a pull request's files with, present in the local repository.
 #[derive(Clone, Debug, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]

crates/ide-github/src/model.rs

@@ -34,6 +34,12 @@ pub struct GhRepo {
     pub name_with_owner: String,
     pub url: String,
     pub default_branch: Option<String>,
+    /// Merge methods the repository allows (all of them when gh does not say).
+    pub merge_commit_allowed: bool,
+    pub squash_merge_allowed: bool,
+    pub rebase_merge_allowed: bool,
+    /// The signed-in user's permission: `ADMIN`, `MAINTAIN`, `WRITE`, `TRIAGE`, `READ`; empty when unknown.
+    pub viewer_permission: String,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
@@ -152,6 +158,8 @@ pub struct PullRequestDetails {
     pub base_oid: String,
     /// `MERGEABLE`, `CONFLICTING`, `UNKNOWN`.
     pub mergeable: String,
+    /// GitHub's merge box state: `CLEAN`, `UNSTABLE`, `HAS_HOOKS`, `BLOCKED`, `BEHIND`, `DIRTY`, `DRAFT`, `UNKNOWN`.
+    pub merge_state_status: String,
     pub is_cross_repository: bool,
     pub merged_at: Option<String>,
     pub closed_at: Option<String>,
@@ -242,7 +250,7 @@ impl RawSummary {
 pub const LIST_FIELDS: &str = "number,title,author,state,isDraft,headRefName,baseRefName,createdAt,updatedAt,labels,reviewDecision,url,additions,deletions";
 
 /// Fields requested from `gh pr view`.
-pub const VIEW_FIELDS: &str = "number,title,author,state,isDraft,headRefName,baseRefName,createdAt,updatedAt,labels,reviewDecision,url,additions,deletions,body,headRefOid,baseRefOid,mergeable,isCrossRepository,mergedAt,closedAt,statusCheckRollup,reviewRequests,reviews,assignees,commits,files,comments";
+pub const VIEW_FIELDS: &str = "number,title,author,state,isDraft,headRefName,baseRefName,createdAt,updatedAt,labels,reviewDecision,url,additions,deletions,body,headRefOid,baseRefOid,mergeable,mergeStateStatus,isCrossRepository,mergedAt,closedAt,statusCheckRollup,reviewRequests,reviews,assignees,commits,files,comments";
 
 pub fn parse_list(json: &str) -> serde_json::Result<Vec<PullRequestSummary>> {
     let raw: Vec<RawSummary> = serde_json::from_str(json)?;
@@ -348,6 +356,7 @@ struct RawDetails {
     head_ref_oid: String,
     base_ref_oid: String,
     mergeable: String,
+    merge_state_status: String,
     is_cross_repository: bool,
     merged_at: Option<String>,
     closed_at: Option<String>,
@@ -442,6 +451,7 @@ pub fn parse_view(json: &str) -> serde_json::Result<PullRequestDetails> {
         head_oid: raw.head_ref_oid,
         base_oid: raw.base_ref_oid,
         mergeable: raw.mergeable,
+        merge_state_status: raw.merge_state_status,
         is_cross_repository: raw.is_cross_repository,
         merged_at: raw.merged_at.filter(|s| !s.is_empty()),
         closed_at: raw.closed_at.filter(|s| !s.is_empty()),
@@ -534,6 +544,10 @@ struct RawRepo {
     name_with_owner: String,
     url: String,
     default_branch_ref: Option<RawBranchRef>,
+    merge_commit_allowed: Option<bool>,
+    squash_merge_allowed: Option<bool>,
+    rebase_merge_allowed: Option<bool>,
+    viewer_permission: Option<String>,
 }
 
 #[derive(Deserialize, Default)]
@@ -542,13 +556,21 @@ struct RawBranchRef {
     name: String,
 }
 
-/// `gh repo view --json nameWithOwner,url,defaultBranchRef`.
+/// Fields requested from `gh repo view`.
+pub const REPO_FIELDS: &str =
+    "nameWithOwner,url,defaultBranchRef,mergeCommitAllowed,squashMergeAllowed,rebaseMergeAllowed,viewerPermission";
+
+/// `gh repo view --json` with [`REPO_FIELDS`].
 pub fn parse_repo(json: &str) -> serde_json::Result<GhRepo> {
     let raw: RawRepo = serde_json::from_str(json)?;
     Ok(GhRepo {
         name_with_owner: raw.name_with_owner,
         url: raw.url,
         default_branch: raw.default_branch_ref.map(|b| b.name).filter(|n| !n.is_empty()),
+        merge_commit_allowed: raw.merge_commit_allowed.unwrap_or(true),
+        squash_merge_allowed: raw.squash_merge_allowed.unwrap_or(true),
+        rebase_merge_allowed: raw.rebase_merge_allowed.unwrap_or(true),
+        viewer_permission: raw.viewer_permission.unwrap_or_default(),
     })
 }
 

crates/ide-github/src/process.rs

@@ -1,11 +1,16 @@
 //! Child processes of the gh CLI: bounded runs and cancellable line streams.
 
+use ide_core::process::terminate_tree;
 use ide_core::{CancellationToken, IdeError, IdeResult};
 use std::io::Read;
 use std::process::{Child, Command, Stdio};
 use std::sync::mpsc;
 use std::time::{Duration, Instant};
 
+/// How long a cancelled or timed-out child's process group (gh spawns git and helpers)
+/// gets to exit on `SIGTERM` before `SIGKILL`: git removes its lock files on `SIGTERM`.
+const KILL_GRACE: Duration = Duration::from_millis(20);
+
 pub(crate) struct Output {
     pub stdout: String,
     pub stderr: String,
@@ -20,36 +25,13 @@ pub(crate) enum Stream {
 
 fn prepare(cmd: &mut Command) {
     cmd.stdin(Stdio::null()).stdout(Stdio::piped()).stderr(Stdio::piped());
-    #[cfg(unix)]
-    {
-        use std::os::unix::process::CommandExt;
-        cmd.process_group(0);
-    }
-    ide_core::process::prepare(cmd);
+    ide_core::process::prepare(ide_core::process::own_group(cmd));
 }
 
 fn spawn(cmd: &mut Command) -> IdeResult<Child> {
     cmd.spawn().map_err(|e| IdeError::unavailable(format!("could not run gh: {e}")))
 }
 
-/// Kills the child and, on Unix, its whole process group (gh spawns git and helpers).
-pub(crate) fn kill(child: &mut Child) {
-    #[cfg(unix)]
-    {
-        let pid = child.id() as libc::pid_t;
-        // SAFETY: plain syscall; the child leads its own process group (`prepare`).
-        unsafe {
-            libc::kill(-pid, libc::SIGTERM);
-        }
-        std::thread::sleep(Duration::from_millis(20));
-        unsafe {
-            libc::kill(-pid, libc::SIGKILL);
-        }
-    }
-    let _ = child.kill();
-    let _ = child.wait();
-}
-
 fn read_all(mut pipe: impl Read + Send + 'static) -> std::thread::JoinHandle<String> {
     std::thread::spawn(move || {
         let mut buf = Vec::new();
@@ -60,9 +42,30 @@ fn read_all(mut pipe: impl Read + Send + 'static) -> std::thread::JoinHandle<Str
 
 /// Runs `cmd` to completion. Fails when it outlives `timeout` or `cancel` fires;
 /// a non-zero exit is reported in [`Output::success`], not as an error.
-pub(crate) fn run(mut cmd: Command, timeout: Duration, cancel: Option<&CancellationToken>) -> IdeResult<Output> {
+pub(crate) fn run(cmd: Command, timeout: Duration, cancel: Option<&CancellationToken>) -> IdeResult<Output> {
+    run_with_input(cmd, None, timeout, cancel)
+}
+
+/// [`run`] with `input` written to the child's stdin (then closed).
+pub(crate) fn run_with_input(
+    mut cmd: Command,
+    input: Option<&str>,
+    timeout: Duration,
+    cancel: Option<&CancellationToken>,
+) -> IdeResult<Output> {
     prepare(&mut cmd);
+    if input.is_some() {
+        cmd.stdin(Stdio::piped());
+    }
     let mut child = spawn(&mut cmd)?;
+    if let (Some(input), Some(mut stdin)) = (input, child.stdin.take()) {
+        let input = input.to_owned();
+        // A writer thread: a large body must not block on a full pipe while gh is not reading yet.
+        std::thread::spawn(move || {
+            use std::io::Write;
+            let _ = stdin.write_all(input.as_bytes());
+        });
+    }
     let out = child.stdout.take().map(read_all);
     let err = child.stderr.take().map(read_all);
     let deadline = Instant::now() + timeout;
@@ -71,11 +74,11 @@ pub(crate) fn run(mut cmd: Command, timeout: Duration, cancel: Option<&Cancellat
             break status;
         }
         if cancel.is_some_and(CancellationToken::is_cancelled) {
-            kill(&mut child);
+            terminate_tree(&mut child, KILL_GRACE);
             return Err(IdeError::cancelled());
         }
         if Instant::now() >= deadline {
-            kill(&mut child);
+            terminate_tree(&mut child, KILL_GRACE);
             return Err(IdeError::unavailable("gh did not respond in time"));
         }
         std::thread::sleep(Duration::from_millis(10));
@@ -149,7 +152,7 @@ pub(crate) fn stream(
     let mut stderr_tail: Vec<String> = Vec::new();
     while open > 0 {
         if cancel.is_cancelled() {
-            kill(&mut child);
+            terminate_tree(&mut child, KILL_GRACE);
             return Err(IdeError::cancelled());
         }
         match rx.recv_timeout(Duration::from_millis(50)) {
@@ -172,7 +175,7 @@ pub(crate) fn stream(
             break status;
         }
         if cancel.is_cancelled() {
-            kill(&mut child);
+            terminate_tree(&mut child, KILL_GRACE);
             return Err(IdeError::cancelled());
         }
         std::thread::sleep(Duration::from_millis(10));

crates/ide-github/tests/fixtures/pr_view.json

@@ -1 +1 @@
-{"additions":42,"assignees":[],"author":{"id":"MDQ6VXNlcjM2NzI4OTMx","is_bot":false,"login":"babakks","name":"Babak K. Shandiz"},"baseRefName":"trunk","baseRefOid":"ae7b9715976c5508398b11dc8546e1279e10f6fc","body":"### Description\n\nThis PR moves gh to the tagged version of `cli/oauth`.","closedAt":"2026-10-21T12:29:58Z","comments":[{"id":"IC_1","author":{"login":"babakks"},"authorAssociation":"MEMBER","body":"Rebased on trunk.","createdAt":"2026-10-21T08:00:00Z","includesCreatedEdit":false,"isMinimized":false,"minimizedReason":"","reactionGroups":[],"url":"https://github.com/cli/cli/pull/14768#issuecomment-1","viewerDidAuthor":false}],"commits":[{"authoredDate":"2026-10-20T16:37:24Z","authors":[{"email":"[email protected]","id":"MDQ6VXNlcjM2NzI4OTMx","login":"babakks","name":"Babak K. Shandiz"}],"committedDate":"2026-10-21T12:06:51Z","messageBody":"cli/oauth v1.3.0 exposes the token expiry fields as time.Duration values.","messageHeadline":"chore(deps): bump github.com/cli/oauth to v1.3.0","oid":"fd1b1feb222dde885d00262b2c21b107c6c6e416"}],"createdAt":"2026-10-20T16:40:41Z","deletions":48,"files":[{"path":"go.mod","additions":1,"deletions":1,"changeType":"MODIFIED"},{"path":"pkg/cmd/status/status.go","additions":3,"deletions":2,"changeType":"MODIFIED"}],"headRefName":"babakks/refresh-token-bump-deps","headRefOid":"6ec1ba54542baca6cc5932582634104c83f36a28","isCrossRepository":false,"isDraft":false,"labels":[],"mergeable":"UNKNOWN","mergedAt":"2026-10-21T12:29:58Z","number":14768,"reviewDecision":"APPROVED","reviewRequests":[{"__typename":"User","login":"niik"}],"reviews":[{"id":"PRR_1","author":{"login":"copilot-pull-request-reviewer"},"authorAssociation":"CONTRIBUTOR","body":"","submittedAt":"2026-10-21T09:46:01Z","includesCreatedEdit":false,"reactionGroups":[],"state":"COMMENTED","commit":{"oid":"831b9343fa77c2f11f521a49fd01da2d2d007b8e"}},{"id":"PRR_2","author":{"login":"williammartin"},"authorAssociation":"MEMBER","body":"LGTM","submittedAt":"2026-10-21T12:20:00Z","includesCreatedEdit":false,"reactionGroups":[],"state":"APPROVED","commit":{"oid":"6ec1ba54542baca6cc5932582634104c83f36a28"}}],"state":"MERGED","statusCheckRollup":[{"__typename":"CheckRun","completedAt":"2026-10-21T12:09:03Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/cli/cli/actions/runs/1/job/1","name":"build (ubuntu)","startedAt":"2026-10-21T12:07:01Z","status":"COMPLETED","workflowName":"Tests"},{"__typename":"CheckRun","completedAt":"0001-01-01T00:00:00Z","conclusion":"","detailsUrl":"https://github.com/cli/cli/actions/runs/1/job/2","name":"build (windows)","startedAt":"2026-10-21T12:07:01Z","status":"IN_PROGRESS","workflowName":"Tests"},{"__typename":"CheckRun","completedAt":"2026-10-21T12:08:00Z","conclusion":"FAILURE","detailsUrl":"https://github.com/cli/cli/actions/runs/1/job/3","name":"lint","startedAt":"2026-10-21T12:07:01Z","status":"COMPLETED","workflowName":"Lint"},{"__typename":"CheckRun","completedAt":"2026-10-21T12:08:00Z","conclusion":"SKIPPED","detailsUrl":"","name":"docs","startedAt":"2026-10-21T12:07:01Z","status":"COMPLETED","workflowName":""},{"__typename":"StatusContext","context":"ci/legacy","state":"PENDING","targetUrl":"https://ci.example.com/1","startedAt":"2026-10-21T12:07:01Z"}],"title":"Refreshable tokens: bump cli/oauth to v1.3.0 and fix `gh status` column width","updatedAt":"2026-10-21T12:30:00Z","url":"https://github.com/cli/cli/pull/14768"}
+{"additions":42,"assignees":[],"author":{"id":"MDQ6VXNlcjM2NzI4OTMx","is_bot":false,"login":"babakks","name":"Babak K. Shandiz"},"baseRefName":"trunk","baseRefOid":"ae7b9715976c5508398b11dc8546e1279e10f6fc","body":"### Description\n\nThis PR moves gh to the tagged version of `cli/oauth`.","closedAt":"2026-10-21T12:29:58Z","comments":[{"id":"IC_1","author":{"login":"babakks"},"authorAssociation":"MEMBER","body":"Rebased on trunk.","createdAt":"2026-10-21T08:00:00Z","includesCreatedEdit":false,"isMinimized":false,"minimizedReason":"","reactionGroups":[],"url":"https://github.com/cli/cli/pull/14768#issuecomment-1","viewerDidAuthor":false}],"commits":[{"authoredDate":"2026-10-20T16:37:24Z","authors":[{"email":"[email protected]","id":"MDQ6VXNlcjM2NzI4OTMx","login":"babakks","name":"Babak K. Shandiz"}],"committedDate":"2026-10-21T12:06:51Z","messageBody":"cli/oauth v1.3.0 exposes the token expiry fields as time.Duration values.","messageHeadline":"chore(deps): bump github.com/cli/oauth to v1.3.0","oid":"fd1b1feb222dde885d00262b2c21b107c6c6e416"}],"createdAt":"2026-10-20T16:40:41Z","deletions":48,"files":[{"path":"go.mod","additions":1,"deletions":1,"changeType":"MODIFIED"},{"path":"pkg/cmd/status/status.go","additions":3,"deletions":2,"changeType":"MODIFIED"}],"headRefName":"babakks/refresh-token-bump-deps","headRefOid":"6ec1ba54542baca6cc5932582634104c83f36a28","isCrossRepository":false,"isDraft":false,"labels":[],"mergeable":"UNKNOWN","mergeStateStatus":"UNKNOWN","mergedAt":"2026-10-21T12:29:58Z","number":14768,"reviewDecision":"APPROVED","reviewRequests":[{"__typename":"User","login":"niik"}],"reviews":[{"id":"PRR_1","author":{"login":"copilot-pull-request-reviewer"},"authorAssociation":"CONTRIBUTOR","body":"","submittedAt":"2026-10-21T09:46:01Z","includesCreatedEdit":false,"reactionGroups":[],"state":"COMMENTED","commit":{"oid":"831b9343fa77c2f11f521a49fd01da2d2d007b8e"}},{"id":"PRR_2","author":{"login":"williammartin"},"authorAssociation":"MEMBER","body":"LGTM","submittedAt":"2026-10-21T12:20:00Z","includesCreatedEdit":false,"reactionGroups":[],"state":"APPROVED","commit":{"oid":"6ec1ba54542baca6cc5932582634104c83f36a28"}}],"state":"MERGED","statusCheckRollup":[{"__typename":"CheckRun","completedAt":"2026-10-21T12:09:03Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/cli/cli/actions/runs/1/job/1","name":"build (ubuntu)","startedAt":"2026-10-21T12:07:01Z","status":"COMPLETED","workflowName":"Tests"},{"__typename":"CheckRun","completedAt":"0001-01-01T00:00:00Z","conclusion":"","detailsUrl":"https://github.com/cli/cli/actions/runs/1/job/2","name":"build (windows)","startedAt":"2026-10-21T12:07:01Z","status":"IN_PROGRESS","workflowName":"Tests"},{"__typename":"CheckRun","completedAt":"2026-10-21T12:08:00Z","conclusion":"FAILURE","detailsUrl":"https://github.com/cli/cli/actions/runs/1/job/3","name":"lint","startedAt":"2026-10-21T12:07:01Z","status":"COMPLETED","workflowName":"Lint"},{"__typename":"CheckRun","completedAt":"2026-10-21T12:08:00Z","conclusion":"SKIPPED","detailsUrl":"","name":"docs","startedAt":"2026-10-21T12:07:01Z","status":"COMPLETED","workflowName":""},{"__typename":"StatusContext","context":"ci/legacy","state":"PENDING","targetUrl":"https://ci.example.com/1","startedAt":"2026-10-21T12:07:01Z"}],"title":"Refreshable tokens: bump cli/oauth to v1.3.0 and fix `gh status` column width","updatedAt":"2026-10-21T12:30:00Z","url":"https://github.com/cli/cli/pull/14768"}

crates/ide-github/tests/parse.rs

@@ -22,6 +22,7 @@ fn pr_view() {
     assert_eq!(pr.summary.number, 14768);
     assert_eq!(pr.summary.head_ref, "babakks/refresh-token-bump-deps");
     assert_eq!(pr.head_oid, "6ec1ba54542baca6cc5932582634104c83f36a28");
+    assert_eq!(pr.merge_state_status, "UNKNOWN");
     assert_eq!(pr.files.len(), 2);
     assert_eq!(pr.files[0].change_type, "MODIFIED");
     assert_eq!(pr.commits[0].headline, "chore(deps): bump github.com/cli/oauth to v1.3.0");
@@ -69,6 +70,16 @@ fn repo_view() {
         .unwrap();
     assert_eq!(r.name_with_owner, "l0ng-ai/openidea");
     assert_eq!(r.default_branch.as_deref(), Some("main"));
+    assert!(r.merge_commit_allowed && r.squash_merge_allowed && r.rebase_merge_allowed, "unknown: allowed");
+    assert_eq!(r.viewer_permission, "");
+
+    let r = parse_repo(
+        r#"{"mergeCommitAllowed":true,"nameWithOwner":"o/r","url":"","rebaseMergeAllowed":false,"squashMergeAllowed":false,"viewerPermission":"WRITE"}"#,
+    )
+    .unwrap();
+    assert!(r.merge_commit_allowed);
+    assert!(!r.squash_merge_allowed && !r.rebase_merge_allowed);
+    assert_eq!(r.viewer_permission, "WRITE");
 }
 
