feat(vcs): show the selected commit's details in the Push dialog

Selecting one outgoing commit in the Push dialog now shows its full message, revision, author and time above its changed files. A Group by Directory toggle switches the files between a directory tree and a flat list (each file with its directory beside the name), and the choice is remembered.

Fixes #1373

.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 @@
+<!-- If this resolves an issue: Closes #<n> -->
+
+## 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/language-smoke.yml

@@ -0,0 +1,124 @@
+name: Language smoke
+# Everyday code intelligence (completion, go to definition, Find Usages, hover, diagnostics
+# with a quick fix, an intention, formatting, rename) per language, against the language
+# server the app starts by default: crates/ide-host/tests/language_smoke.rs.
+# Opening the fixture with its build tool and SDK (Maven / Gradle sync, the virtualenv, the
+# JDK): the ignored tests of crates/ide-host/tests/project_smoke.rs.
+# Then running and testing each fixture through the run store and openidea-server
+# (Run, Run tests, the test tree, Rerun Failed Tests): smoke/run.test.ts; and debugging its
+# entry point with the debugger the IDE installs (breakpoint, frames, variables, evaluate,
+# Step Over, Resume): smoke/debug.test.ts.
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+    types: [opened, synchronize, reopened]
+    paths:
+      - "crates/**"
+      - "languages/**"
+      - "fixtures/**"
+      - "Cargo.toml"
+      - "Cargo.lock"
+      - "src/features/run/**"
+      - "src/features/debugger/**"
+      - "src/platform/**"
+      - "smoke/**"
+      - "package.json"
+      - "pnpm-lock.yaml"
+      - ".github/workflows/language-smoke.yml"
+  workflow_dispatch:
+
+concurrency:
+  group: language-smoke-${{ github.ref }}
+  # A new push supersedes a PR's run; on main every merge runs to the end (and saves the cache).
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
+env:
+  CARGO_TERM_COLOR: always
+  CARGO_INCREMENTAL: 0
+  # Pinned so a server release can't fail an unrelated PR; bump them deliberately.
+  VTSLS: 0.3.0
+  TYPESCRIPT: 6.0.3
+  BASEDPYRIGHT: 1.40.2
+  RUFF: 0.17.3
+  GOPLS: v0.24.0
+  JDTLS: 1.63.0-202610191322
+  KOTLIN_LSP: 263.7084.0
+  GRADLE: 8.14.3
+
+jobs:
+  smoke:
+    name: Language smoke (${{ matrix.language }})
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [typescript, python, rust, go, java, kotlin]
+    runs-on: ubuntu-22.04
+    timeout-minutes: 40
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with: { components: "rust-analyzer, rustfmt" }
+      # One build cache for every language; main saves it.
+      - uses: Swatinem/rust-cache@v2
+        with:
+          shared-key: language-smoke
+          save-if: ${{ github.ref == 'refs/heads/main' && matrix.language == 'rust' }}
+
+      - uses: pnpm/action-setup@v4
+        with: { version: 11 }
+      - uses: actions/setup-node@v4
+        with: { node-version: 22, cache: pnpm }
+      - if: matrix.language == 'typescript'
+        run: npm install --global "@vtsls/language-server@$VTSLS" "typescript@$TYPESCRIPT"
+
+      - if: matrix.language == 'python'
+        uses: actions/setup-python@v5
+        with: { python-version: "3.12" }
+      - if: matrix.language == 'python'
+        run: pip install "basedpyright==$BASEDPYRIGHT" "ruff==$RUFF"
+
+      - if: matrix.language == 'go'
+        uses: actions/setup-go@v5
+        with: { go-version: "1.27", cache: false }
+      - if: matrix.language == 'go'
+        run: go install "golang.org/x/tools/gopls@$GOPLS"
+
+      - if: matrix.language == 'java' || matrix.language == 'kotlin'
+        uses: actions/setup-java@v4
+        with: { distribution: temurin, java-version: "21" }
+      - if: matrix.language == 'java'
+        run: |
+          mkdir -p "$RUNNER_TEMP/jdtls"
+          curl -fsSL "https://download.eclipse.org/jdtls/milestones/${JDTLS%-*}/jdt-language-server-$JDTLS.tar.gz" \
+            | tar xz -C "$RUNNER_TEMP/jdtls"
+          echo "$RUNNER_TEMP/jdtls/bin" >> "$GITHUB_PATH"
+
+      # The Kotlin fixture has no Gradle wrapper: the server imports it with the Gradle on PATH.
+      - if: matrix.language == 'kotlin'
+        uses: gradle/actions/setup-gradle@v4
+        with: { gradle-version: "${{ env.GRADLE }}" }
+      - if: matrix.language == 'kotlin'
+        run: |
+          mkdir -p "$RUNNER_TEMP/kotlin-lsp" "$RUNNER_TEMP/bin"
+          curl -fsSL "https://download.jetbrains.com/language-server/kotlin-server/$KOTLIN_LSP/kotlin-server-$KOTLIN_LSP.tar.gz" \
+            | tar xz -C "$RUNNER_TEMP/kotlin-lsp" --strip-components=1
+          ln -s "$RUNNER_TEMP/kotlin-lsp/kotlin-lsp.sh" "$RUNNER_TEMP/bin/kotlin-lsp"
+          echo "$RUNNER_TEMP/bin" >> "$GITHUB_PATH"
+
+      - run: cargo test --locked -p ide-host --test language_smoke --no-run
+      - run: cargo test --locked -p ide-host --test language_smoke -- --ignored --exact ${{ matrix.language }}
+      - if: matrix.language == 'java'
+        run: cargo test --locked -p ide-host --test project_smoke -- --ignored --exact maven_sync jdk
+      - if: matrix.language == 'kotlin'
+        run: cargo test --locked -p ide-host --test project_smoke -- --ignored --exact gradle_sync
+      - if: matrix.language == 'python'
+        run: cargo test --locked -p ide-host --test project_smoke -- --ignored --exact python_venv
+
+      - run: pnpm install --frozen-lockfile
+      - run: cargo build --locked -p ide-host --bin openidea-server
+      - run: pnpm smoke smoke/run.test.ts -t "^${{ matrix.language }}$"
+      - run: pnpm smoke smoke/debug.test.ts -t "^${{ matrix.language }}$"
+        # The IDE installs the debugger from GitHub releases: authenticated, against rate limits.
+        env: { GITHUB_TOKEN: "${{ github.token }}" }