 #[test]
@@ -87,3 +98,24 @@ fn list_arguments() {
     assert!(joined.contains("--limit 500 --state merged --author @me"));
     assert_eq!(args.last().map(String::as_str), Some("review-requested:@me fix login"));
 }
+
+#[test]
+fn api_arguments() {
+    let req =
+        GhApiRequest { method: "post".into(), endpoint: "graphql".into(), body: Some("{}".into()), paginate: false };
+    assert_eq!(api_args(&req).unwrap(), ["api", "--method", "POST", "graphql", "--input", "-"]);
+    let req = GhApiRequest {
+        method: "GET".into(),
+        endpoint: "repos/{owner}/{repo}/labels".into(),
+        body: None,
+        paginate: true,
+    };
+    assert_eq!(
+        api_args(&req).unwrap(),
+        ["api", "--method", "GET", "repos/{owner}/{repo}/labels", "--paginate", "--slurp"]
+    );
+    for bad in ["--hostname", "https://evil.example/x", ""] {
+        assert!(api_args(&GhApiRequest { endpoint: bad.into(), ..req.clone() }).is_err(), "{bad}");
+    }
+    assert!(api_args(&GhApiRequest { method: "TRACE".into(), ..req }).is_err());
+}

crates/ide-host/Cargo.toml

@@ -30,15 +30,23 @@ ide-terminal.workspace = true
 ide-run.workspace = true
 ide-sdk.workspace = true
 ide-http.workspace = true
+reqwest.workspace = true
+ignore.workspace = true
+base64.workspace = true
+getrandom = "0.3"
+globset.workspace = true
 ide-db.workspace = true
 ide-ssh.workspace = true
 ide-remote.workspace = true
 ide-jsonrpc.workspace = true
 ide-agent.workspace = true
 ide-notebook.workspace = true
+ide-extension.workspace = true
+ide-plugin.workspace = true
 ide-tools = { path = "../ide-tools" }
 serde.workspace = true
 serde_json.workspace = true
+toml.workspace = true
 specta.workspace = true
 specta-typescript.workspace = true
 tokio = { workspace = true, features = ["io-std"] }
@@ -48,7 +56,20 @@ parking_lot.workspace = true
 dunce.workspace = true
 dirs.workspace = true
 uuid.workspace = true
+tempfile.workspace = true
 
 [dev-dependencies]
+ide-ssh = { workspace = true, features = ["testing"] }
 tokio = { workspace = true, features = ["rt-multi-thread", "macros", "io-util", "test-util"] }
-tempfile.workspace = true
+criterion = { version = "0.5", default-features = false }
+zip.workspace = true
+
+[target.'cfg(unix)'.dependencies]
+rustix = { version = "1.1", features = ["fs", "process"] }
+
+[target.'cfg(windows)'.dependencies]
+windows-sys = { version = "0.61", features = ["Win32_Storage_FileSystem"] }
+
+[[bench]]
+name = "plugins"
+harness = false

crates/ide-host/benches/plugins.rs

@@ -0,0 +1,149 @@
+//! `cargo bench -p ide-host`: the plugin runtime budgets, checked by `pnpm perf:rust` against
+//! `perf/budgets.json` › rust (`plugins/…`).
+//!
+//! - `load_50`: start-up load of 50 installed plugins (20 with code, 10
+//!   languages with a syntax provider, 10 icon themes, 10 declarations only),
+//!   from the contribution index; no Wasm is instantiated.
+//! - `cold_activation`: an idle-reclaimed plugin's next command: activation
+//!   from the precompiled component plus the call.
+//! - `syntax_highlights_2k_lines`: an edit-path call (Solidity highlighting).
+
+use criterion::{Criterion, black_box, criterion_group, criterion_main};
+use ide_core::LanguageId;
+use ide_host::plugins::{Consent, PluginHost};
+use ide_plugin::{Invocation, Limits};
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+use std::time::Duration;
+
+fn repo() -> PathBuf {
+    Path::new(env!("CARGO_MANIFEST_DIR")).join("../..").canonicalize().unwrap()
+}
+
+fn copy_dir(from: &Path, to: &Path) {
+    std::fs::create_dir_all(to).unwrap();
+    for e in std::fs::read_dir(from).unwrap().flatten() {
+        let name = e.file_name();
+        if matches!(name.to_str(), Some("target" | "src" | "Cargo.lock" | ".gitignore")) {
+            continue;
+        }
+        let dst = to.join(&name);
+        if e.path().is_dir() { copy_dir(&e.path(), &dst) } else { std::fs::copy(e.path(), &dst).map(|_| ()).unwrap() }
+    }
+}
+
+/// A copy of `src` installed under a new id (and new language / theme ids).
+fn variant(work: &Path, src: &Path, n: usize, rename: &[(&str, String)]) -> PathBuf {
+    let dir = work.join(format!("pkg{n}"));
+    copy_dir(src, &dir);
+    for file in ["plugin.toml", "languages/solidity.toml"] {
+        let path = dir.join(file);
+        if let Ok(mut text) = std::fs::read_to_string(&path) {
+            for (from, to) in rename {
+                text = text.replace(from, to);
+            }
+            std::fs::write(&path, text).unwrap();
+        }
+    }
+    dir
+}
+
+fn sink() -> Arc<dyn ide_host::plugins::PluginEventSink> {
+    Arc::new(|_: Option<&str>, _| {})
+}
+
+fn install_50(plugins: &Path, work: &Path) {
+    let host = PluginHost::new(plugins.to_path_buf(), sink(), Limits::default()).unwrap();
+    host.load_all();
+    let root = repo();
+    let mut n = 0;
+    let mut install = |src: PathBuf, rename: Vec<(&str, String)>| {
+        let pkg = variant(work, &src, n, &rename);
+        n += 1;
+        host.install_from_dir(&pkg, &Consent::default()).unwrap();
+    };
+    for i in 0..20 {
+        install(
+            root.join("crates/ide-plugin/tests/fixtures/hello"),
+            vec![("id = \"hello\"", format!("id = \"bench.hello{i}\""))],
+        );
+    }
+    for i in 0..10 {
+        install(
+            root.join("plugins/official/solidity"),
+            vec![
+                ("openidea.solidity", format!("bench.solidity{i}")),
+                ("id = \"solidity\"", format!("id = \"solidity{i}\"")),
+                ("extensions = [\"sol\"]", format!("extensions = [\"sol{i}\"]")),
+                ("on-language:solidity", format!("on-language:solidity{i}")),
+                ("id = \"forge-", format!("id = \"f{i}-")),
+                ("id = \"hardhat-", format!("id = \"h{i}-")),
+            ],
+        );
+    }
+    for i in 0..10 {
+        install(
+            root.join("plugins/official/material-icons"),
+            vec![
+                ("openidea.material-icons", format!("bench.icons{i}")),
+                ("id = \"material\"", format!("id = \"material{i}\"")),
+            ],
+        );
+    }
+    for i in 0..10 {
+        let dir = work.join(format!("static{i}"));
+        std::fs::create_dir_all(&dir).unwrap();
+        std::fs::write(
+            dir.join("plugin.toml"),
+            format!(
+                "id = \"bench.static{i}\"\nname = \"Static {i}\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.0\"\n\
+                 [[contributes.commands]]\nid = \"a\"\ntitle = \"Static {i}: A\"\nwhen = \"editorLang == rust\"\n"
+            ),
+        )
+        .unwrap();
+        host.install_from_dir(&dir, &Consent::default()).unwrap();
+    }
+}
+
+fn bench(c: &mut Criterion) {
+    let tmp = tempfile::tempdir().unwrap();
+    let plugins = tmp.path().join("plugins");
+    install_50(&plugins, &tmp.path().join("work"));
+
+    let mut g = c.benchmark_group("plugins");
+    g.sample_size(20);
+    g.bench_function("load_50", |b| {
+        b.iter(|| {
+            let host = PluginHost::new(plugins.clone(), sink(), Limits::default()).unwrap();
+            host.load_all();
+            assert_eq!(host.instances(), 0, "start-up instantiates no Wasm");
+            black_box(host.list(None).plugins.len())
+        })
+    });
+
+    let limits = Limits { idle_timeout: Some(Duration::ZERO), ..Limits::default() };
+    let host = Arc::new(PluginHost::new(plugins.clone(), sink(), limits).unwrap());
+    host.load_all();
+    host.warm_component_cache();
+    g.bench_function("cold_activation", |b| {
+        b.iter(|| {
+            host.tick();
+            // Fails for want of an editor, after activating and running.
+            let r = host.run_command("bench.hello0", "word-count", None, Invocation::default());
+            black_box(r.is_err())
+        })
+    });
+
+    let provider = host.syntax_provider();
+    let lang = LanguageId::new("solidity0");
+    let unit = "contract Token {\n    uint256 public total;\n    mapping(address => uint256) balances;\n    event Sent(address to, uint256 v);\n    function send(address to, uint256 v) public returns (bool) {\n        // move funds\n        balances[to] += v;\n        emit Sent(to, v);\n        return true;\n    }\n}\n";
+    let text = unit.repeat(2000 / unit.lines().count());
+    assert!(provider.highlights(&lang, &text).is_some());
+    g.bench_function("syntax_highlights_2k_lines", |b| {
+        b.iter(|| black_box(provider.highlights(&lang, &text).map(|t| t.len())))
+    });
+    g.finish();
+}
+
+criterion_group!(benches, bench);
+criterion_main!(benches);

crates/ide-host/src/bin/openidea-plugin/main.rs

@@ -0,0 +1,624 @@
+//! `openidea-plugin`: scaffolds, builds, checks and links OpenIDEA plugins.
+//!
+//! ```text
+//! openidea-plugin new <dir> [--template command|theme|icon-theme|language] [--id ID] [--name NAME] [--sdk PATH]
+//! openidea-plugin build [dir] [--debug]   # cargo → dist/plugin.wasm, then `check`
+//! openidea-plugin check [dir]             # validate the package as the IDE would install it
+//! openidea-plugin link [dir]              # load the folder in the IDE without installing it
+//! openidea-plugin unlink [dir]
+//! openidea-plugin links                   # list linked folders
+//! openidea-plugin keygen <key-file>       # a publisher's Ed25519 key
+//! openidea-plugin pack [dir] [--key F --publisher ID] [--out FILE]   # <id>-<version>.oiplugin
+//! openidea-plugin index <dir> --publisher ID --name NAME --key F     # marketplace index.json
+//! ```
+//!
+//! `link` writes `links.json` in the IDE's plugins directory
+//! (`$OPENIDEA_PLUGINS_DIR`, or the app data directory); the IDE picks the
+//! change up when Settings › Plugins is opened or refreshed. Linked plugins
+//! are re-read from the folder, so `build` + refresh is the edit loop.
+
+mod templates;
+
+use ide_extension::{Manifest, validate_plugin_id};
+use ide_host::plugins::PluginHost;
+use ide_plugin::{Limits, PluginEngine};
+use std::path::{Path, PathBuf};
+use std::process::{Command, ExitCode};
+use std::sync::Arc;
+
+const USAGE: &str = "\
+usage: openidea-plugin <command> [options]
+
+commands:
+  new <dir> [--template T] [--id ID] [--name NAME] [--sdk PATH]
+        create a plugin; T = command (default), theme, icon-theme, language
+  build [dir] [--debug]   compile a Rust plugin to dist/plugin.wasm and check it
+  check [dir]             validate the package as the IDE would install it
+  link [dir]              load the folder in the IDE without installing it
+  unlink [dir]            stop loading a linked folder
+  links                   list linked folders
+  keygen <key-file>       create a publisher signing key (keep the file secret)
+  pack [dir] [--key F --publisher ID] [--out FILE]
+                          write <id>-<version>.oiplugin, signed with the key
+  index <dir> --publisher ID --name NAME --key F [--out FILE]
+                          write the marketplace index.json for the packages in dir
+
+environment:
+  OPENIDEA_PLUGINS_DIR    the IDE's plugins directory (default: the app data directory)";
+
+fn main() -> ExitCode {
+    let args: Vec<String> = std::env::args().skip(1).collect();
+    let result = match args.first().map(String::as_str) {
+        Some("new") => cmd_new(&args[1..]),
+        Some("build") => cmd_build(&args[1..]),
+        Some("check") => dir_arg(&args[1..]).and_then(|d| check(&d)),
+        Some("link") => dir_arg(&args[1..]).and_then(|d| link(&d, true)),
+        Some("unlink") => dir_arg(&args[1..]).and_then(|d| link(&d, false)),
+        Some("links") => list_links(),
+        Some("keygen") => cmd_keygen(&args[1..]),
+        Some("pack") => cmd_pack(&args[1..]),
+        Some("index") => cmd_index(&args[1..]),
+        Some("--version" | "-V") => {
+            println!("openidea-plugin {} (plugin API {})", env!("CARGO_PKG_VERSION"), ide_extension::ENGINE_VERSION);
+            Ok(())
+        }
+        Some("help" | "--help" | "-h") | None => {
+            println!("{USAGE}");
+            Ok(())
+        }
+        Some(other) => Err(format!("unknown command {other:?}\n\n{USAGE}")),
+    };
+    match result {
+        Ok(()) => ExitCode::SUCCESS,
+        Err(e) => {
+            eprintln!("error: {e}");
+            ExitCode::FAILURE
+        }
+    }
+}
+
+/// Splits `args` into positionals and `--flag value` / `--switch` options.
+struct Args {
+    positional: Vec<String>,
+    options: Vec<(String, Option<String>)>,
+}
+
+impl Args {
+    fn parse(args: &[String], switches: &[&str], valued: &[&str]) -> Result<Self, String> {
+        let mut out = Args { positional: Vec::new(), options: Vec::new() };
+        let mut it = args.iter();
+        while let Some(a) = it.next() {
+            if let Some(name) = a.strip_prefix("--") {
+                let (name, inline) = match name.split_once('=') {
+                    Some((n, v)) => (n, Some(v.to_owned())),
+                    None => (name, None),
+                };
+                if switches.contains(&name) && inline.is_none() {
+                    out.options.push((name.into(), None));
+                } else if valued.contains(&name) {
+                    let v = inline.or_else(|| it.next().cloned()).ok_or_else(|| format!("--{name} needs a value"))?;
+                    out.options.push((name.into(), Some(v)));
+                } else {
+                    return Err(format!("unknown option --{name}"));
+                }
+            } else {
+                out.positional.push(a.clone());
+            }
+        }
+        Ok(out)
+    }
+
+    fn value(&self, name: &str) -> Option<&str> {
+        self.options.iter().rev().find(|(n, _)| n == name).and_then(|(_, v)| v.as_deref())
+    }
+
+    fn has(&self, name: &str) -> bool {
+        self.options.iter().any(|(n, _)| n == name)
+    }
+
+    fn dir(&self) -> Result<PathBuf, String> {
+        match self.positional.as_slice() {
+            [] => Ok(PathBuf::from(".")),
+            [d] => Ok(PathBuf::from(d)),
+            _ => Err("expected at most one directory".into()),
+        }
+    }
+}
+
+fn dir_arg(args: &[String]) -> Result<PathBuf, String> {
+    Args::parse(args, &[], &[])?.dir()
+}
+
+fn canonical(dir: &Path) -> Result<PathBuf, String> {
+    dunce::canonicalize(dir).map_err(|e| format!("{}: {e}", dir.display()))
+}
+
+// ---------------------------------------------------------------- new
+
+fn cmd_new(args: &[String]) -> Result<(), String> {
+    let a = Args::parse(args, &[], &["template", "id", "name", "sdk"])?;
+    let [dir] = a.positional.as_slice() else {
+        return Err("usage: openidea-plugin new <dir> [--template T] [--id ID] [--name NAME]".into());
+    };
+    let dir = PathBuf::from(dir);
+    let template = templates::Template::parse(a.value("template").unwrap_or("command"))?;
+    let base = dir.file_name().and_then(|n| n.to_str()).ok_or("the directory needs a name")?;
+    let id = match a.value("id") {
+        Some(id) => id.to_owned(),
+        None => slugify(base),
+    };
+    validate_plugin_id(&id)?;
+    let name = match a.value("name") {
+        Some(n) => n.to_owned(),
+        None => title_case(id.rsplit('.').next().unwrap_or(&id)),
+    };
+    if name.trim().is_empty() || name.contains(['"', '\\', '\n']) {
+        return Err("--name must not be empty or contain quotes, backslashes or newlines".into());
+    }
+    if dir.exists() && std::fs::read_dir(&dir).map_err(|e| e.to_string())?.next().is_some() {
+        return Err(format!("{} already exists and is not empty", dir.display()));
+    }
+    std::fs::create_dir_all(&dir).map_err(|e| format!("{}: {e}", dir.display()))?;
+    let dir = canonical(&dir)?;
+    let sdk = match template {
+        templates::Template::Command => Some(sdk_path(a.value("sdk"), &dir)?),
+        _ => None,
+    };
+    let vars = templates::Vars { id: &id, name: &name, sdk: sdk.as_deref() };
+    let files = templates::render(template, &vars);
+    for (rel, content) in &files {
+        let path = dir.join(rel);
+        if let Some(parent) = path.parent() {
+            std::fs::create_dir_all(parent).map_err(|e| format!("{}: {e}", parent.display()))?;
+        }
+        std::fs::write(&path, content).map_err(|e| format!("{}: {e}", path.display()))?;
+    }
+    // Generated packages must be valid as written.
+    Manifest::load(&dir).map_err(|e| format!("internal error: the template is invalid: {e}"))?;
+    println!("created {} ({id}) in {}", template.label(), dir.display());
+    let shown = std::env::current_dir().ok().and_then(|cwd| dir.strip_prefix(cwd).ok().map(Path::to_path_buf));
+    let shown = shown.as_deref().unwrap_or(&dir).display().to_string();
+    println!();
+    println!("next:");
+    if template == templates::Template::Command {
+        println!("  cargo test --manifest-path {shown}/Cargo.toml   # unit tests against the mock host");
+        println!("  openidea-plugin build {shown}");
+    } else {
+        println!("  openidea-plugin check {shown}");
+    }
+    println!("  openidea-plugin link {shown}                  # then Settings › Plugins");
+    Ok(())
+}
+
+/// `My Cool_Plugin` → `my-cool-plugin`.
+fn slugify(s: &str) -> String {
+    let mut out = String::new();
+    for c in s.chars() {
+        match c {
+            'a'..='z' | '0'..='9' | '.' => out.push(c),
+            'A'..='Z' => out.push(c.to_ascii_lowercase()),
+            _ if !out.ends_with('-') && !out.is_empty() => out.push('-'),
+            _ => {}
+        }
+    }
+    out.trim_matches(['-', '.']).to_owned()
+}
+
+/// `my-cool_plugin` → `My Cool Plugin`.
+fn title_case(s: &str) -> String {
+    s.split(['-', '_'])
+        .filter(|w| !w.is_empty())
+        .map(|w| {
+            let mut c = w.chars();
+            c.next().map(|f| f.to_uppercase().chain(c).collect::<String>()).unwrap_or_default()
+        })
+        .collect::<Vec<_>>()
+        .join(" ")
+}
+
+/// The SDK dependency path written into a new plugin's Cargo.toml: `--sdk`,
+/// or the SDK of the source tree this tool was built from.
+fn sdk_path(explicit: Option<&str>, plugin_dir: &Path) -> Result<String, String> {
+    let sdk = match explicit {
+        Some(p) => PathBuf::from(p),
+        None => PathBuf::from(concat!(env!("CARGO_MANIFEST_DIR"), "/../../sdk/rust/openidea-plugin")),
+    };
+    let sdk = dunce::canonicalize(&sdk).map_err(|_| {
+        format!("the plugin SDK was not found at {}; pass --sdk <path to sdk/rust/openidea-plugin>", sdk.display())
+    })?;
+    if !sdk.join("Cargo.toml").is_file() {
+        return Err(format!("{} is not the openidea-plugin SDK (no Cargo.toml)", sdk.display()));
+    }
+    let path = relative(plugin_dir, &sdk).unwrap_or(sdk);
+    Ok(path.to_string_lossy().replace('\\', "/"))
+}
+
+/// `to` relative to `from` when they share a root (keeps packages in a repo movable).
+fn relative(from: &Path, to: &Path) -> Option<PathBuf> {
+    let (f, t): (Vec<_>, Vec<_>) = (from.components().collect(), to.components().collect());
+    let common = f.iter().zip(&t).take_while(|(a, b)| a == b).count();
+    if common <= 1 {
+        return None;
+    }
+    let mut out = PathBuf::new();
+    for _ in common..f.len() {
+        out.push("..");
+    }
+    for c in &t[common..] {
+        out.push(c);
+    }
+    Some(out)
+}
+
+// ---------------------------------------------------------------- build / check
+
+fn cmd_build(args: &[String]) -> Result<(), String> {
+    let a = Args::parse(args, &["debug"], &[])?;
+    let dir = canonical(&a.dir()?)?;
+    let manifest = Manifest::load(&dir)?;
+    let cargo_toml = dir.join("Cargo.toml");
+    if !cargo_toml.is_file() {
+        if manifest.wasm.is_some() {
+            return Err(format!(
+                "{} has no Cargo.toml: build the component with your toolchain, then run `check`",
+                dir.display()
+            ));
+        }
+        println!("{} has no code to build", manifest.id);
+        return check(&dir);
+    }
+    let wasm_rel = manifest.wasm.clone().ok_or("plugin.toml has no `wasm = \"dist/plugin.wasm\"`")?;
+    let crate_name = crate_name(&cargo_toml)?;
+    ensure_wasm_target();
+    let release = !a.has("debug");
+    let target_dir = std::env::var_os("CARGO_TARGET_DIR").map(PathBuf::from).unwrap_or_else(|| dir.join("target"));
+    let mut cmd = Command::new(std::env::var_os("CARGO").unwrap_or_else(|| "cargo".into()));
+    cmd.arg("build").arg("--manifest-path").arg(&cargo_toml).args(["--target", "wasm32-wasip2"]);
+    if release {
+        cmd.arg("--release");
+    }
+    cmd.env("CARGO_TARGET_DIR", &target_dir);
+    println!("building {crate_name} for wasm32-wasip2 ({})", if release { "release" } else { "debug" });
+    let status = cmd.status().map_err(|e| format!("cannot run cargo: {e}"))?;
+    if !status.success() {
+        return Err("cargo build failed".into());
+    }
+    let built = target_dir
+        .join("wasm32-wasip2")
+        .join(if release { "release" } else { "debug" })
+        .join(format!("{}.wasm", crate_name.replace('-', "_")));
+    if !built.is_file() {
+        return Err(format!("{} was not produced: is `crate-type = [\"cdylib\"]` set in Cargo.toml?", built.display()));
+    }
+    let out = dir.join(&wasm_rel);
+    if let Some(parent) = out.parent() {
+        std::fs::create_dir_all(parent).map_err(|e| format!("{}: {e}", parent.display()))?;
+    }
+    std::fs::copy(&built, &out).map_err(|e| format!("{}: {e}", out.display()))?;
+    let size = std::fs::metadata(&out).map(|m| m.len()).unwrap_or(0);
+    println!("  -> {} ({})", wasm_rel.display(), human_size(size));
+    check(&dir)
+}
+
+fn crate_name(cargo_toml: &Path) -> Result<String, String> {
+    let src = std::fs::read_to_string(cargo_toml).map_err(|e| format!("{}: {e}", cargo_toml.display()))?;
+    let doc: toml::Table = src.parse().map_err(|e| format!("{}: {e}", cargo_toml.display()))?;
+    let package = doc.get("package").and_then(|p| p.as_table());
+    let lib_name = doc.get("lib").and_then(|l| l.get("name")).and_then(|n| n.as_str());
+    lib_name
+        .or_else(|| package.and_then(|p| p.get("name")).and_then(|n| n.as_str()))
+        .map(str::to_owned)
+        .ok_or_else(|| format!("{}: no [package] name", cargo_toml.display()))
+}
+
+/// Installs the target through rustup when it is missing (no-op without rustup).
+fn ensure_wasm_target() {
+    let Ok(out) = Command::new("rustup").args(["target", "list", "--installed"]).output() else { return };
+    if String::from_utf8_lossy(&out.stdout).lines().any(|l| l.trim() == "wasm32-wasip2") {
+        return;
+    }
+    println!("installing the wasm32-wasip2 target");
+    let _ = Command::new("rustup").args(["target", "add", "wasm32-wasip2"]).status();
+}
+
+/// Validates `dir` exactly as Install from Disk would, and checks the
+/// component imports only the plugin API.
+fn check(dir: &Path) -> Result<(), String> {
+    let dir = canonical(dir)?;
+    let scratch = std::env::temp_dir().join(format!("openidea-plugin-check-{}", std::process::id()));
+    let result = (|| {
+        let host = PluginHost::new(scratch.clone(), Arc::new(|_: Option<&str>, _| {}), Limits::default())
+            .map_err(|e| e.to_string())?;
+        let preview = host.preview_install(&dir).map_err(|e| e.to_string())?;
+        let manifest = Manifest::load(&dir)?;
+        println!("{} {} — {}", preview.id, preview.version, preview.name);
+        if manifest.legacy {
+            println!("  note: plugin.toml uses the 0.1 format (`openidea-api`); see plugins/README.md to move to 0.2");
+        }
+        if let Some(wasm) = &manifest.wasm {
+            let engine = PluginEngine::new()?;
+            let component = engine.compile(&dir.join(wasm))?;
+            let built_for = engine.check_component(&component)?;
+            let size = std::fs::metadata(dir.join(wasm)).map(|m| m.len()).unwrap_or(0);
+            let api = built_for.map(|v| format!(", plugin API {}.{}", v.major, v.minor)).unwrap_or_default();
+            println!("  code: {} ({}{api})", wasm.display(), human_size(size));
+        } else {
+            println!("  code: none (contributions only)");
+        }
+        if !manifest.activation.is_empty() {
+            let events: Vec<String> = manifest.activation.iter().map(ToString::to_string).collect();
+            println!("  activation: {}", events.join(", "));
+        }
+        for c in &preview.contributions {
+            println!("  contributes {} × {}", c.count, c.point);
+        }
+        for c in &preview.capabilities {
+            let kind = if c.optional { "optional" } else { "required" };
+            println!("  capability {} ({kind}, {:?} risk): {}", c.id, c.risk, c.description);
+        }
+        for w in &preview.warnings {
+            println!("  warning: {w}");
+        }
+        println!("ok");
+        Ok(())
+    })();
+    let _ = std::fs::remove_dir_all(&scratch);
+    result
+}
+
+fn human_size(bytes: u64) -> String {
+    match bytes {
+        b if b >= 1 << 20 => format!("{:.1} MiB", b as f64 / (1 << 20) as f64),
+        b if b >= 1 << 10 => format!("{:.1} KiB", b as f64 / 1024.0),
+        b => format!("{b} B"),
+    }
+}
+
+// ---------------------------------------------------------------- link
+
+fn plugins_dir() -> Result<PathBuf, String> {
+    if let Some(dir) = std::env::var_os("OPENIDEA_PLUGINS_DIR") {
+        return Ok(PathBuf::from(dir));
+    }
+    dirs::data_dir()
+        .map(|d| d.join("ai.l0ng.openidea").join("plugins"))
+        .ok_or_else(|| "cannot find the app data directory; set OPENIDEA_PLUGINS_DIR".into())
+}
+
+#[derive(Default, serde::Serialize, serde::Deserialize)]
+struct Links {
+    #[serde(default)]
+    paths: Vec<PathBuf>,
+}
+
+fn read_links(file: &Path) -> Result<Links, String> {
+    match std::fs::read_to_string(file) {
+        Ok(s) => serde_json::from_str(&s).map_err(|e| format!("{}: {e}", file.display())),
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(Links::default()),
+        Err(e) => Err(format!("{}: {e}", file.display())),
+    }
+}
+
+fn link(dir: &Path, add: bool) -> Result<(), String> {
+    let plugins = plugins_dir()?;
+    let file = plugins.join("links.json");
+    let mut links = read_links(&file)?;
+    let dir = if add {
+        let dir = canonical(dir)?;
+        let m = Manifest::load(&dir)?;
+        if let Some(wasm) = &m.wasm
+            && !dir.join(wasm).is_file()
+        {
+            println!("note: {} does not exist yet; run `openidea-plugin build` first", wasm.display());
+        }
+        if links.paths.contains(&dir) {
+            println!("{} is already linked", dir.display());
+            return Ok(());
+        }
+        println!("linked {} ({})", m.id, dir.display());
+        links.paths.push(dir.clone());
+        dir
+    } else {
+        let dir = dunce::canonicalize(dir).unwrap_or_else(|_| dir.to_path_buf());
+        let before = links.paths.len();
+        links.paths.retain(|p| p != &dir);
+        if links.paths.len() == before {
+            return Err(format!("{} is not linked", dir.display()));
+        }
+        println!("unlinked {}", dir.display());
+        dir
+    };
+    let _ = dir;
+    std::fs::create_dir_all(&plugins).map_err(|e| format!("{}: {e}", plugins.display()))?;
+    let json = serde_json::to_string_pretty(&links).map_err(|e| e.to_string())?;
+    let tmp = file.with_extension("json.tmp");
+    std::fs::write(&tmp, json)
+        .and_then(|()| std::fs::rename(&tmp, &file))
+        .map_err(|e| format!("{}: {e}", file.display()))?;
+    println!("open Settings › Plugins in OpenIDEA to load the change");
+    Ok(())
+}
+
+fn list_links() -> Result<(), String> {
+    let links = read_links(&plugins_dir()?.join("links.json"))?;
+    if links.paths.is_empty() {
+        println!("no linked plugins");
+    }
+    for p in links.paths {
+        let id = Manifest::load(&p).map(|m| m.id).unwrap_or_else(|e| format!("invalid: {e}"));
+        println!("{id}\t{}", p.display());
+    }
+    Ok(())
+}
+
+// ---------------------------------------------------------------- distribution
+
+use ide_extension::package::{self, Index, IndexEntry, KeyEntry, PublisherKey};
+
+fn read_key(path: &str) -> Result<PublisherKey, String> {
+    PublisherKey::from_base64(&std::fs::read_to_string(path).map_err(|e| format!("{path}: {e}"))?)
+}
+
+fn cmd_keygen(args: &[String]) -> Result<(), String> {
+    let a = Args::parse(args, &[], &[])?;
+    let [file] = a.positional.as_slice() else { return Err("usage: openidea-plugin keygen <key-file>".into()) };
+    if Path::new(file).exists() {
+        return Err(format!("{file} exists; not overwriting a key"));
+    }
+    let mut seed = [0u8; 32];
+    getrandom::fill(&mut seed).map_err(|e| format!("random: {e}"))?;
+    let key = PublisherKey::from_seed(seed);
+    std::fs::write(file, key.seed_base64()).map_err(|e| format!("{file}: {e}"))?;
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        let _ = std::fs::set_permissions(file, std::fs::Permissions::from_mode(0o600));
+    }
+    println!("public key: {}", key.public_base64());
+    println!("register it with your publisher id in the marketplace index; keep {file} secret");
+    Ok(())
+}
+
+/// A scratch host to list a package's files as the IDE would.
+fn with_scratch_host<T>(f: impl FnOnce(&PluginHost) -> Result<T, String>) -> Result<T, String> {
+    let scratch = std::env::temp_dir().join(format!("openidea-plugin-pack-{}", std::process::id()));
+    let result = PluginHost::new(scratch.clone(), Arc::new(|_: Option<&str>, _| {}), Limits::default())
+        .map_err(|e| e.to_string())
+        .and_then(|h| f(&h));
+    let _ = std::fs::remove_dir_all(&scratch);
+    result
+}
+
+fn cmd_pack(args: &[String]) -> Result<(), String> {
+    let a = Args::parse(args, &[], &["key", "publisher", "out"])?;
+    let dir = canonical(&a.dir()?)?;
+    check(&dir)?;
+    let manifest = Manifest::load(&dir)?;
+    let mut files = with_scratch_host(|h| h.package_files_of(&dir).map_err(|e| e.to_string()))?;
+    let digest = package::package_digest(&dir, &files).map_err(|e| e.to_string())?;
+    let signature = match (a.value("key"), a.value("publisher")) {
+        (Some(key), Some(publisher)) => {
+            if !manifest.id.starts_with(&format!("{publisher}.")) {
+                return Err(format!("publisher {publisher:?} may only sign plugins named {publisher}.*"));
+            }
+            Some(read_key(key)?.sign(publisher, &manifest.id, &manifest.version, &digest))
+        }
+        (None, None) => None,
+        _ => return Err("--key and --publisher go together".into()),
+    };
+    for lic in ["LICENSE", "LICENSE.md", "LICENSE.txt", "NOTICE", "NOTICE.md", "COPYING", "README.md"] {
+        if dir.join(lic).is_file() {
+            files.push(PathBuf::from(lic));
+        }
+    }
+    let out = a.value("out").map(PathBuf::from).unwrap_or_else(|| {
+        PathBuf::from(format!("{}-{}.{}", manifest.id, manifest.version, package::PACKAGE_EXTENSION))
+    });
+    package::pack(&dir, &files, &out, signature.as_ref())?;
+    let size = std::fs::metadata(&out).map(|m| m.len()).unwrap_or(0);
+    let signed = signature.as_ref().map_or("unsigned".to_owned(), |s| format!("signed by {}", s.publisher));
+    println!("-> {} ({}, {signed})", out.display(), human_size(size));
+    Ok(())
+}
+
+fn cmd_index(args: &[String]) -> Result<(), String> {
+    let a = Args::parse(args, &[], &["publisher", "name", "key", "out"])?;
+    let dir = canonical(&a.dir()?)?;
+    let publisher = a.value("publisher").ok_or("--publisher is required")?;
+    let name = a.value("name").unwrap_or(publisher);
+    let key = read_key(a.value("key").ok_or("--key is required")?)?;
+    let out = a.value("out").map(PathBuf::from).unwrap_or_else(|| dir.join("index.json"));
+    // Revocations and other publishers of an existing index are kept.
+    let mut index = match std::fs::read_to_string(&out) {
+        Ok(text) => Index::parse(&text)?,
+        Err(_) => Index { format: package::INDEX_FORMAT, ..Index::default() },
+    };
+    // Earlier keys of the publisher stay listed (packages they signed remain valid until revoked).
+    let current = key.public_base64();
+    let earlier: Vec<KeyEntry> = index
+        .publishers
+        .iter()
+        .filter(|p| p.id == publisher)
+        .flat_map(|p| p.keys.iter().filter(|k| k.key != current).cloned())
+        .collect();
+    index.publishers.retain(|p| p.id != publisher);
+    let keys: Vec<KeyEntry> = std::iter::once(KeyEntry { key: current, revoked: false }).chain(earlier).collect();
+    index.publishers.push(package::Publisher { id: publisher.into(), name: name.into(), keys });
+    index.plugins.clear();
+    let mut packages: Vec<PathBuf> = std::fs::read_dir(&dir)
+        .map_err(|e| e.to_string())?
+        .flatten()
+        .map(|e| e.path())
+        .filter(|p| p.extension().is_some_and(|e| e == package::PACKAGE_EXTENSION))
+        .collect();
+    packages.sort();
+    for path in packages {
+        let scratch = std::env::temp_dir().join(format!("openidea-plugin-index-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&scratch);
+        let unpacked = package::unpack(&path, &scratch)?;
+        let entry = (|| {
+            let m = Manifest::load(&scratch)?;
+            let files = with_scratch_host(|h| h.package_files_of(&scratch).map_err(|e| e.to_string()))?;
+            let digest = package::package_digest(&scratch, &files).map_err(|e| e.to_string())?;
+            let sig = unpacked.signature.as_ref().ok_or_else(|| format!("{}: not signed", path.display()))?;
+            sig.check(&m.id, &m.version, &digest).map_err(|e| format!("{}: {e}", path.display()))?;
+            Ok::<_, String>(IndexEntry {
+                id: m.id.clone(),
+                name: m.name.clone(),
+                version: m.version.clone(),
+                description: m.description.clone(),
+                authors: m.authors.clone(),
+                publisher: sig.publisher.clone(),
+                download: path.file_name().map(|n| n.to_string_lossy().into_owned()).unwrap_or_default(),
+                digest,
+                capabilities: m.capabilities.all().map(|c| c.to_string()).collect(),
+            })
+        })();
+        let _ = std::fs::remove_dir_all(&scratch);
+        let entry = entry?;
+        println!("  {} {}", entry.id, entry.version);
+        index.plugins.push(entry);
+    }
+    let json = serde_json::to_string_pretty(&index).map_err(|e| e.to_string())?;
+    std::fs::write(&out, json).map_err(|e| format!("{}: {e}", out.display()))?;
+    println!("-> {} ({} plugins)", out.display(), index.plugins.len());
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn names() {
+        assert_eq!(slugify("My Cool_Plugin"), "my-cool-plugin");
+        assert_eq!(slugify("acme.Tools"), "acme.tools");
+        assert_eq!(title_case("material-icons"), "Material Icons");
+        assert_eq!(
+            relative(Path::new("/a/b/plugins/x"), Path::new("/a/b/sdk/rust/p")).unwrap(),
+            PathBuf::from("../../sdk/rust/p")
+        );
+        assert_eq!(relative(Path::new("/x/y"), Path::new("/z")), None);
+    }
+
+    #[test]
+    fn every_template_is_a_valid_package() {
+        for t in templates::Template::ALL {
+            let dir =
+                std::env::temp_dir().join(format!("openidea-plugin-template-{}-{}", t.label(), std::process::id()));
+            let _ = std::fs::remove_dir_all(&dir);
+            let vars = templates::Vars { id: "acme.sample", name: "Sample", sdk: Some("../sdk") };
+            for (rel, content) in templates::render(t, &vars) {
+                let path = dir.join(rel);
+                std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+                std::fs::write(path, content).unwrap();
+            }
+            let m = Manifest::load(&dir).unwrap_or_else(|e| panic!("{}: {e}", t.label()));
+            assert_eq!(m.id, "acme.sample");
+            if m.wasm.is_none() {
+                check(&dir).unwrap_or_else(|e| panic!("{}: {e}", t.label()));
+            }
+            std::fs::remove_dir_all(&dir).unwrap();
+        }
+    }
+}