.github/workflows/plugins-index.yml

@@ -0,0 +1,46 @@
+name: Plugin index
+
+# Refreshes the community plugins in the latest release's plugins-index.json
+# (what released apps read) from the registry, l0ng-ai/openidea-plugins. The
+# official plugins, their key and revocations stay as the release wrote them.
+on:
+  schedule:
+    - cron: "17 * * * *"
+  workflow_dispatch:
+  # Sent by the registry when its index changes.
+  repository_dispatch:
+    types: [community-plugins]
+
+permissions:
+  contents: write
+
+concurrency:
+  group: plugins-index
+
+env:
+  COMMUNITY_PLUGINS_INDEX: https://github.com/l0ng-ai/openidea-plugins/releases/download/index/index.json
+
+jobs:
+  merge:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Merge the community index
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          cd "$RUNNER_TEMP"
+          tag="$(gh release view --repo "$GITHUB_REPOSITORY" --json tagName -q .tagName)"
+          tool=openidea-plugin-linux-x86_64
+          if ! gh release download "$tag" --repo "$GITHUB_REPOSITORY" -p plugins-index.json -p "$tool.gz"; then
+            echo "::notice::$tag has no plugin index or openidea-plugin tool yet"
+            exit 0
+          fi
+          gunzip "$tool.gz" && chmod +x "$tool"
+          cp plugins-index.json before.json
+          "./$tool" merge plugins-index.json "$COMMUNITY_PLUGINS_INDEX" --keep openidea
+          if cmp -s before.json plugins-index.json; then
+            echo "unchanged"
+          else
+            gh release upload "$tag" plugins-index.json --repo "$GITHUB_REPOSITORY" --clobber
+          fi

.github/workflows/pr-check.yml

@@ -0,0 +1,60 @@
+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-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  check:
+    if: github.event.pull_request.user.type != 'Bot' && !github.event.pull_request.draft
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/github-script@v7
+        with:
+          script: |
+            const pr = context.payload.pull_request;
+            const LABEL = 'needs-info';
+            const MARKER = '<!-- pr-check -->';
+            const body = (pr.body || '').replace(/<!--[\s\S]*?-->/g, '');
+            const problems = [];
+
+            const verified = body.match(/^##+\s*How it was verified\s*$([\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