crates/ide-host/src/bin/openidea-plugin/templates.rs

@@ -0,0 +1,278 @@
+//! The files of `openidea-plugin new`. Placeholders: `__ID__` (plugin id),
+//! `__SLUG__` (last id segment), `__NAME__`, `__CRATE__`, `__SDK__`.
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Template {
+    Command,
+    Theme,
+    IconTheme,
+    Language,
+}
+
+impl Template {
+    pub const ALL: [Template; 4] = [Self::Command, Self::Theme, Self::IconTheme, Self::Language];
+
+    pub fn parse(s: &str) -> Result<Self, String> {
+        Self::ALL
+            .into_iter()
+            .find(|t| t.label() == s)
+            .ok_or_else(|| format!("unknown template {s:?} (command, theme, icon-theme, language)"))
+    }
+
+    pub fn label(self) -> &'static str {
+        match self {
+            Self::Command => "command",
+            Self::Theme => "theme",
+            Self::IconTheme => "icon-theme",
+            Self::Language => "language",
+        }
+    }
+}
+
+pub struct Vars<'a> {
+    pub id: &'a str,
+    pub name: &'a str,
+    pub sdk: Option<&'a str>,
+}
+
+/// `(relative path, contents)` of every file of the template.
+pub fn render(template: Template, vars: &Vars) -> Vec<(String, String)> {
+    let slug = vars.id.rsplit('.').next().unwrap_or(vars.id).to_owned();
+    let crate_name = format!("openidea-plugin-{}", vars.id.replace('.', "-"));
+    let fill = |s: &str| {
+        s.replace("__ID__", vars.id)
+            .replace("__SLUG__", &slug)
+            .replace("__NAME__", vars.name)
+            .replace("__CRATE__", &crate_name)
+            .replace("__SDK__", vars.sdk.unwrap_or(""))
+            // The theme files come from the Harbor Night plugin.
+            .replace("harbor-night", &slug)
+            .replace("Harbor Night", vars.name)
+    };
+    let files: Vec<(String, &str)> = match template {
+        Template::Command => vec![
+            ("plugin.toml".into(), COMMAND_MANIFEST),
+            ("Cargo.toml".into(), COMMAND_CARGO),
+            ("src/lib.rs".into(), COMMAND_LIB),
+            (".gitignore".into(), "/target\n"),
+            ("README.md".into(), COMMAND_README),
+        ],
+        Template::Theme => vec![
+            ("plugin.toml".into(), THEME_MANIFEST),
+            (format!("themes/{slug}.theme.json"), THEME_UI),
+            (format!("themes/{slug}.scheme.json"), THEME_SCHEME),
+        ],
+        Template::IconTheme => vec![
+            ("plugin.toml".into(), ICON_MANIFEST),
+            ("icons/theme.json".into(), ICON_THEME),
+            ("icons/file.svg".into(), ICON_FILE),
+            ("icons/folder.svg".into(), ICON_FOLDER),
+            ("icons/folder-open.svg".into(), ICON_FOLDER_OPEN),
+            ("icons/markdown.svg".into(), ICON_MARKDOWN),
+        ],
+        Template::Language => {
+            vec![("plugin.toml".into(), LANGUAGE_MANIFEST), (format!("languages/{slug}.toml"), LANGUAGE_DEF)]
+        }
+    };
+    files.into_iter().map(|(path, content)| (path, fill(content))).collect()
+}
+
+const COMMAND_MANIFEST: &str = r#"id = "__ID__"
+name = "__NAME__"
+version = "0.1.0"
+description = "Adds two sample commands."
+authors = []
+engines.openidea = "^1.0"
+# Built by `openidea-plugin build`. The code is loaded the first time one of
+# its commands runs; the commands below show in Find Action before that.
+wasm = "dist/plugin.wasm"
+
+# What the code may do. The user approves these when installing.
+[capabilities]
+required = ["editor.read"]
+
+[[contributes.commands]]
+id = "say-hello"
+title = "__NAME__: Say Hello"
+category = "__NAME__"
+
+[[contributes.commands]]
+id = "line-count"
+title = "__NAME__: Line Count of Active File"
+category = "__NAME__"
+"#;
+
+const COMMAND_CARGO: &str = r#"[package]
+name = "__CRATE__"
+version = "0.1.0"
+edition = "2024"
+publish = false
+
+# A plugin builds on its own (target wasm32-wasip2), outside any IDE workspace.
+[workspace]
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[dependencies]
+openidea-plugin = { path = "__SDK__" }
+
+[profile.release]
+opt-level = "s"
+lto = true
+strip = true
+codegen-units = 1
+panic = "abort"
+"#;
+
+const COMMAND_LIB: &str = r#"//! __NAME__: an OpenIDEA plugin.
+
+use openidea_plugin::{Invocation, NotificationLevel, Plugin, host, register_plugin};
+
+#[derive(Default)]
+pub struct Main {
+    greetings: u32,
+}
+
+impl Plugin for Main {
+    fn run_command(&mut self, id: &str, ctx: &Invocation, _arg: Option<&str>) -> Result<Option<String>, String> {
+        match id {
+            "say-hello" => {
+                // Instance state lasts until the plugin is idle for a while;
+                // keep what must survive in `host::storage`.
+                self.greetings += 1;
+                let body = format!("Hello #{} from __NAME__!", self.greetings);
+                host::notify(NotificationLevel::Info, "__NAME__", &body);
+                Ok(None)
+            }
+            "line-count" => {
+                let editor = ctx.editor().ok_or("no file is open")?;
+                let text = editor.document()?.text;
+                Ok(Some(format!("{} lines in {}", text.lines().count(), editor.path())))
+            }
+            _ => Err(format!("unknown command {id}")),
+        }
+    }
+}
+
+register_plugin!(Main);
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use openidea_plugin::mock::MockHost;
+
+    #[test]
+    fn says_hello() {
+        let host = MockHost::install();
+        let mut plugin = Main::default();
+        plugin.run_command("say-hello", &host.invocation(), None).unwrap();
+        plugin.run_command("say-hello", &host.invocation(), None).unwrap();
+        assert_eq!(host.notifications()[1].body, "Hello #2 from __NAME__!");
+    }
+
+    #[test]
+    fn counts_lines() {
+        let host = MockHost::install();
+        host.open_editor("/project/src/main.rs", "rust", "fn main() {\n}\n", &[]);
+        let out = Main::default().run_command("line-count", &host.invocation(), None).unwrap();
+        assert_eq!(out.as_deref(), Some("2 lines in /project/src/main.rs"));
+    }
+}
+"#;
+
+const COMMAND_README: &str = r#"# __NAME__
+
+An OpenIDEA plugin.
+
+```sh
+cargo test                       # logic, against the SDK's mock host
+openidea-plugin build            # → dist/plugin.wasm, validated like an install
+openidea-plugin link             # load this folder in the IDE (Settings › Plugins)
+```
+
+`plugin.toml` declares the commands, so they appear in Find Action before the
+code is loaded, and the capabilities the code needs. `src/lib.rs` implements
+them with the `openidea-plugin` SDK.
+"#;
+
+const THEME_MANIFEST: &str = r#"id = "__ID__"
+name = "__NAME__"
+version = "0.1.0"
+description = "A dark theme."
+authors = []
+engines.openidea = "^1.0"
+
+# One entry per theme. `editor-scheme` is optional: its tokens are merged over
+# the theme's (IntelliJ's .theme.json + .icls pair). Reference: docs/plugins/themes.md.
+[[contributes.themes]]
+path = "themes/__SLUG__.theme.json"
+editor-scheme = "themes/__SLUG__.scheme.json"
+"#;
+
+const THEME_UI: &str = include_str!("../../../../../plugins/official/harbor-night/themes/harbor-night.theme.json");
+const THEME_SCHEME: &str = include_str!("../../../../../plugins/official/harbor-night/themes/harbor-night.scheme.json");
+
+const ICON_MANIFEST: &str = r#"id = "__ID__"
+name = "__NAME__"
+version = "0.1.0"
+description = "File and folder icons."
+authors = []
+engines.openidea = "^1.0"
+
+# Apply it in Settings › Plugins › __NAME__. SVGs are sanitised on install:
+# no scripts, event handlers, external references or entities.
+[[contributes.iconThemes]]
+id = "__SLUG__"
+label = "__NAME__"
+path = "icons/theme.json"
+"#;
+
+const ICON_THEME: &str = r#"{
+  "iconDefinitions": {
+    "file": "icons/file.svg",
+    "folder": "icons/folder.svg",
+    "folder-open": "icons/folder-open.svg",
+    "markdown": "icons/markdown.svg"
+  },
+  "file": "file",
+  "folder": "folder",
+  "folderExpanded": "folder-open",
+  "fileExtensions": { "md": "markdown", "markdown": "markdown" },
+  "fileNames": { "readme": "markdown" },
+  "folderNames": {}
+}
+"#;
+
+const ICON_FILE: &str = r##"<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><path fill="#90a4ae" d="M4 1.5h5.5L13 5v9.5H4z"/><path fill="#cfd8dc" d="M9.5 1.5V5H13z"/></svg>
+"##;
+
+const ICON_FOLDER: &str = r##"<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><path fill="#90a4ae" d="M1.5 3h5l1.5 1.5h6.5v9h-13z"/></svg>
+"##;
+
+const ICON_FOLDER_OPEN: &str = r##"<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><path fill="#90a4ae" d="M1.5 3h5l1.5 1.5h6v2h-10l-2 7h-.5z"/><path fill="#b0bec5" d="M4 7.5h11.5l-2 6H2z"/></svg>
+"##;
+
+const ICON_MARKDOWN: &str = r##"<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><rect x="1" y="3.5" width="14" height="9" rx="1.5" fill="#42a5f5"/><path fill="#fff" d="M3 10.5v-5h1.5L6 7.5l1.5-2H9v5H7.5V8L6 10 4.5 8v2.5zm8 0L9.5 8h1V5.5H12V8h1z"/></svg>
+"##;
+
+const LANGUAGE_MANIFEST: &str = r#"id = "__ID__"
+name = "__NAME__"
+version = "0.1.0"
+description = "Language support for .__SLUG__ files: detection, comments and indentation."
+authors = []
+engines.openidea = "^1.0"
+
+# Same format as languages/<id>.toml in the IDE repository.
+[[contributes.languages]]
+path = "languages/__SLUG__.toml"
+"#;
+
+const LANGUAGE_DEF: &str = r##"id = "__SLUG__"
+name = "__NAME__"
+extensions = ["__SLUG__"]
+line-comment = "#"
+indent = { tab-size = 2, insert-spaces = true }
+# Borrow an existing CodeMirror mode for instant highlighting.
+ui-mode = "Properties files"
+"##;

crates/ide-host/src/bin/server.rs

@@ -1,6 +1,8 @@
 //! `openidea-server --stdio`: the IDE backend for remote development, serving
 //! one desktop client over stdin / stdout (started by the client over SSH).
 