@@ -18,6 +18,7 @@ env:
   CARGO_TERM_COLOR: always
   CARGO_INCREMENTAL: 0
   TAG: ${{ github.event.inputs.tag || github.ref_name }}
+  COMMUNITY_PLUGINS_INDEX: https://github.com/l0ng-ai/openidea-plugins/releases/download/index/index.json
 
 jobs:
   # Creates (or reuses) one draft release that every platform build uploads into.
@@ -25,6 +26,7 @@ jobs:
     runs-on: ubuntu-latest
     outputs:
       release_id: ${{ steps.release.outputs.id }}
+      official_plugin_keys: ${{ steps.plugin-keys.outputs.keys }}
     steps:
       - uses: actions/checkout@v4
         with: { ref: "${{ env.TAG }}" }
@@ -35,6 +37,20 @@ jobs:
             echo "::error::tag $TAG does not match tauri.conf.json version $app"
             exit 1
           fi
+      # The official plugins' public key (from PLUGIN_SIGNING_KEY, the seed
+      # `openidea-plugin keygen` writes), built into the app: their packages
+      # must carry its signature whatever the marketplace index lists. Without
+      # the secret the app takes the index's word, as development builds do.
+      - id: plugin-keys
+        env:
+          SIGNING_KEY: ${{ secrets.PLUGIN_SIGNING_KEY }}
+        run: |
+          if [ -n "$SIGNING_KEY" ]; then
+            seed="$(printf %s "$SIGNING_KEY" | base64 -d | od -An -tx1 | tr -d ' \n')"
+            key="$(printf '302e020100300506032b657004220420%s' "$seed" | xxd -r -p |
+              openssl pkey -inform DER -pubout -outform DER | tail -c 32 | base64)"
+            echo "keys=$key" >> "$GITHUB_OUTPUT"
+          fi
       - id: release
         uses: actions/github-script@v7
         with:
@@ -57,6 +73,8 @@ jobs:
   build:
     needs: create-release
     name: Build (${{ matrix.name }})
+    env:
+      OPENIDEA_OFFICIAL_PLUGIN_KEYS: ${{ needs.create-release.outputs.official_plugin_keys }}
     strategy:
       fail-fast: false
       matrix:
@@ -180,6 +198,79 @@ jobs:
           if command -v sha256sum >/dev/null; then sha256sum "$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. The index also lists
+  # the community plugins of the registry (COMMUNITY_PLUGINS_INDEX; refreshed
+  # between releases by plugins-index.yml), and the release carries the
+  # openidea-plugin tool for Linux x64, which that workflow and the registry's
+  # checks run.
+  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-$version.oiplugin"
+          done
+          # The published index's revocations, earlier keys and community plugins carry over.
+          curl -fsSL "https://github.com/$GITHUB_REPOSITORY/releases/latest/download/plugins-index.json" \
+            -o "$out/plugins-index.json" || rm -f "$out/plugins-index.json"
+          # Downloads point at this release: older versions kept for older IDEs stay where they were published.
+          "$tool" index "$out" --publisher openidea --name OpenIDEA --key "$key" --out "$out/plugins-index.json" \
+            --download-base "https://github.com/$GITHUB_REPOSITORY/releases/download/$TAG"
+          "$tool" merge "$out/plugins-index.json" "$COMMUNITY_PLUGINS_INDEX" --keep openidea ||
+            echo "::warning::the community plugins were not refreshed"
+          gzip -9 -c "$tool" > "$out/openidea-plugin-linux-x86_64.gz"
+          gh release upload "$TAG" "$out"/*.oiplugin "$out/plugins-index.json" \
+            "$out/openidea-plugin-linux-x86_64.gz" --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:
@@ -243,7 +334,7 @@ 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 +1,129 @@
+# 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 and the
+  `openidea-plugin` CLI (plugin starter templates live in its `templates.rs`).
+- `wit/` — plugin interface definitions; `plugins/` — sample and bundled plugins.
+  Plugin docs: `plugins/README.md`, `docs/plugins/themes.md`.
+- `java/` — JDT LS extension bundles (`java-usages`, `kotlin-bridge`) and the patched
+  Lombok agent, embedded into the app by `ide-sdk` / `ide-tools`.
+- `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).
+  Other locales may lack entries; their UI shows the English text until a translator adds 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 problem per PR
+(`Closes #<n>` when it resolves an issue), 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`.
+- `cargo test -p ide-host --test language_smoke -- --ignored --exact <language>` — code intelligence
+  on `fixtures/` with that language's real server installed (CI: `Language smoke`, pinned versions).
+- `pnpm smoke smoke/run.test.ts -t <language>` — run and test that language's fixture through the
+  run store and a real `openidea-server` (build it first: `cargo build -p ide-host --bin openidea-server`).
+- `pnpm smoke smoke/debug.test.ts -t <language>` — debug that fixture's entry point the same way, with
+  the debugger the IDE installs (on macOS, CodeLLDB and Delve may need Developer Mode:
+  `sudo DevToolsSecurity -enable`).
+- `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 +1,38 @@
+# 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 problem per PR. If it resolves an issue, link it with `Closes #123`.
+- 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.
+
+Plugins: pull requests here add or change official plugins (`plugins/official/`)
+and the plugin API. Community plugins live in their authors' repositories and
+are listed through [l0ng-ai/openidea-plugins](https://github.com/l0ng-ai/openidea-plugins);
+see [`plugins/README.md`](plugins/README.md) § 8.1.
+
+A check on each PR adds `needs-info` when the verification section is missing, and removes it once it's filled in.

Cargo.lock

@@ -4038,7 +4038,7 @@ checksum = "3d3067d79b975e8844ca9eb072e16b31c3c1c36928edf9c6789548c524d0d954"
 
 [[package]]
 name = "ide-agent"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4061,7 +4061,7 @@ dependencies = [
 
 [[package]]
 name = "ide-analysis"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ast-grep-core",
  "ide-core",
@@ -4075,22 +4075,22 @@ dependencies = [
 
 [[package]]
 name = "ide-build"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "dirs 6.0.0",
  "dunce",
  "ide-core",
- "libc",
  "serde",
  "serde_json",
  "specta",
  "tempfile",
  "tracing",
+ "zip",
 ]
 
 [[package]]
 name = "ide-clipboard"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "objc2 0.6.5",
  "objc2-app-kit 0.3.2",
@@ -4099,10 +4099,11 @@ dependencies = [
 
 [[package]]
 name = "ide-core"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "dunce",
  "encoding_rs",
+ "libc",
  "serde",
  "serde_json",
  "specta",
@@ -4115,7 +4116,7 @@ dependencies = [
 
 [[package]]
 name = "ide-coverage"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
  "ide-run",
@@ -4129,7 +4130,7 @@ dependencies = [
 
 [[package]]
 name = "ide-dap"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
  "ide-jsonrpc",
@@ -4147,14 +4148,17 @@ dependencies = [
 
 [[package]]
 name = "ide-db"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "bb8",
  "dirs 6.0.0",
  "futures",
  "ide-core",
+ "ide-http",
  "ide-ssh",
  "parking_lot",
+ "reqwest",
+ "rustls",
  "serde",
  "serde_json",
  "specta",
@@ -4165,14 +4169,14 @@ dependencies = [
  "tokio-util",
  "toml 0.9.12+spec-1.1.0",
  "tracing",
+ "uuid",
 ]
 
 [[package]]
 name = "ide-docker"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
- "libc",
  "serde",
  "serde_json",
  "specta",
@@ -4181,9 +4185,29 @@ dependencies = [
  "which",
 ]
 
+[[package]]
+name = "ide-extension"
+version = "0.1.36"
+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 = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "objc2-core-foundation",
  "objc2-core-text",
@@ -4195,11 +4219,10 @@ dependencies = [
 
 [[package]]
 name = "ide-github"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
  "ide-vcs",
- "libc",
  "serde",
  "serde_json",
  "specta",
@@ -4209,11 +4232,15 @@ dependencies = [
 
 [[package]]
 name = "ide-host"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
+ "base64 0.22.1",
+ "criterion",
  "dirs 6.0.0",
  "dunce",
  "encoding_rs",
+ "getrandom 0.3.4",
+ "globset",
  "ide-agent",
  "ide-analysis",
  "ide-build",
@@ -4221,12 +4248,15 @@ dependencies = [
  "ide-coverage",
  "ide-dap",
  "ide-db",
+ "ide-docker",
+ "ide-extension",
  "ide-http",
  "ide-index",
  "ide-jsonrpc",
  "ide-language",
  "ide-lsp",
  "ide-notebook",
+ "ide-plugin",
  "ide-remote",
  "ide-run",
  "ide-sdk",
@@ -4240,21 +4270,30 @@ dependencies = [
  "ide-vcs",
  "ide-vfs",
  "ide-workspace",
+ "ignore",
  "parking_lot",
+ "quick-xml",
+ "regex-syntax",
+ "reqwest",
+ "rustix",
+ "semver",
  "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 = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
  "parking_lot",
@@ -4272,7 +4311,7 @@ dependencies = [
 