+use ide_host::plugins::remote::{RemotePluginLanguages, SYNC_COMMAND};
+use ide_host::plugins::remote_host::RemotePlugins;
 use ide_host::rpc::{self, Dispatcher};
 use ide_host::{Host, HostConfig};
 use ide_language::LanguageRegistry;
@@ -51,10 +53,15 @@ async fn run(base: PathBuf) -> i32 {
             return 1;
         }
     };
+    // The desktop's plugin languages (`plugin_sync_languages`); programs pinned on this machine.
+    let plugin_languages = RemotePluginLanguages::new(Some(&data_dir));
+    languages.attach_plugins(plugin_languages.store().clone());
     let peer = Arc::new(OnceLock::new());
     let sink_peer = peer.clone();
+    let plugins_data = data_dir.clone();
     let host = Arc::new(Host::new(HostConfig {
         config_dir,
+        local_data_dir: data_dir.clone(),
         data_dir,
         languages,
         syntax: Arc::default(),
@@ -63,8 +70,31 @@ async fn run(base: PathBuf) -> i32 {
         runtime: tokio::runtime::Handle::current(),
         project_environment: true,
     }));
+    // The desktop's code plugins run here, next to the project (`plugin_sync_packages`).
+    let plugins = match RemotePlugins::start(&plugins_data, &host, peer.clone()) {
+        Ok(p) => Some(p),
+        Err(e) => {
+            tracing::warn!("plugins are unavailable: {e}");
+            None
+        }
+    };
     tracing::info!("openidea-server {} ready", env!("CARGO_PKG_VERSION"));
-    rpc::serve(host.clone(), Dispatcher::standard(), peer, tokio::io::stdin(), tokio::io::stdout()).await;
+    let mut dispatcher = Dispatcher::standard();
+    if let Some(plugins) = &plugins {
+        plugins.register(&mut dispatcher);
+    }
+    dispatcher.add(SYNC_COMMAND, move |c| {
+        let remote = plugin_languages.clone();
+        async move {
+            let report = remote.sync(c.arg("languages")?);
+            c.host.plugin_languages_changed();
+            Ok(report)
+        }
+    });
+    rpc::serve(host.clone(), dispatcher, peer, tokio::io::stdin(), tokio::io::stdout()).await;
+    if let Some(plugins) = &plugins {
+        plugins.host().shutdown();
+    }
     // `process::exit` skips destructors: nothing started for the client may outlive it.
     if tokio::time::timeout(std::time::Duration::from_secs(10), host.shutdown()).await.is_err() {
         tracing::warn!("language servers did not shut down in time");

crates/ide-host/src/data_dirs.rs

@@ -0,0 +1,476 @@
+//! Storage policy and best-effort migration of rebuildable desktop data.
+
+use std::fs;
+use std::io;
+use std::path::{Path, PathBuf};
+
+/// Unknown entries and recovery/user content deliberately stay in roaming data.
+pub fn is_local(entry: &Path) -> bool {
+    ["tools", "language-server-runtimes", "index", "cache", "lsp", "notebook-runtime", "server", "logs"]
+        .iter()
+        .any(|root| entry.starts_with(root))
+        || entry.starts_with("agents/tools")
+        || entry == Path::new("agents/registry.json")
+        || (entry.components().count() == 1
+            && entry.file_name().is_some_and(|name| name.to_string_lossy().starts_with("java-usages-"))
+            && entry.extension().is_some_and(|ext| ext == "jar" || ext == "tmp"))
+}
+
+pub fn data_path(data: &Path, local: &Path, entry: &Path) -> PathBuf {
+    if is_local(entry) { local.join(entry) } else { data.join(entry) }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+enum Action {
+    Skip,
+    Rename,
+}
+
+fn action(same_root: bool, source_exists: bool, target_exists: bool) -> Action {
+    if same_root || !source_exists || target_exists { Action::Skip } else { Action::Rename }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+enum RenameFailure {
+    Copy,
+    KeepSource,
+}
+
+fn rename_failure(error: &io::Error) -> RenameFailure {
+    if error.kind() == io::ErrorKind::CrossesDevices { RenameFailure::Copy } else { RenameFailure::KeepSource }
+}
+
+/// Only Windows splits these paths. Renames are cheap; cross-volume copies run in
+/// the background. Consumers always use Local, even when migration fails.
+pub fn migrate(data: &Path, local: &Path) {
+    if cfg!(target_os = "windows") && data != local {
+        migrate_entries(data, local);
+    }
+}
+
+fn migrate_entries(data: &Path, local: &Path) {
+    let mut entries: Vec<PathBuf> = [
+        "language-server-runtimes",
+        "index",
+        "cache",
+        "lsp",
+        "notebook-runtime",
+        "server",
+        "java-usages-1.1.1.jar",
+        "java-usages-1.2.0.jar",
+        "agents/registry.json",
+    ]
+    .into_iter()
+    .map(PathBuf::from)
+    .collect();
+    // Virtual environments contain absolute interpreter paths. Keep the old copy
+    // intact; these tools are installed afresh in Local when requested. Registry
+    // agents also have absolute commands in user config, so leave legacy installs.
+    match fs::read_dir(data.join("tools")) {
+        Ok(tools) => {
+            for entry in tools {
+                let entry = match entry {
+                    Ok(entry) => entry,
+                    Err(error) => {
+                        tracing::warn!(%error, "cannot enumerate legacy tool; keeping old data, using Local");
+                        continue;
+                    }
+                };
+                let name = entry.file_name();
+                let venv = ide_tools::registry::TOOLS.iter().any(|tool| {
+                    name == tool.name && matches!(tool.method, ide_tools::registry::Method::PipVenv { .. })
+                });
+                if venv {
+                    tracing::info!(?name, "leaving non-relocatable legacy tool; reinstall into Local when needed");
+                } else {
+                    entries.push(Path::new("tools").join(name));
+                }
+            }
+        }
+        Err(error) if error.kind() == io::ErrorKind::NotFound => {}
+        Err(error) => tracing::warn!(%error, "cannot enumerate legacy tools; keeping old data, using Local"),
+    }
+    let mut copies = Vec::new();
+    for entry in entries {
+        let source = data.join(&entry);
+        let target = data_path(data, local, &entry);
+        match try_rename(&source, &target) {
+            Ok(true) => copies.push((source, target)),
+            Ok(false) => {}
+            Err(error) => {
+                tracing::warn!(?source, ?target, %error, "data migration failed; keeping old data, using Local")
+            }
+        }
+    }
+    if !copies.is_empty() {
+        let result = std::thread::Builder::new().name("openidea-data-migration".into()).spawn(move || {
+            for (source, target) in copies {
+                tracing::info!(?source, ?target, "copying legacy data in background");
+                if let Err(error) = copy_then_remove(&source, &target) {
+                    tracing::warn!(?source, ?target, %error, "data copy failed; keeping old data, using Local");
+                }
+            }
+        });
+        if let Err(error) = result {
+            tracing::warn!(%error, "cannot start data migration worker; keeping old data, using Local");
+        }
+    }
+}
+
+/// Returns true when a cross-volume copy is needed.
+fn try_rename(source: &Path, target: &Path) -> io::Result<bool> {
+    if action(source == target, source.try_exists()?, target.try_exists()?) == Action::Skip {
+        return Ok(false);
+    }
+    if fs::symlink_metadata(source)?.file_type().is_symlink() {
+        return Err(io::Error::other("refusing to migrate a linked data entry"));
+    }
+    fs::create_dir_all(target.parent().ok_or_else(|| io::Error::other("missing data parent"))?)?;
+    // Relative wrappers work at the old location too, so even a failed rename
+    // leaves the old installation usable and needs no rollback.
+    relocate_shims(source, source)?;
+    match rename_missing(source, target) {
+        Ok(()) => {
+            tracing::info!(?source, ?target, "moved legacy data to Local");
+            Ok(false)
+        }
+        Err(error) if rename_failure(&error) == RenameFailure::Copy => Ok(true),
+        Err(error) => Err(error),
+    }
+}
+
+fn copy_then_remove(source: &Path, target: &Path) -> io::Result<()> {
+    if target.try_exists()? {
+        return Ok(());
+    }
+    let parent = target.parent().ok_or_else(|| io::Error::other("missing data parent"))?;
+    fs::create_dir_all(parent)?;
+    let staging = parent.join(format!(".migration-{}", uuid::Uuid::new_v4()));
+    let result = (|| {
+        copy_tree(source, &staging)?;
+        relocate_shims(&staging, source)?;
+        // A tool may have been installed or a cache rebuilt while copying. Never
+        // merge into or overwrite it, and retain the original for recovery.
+        if target.try_exists()? {
+            tracing::info!(?source, ?target, "Local data created during migration; retaining legacy copy");
+            return Ok(());
+        }
+        rename_missing(&staging, target)?;
+        remove_entry(source)?;
+        tracing::info!(?source, ?target, "copied legacy data to Local");
+        Ok(())
+    })();
+    if staging.exists() {
+        let _ = remove_entry(&staging);
+    }
+    result
+}
+
+// std::fs::rename may replace even an empty directory on modern Windows.
+#[cfg(windows)]
+fn rename_missing(source: &Path, target: &Path) -> io::Result<()> {
+    use std::os::windows::ffi::OsStrExt;
+    use windows_sys::Win32::Storage::FileSystem::MoveFileExW;
+
+    // canonicalize supplies extended-length paths, including redirected UNC roots.
+    let source = fs::canonicalize(source)?;
+    let target = fs::canonicalize(target.parent().ok_or_else(|| io::Error::other("missing data parent"))?)?
+        .join(target.file_name().ok_or_else(|| io::Error::other("missing data name"))?);
+    let wide = |path: &Path| -> io::Result<Vec<u16>> {
+        let mut value: Vec<u16> = path.as_os_str().encode_wide().collect();
+        if value.contains(&0) {
+            return Err(io::Error::new(io::ErrorKind::InvalidInput, "NUL in data path"));
+        }
+        value.push(0);
+        Ok(value)
+    };
+    let source = wide(&source)?;
+    let target = wide(&target)?;
+    // SAFETY: both paths are valid NUL-terminated UTF-16 buffers. No flags means
+    // neither replacement nor implicit cross-volume copying is permitted.
+    if unsafe { MoveFileExW(source.as_ptr(), target.as_ptr(), 0) } == 0 {
+        Err(io::Error::last_os_error())
+    } else {
+        Ok(())
+    }
+}
+
+// Filesystem tests run on Unix too; production migration is Windows-only.
+#[cfg(not(windows))]
+fn rename_missing(source: &Path, target: &Path) -> io::Result<()> {
+    if target.try_exists()? {
+        return Err(io::Error::from(io::ErrorKind::AlreadyExists));
+    }
+    fs::rename(source, target)
+}
+
+fn remove_entry(path: &Path) -> io::Result<()> {
+    if fs::symlink_metadata(path)?.is_dir() { fs::remove_dir_all(path) } else { fs::remove_file(path) }
+}
+
+fn copy_tree(source: &Path, target: &Path) -> io::Result<()> {
+    let metadata = fs::symlink_metadata(source)?;
+    if metadata.file_type().is_symlink() {
+        return Err(io::Error::other("refusing to follow a link during data migration"));
+    }
+    if metadata.is_dir() {
+        fs::create_dir(target)?;
+        for entry in fs::read_dir(source)? {
+            let entry = entry?;
+            copy_tree(&entry.path(), &target.join(entry.file_name()))?;
+        }
+    } else if metadata.is_file() {
+        fs::copy(source, target)?;
+    } else {
+        return Err(io::Error::other("unsupported data entry"));
+    }
+    Ok(())
+}
+
+/// Make our absolute .cmd wrappers relative to their bin directory. They remain
+/// valid in both locations if the move must be rolled back. npm shims already use
+/// relative paths; payloads and user configuration are never rewritten.
+fn relocate_shims(root: &Path, source: &Path) -> io::Result<()> {
+    if source.parent().and_then(Path::file_name).is_none_or(|name| name != "tools") {
+        return Ok(());
+    }
+    let bin = root.join("bin");
+    if !bin.is_dir() {
+        return Ok(());
+    }
+    for entry in fs::read_dir(bin)? {
+        let path = entry?.path();
+        if path.extension().is_none_or(|ext| ext != "cmd") {
+            continue;
+        }
+        let text = fs::read_to_string(&path)?;
+        if text.starts_with("@echo off\r\n") {
+            let updated = relative_wrapper(&text, source);
+            if updated != text {
+                fs::write(path, updated)?;
+            }
+        }
+    }
+    Ok(())
+}
+
+fn relative_wrapper(text: &str, source: &Path) -> String {
+    // PathBuf can contain both separators (notably roots joined with "tools/demo").
+    // Compare normalized paths, but retain every other byte of the managed wrapper.
+    let normalized = text.replace('\\', "/");
+    let prefix = source.to_string_lossy().replace('\\', "/");
+    #[cfg(windows)]
+    let (normalized, prefix) = (normalized.to_ascii_lowercase(), prefix.to_ascii_lowercase());
+    let mut updated = text.to_owned();
+    let offsets: Vec<_> = normalized.match_indices(&prefix).map(|(offset, _)| offset).collect();
+    for offset in offsets.into_iter().rev() {
+        let end = offset + prefix.len();
+        if normalized.as_bytes().get(end) == Some(&b'/') {
+            updated.replace_range(offset..end, "%~dp0..");
+        }
+    }
+    updated
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn wrappers_accept_mixed_separators_without_rewriting_neighbor_paths() {
+        let text = "@echo off\r\n\"C:\\old\\tools/demo\\payload.exe\" \"C:\\old\\tools/demo-other\\x\" %*\r\n";
+        assert_eq!(
+            relative_wrapper(text, Path::new("C:/old/tools/demo")),
+            "@echo off\r\n\"%~dp0..\\payload.exe\" \"C:\\old\\tools/demo-other\\x\" %*\r\n"
+        );
+    }
+
+    #[test]
+    fn storage_policy_is_conservative_and_preserves_unix_layout() {
+        for entry in [
+            "tools/jdks",
+            "language-server-runtimes",
+            "lsp/jdtls",
+            "index/x",
+            "cache/x",
+            "notebook-runtime",
+            "server",
+            "logs",
+            "agents/tools",
+            "agents/registry.json",
+            "java-usages-1.1.1.jar",
+            "java-usages-1.2.0.jar",
+        ] {
+            assert!(is_local(Path::new(entry)), "{entry}");
+            assert_eq!(
+                data_path(Path::new("roaming"), Path::new("local"), Path::new(entry)),
+                Path::new("local").join(entry)
+            );
+            assert_eq!(
+                data_path(Path::new("data"), Path::new("data"), Path::new(entry)),
+                Path::new("data").join(entry)
+            );
+        }
+        for entry in [
+            "git-credentials.json",
+            "history",
+            "remote",
+            "scratches",
+            "consoles",
+            "plugins",
+            "workspaces",
+            "agents/models.json",
+            "agents/project",
+            "unknown",
+        ] {
+            assert!(!is_local(Path::new(entry)), "{entry}");
+            assert_eq!(
+                data_path(Path::new("roaming"), Path::new("local"), Path::new(entry)),
+                Path::new("roaming").join(entry)
+            );
+        }
+    }
+
+    #[cfg(not(target_os = "windows"))]
+    #[test]
+    fn unix_startup_does_not_migrate_even_if_given_distinct_roots() {
+        assert_eq!(dirs::data_dir(), dirs::data_local_dir());
+        let tmp = tempfile::tempdir().unwrap();
+        let old = tmp.path().join("old");
+        let new = tmp.path().join("new");
+        fs::create_dir_all(old.join("index")).unwrap();
+        migrate(&old, &new);
+        assert!(old.join("index").exists());
+        assert!(!new.exists());
+    }
+
+    #[test]
+    fn decisions_cover_missing_existing_and_failed_renames() {
+        assert_eq!(action(true, true, false), Action::Skip);
+        assert_eq!(action(false, false, false), Action::Skip);
+        assert_eq!(action(false, true, true), Action::Skip);
+        assert_eq!(action(false, true, false), Action::Rename);
+        assert_eq!(rename_failure(&io::Error::from(io::ErrorKind::CrossesDevices)), RenameFailure::Copy);
+        for kind in [io::ErrorKind::PermissionDenied, io::ErrorKind::AlreadyExists, io::ErrorKind::NotFound] {
+            assert_eq!(rename_failure(&io::Error::from(kind)), RenameFailure::KeepSource);
+        }
+    }
+
+    #[test]
+    fn same_volume_moves_and_second_start_does_not_overwrite() {
+        let tmp = tempfile::tempdir().unwrap();
+        let old = tmp.path().join("old");
+        let new = tmp.path().join("new");
+        fs::create_dir_all(old.join("tools/demo/bin")).unwrap();
+        let wrapper = format!("@echo off\r\n\"{}/payload.exe\" %*\r\n", old.join("tools/demo").display());
+        fs::write(old.join("tools/demo/bin/demo.cmd"), wrapper).unwrap();
+        fs::create_dir_all(old.join("tools/ty/venv")).unwrap();
+        fs::write(old.join("git-credentials.json"), "secret").unwrap();
+        fs::create_dir_all(old.join("index")).unwrap();
+        migrate_entries(&old, &new);
+        assert!(!old.join("tools/demo").exists());
+        assert!(old.join("tools/ty/venv").exists());
+        assert!(old.join("git-credentials.json").exists());
+        assert!(fs::read_to_string(new.join("tools/demo/bin/demo.cmd")).unwrap().contains("%~dp0.."));
+        fs::create_dir_all(old.join("index")).unwrap();
+        fs::write(old.join("index/legacy"), "old").unwrap();
+        migrate_entries(&old, &new);
+        assert!(old.join("index/legacy").exists());
+        assert!(!new.join("index/legacy").exists());
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn copy_failure_does_not_publish_or_remove_source() {
+        let tmp = tempfile::tempdir().unwrap();
+        let old = tmp.path().join("old");
+        let new = tmp.path().join("new");
+        fs::create_dir(&old).unwrap();
+        fs::write(old.join("payload"), "old").unwrap();
+        std::os::unix::fs::symlink(old.join("payload"), old.join("link")).unwrap();
+        assert!(copy_then_remove(&old, &new).is_err());
+        assert!(old.join("payload").exists());
+        assert!(!new.exists());
+        assert_eq!(fs::read_dir(tmp.path()).unwrap().count(), 1);
+    }
+
+    #[test]
+    fn staged_copy_publishes_complete_data_and_preserves_existing_target() {
+        let tmp = tempfile::tempdir().unwrap();
+        let old = tmp.path().join("old");
+        let new = tmp.path().join("new");
+        fs::create_dir_all(old.join("nested")).unwrap();
+        fs::write(old.join("nested/tool.exe"), "payload").unwrap();
+        copy_then_remove(&old, &new).unwrap();
+        assert!(!old.exists());
+        assert_eq!(fs::read_to_string(new.join("nested/tool.exe")).unwrap(), "payload");
+        fs::create_dir(&old).unwrap();
+        fs::write(old.join("legacy"), "old").unwrap();
+        copy_then_remove(&old, &new).unwrap();
+        assert!(old.join("legacy").exists());
+        assert!(!new.join("legacy").exists());
+        let old_file = tmp.path().join("registry-old.json");
+        let new_file = tmp.path().join("registry-new.json");
+        fs::write(&old_file, "cached registry").unwrap();
+        copy_then_remove(&old_file, &new_file).unwrap();
+        assert!(!old_file.exists());
+        assert_eq!(fs::read_to_string(new_file).unwrap(), "cached registry");
+    }
+
+    #[test]
+    fn publication_refuses_existing_files_and_empty_directories() {
+        let tmp = tempfile::tempdir().unwrap();
+        for directory in [false, true] {
+            let old = tmp.path().join(if directory { "old-dir" } else { "old-file" });
+            let new = tmp.path().join(if directory { "new-dir" } else { "new-file" });
+            if directory {
+                fs::create_dir(&old).unwrap();
+                fs::create_dir(&new).unwrap();
+                fs::write(old.join("payload"), "old").unwrap();
+            } else {
+                fs::write(&old, "old").unwrap();
+                fs::write(&new, "new").unwrap();
+            }
+            assert!(rename_missing(&old, &new).is_err());
+            assert!(old.exists() && new.exists());
+            if directory {
+                assert!(!new.join("payload").exists());
+            } else {
+                assert_eq!(fs::read_to_string(new).unwrap(), "new");
+            }
+        }
+    }
+
+    #[test]
+    fn wrapper_failure_keeps_the_old_installation() {
+        let tmp = tempfile::tempdir().unwrap();
+        let old = tmp.path().join("old/tools/demo");
+        let new = tmp.path().join("new/tools/demo");
+        fs::create_dir_all(old.join("bin")).unwrap();
+        fs::write(old.join("bin/demo.cmd"), [0xff, 0xfe]).unwrap();
+        assert!(try_rename(&old, &new).is_err());
+        assert!(old.join("bin/demo.cmd").exists());
+        assert!(!new.exists());
+    }
+
+    #[test]
+    fn failures_keep_source_without_publishing_partial_data() {
+        let tmp = tempfile::tempdir().unwrap();
+        let old = tmp.path().join("old");
+        let blocker = tmp.path().join("blocker");
+        fs::create_dir(&old).unwrap();
+        fs::write(old.join("payload"), "old").unwrap();
+        fs::write(&blocker, "file").unwrap();
+        assert!(try_rename(&old, &blocker.join("target")).is_err());
+        assert!(copy_then_remove(&old, &blocker.join("target")).is_err());
+        assert!(old.join("payload").exists());
+        assert!(copy_then_remove(&tmp.path().join("missing"), &tmp.path().join("new")).is_err());
+        assert!(!tmp.path().join("new").exists());
+        assert!(
+            !fs::read_dir(tmp.path())
+                .unwrap()
+                .flatten()
+                .any(|e| e.file_name().to_string_lossy().starts_with(".migration-"))
+        );
+    }
+}

crates/ide-host/src/environment.rs

@@ -44,6 +44,7 @@ struct State {
     project: Changes,
     /// Project roots whose `postStartCommand` ran in this process.
     post_started: HashSet<PathBuf>,
+    post_commands: std::collections::HashMap<PathBuf, CancellationToken>,
 }
 
 pub struct Environment {
@@ -78,7 +79,12 @@ impl Environment {
 
     pub(crate) fn project_closed(&self) {
         if self.project_env {
-            self.state.lock().project.clear();
+            let mut state = self.state.lock();
+            for (_, token) in state.post_commands.drain() {
+                token.cancel();
+            }
+            state.project.clear();
+            drop(state);
             self.publish();
         }
     }
@@ -144,6 +150,7 @@ impl Environment {
     /// a failure is a notification.
     pub(crate) fn spawn_post_start(&self, cmd: LifecycleCommand, root: PathBuf, sink: SharedSink) {
         let cancel = self.cancel.child_token();
+        self.state.lock().post_commands.insert(root.clone(), cancel.clone());
         let spawned = std::thread::Builder::new().name("openidea-post-start".into()).spawn(move || {
             run_post_start(&cmd, &root, &sink, &cancel);
         });
@@ -263,6 +270,9 @@ fn run_post_start(cmd: &LifecycleCommand, root: &Path, sink: &SharedSink, cancel
 /// Runs `argv` in `root` with the children's environment, its stdout and stderr line by line
 /// to `on_line`; `Err` says how it failed.
 fn run_one(argv: &[String], root: &Path, cancel: &CancellationToken, on_line: &dyn Fn(String)) -> Result<(), String> {
+    if cancel.is_cancelled() {
+        return Err("cancelled".into());
+    }
     let (program, args) = argv.split_first().ok_or("empty command")?;
     let mut child = ide_core::process::prepare(&mut Command::new(program))
         .args(args)

crates/ide-host/src/formatter.rs

@@ -0,0 +1,195 @@
+//! Select the document's formatting provider before executing it on this host.
+
+use crate::Host;
+use ide_core::event::NotifyLevel;
+use ide_core::settings::{ExternalFormatter, LanguagesSettings};
+use ide_core::{DocId, IdeError, IdeEvent, IdeResult, Range, TextEdit};
+use ide_language::LanguageConfig;
+use ide_lsp::types::FormatOptions;
+use ide_tools::{Tools, formatter};
+use std::path::Path;
+
+const OXFMT_CONFIGS: [&str; 4] = [".oxfmtrc.json", ".oxfmtrc.jsonc", "oxfmt.config.ts", "oxfmt.config.mts"];
+
+/// The external formatter of a file, for a language with an external formatter.
+/// `forced` names the tool (Reformat with Prettier/oxfmt). Otherwise oxfmt
+/// applies when it is enabled for the language and either an oxfmt
+/// configuration is found above the file or oxfmt is the selected provider;
+/// else Prettier, when it is enabled. Turning Prettier off for a language
+/// leaves it to the language server, not to oxfmt.
+fn external_tool(
+    forced: Option<ExternalFormatter>,
+    language: Option<&LanguageConfig>,
+    file: &Path,
+    settings: &LanguagesSettings,
+) -> IdeResult<Option<ExternalFormatter>> {
+    use ExternalFormatter::{Oxfmt, Prettier};
+    let Some(language) = language.filter(|l| l.formatter.as_ref().is_some_and(|f| f.tool == "prettier")) else {
+        return match forced {
+            Some(tool) => Err(IdeError::invalid(format!(
+                "{} cannot format {} files",
+                formatter::display_name(tool.name()),
+                language.map_or("these", |l| l.name.as_str())
+            ))),
+            None => Ok(None),
+        };
+    };
+    if forced.is_some() {
+        return Ok(forced);
+    }
+    let enabled = |tool| settings.formatter(tool).languages.iter().any(|l| l == language.id.as_str());
+    let oxfmt_config = || OXFMT_CONFIGS.iter().any(|name| formatter::find_up(file, Path::new(name)).is_some());
+    Ok(if enabled(Oxfmt) && (settings.oxfmt.prefer || oxfmt_config()) {
+        Some(Oxfmt)
+    } else {
+        enabled(Prettier).then_some(Prettier)
+    })
+}
+
+pub async fn format(
+    host: &Host,
+    window: &str,
+    doc: DocId,
+    range: Option<Range>,
+    options: FormatOptions,
+) -> IdeResult<Vec<TextEdit>> {
+    let project = host.project(window)?;
+    let snap = project.documents.snapshot(doc)?;
+    let settings = project.settings.effective();
+    let language = project.languages.get(&snap.language);
+    let mut selected = external_tool(options.tool, language.as_ref(), &snap.path, &settings.languages)?;
+    if let Some(tool) = selected
+        && options.tool.is_none()
+        && !settings.languages.formatter(tool).prefer
+        && project.lsp.can_format(doc).await?
+    {
+        selected = None;
+    }
+    let Some(selected) = selected else {
+        if options.on_save && !settings.editor.format_on_save {
+            return Ok(Vec::new());
+        }
+        return project.lsp.format(doc, range, options).await;
+    };
+    let tool_settings = settings.languages.formatter(selected);
+    if options.on_save && !tool_settings.run_on_save {
+        return Ok(Vec::new());
+    }
+    host.require_trust(window)?;
+    if snap.read_only {
+        return Err(IdeError::invalid("The file is read-only"));
+    }
+    let config = language.and_then(|l| l.formatter).expect("external_tool selects languages with a formatter");
+    let tool = selected.name();
+    let name = formatter::display_name(tool);
+    let custom = ide_sdk::apply::setting_path(&project.root, &tool_settings.path);
+    let tools = Tools::new(&host.local_data_dir);
+    let whole_selection = range.is_some() && !formatter::supports_range(tool, &config);
+    let edits: IdeResult<Vec<TextEdit>> = tokio::task::spawn_blocking(move || {
+        let text = ide_text::Document::new(&snap.text);
+        let offsets = range.map(|r| (text.pos_to_offset(r.start), text.pos_to_offset(r.end)));
+        let mut command = tools.formatter_command(tool, &snap.path, custom.as_deref())?;
+        let dir = snap.path.parent().ok_or_else(|| IdeError::invalid(format!("{name}: file has no directory")))?;
+        command.current_dir(dir);
+        command.args(formatter::arguments(tool, &config, &snap.path, options.tab_size, options.insert_spaces, offsets));
+        let formatted = formatter::run(tool, command, &snap.text, &Default::default())?;
+        Ok(text
+            .diff(&formatted)
+            .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())
+    })
+    .await
+    .map_err(|e| IdeError::internal(e.to_string()))?;
+    if edits.is_ok() && whole_selection {
+        project.sink.emit(IdeEvent::Notify {
+            level: NotifyLevel::Info,
+            title: name.into(),
+            body: Some(format!(
+                "{name} does not support selection formatting for this language; formatted the whole file"
+            )),
+        });
+    }
+    edits.map_err(|e| e.with_tool(tool))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use ExternalFormatter::{Oxfmt, Prettier};
+    use ide_core::LanguageId;
+    use ide_language::LanguageRegistry;
+
+    fn tool(
+        forced: Option<ExternalFormatter>,
+        language: &str,
+        file: &Path,
+        settings: &LanguagesSettings,
+    ) -> IdeResult<Option<ExternalFormatter>> {
+        let language = LanguageRegistry::load(None).unwrap().get(&LanguageId::new(language));
+        external_tool(forced, language.as_ref(), file, settings)
+    }
+
+    #[test]
+    fn default_settings_give_every_external_formatter_language_to_prettier() {
+        let settings = LanguagesSettings::default();
+        let file = Path::new("/project/file");
+        for lang in LanguageRegistry::load(None).unwrap().all() {
+            let configured = lang.formatter.as_ref().is_some_and(|f| f.tool == "prettier");
+            let selected = external_tool(None, Some(&lang), file, &settings).unwrap();
+            assert_eq!(selected, configured.then_some(Prettier), "{}", lang.id);
+        }
+        assert_eq!(external_tool(None, None, file, &settings).unwrap(), None);
+    }
+
+    #[test]
+    fn oxfmt_config_selects_oxfmt_for_its_enabled_languages() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        std::fs::create_dir_all(root.join("web/src")).unwrap();
+        let (web, api) = (root.join("web/src/app.ts"), root.join("api/main.ts"));
+        let mut settings = LanguagesSettings::default();
+        assert_eq!(tool(None, "typescript", &web, &settings).unwrap(), Some(Prettier));
+        for config in OXFMT_CONFIGS {
+            std::fs::write(root.join("web").join(config), "{}").unwrap();
+            assert_eq!(tool(None, "typescript", &web, &settings).unwrap(), Some(Oxfmt), "{config}");
+            assert_eq!(tool(None, "typescript", &api, &settings).unwrap(), Some(Prettier), "{config}");
+            std::fs::remove_file(root.join("web").join(config)).unwrap();
+        }
+        std::fs::write(root.join("web/.oxfmtrc.json"), "{}").unwrap();
+        settings.oxfmt.languages.retain(|l| l != "markdown");
+        assert_eq!(tool(None, "markdown", &web, &settings).unwrap(), Some(Prettier));
+        assert_eq!(tool(None, "typescript", &web, &settings).unwrap(), Some(Oxfmt));
+    }
+
+    #[test]
+    fn oxfmt_provider_selects_oxfmt_without_a_config_and_prettier_off_leaves_the_language_server() {
+        let file = Path::new("/project/src/app.ts");
+        let mut settings = LanguagesSettings::default();
+        settings.oxfmt.prefer = true;
+        assert_eq!(tool(None, "typescript", file, &settings).unwrap(), Some(Oxfmt));
+        settings.oxfmt.prefer = false;
+        settings.prettier.languages.clear();
+        assert_eq!(tool(None, "typescript", file, &settings).unwrap(), None);
+        settings.oxfmt.prefer = true;
+        settings.oxfmt.languages.clear();
+        assert_eq!(tool(None, "typescript", file, &settings).unwrap(), None);
+    }
+
+    #[test]
+    fn forced_tool_runs_that_formatter_or_reports_why_not() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::write(dir.path().join(".oxfmtrc.json"), "{}").unwrap();
+        let file = dir.path().join("app.ts");
+        let mut settings = LanguagesSettings::default();
+        settings.oxfmt.languages.clear();
+        assert_eq!(tool(Some(Prettier), "typescript", &file, &settings).unwrap(), Some(Prettier));
+        assert_eq!(tool(Some(Oxfmt), "typescript", &file, &settings).unwrap(), Some(Oxfmt));
+        let rust = tool(Some(Oxfmt), "rust", &dir.path().join("main.rs"), &settings).unwrap_err();
+        assert_eq!(rust.message, "oxfmt cannot format Rust files");
+    }
+}