 [[package]]
 name = "ide-index"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "blake3",
  "criterion",
@@ -4294,7 +4333,7 @@ dependencies = [
 
 [[package]]
 name = "ide-jsonrpc"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "encoding_rs",
  "futures",
@@ -4302,6 +4341,7 @@ dependencies = [
  "parking_lot",
  "serde",
  "serde_json",
+ "tempfile",
  "thiserror 2.0.21",
  "tokio",
  "tokio-util",
@@ -4310,11 +4350,12 @@ dependencies = [
 
 [[package]]
 name = "ide-language"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "blake3",
  "criterion",
  "ide-core",
+ "ide-extension",
  "ide-text",
  "parking_lot",
  "regex-lite",
@@ -4365,7 +4406,7 @@ dependencies = [
 
 [[package]]
 name = "ide-lsp"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "dunce",
  "futures",
@@ -4374,6 +4415,7 @@ dependencies = [
  "ide-jsonrpc",
  "ide-language",
  "ide-text",
+ "ide-vfs",
  "ignore",
  "lsp-types",
  "parking_lot",
@@ -4385,11 +4427,12 @@ dependencies = [
  "tokio",
  "toml 0.9.12+spec-1.1.0",
  "tracing",
+ "zip",
 ]
 
 [[package]]
 name = "ide-notebook"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "futures",
  "ide-core",
@@ -4412,17 +4455,19 @@ dependencies = [
 
 [[package]]
 name = "ide-plugin"
-version = "0.1.32"
+version = "0.1.36"
 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",
@@ -4430,7 +4475,7 @@ dependencies = [
 
 [[package]]
 name = "ide-profiler"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
  "ide-run",
@@ -4443,7 +4488,7 @@ dependencies = [
 
 [[package]]
 name = "ide-remote"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "globset",
  "ide-core",
@@ -4460,7 +4505,7 @@ dependencies = [
 
 [[package]]
 name = "ide-run"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4483,7 +4528,7 @@ dependencies = [
 
 [[package]]
 name = "ide-sdk"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "dunce",
  "ide-core",
@@ -4502,7 +4547,7 @@ dependencies = [
 
 [[package]]
 name = "ide-search"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "criterion",
  "globset",
@@ -4522,7 +4567,7 @@ dependencies = [
 
 [[package]]
 name = "ide-spell"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
  "parking_lot",
@@ -4535,7 +4580,7 @@ dependencies = [
 
 [[package]]
 name = "ide-ssh"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "dirs 6.0.0",
  "flate2",
@@ -4554,7 +4599,7 @@ dependencies = [
 
 [[package]]
 name = "ide-syntax"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
  "ide-language",
@@ -4569,7 +4614,7 @@ dependencies = [
 
 [[package]]
 name = "ide-terminal"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
  "libc",
@@ -4582,7 +4627,7 @@ dependencies = [
 
 [[package]]
 name = "ide-text"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "criterion",
  "ide-core",
@@ -4594,7 +4639,7 @@ dependencies = [
 
 [[package]]
 name = "ide-tools"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "flate2",
  "hex",
@@ -4615,14 +4660,16 @@ dependencies = [
 
 [[package]]
 name = "ide-vcs"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
+ "blake3",
  "dunce",
  "encoding_rs",
  "gix",
  "ide-core",
  "ignore",
  "libc",
+ "redb",
  "regex-lite",
  "serde",
  "serde_json",
@@ -4634,7 +4681,7 @@ dependencies = [
 
 [[package]]
 name = "ide-vfs"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "chardetng",
  "dunce",
@@ -4656,7 +4703,7 @@ dependencies = [
 
 [[package]]
 name = "ide-web"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "ide-core",
  "open",
@@ -4672,7 +4719,7 @@ dependencies = [
 
 [[package]]
 name = "ide-workspace"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
  "blake3",
  "dunce",
@@ -4682,6 +4729,7 @@ dependencies = [
  "ide-text",
  "ide-vfs",
  "parking_lot",
+ "semver",
  "serde",
  "serde_json",
  "specta",
@@ -4689,6 +4737,7 @@ dependencies = [
  "toml 0.9.12+spec-1.1.0",
  "toml_edit 0.25.17+spec-1.1.0",
  "tracing",
+ "uuid",
  "zip",
 ]
 