crates/ide-host/src/kotlin_bridge.rs

@@ -0,0 +1,429 @@
+//! Saved Kotlin -> isolated Maven output -> marked JDT libraries.
+
+use ide_build::kotlin_bridge::{self, Outcome, ProjectLibraries};
+use ide_core::event::NotifyLevel;
+use ide_core::{CancellationToken, Diagnostic, IdeEvent, Pos, Range, Severity, SharedSink};
+use ide_lsp::LspManager;
+use ide_workspace::SettingsStore;
+use ide_workspace::documents::DocumentObserver;
+use parking_lot::Mutex;
+use serde::{Deserialize, Serialize};
+use std::collections::BTreeSet;
+use std::path::{Path, PathBuf};
+use std::sync::{
+    Arc,
+    atomic::{AtomicBool, Ordering},
+};
+use std::time::Duration;
+use tokio::sync::Notify;
+
+const DELAY: Duration = Duration::from_millis(750);
+const SOURCE: &str = "kotlin-bridge";
+const COMMAND: &str = "openidea.kotlin.replace";
+
+#[derive(Default)]
+struct Revision {
+    generation: u64,
+    cancel: CancellationToken,
+}
+
+impl Revision {
+    fn change(&mut self) {
+        self.cancel.cancel();
+        self.generation += 1;
+        self.cancel = CancellationToken::new();
+    }
+    fn current(&self, generation: u64) -> bool {
+        self.generation == generation && !self.cancel.is_cancelled()
+    }
+}
+
+#[derive(Clone, Default, Serialize, Deserialize)]
+struct MavenOptions {
+    offline: bool,
+    profiles: Vec<String>,
+}
+
+pub(crate) struct KotlinBridge {
+    root: PathBuf,
+    cache: PathBuf,
+    bundle: Option<PathBuf>,
+    settings: Arc<SettingsStore>,
+    lsp: Arc<LspManager>,
+    sink: SharedSink,
+    trusted: Arc<AtomicBool>,
+    lifetime: CancellationToken,
+    revision: Mutex<Revision>,
+    changed: Notify,
+    options: Mutex<MavenOptions>,
+    worker: Mutex<Option<tokio::task::JoinHandle<()>>>,
+}
+
+impl KotlinBridge {
+    pub(crate) fn new(
+        root: PathBuf,
+        cache: PathBuf,
+        data: &Path,
+        settings: Arc<SettingsStore>,
+        lsp: Arc<LspManager>,
+        sink: SharedSink,
+        trusted: Arc<AtomicBool>,
+    ) -> Arc<Self> {
+        let options = std::fs::read(cache.join("kotlin-bridge-options.json"))
+            .ok()
+            .and_then(|bytes| serde_json::from_slice(&bytes).ok())
+            .unwrap_or_default();
+        Arc::new(Self {
+            root,
+            cache,
+            bundle: ide_sdk::java::kotlin_bridge_bundle(data),
+            settings,
+            lsp,
+            sink,
+            trusted,
+            lifetime: CancellationToken::new(),
+            revision: Mutex::new(Revision::default()),
+            changed: Notify::new(),
+            options: Mutex::new(options),
+            worker: Mutex::new(None),
+        })
+    }
+
+    pub(crate) fn start(self: &Arc<Self>, runtime: &tokio::runtime::Handle) {
+        let bridge = self.clone();
+        *self.worker.lock() = Some(runtime.spawn(async move { bridge.run().await }));
+        self.schedule();
+    }
+
+    pub(crate) fn configure_maven(&self, offline: bool, profiles: Vec<String>) {
+        let options = MavenOptions { offline, profiles };
+        if let Ok(bytes) = serde_json::to_vec(&options) {
+            let _ = std::fs::create_dir_all(&self.cache);
+            let _ = std::fs::write(self.cache.join("kotlin-bridge-options.json"), bytes);
+        }
+        *self.options.lock() = options;
+        self.schedule();
+    }
+
+    pub(crate) async fn shutdown(&self) {
+        self.stop();
+        let worker = self.worker.lock().take();
+        if let Some(worker) = worker {
+            let _ = worker.await;
+        }
+    }
+
+    pub(crate) fn schedule(&self) {
+        if self.lifetime.is_cancelled() {
+            return;
+        }
+        self.revision.lock().change();
+        self.changed.notify_one();
+    }
+
+    pub(crate) fn files_changed<'a>(&self, mut paths: impl Iterator<Item = &'a PathBuf>) {
+        let settings = self.settings.effective();
+        if paths.any(|path| relevant_change(&self.root, path, &settings)) {
+            self.schedule();
+        }
+    }
+
+    pub(crate) fn stop(&self) {
+        self.lifetime.cancel();
+        self.revision.lock().cancel.cancel();
+    }
+
+    async fn replace(&self, projects: &[ProjectLibraries], cancel: &CancellationToken) -> ide_core::IdeResult<()> {
+        let snapshot = serde_json::to_value(projects).map_err(|e| ide_core::IdeError::internal(e.to_string()))?;
+        let response = self.lsp.jdtls_command_cancellable(&self.root, COMMAND, vec![snapshot], cancel).await?;
+        if response.as_u64().is_none() {
+            return Err(ide_core::IdeError::unavailable(
+                "Kotlin bridge command did not acknowledge its library snapshot",
+            ));
+        }
+        Ok(())
+    }
+
+    async fn run(self: Arc<Self>) {
+        let mut diagnostics = BTreeSet::new();
+        let mut last_failure = String::new();
+        let mut initialized = false;
+        // Also retain directories from unacknowledged replacements: JDT may have applied them.
+        let mut published = Vec::new();
+        loop {
+            tokio::select! {
+                _ = self.lifetime.cancelled() => return,
+                _ = self.changed.notified() => {},
+            }
+            let (generation, cancel) = {
+                let state = self.revision.lock();
+                (state.generation, state.cancel.clone())
+            };
+            if !self.trusted.load(Ordering::Acquire) {
+                continue;
+            }
+            if !debounce(&cancel, &self.lifetime).await {
+                continue;
+            }
+            let root = self.root.clone();
+            let cache = self.cache.clone();
+            let settings = self.settings.effective();
+            let has_sources = tokio::task::spawn_blocking(move || {
+                let model = crate::ops::build::load(&root, &cache, &settings);
+                let enabled =
+                    model.maven.as_ref().is_some_and(|m| !m.projects.is_empty()) && kotlin_bridge::has_kotlin(&root);
+                (model, enabled)
+            })
+            .await;
+            let Ok((mut model, enabled)) = has_sources else { continue };
+            if !self.revision.lock().current(generation) {
+                continue;
+            }
+            if !enabled {
+                if self.cache.join("kotlin-bridge").exists()
+                    && let Err(error) = self.replace(&[], &cancel).await
+                {
+                    if !cancel.is_cancelled() {
+                        tracing::warn!("Kotlin library withdrawal: {error}");
+                    }
+                    continue;
+                }
+                for old in published.drain(..) {
+                    remove_directory(old).await;
+                }
+                self.clear_diagnostics(&mut diagnostics);
+                last_failure.clear();
+                continue;
+            }
+            if let Some(maven) = &mut model.maven {
+                let options = self.options.lock();
+                for module in &mut maven.projects {
+                    if options.offline {
+                        module.options.push("-o".into());
+                    }
+                    if !options.profiles.is_empty() {
+                        module.options.push(format!("-P{}", options.profiles.join(",")));
+                    }
+                }
+            }
+            let Some(bundle) = self.bundle.clone() else {
+                self.failure("Kotlin bridge bundle is unavailable".into(), &mut diagnostics, &mut last_failure);
+                continue;
+            };
+            // Clear entries persisted by an earlier incarnation only before our first build.
+            if !initialized {
+                if let Err(error) = self.replace(&[], &cancel).await {
+                    if !cancel.is_cancelled() {
+                        self.failure(error.message, &mut diagnostics, &mut last_failure);
+                    }
+                    continue;
+                }
+                initialized = true;
+            }
+            let directory = self.cache.join(format!("kotlin-bridge/{}", uuid::Uuid::new_v4()));
+            let staging = directory.clone();
+            let root = self.root.clone();
+            let token = cancel.clone();
+            let result =
+                tokio::task::spawn_blocking(move || kotlin_bridge::build(&root, &model, &bundle, &staging, &token))
+                    .await;
+            if !self.revision.lock().current(generation) || self.lifetime.is_cancelled() {
+                remove_directory(directory).await;
+                continue;
+            }
+            match result {
+                Ok(Ok(Outcome { success: true, projects, .. })) => {
+                    match self.replace(&projects, &cancel).await {
+                        Ok(()) => {
+                            for old in published.drain(..) {
+                                remove_directory(old).await;
+                            }
+                            published.push(directory);
+                            self.clear_diagnostics(&mut diagnostics);
+                            last_failure.clear();
+                        }
+                        Err(error) => {
+                            // Keep both snapshots until an acknowledged replacement.
+                            published.push(directory);
+                            if !cancel.is_cancelled() {
+                                self.failure(error.message, &mut diagnostics, &mut last_failure);
+                            }
+                        }
+                    }
+                }
+                other => {
+                    let text = match other {
+                        Ok(Ok(outcome)) => outcome
+                            .messages
+                            .iter()
+                            .filter(|m| m.severity == Severity::Error)
+                            .map(|m| m.text.as_str())
+                            .collect::<Vec<_>>()
+                            .join("\n"),
+                        Ok(Err(error)) => error.message,
+                        Err(error) => error.to_string(),
+                    };
+                    self.failure(text, &mut diagnostics, &mut last_failure);
+                    remove_directory(directory).await;
+                }
+            }
+        }
+    }
+
+    fn clear_diagnostics(&self, paths: &mut BTreeSet<PathBuf>) {
+        for path in std::mem::take(paths) {
+            self.sink.emit(IdeEvent::Diagnostics { path: path.into(), source: SOURCE.into(), items: Vec::new() });
+        }
+    }
+
+    fn failure(&self, text: String, paths: &mut BTreeSet<PathBuf>, previous: &mut String) {
+        let text = if text.is_empty() { "Kotlin compilation failed".to_owned() } else { text };
+        let text = format!("{text}\nJava temporarily uses the last successfully compiled Kotlin API.");
+        self.clear_diagnostics(paths);
+        let path = self.root.join("pom.xml");
+        paths.insert(path.clone());
+        self.sink.emit(IdeEvent::Diagnostics {
+            path: path.into(),
+            source: SOURCE.into(),
+            items: vec![Diagnostic {
+                range: Range { start: Pos { line: 0, col: 0 }, end: Pos { line: 0, col: 0 } },
+                severity: Severity::Error,
+                message: text.clone(),
+                source: Some(SOURCE.into()),
+                server: Some(SOURCE.into()),
+                code: None,
+                unnecessary: false,
+                deprecated: false,
+            }],
+        });
+        if previous != &text {
+            self.sink.emit(IdeEvent::Notify {
+                level: NotifyLevel::Error,
+                title: "Kotlin editor compilation failed".into(),
+                body: Some(text.clone()),
+            });
+            *previous = text;
+        }
+    }
+}
+
+fn relevant_change(root: &Path, path: &Path, settings: &ide_core::settings::Settings) -> bool {
+    let input = path.extension().is_some_and(|e| e == "kt")
+        || path.file_name().is_some_and(|n| n == "pom.xml" || n == "mvnw" || n == "mvnw.cmd")
+        || path.components().any(|c| c.as_os_str() == ".mvn");
+    let Ok(relative) = path.strip_prefix(root) else {
+        // Content roots outside the project only contribute Kotlin sources.
+        return path.extension().is_some_and(|e| e == "kt");
+    };
+    // Build outputs and generated sources (e.g. KSP's `.kt` under target/) never trigger,
+    // so a build cannot schedule itself.
+    if relative.components().any(|c| {
+        matches!(
+            c.as_os_str().to_str(),
+            Some("target" | "build" | "out" | "bin" | ".git" | "node_modules" | ".openidea")
+        )
+    }) || ide_vfs::ExcludeMatcher::new(&settings.exclude_globs()).is_excluded(relative)
+    {
+        return false;
+    }
+    if input {
+        return true;
+    }
+    if path.extension().is_some() {
+        return false;
+    }
+    // Works for deleted directories too; the module POM remains on disk.
+    path.ancestors().take_while(|ancestor| ancestor.starts_with(root)).any(|ancestor| {
+        ancestor.file_name().is_some_and(|name| name == "src")
+            && ancestor.parent().is_some_and(|module| module.join("pom.xml").is_file())
+    })
+}
+
+async fn debounce(cancel: &CancellationToken, lifetime: &CancellationToken) -> bool {
+    tokio::select! {
+        _ = lifetime.cancelled() => false,
+        _ = cancel.cancelled() => false,
+        _ = tokio::time::sleep(DELAY) => true,
+    }
+}
+
+async fn remove_directory(path: PathBuf) {
+    let _ = tokio::task::spawn_blocking(move || std::fs::remove_dir_all(path)).await;
+}
+
+impl DocumentObserver for KotlinBridge {
+    fn saved(&self, _doc: ide_core::DocId, path: &Path, _text: &str) {
+        self.files_changed(std::iter::once(&path.to_path_buf()));
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn target_package_directory_does_not_trigger() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::write(dir.path().join("pom.xml"), "").unwrap();
+        assert!(!relevant_change(dir.path(), &dir.path().join("target/classes/probe"), &Default::default()));
+        let generated = dir.path().join("target/generated-sources/ksp/main/kotlin/Gen.kt");
+        assert!(!relevant_change(dir.path(), &generated, &Default::default()));
+        assert!(relevant_change(dir.path(), &dir.path().join("src/main/kotlin/A.kt"), &Default::default()));
+    }
+
+    #[test]
+    fn deleted_source_package_triggers_unless_excluded() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::create_dir_all(dir.path().join("module")).unwrap();
+        std::fs::write(dir.path().join("module/pom.xml"), "").unwrap();
+        let path = dir.path().join("module/src/main/kotlin/pkg");
+        let mut settings = ide_core::settings::Settings::default();
+        assert!(relevant_change(dir.path(), &path, &settings));
+        settings.project_structure.excluded.push("module/src/main/kotlin".into());
+        assert!(!relevant_change(dir.path(), &path, &settings));
+        assert!(!relevant_change(dir.path(), &dir.path().join("module/src/build/pkg"), &Default::default()));
+    }
+
+    #[test]
+    fn extensionless_root_file_does_not_trigger() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::write(dir.path().join("pom.xml"), "").unwrap();
+        assert!(!relevant_change(dir.path(), &dir.path().join("LICENSE"), &Default::default()));
+    }
+
+    #[tokio::test(start_paused = true)]
+    async fn burst_saves_cancel_the_pending_debounce() {
+        let mut state = Revision::default();
+        state.change();
+        let token = state.cancel.clone();
+        let lifetime = CancellationToken::new();
+        let pending_lifetime = lifetime.clone();
+        let waiting = tokio::spawn(async move { debounce(&token, &pending_lifetime).await });
+        tokio::task::yield_now().await;
+        tokio::time::advance(DELAY - Duration::from_millis(1)).await;
+        assert!(!waiting.is_finished());
+        for _ in 0..20 {
+            state.change();
+        }
+        assert!(!waiting.await.unwrap());
+        let current = state.generation;
+        assert!(debounce(&state.cancel, &lifetime).await);
+        assert!(state.current(current));
+        lifetime.cancel();
+        assert!(!debounce(&state.cancel, &lifetime).await);
+    }
+
+    #[test]
+    fn superseded_and_cancelled_builds_cannot_publish() {
+        let mut state = Revision::default();
+        state.change();
+        let first = state.generation;
+        let token = state.cancel.clone();
+        state.change();
+        assert!(token.is_cancelled());
+        assert!(!state.current(first));
+        assert!(state.current(state.generation));
+        state.cancel.cancel();
+        assert!(!state.current(state.generation));
+    }
+}

crates/ide-host/src/lib.rs

@@ -1,17 +1,22 @@
 //! The IDE backend without a UI toolkit: open projects per window, terminals,
 //! processes, settings and the remote services. The desktop shell (`src-tauri`)
-//! wraps one [`Host`] and adds windows, menus and plugins; `openidea-server`
+//! wraps one [`Host`] and adds windows and menus; `openidea-server`
 //! runs one on a remote machine and serves it over JSON-RPC ([`rpc`]).
 
+pub mod data_dirs;
 pub mod environment;
+mod formatter;
 mod java_runtime;
+mod kotlin_bridge;
 pub mod notebook;
 pub mod ops;
+pub mod plugins;
 mod project;
 mod proxy;
 mod requests;
 pub mod rpc;
 pub mod shell_env;
+pub mod trust;
 
 pub use project::{Project, apply_git_executable, apply_workspace_edit, history_retention};
 
@@ -30,7 +35,10 @@ pub type SinkFactory = Box<dyn Fn(&str) -> SharedSink + Send + Sync>;
 
 pub struct HostConfig {
     pub config_dir: PathBuf,
+    /// Persistent user state, including credentials and recovery history.
     pub data_dir: PathBuf,
+    /// Machine-local tools and rebuildable caches.
+    pub local_data_dir: PathBuf,
     pub languages: Arc<LanguageRegistry>,
     /// Grammars, possibly still being built on another thread.
     pub syntax: Arc<OnceLock<Arc<Syntax>>>,
@@ -44,11 +52,16 @@ pub struct HostConfig {
 }
 
 pub struct Host {
+    pub trust: trust::TrustStore,
     pub config_dir: PathBuf,
+    /// Persistent user state, including credentials and recovery history.
     pub data_dir: PathBuf,
+    /// Machine-local tools and rebuildable caches.
+    pub local_data_dir: PathBuf,
     pub languages: Arc<LanguageRegistry>,
     syntax: Arc<OnceLock<Arc<Syntax>>>,
     pub global_settings: SettingsStore,
+    pub dependency_versions: Arc<ide_workspace::dependencies::VersionCache>,
     pub terminals: TerminalManager,
     pub processes: ProcessManager,
     /// Debug sessions (adapters run on this machine, next to the project).
@@ -67,21 +80,35 @@ pub struct Host {
     /// One project per window, keyed by window label.
     projects: RwLock<HashMap<String, Arc<Project>>>,
     requests: requests::Requests,
+    project_requests: RwLock<HashMap<String, Vec<RequestId>>>,
 }
 
 impl Host {
     pub fn new(config: HostConfig) -> Self {
-        let HostConfig { config_dir, data_dir, languages, syntax, sink_for, owner, runtime, project_environment } =
-            config;
+        let HostConfig {
+            config_dir,
+            data_dir,
+            local_data_dir,
+            languages,
+            syntax,
+            sink_for,
+            owner,
+            runtime,
+            project_environment,
+        } = config;
         let global_settings = SettingsStore::load(&config_dir, None);
         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 {
+            trust: trust::TrustStore::load(&config_dir, &data_dir),
             proxy_password: ide_ssh::secrets::SecretFile::new(data_dir.join("proxy-password.json")),
             remote: Arc::new(ide_remote::RemoteService::new(ssh.clone(), data_dir.join("remote"))),
             ssh,
-            environment: environment::Environment::new(project_environment, data_dir.clone()),
+            environment: environment::Environment::new(project_environment, local_data_dir.clone()),
             global_settings,
+            dependency_versions: Arc::new(ide_workspace::dependencies::VersionCache::new(
+                data_dir.join("cache/dependency-versions"),
+            )),
             // Sessions, runs and terminals report to the window that started them (`window_sink`).
             terminals: TerminalManager::new(),
             processes: ProcessManager::new(),
@@ -90,11 +117,13 @@ impl Host {
             syntax,
             config_dir,
             data_dir,
+            local_data_dir,
             sink_for,
             owner,
             runtime,
             projects: RwLock::default(),
             requests: Default::default(),
+            project_requests: RwLock::default(),
         };
         host.apply_proxy();
         host
@@ -105,6 +134,17 @@ impl Host {
         self.syntax.get_or_init(|| Arc::new(Syntax::new())).clone()
     }
 
+    /// Plugin languages or the servers they may start changed (they are part
+    /// of [`Self::languages`] and every project's fork): open documents are
+    /// detected again and language servers follow their new configuration.
+    pub fn plugin_languages_changed(&self) {
+        for project in self.projects() {
+            project.documents.redetect_languages();
+            let lsp = project.lsp.clone();
+            self.runtime.spawn(async move { lsp.reconfigure().await });
+        }
+    }
+
     /// Every open project (all windows).
     pub fn projects(&self) -> Vec<Arc<Project>> {
         self.projects.read().values().cloned().collect()
@@ -119,6 +159,10 @@ impl Host {
             .ok_or_else(|| IdeError::not_found("no project is open in this window"))
     }
 
+    pub fn require_trust(&self, window: &str) -> IdeResult<()> {
+        self.project(window)?.require_trust()
+    }
+
     /// The window that owns what `window` starts.
     pub fn owner_window<'a>(&self, window: &'a str) -> &'a str {
         (self.owner)(window)
@@ -139,17 +183,42 @@ impl Host {
             if !project.light {
                 self.environment.project_closed();
             }
+            if let Some(bridge) = &project.kotlin_bridge {
+                bridge.stop();
+            }
+            project.documents.clear_workspace_edit_history();
             project.agents.shutdown();
             project.notebooks.stop_admission();
-            self.shutdown_notebooks_blocking(vec![project.notebooks.clone()]);
-            let lsp = project.lsp.clone();
-            self.runtime.spawn(async move { lsp.shutdown_all().await });
+            // What the closing window started goes with it — the builds and searches it
+            // asked for, its runs, its shells and its debug sessions — and the language
+            // servers finish shutting down before the window is gone, as IDEA closes a
+            // project's processes.
+            for request in self.project_requests.write().remove(self.owner_window(window)).unwrap_or_default() {
+                self.cancel_request(request);
+            }
+            self.processes.kill_project(&project.root);
+            self.terminals.kill_key(self.owner_window(window));
+            self.shutdown_project_workers_blocking(
+                vec![project.notebooks.clone()],
+                project.kotlin_bridge.iter().cloned().collect(),
+                Some(project.lsp.clone()),
+                Some((self.debugger.clone(), window.to_owned())),
+            );
         }
     }
 
     /// Synchronous project/window destruction must finish owned kernel cleanup,
     /// not enqueue work which can be lost as the desktop runtime exits.
-    fn shutdown_notebooks_blocking(&self, notebooks: Vec<Arc<notebook::NotebookService>>) {
+    fn shutdown_project_workers_blocking(
+        &self,
+        notebooks: Vec<Arc<notebook::NotebookService>>,
+        bridges: Vec<Arc<kotlin_bridge::KotlinBridge>>,
+        lsp: Option<Arc<ide_lsp::LspManager>>,
+        debug: Option<(Arc<ide_dap::DebugManager>, String)>,
+    ) {
+        for bridge in &bridges {
+            bridge.stop();
+        }
         for service in &notebooks {
             service.stop_admission();
         }
@@ -157,9 +226,18 @@ impl Host {
         let wait = move || {
             let worker = std::thread::spawn(move || {
                 runtime.block_on(async move {
+                    for bridge in bridges {
+                        bridge.shutdown().await;
+                    }
                     for service in notebooks {
                         service.shutdown().await;
                     }
+                    if let Some(lsp) = lsp {
+                        lsp.shutdown_all().await;
+                    }
+                    if let Some((debug, key)) = debug {
+                        debug.stop_key(&key).await;
+                    }
                 });
             });
             if let Err(error) = worker.join() {
@@ -177,7 +255,20 @@ impl Host {
 