@@ -6143,12 +6192,14 @@ dependencies = [
 
 [[package]]
 name = "openidea"
-version = "0.1.32"
+version = "0.1.36"
 dependencies = [
+ "base64 0.22.1",
  "blake3",
  "block2 0.6.2",
  "dirs 6.0.0",
  "dunce",
+ "gtk",
  "ide-agent",
  "ide-analysis",
  "ide-build",
@@ -6158,6 +6209,7 @@ dependencies = [
  "ide-dap",
  "ide-db",
  "ide-docker",
+ "ide-extension",
  "ide-fonts",
  "ide-github",
  "ide-host",
@@ -6189,6 +6241,8 @@ dependencies = [
  "objc2-foundation 0.3.2",
  "objc2-web-kit 0.3.2",
  "parking_lot",
+ "percent-encoding",
+ "security-framework",
  "serde",
  "serde_json",
  "specta",
@@ -6206,6 +6260,7 @@ dependencies = [
  "tracing",
  "tracing-appender",
  "tracing-subscriber",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -7089,6 +7144,7 @@ dependencies = [
  "rustls-platform-verifier",
  "serde",
  "serde_json",
+ "serde_urlencoded",
  "sync_wrapper",
  "tokio",
  "tokio-rustls",
@@ -7447,6 +7503,12 @@ dependencies = [
  "wait-timeout",
 ]
 
+[[package]]
+name = "ryu"
+version = "1.0.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9774ba4a74de5f7b1c1451ed6cd5285a32eddb5cccb8cc655a4e50009e06477f"
+
 [[package]]
 name = "saa"
 version = "5.6.2"
@@ -7751,6 +7813,18 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "serde_urlencoded"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3491c14715ca2294c4d6a88f15e84739788c1d030eed8c110436aafdaa2f3fd"
+dependencies = [
+ "form_urlencoded",
+ "itoa",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "serde_with"
 version = "3.24.0"

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 = "0.1.32"
+version = "0.1.36"
 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"
@@ -81,6 +86,7 @@ zip = { version = "9", default-features = false, features = ["deflate"] }
 # search, index, language
 grep-searcher = "0.1"
 grep-regex = "0.1"
+regex-syntax = "0.8"
 grep-matcher = "0.1"
 nucleo-matcher = "0.3"
 redb = "4"

README.md

@@ -14,7 +14,7 @@
    · 
   <a href="#benchmark">Benchmark</a>
   &nbsp;·&nbsp;
-  <a href="#build">Build</a>
+  <a href="#plugins">Plugins</a>
   &nbsp;·&nbsp;
   <a href="https://discord.gg/2Zy4yn7gP">Discord</a>
 </p>
@@ -47,23 +47,15 @@ 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
+## Plugins
 
-```sh
-pnpm install
-pnpm tauri dev
-```
+Plugins add actions, completion, quick fixes, tool windows, custom editors,
+themes, file icons and languages. They run as sandboxed WebAssembly components;
+themes, icon themes and languages need no code at all.
 
-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
-```
+Install them from Settings › Plugins, or start your own with
+`openidea-plugin new` — see [Writing OpenIDEA plugins](plugins/README.md) and
+the [official plugins](plugins/official). The plugin API is still a preview.
 
 ## License
 

THIRD_PARTY_LICENSES.md

@@ -2,11 +2,12 @@
 
 ## Project Lombok
 
-`plugins/lombok/lombok-1.18.48-openidea.1.jar` contains Project Lombok v1.18.48 with the Equinox
-classloader fix from [projectlombok/lombok#4059](https://github.com/projectlombok/lombok/pull/4059).
+`java/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).
+notices are retained in [java/lombok/LICENSE](java/lombok/LICENSE) and inside the jar.
+Source tag, patch commits and build instructions: [java/lombok/README.md](java/lombok/README.md).
 
 ## JetBrains IntelliJ Platform icons
 
@@ -51,6 +52,15 @@ Their original copyright headers and Apache-2.0 licensing are retained.
 
 At render time `src/ui/icons.tsx` may recolour monochrome icons to `currentColor`.
 
+## JetBrains IntelliJ Platform VCS log graph algorithms
+
+`crates/ide-vcs/src/bek.rs` and `src/features/vcs/graph.ts` adapt the Bek ordering,
+graph layout and LinearBek merge linearization algorithms from
+[intellij-community](https://github.com/JetBrains/intellij-community/tree/1d70d5c54302d655758edbd2f808fb8dea8b1764/platform/vcs-log/graph/src/com/intellij/vcs/log/graph)
+(`impl/facade/sort/bek`, `impl/permanent/GraphLayoutBuilder.kt` and
+`linearBek/LinearBekGraphBuilder.java`). Modified from the originals.
+Copyright 2000-2026 JetBrains s.r.o. and contributors. Apache License 2.0 (below).
+
 ## JetBrains IntelliJ Platform diff algorithm
 
 `src/features/vcs/comparison/**` is a TypeScript port of the text comparison of
@@ -64,6 +74,11 @@ 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, Ruby, Dart, Lua, Zig,
 Svelte, …). Those using the page-with-corner-badge layout (`goMod`, `goWork`,

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;
 
@@ -44,15 +44,22 @@ 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`.
 const PROBE_TIMEOUT: Duration = Duration::from_secs(30);
+/// How long deleting a task waits for its agent to exit before removing the worktree.
+const EXIT_WAIT: Duration = Duration::from_secs(5);
 
 /// The agent tasks of one project.
 pub struct AgentManager {
@@ -90,6 +97,8 @@ 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 +214,8 @@ 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 +237,8 @@ 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 +249,11 @@ 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 +278,7 @@ 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 +320,49 @@ 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())
+    }
+
+    /// Sets the environment variables built-in `id` starts with; empty clears them.
+    pub fn set_builtin_env(&self, id: &str, env: std::collections::BTreeMap<String, 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_env(&dir, id, env)
+    }
+
+    /// 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.
@@ -796,7 +841,7 @@ impl AgentManager {
     /// Forgets the task; with `remove_worktree` also deletes its worktree (the branch stays).
     pub async fn delete(&self, id: &str, remove_worktree: bool) -> IdeResult<()> {
         let task = self.task(id)?;
-        task.kill();
+        let live = task.kill();
         let (isolation, cwd, root) = {
             let s = task.state.lock();
             (
@@ -808,7 +853,13 @@ 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?;
+            // On Windows the agent's processes lock the folder (their working directory,
+            // open files) until they have exited.
+            if let Some(peer) = live {
+                let _ = tokio::time::timeout(EXIT_WAIT, peer.exited()).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 +918,7 @@ 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 +1061,42 @@ 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 +1157,7 @@ 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 +1354,7 @@ 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 +1436,13 @@ 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());
@@ -1522,11 +1612,12 @@ impl Task {
         }
     }
 
-    fn kill(&self) {
+    /// Stops the agent; returns its connection, to wait for its process to exit.
+    fn kill(&self) -> Option<acp::Conn> {
         self.cancel_permissions();
-        if let Some(live) = self.live.lock().take() {
-            live.peer.kill();
-        }
+        let live = self.live.lock().take()?;
+        live.peer.kill();
+        Some(live.peer)
     }
 }
 

crates/ide-agent/src/model.rs

@@ -3,6 +3,7 @@
 use ide_core::IpcPath;
 use serde::{Deserialize, Serialize};
 use specta::Type;
+use std::collections::BTreeMap;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
@@ -154,6 +155,30 @@ 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)]
@@ -322,8 +347,19 @@ 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,
+    /// Environment variables it starts with (from its agent file).
+    pub env: BTreeMap<String, String>,
     /// Settings (models, modes…) the agent offered last time it ran; empty before its first session.
     pub config: Vec<AgentConfigOption>,
     /// Slash commands it offered last time.
@@ -331,6 +367,15 @@ 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 +458,11 @@ 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);

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

@@ -1013,6 +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/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 +81,103 @@ 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),
+        env: spec.env.iter().cloned().collect(),
+        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<()> {
+    update_builtin(custom_dir, id, |agent, builtin| agent.command = command.unwrap_or(&builtin.command).to_owned())
+}
+
+/// The environment built-in `id` starts with, through its agent file (empty clears it).
+pub(crate) fn set_builtin_env(custom_dir: &Path, id: &str, env: BTreeMap<String, String>) -> IdeResult<()> {
+    update_builtin(custom_dir, id, |agent, _| agent.env = env)
+}
+
+/// Changes built-in `id`'s agent file; a file left with only the built-in's values is removed.
+fn update_builtin(custom_dir: &Path, id: &str, change: impl FnOnce(&mut CustomAgent, &ProviderSpec)) -> 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")));
+    }
+    change(&mut agent, &builtin);
+    if agent.command == builtin.command
+        && 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.write(&file)?;
+    Ok(())
 }
 