     /// Called before the desktop runtime exits, including update/restart exits.
     pub fn shutdown_notebooks_on_exit(&self) {
-        self.shutdown_notebooks_blocking(self.projects().iter().map(|project| project.notebooks.clone()).collect());
+        let projects = self.projects();
+        self.shutdown_project_workers_blocking(
+            projects.iter().map(|project| project.notebooks.clone()).collect(),
+            projects.iter().filter_map(|project| project.kotlin_bridge.clone()).collect(),
+            None,
+            None,
+        );
+    }
+
+    /// Called before desktop exit, which may bypass document destructors.
+    pub fn clear_workspace_edit_history_on_exit(&self) {
+        for project in self.projects() {
+            project.documents.clear_workspace_edit_history();
+        }
     }
 
     /// Stops what this host started: notebook kernels, language servers, agents, runs and terminals.
@@ -188,12 +279,19 @@ impl Host {
         self.terminals.kill_all();
         let projects: Vec<_> = self.projects.write().drain().map(|(_, p)| p).collect();
         for project in &projects {
+            if let Some(bridge) = &project.kotlin_bridge {
+                bridge.stop();
+            }
+            project.documents.clear_workspace_edit_history();
             project.notebooks.stop_admission();
             project.agents.shutdown();
         }
         // Kernel cleanup owns its interrupt/termination/reaping deadlines. An
         // outer LSP timeout must never abort it before owned children are reaped.
         for project in &projects {
+            if let Some(bridge) = &project.kotlin_bridge {
+                bridge.shutdown().await;
+            }
             project.notebooks.shutdown().await;
         }
         let stop_language_servers = async {
@@ -212,7 +310,19 @@ impl Host {
         self.requests.begin(id)
     }
 
+    pub fn begin_project_request(&self, window: &str, id: RequestId) -> CancellationToken {
+        let token = self.begin_request(id);
+        self.project_requests.write().entry(self.owner_window(window).to_owned()).or_default().push(id);
+        if self.project(window).is_ok_and(|p| !p.is_trusted()) {
+            token.cancel();
+        }
+        token
+    }
+
     pub fn end_request(&self, id: RequestId) {
+        for ids in self.project_requests.write().values_mut() {
+            ids.retain(|entry| *entry != id);
+        }
         self.requests.end(id);
     }
 

crates/ide-host/src/notebook.rs

@@ -407,6 +407,24 @@ impl NotebookService {
         }
     }
 
+    pub async fn restrict(&self) {
+        let documents: Vec<_> = self.registry.lock().documents.values().cloned().collect();
+        for document in &documents {
+            let mut state = document.state.lock();
+            state.generation += 1;
+            if let Some(batch) = &state.active {
+                batch.cancel.cancel();
+            }
+        }
+        for document in documents {
+            let _ = self.kernels.shutdown_kernel(&document.path).await;
+            let batch = document.state.lock().active.clone();
+            if let Err(error) = self.drain(&document, batch).await {
+                tracing::warn!("notebook restriction: {error}");
+            }
+        }
+    }
+
     pub async fn shutdown(&self) {
         self.stop_admission();
         self.kernels.shutdown().await;

crates/ide-host/src/ops/agent.rs

@@ -17,14 +17,22 @@ pub fn subscribe(host: &Host, window: &str, on_event: Emit<AgentEvent>) -> IdeRe
 }
 
 pub fn providers(host: &Host, window: &str) -> IdeResult<Vec<AgentProvider>> {
+    host.require_trust(window)?;
     let mut providers = host.project(window)?.agents.providers();
     ide_agent::registry::mark_updates(&registry_paths(host), &mut providers);
     Ok(providers)
 }
 
+/// Overrides built-in agent `id`'s command with `command` (its agent file keeps the
+/// built-in's driver and arguments), or returns it to auto-detection with `None`.
+pub fn set_command(host: &Host, window: &str, id: String, command: Option<String>) -> IdeResult<()> {
+    host.require_trust(window)?;
+    host.project(window)?.agents.set_builtin_command(&id, command)
+}
+
 /// Where ACP Registry agents are saved (`<config>/agents`, like the user's own) and installed.
 pub(crate) fn registry_paths(host: &Host) -> RegistryPaths {
-    RegistryPaths::new(&host.config_dir, &host.data_dir)
+    RegistryPaths::new(&host.config_dir, &host.local_data_dir)
 }
 
 fn join_err(e: impl std::fmt::Display) -> IdeError {
@@ -62,13 +70,21 @@ pub async fn registry_install(
     .await
     .map_err(join_err);
     host.end_request(request);
-    result?
+    result??;
+    for project in host.projects() {
+        project.agents.reload_providers();
+    }
+    Ok(())
 }
 
 /// Removes a registry agent: its agent file and installed files.
 pub async fn registry_remove(host: &Host, _window: &str, id: String) -> IdeResult<()> {
     let paths = registry_paths(host);
-    tokio::task::spawn_blocking(move || ide_agent::registry::remove(&paths, &id)).await.map_err(join_err)?
+    tokio::task::spawn_blocking(move || ide_agent::registry::remove(&paths, &id)).await.map_err(join_err)??;
+    for project in host.projects() {
+        project.agents.reload_providers();
+    }
+    Ok(())
 }
 
 /// Slash commands to complete for `provider` in `task`'s directory, or in the project
@@ -88,6 +104,7 @@ pub fn entries(host: &Host, window: &str, task: String, subagent: Option<String>
 }
 
 pub async fn create(host: &Host, window: &str, mut request: NewAgentTask) -> IdeResult<AgentTask> {
+    host.require_trust(window)?;
     let project = host.project(window)?;
     let root = project.root.clone();
     let requested = request.project_root.take();
@@ -99,6 +116,7 @@ pub async fn create(host: &Host, window: &str, mut request: NewAgentTask) -> Ide
 
 /// Sends a message; while the agent works it is queued, or with `now` it interrupts the turn.
 pub async fn prompt(host: &Host, window: &str, task: String, prompt: AgentPrompt, now: bool) -> IdeResult<()> {
+    host.require_trust(window)?;
     host.project(window)?.agents.prompt(&task, prompt, now).await
 }
 
@@ -109,26 +127,31 @@ pub fn unqueue(host: &Host, window: &str, task: String, queued: String) -> IdeRe
 
 /// Sends a queued message now, interrupting the current turn.
 pub fn send_queued_now(host: &Host, window: &str, task: String, queued: String) -> IdeResult<()> {
+    host.require_trust(window)?;
     host.project(window)?.agents.send_queued_now(&task, &queued)
 }
 
 /// Changes a session setting (model, mode, thinking effort…).
 pub async fn set_config(host: &Host, window: &str, task: String, option: String, value: String) -> IdeResult<()> {
+    host.require_trust(window)?;
     host.project(window)?.agents.set_config(&task, &option, value).await
 }
 
 /// Copies the task's conversation into a new task, up to its first `turns` turns (all when `None`).
 pub async fn fork(host: &Host, window: &str, task: String, turns: Option<u32>) -> IdeResult<AgentTask> {
+    host.require_trust(window)?;
     host.project(window)?.agents.fork(&task, turns).await
 }
 
 /// Drops the task's turns after its first `turns`; returns the message of the first dropped one.
 pub async fn rollback(host: &Host, window: &str, task: String, turns: u32) -> IdeResult<Option<AgentPrompt>> {
+    host.require_trust(window)?;
     host.project(window)?.agents.rollback(&task, turns).await
 }
 
 /// What the agent reports about itself when it starts, without opening a session.
 pub async fn probe(host: &Host, window: &str, provider: String, refresh: bool) -> IdeResult<AgentProbe> {
+    host.require_trust(window)?;
     host.project(window)?.agents.probe(&provider, refresh).await
 }
 
@@ -139,6 +162,7 @@ pub fn cancel(host: &Host, window: &str, task: String, subagent: Option<String>)
 
 /// Answers a permission request; `option: None` cancels it.
 pub fn respond(host: &Host, window: &str, task: String, permission: u32, option: Option<String>) -> IdeResult<()> {
+    host.require_trust(window)?;
     host.project(window)?.agents.respond(&task, permission, option)
 }
 
@@ -151,15 +175,18 @@ pub fn unarchive(host: &Host, window: &str, task: String) -> IdeResult<()> {
 }
 
 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
 }
 
 pub async fn changes(host: &Host, window: &str, task: String) -> IdeResult<Vec<AgentChange>> {
+    host.require_trust(window)?;
     host.project(window)?.agents.changes(&task).await
 }
 
 /// Content of `path` when the task started (left side of its diff).
 pub async fn base_text(host: &Host, window: &str, task: String, path: IpcPath) -> IdeResult<Option<String>> {
+    host.require_trust(window)?;
     host.project(window)?.agents.base_text(&task, path.into_path_buf()).await
 }
 
@@ -167,6 +194,7 @@ pub async fn base_text(host: &Host, window: &str, task: String, path: IpcPath) -
 pub(crate) fn register(d: &mut Dispatcher) {
     d.add("agent_subscribe", |c| async move { subscribe(&c.host, &c.window, c.channel("onEvent")?) });
     d.add("agent_providers", |c| async move { providers(&c.host, &c.window) });
+    d.add("agent_set_command", |c| async move { set_command(&c.host, &c.window, c.arg("id")?, c.arg("command")?) });
     d.add("agent_registry_list", |c| async move { registry_list(&c.host, &c.window, c.arg("request")?).await });
     d.add("agent_registry_install", |c| async move {
         registry_install(&c.host, &c.window, c.arg("id")?, c.arg("request")?, c.sender("onEvent")?).await

crates/ide-host/src/ops/analysis.rs

@@ -39,12 +39,13 @@ fn load(project: &Project, languages: &LanguageRegistry, path: &Path) -> Option<
         let snap = project.documents.text_snapshot(doc).ok()?;
         return (!snap.large).then_some((snap.language, snap.text));
     }
-    let loaded = ide_vfs::load_text(path).ok()?;
+    let loaded = project.documents.load_file(path).ok()?;
     if loaded.binary || loaded.large || loaded.too_large {
         return None;
     }
-    let language = languages.detect(path, loaded.text.lines().next());
-    Some((language, loaded.text))
+    let text = ide_text::normalize_line_endings(&loaded.text).into_owned();
+    let language = languages.detect(path, text.lines().next());
+    Some((language, text))
 }
 
 // ---- Inspect Code ----

crates/ide-host/src/ops/build.rs

@@ -74,8 +74,21 @@ pub fn load(root: &Path, cache: &Path, settings: &Settings) -> BuildModel {
     model
 }
 
+/// `model` building with the Maven profiles of the last sync (`-P`), as Maven runs from
+/// the tool window do.
+fn with_profiles(mut model: BuildModel, cache: &Path) -> BuildModel {
+    let profiles = ide_build::maven_profiles(cache);
+    if let (Some(m), false) = (&mut model.maven, profiles.is_empty()) {
+        for p in &mut m.projects {
+            p.options.push(format!("-P{}", profiles.join(",")));
+        }
+    }
+    model
+}
+
 /// Maven and Gradle projects of the window's project, from the build files plus the last sync.
 pub async fn build_model(host: &Host, window: &str) -> IdeResult<BuildModel> {
+    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 || load(&root, &cache, &settings)).await.map_err(join_err)
@@ -93,9 +106,17 @@ pub async fn build_sync(
     profiles: Vec<String>,
     on_progress: Channel<SyncProgress>,
 ) -> IdeResult<BuildModel> {
+    host.require_trust(window)?;
     let project = host.project(window)?;
     let (root, cache, settings) = (project.root.clone(), project.build_cache_dir(), project.settings.effective());
-    let token = host.begin_request(request);
+    let bridge_profiles = profiles.clone();
+    // What the Java language server and Build Project resolve the project with from now on.
+    let profiles_changed = tool == BuildTool::Maven
+        && ide_build::save_maven_profiles(&cache, &profiles).unwrap_or_else(|e| {
+            tracing::warn!("Maven profiles not saved: {e}");
+            false
+        });
+    let token = host.begin_project_request(window, request);
     let result = tokio::task::spawn_blocking(move || {
         let current = load(&root, &cache, &settings);
         let env = match tool {
@@ -129,20 +150,50 @@ pub async fn build_sync(
     .map_err(join_err);
     host.end_request(request);
     let model = result??;
-    if tool == BuildTool::Maven
-        && let Some(maven) = &model.maven
-    {
-        // jdtls re-imports on pom changes but misses artifacts added to ~/.m2
-        // meanwhile ("missing artifact" stays until Invalidate Caches); asking it
-        // to update the project configurations re-resolves them (#436).
-        let lsp = project.lsp.clone();
-        let uris = maven.projects.iter().map(|p| ide_lsp::path_to_uri_string(&project.root.join(&p.pom))).collect();
-        tokio::spawn(async move {
-            if let Err(e) = lsp.java_update_project_configs(&project.root, uris).await {
-                tracing::debug!("java/projectConfigurationsUpdate: {e}");
-            }
-        });
+    if tool == BuildTool::Gradle {
+        // The sync may report project folders outside the project (`includeFlat`): index and list them.
+        project.refresh_index_scope();
+        project.sink.emit(ide_core::IdeEvent::ProjectRootsChanged { root: project.root.clone().into() });
+        let p = project.clone();
+        tokio::task::spawn_blocking(move || p.refresh_repositories());
     }
+    if tool == BuildTool::Maven
+        && model.maven.is_some()
+        && let Some(bridge) = &project.kotlin_bridge
+    {
+        bridge.configure_maven(offline, bridge_profiles);
+    }
+    // jdtls re-imports on pom changes but misses artifacts added to ~/.m2
+    // meanwhile ("missing artifact" stays until Invalidate Caches); asking it
+    // to update the project configurations re-resolves them (#436). The same
+    // holds for Gradle: it reuses its cached classpath on restart, so a
+    // dependency added to `build.gradle` stays unresolved until told to sync.
+    let build_files: Vec<String> = match tool {
+        BuildTool::Maven => model.maven.iter().flat_map(|m| m.projects.iter().map(|p| p.pom.clone())).collect(),
+        BuildTool::Gradle => {
+            model.gradle.iter().flat_map(|g| g.projects.iter().filter_map(|p| p.build_file.clone())).collect()
+        }
+    };
+    let lsp = project.lsp.clone();
+    // With a module of a reactor unlinked, jdtls imports the other modules one by one and
+    // not the reactor: naming the reactor here would import it again, all modules included.
+    let imported = match tool {
+        BuildTool::Maven => crate::project::jdtls_maven_import(&project.root, &project.settings.effective()).1,
+        BuildTool::Gradle => None,
+    };
+    let uris = match imported {
+        Some(files) => files.into_iter().filter(|f| f.ends_with("/pom.xml")).collect(),
+        None => build_files.iter().map(|f| ide_lsp::path_to_uri_string(&project.root.join(f))).collect(),
+    };
+    tokio::spawn(async move {
+        if profiles_changed {
+            // jdtls takes the profiles from its Maven settings (see `ide_sdk::maven_profiles`).
+            lsp.reconfigure().await;
+        }
+        if let Err(e) = lsp.java_update_project_configs(&project.root, uris).await {
+            tracing::debug!("java/projectConfigurationsUpdate: {e}");
+        }
+    });
     Ok(model)
 }
 
@@ -197,8 +248,10 @@ pub async fn maven_exclude_dependency(
         let (path, text, range) = declaring_pom(&project, &pom, &dependency)?;
         match ide_build::pom_edit::add_exclusion(&text, &dependency, &exclusion) {
             Some(Exclusion::Edit(edit)) => {
-                let edit =
-                    WorkspaceEdit { files: vec![FileEdit::Edit { path: path.clone().into(), edits: vec![edit] }] };
+                let edit = WorkspaceEdit {
+                    files: vec![FileEdit::Edit { path: path.clone().into(), edits: vec![edit], version: None }],
+                    ..Default::default()
+                };
                 apply_workspace_edit(&project.documents, &edit)?;
             }
             Some(Exclusion::Present) => {}
@@ -223,11 +276,12 @@ pub async fn build_run(
     clear: Vec<std::path::PathBuf>,
     on_event: Channel<BuildEvent>,
 ) -> IdeResult<BuildResult> {
+    host.require_trust(window)?;
     let project = host.project(window)?;
     let (root, cache, sink) = (project.root.clone(), project.build_cache_dir(), project.sink.clone());
     let settings = project.settings.effective();
     let config_dir = host.config_dir.clone();
-    let token = host.begin_request(request);
+    let token = host.begin_project_request(window, request);
     let result = tokio::task::spawn_blocking(move || {
         for path in clear {
             sink.emit(IdeEvent::Diagnostics {
@@ -241,7 +295,8 @@ pub async fn build_run(
             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();
                 let member_cache = cache.join(crate::project::project_key(member));
-                let plan = compile::plan(member, &load(member, &member_cache, &settings), kind, file.as_deref())?;
+                let model = with_profiles(load(member, &member_cache, &settings), &member_cache);
+                let plan = compile::plan(member, &model, kind, file.as_deref())?;
                 match &mut combined {
                     Some(combined) => combined.steps.extend(plan.steps),
                     None => combined = Some(plan),
@@ -251,7 +306,7 @@ pub async fn build_run(
             plan.title = workspace.name;
             plan
         } else {
-            compile::plan(&root, &load(&root, &cache, &settings), kind, file.as_deref())?
+            compile::plan(&root, &with_profiles(load(&root, &cache, &settings), &cache), kind, file.as_deref())?
         };
         let result = compile::run(&root, &plan, &token, &|e| {
             let _ = on_event.send(e);