 /// An agent file, `<config>/agents/<id>.toml`.
@@ -162,7 +257,7 @@ 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 +268,13 @@ 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 +312,54 @@ 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 +379,107 @@ mod tests {
         assert!(installed("sh"));
     }
 
+    #[test]
+    fn set_builtin_env_writes_and_clears_the_environment() {
+        let dir = tempfile::tempdir().unwrap();
+        let env = BTreeMap::from([("CLAUDE_CODE_ENTRYPOINT".to_owned(), "openidea".to_owned())]);
+        set_builtin_env(dir.path(), "claude", env.clone()).unwrap();
+        let claude = load(Some(dir.path())).into_iter().find(|s| s.id == "claude").unwrap();
+        assert_eq!(claude.env, vec![("CLAUDE_CODE_ENTRYPOINT".to_owned(), "openidea".to_owned())]);
+        assert_eq!(describe(&claude).env, env);
+        // The command override and the environment are kept independently.
+        set_builtin_command(dir.path(), "claude", Some("/opt/claude")).unwrap();
+        set_builtin_command(dir.path(), "claude", None).unwrap();
+        assert!(dir.path().join("claude.toml").is_file());
+        set_builtin_env(dir.path(), "claude", BTreeMap::new()).unwrap();
+        assert!(!dir.path().join("claude.toml").exists());
+        set_builtin_env(dir.path(), "not-a-builtin", env).unwrap_err();
+    }
+
+    #[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())
 }
 
@@ -232,11 +239,16 @@ fn choose<'a>(entry: &'a Entry, platform: Platform, on_path: &dyn Fn(&str) -> bo
     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 {
@@ -387,6 +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,
@@ -618,6 +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}")));
     }
@@ -812,15 +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!(
@@ -946,4 +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 +981,242 @@ 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();
+}
+
+/// Deleting a task whose agent still runs in the worktree removes both and leaves no
+/// process behind, whether it is waiting for permission or idle without session/load.
+#[tokio::test(flavor = "multi_thread")]
+async fn deleting_a_task_waits_for_its_agent_to_exit_before_removing_the_worktree() {
+    for no_load in [false, true] {
+        delete_running_agent(no_load).await;
+    }
+}
+
+async fn delete_running_agent(no_load: bool) {
+    let tmp = tempfile::tempdir().unwrap();
+    let root = dunce::canonicalize(tmp.path()).unwrap();
+    let git = |args: &[&str]| {
+        let out = std::process::Command::new("git")
+            .args(["-c", "user.name=t", "-c", "user.email=t@t", "-c", "commit.gpgsign=false"])
+            .args(args)
+            .current_dir(&root)
+            .output()
+            .unwrap();
+        assert!(out.status.success(), "{}", String::from_utf8_lossy(&out.stderr));
+    };
+    git(&["init", "-q", "-b", "main"]);
+    std::fs::write(root.join("file.txt"), "original\n").unwrap();
+    git(&["add", "."]);
+    git(&["commit", "-qm", "initial"]);
+
+    let agent = Arc::new(FakeAgent { no_load, ..FakeAgent::default() });
+    let pids: Arc<Mutex<Vec<u32>>> = Arc::default();
+    let (fake, started) = (agent.clone(), pids.clone());
+    // The fake agent, served on behalf of a real process that exits only when killed.
+    let connector: Connector = Arc::new(move |_spec, cwd, client, _stderr| {
+        #[cfg(unix)]
+        let mut cmd = {
+            let mut cmd = tokio::process::Command::new("sleep");
+            cmd.arg("30");
+            cmd
+        };
+        #[cfg(windows)]
+        let mut cmd = {
+            let mut cmd = tokio::process::Command::new("cmd");
+            cmd.args(["/D", "/C", "echo ready>agent-ready & ping -n 30 127.0.0.1 >nul"]);
+            cmd
+        };
+        ide_core::process::prepare(cmd.as_std_mut());
+        ide_core::process::own_group(cmd.as_std_mut());
+        cmd.current_dir(cwd).kill_on_drop(true);
+        let child = cmd.spawn()?;
+        started.lock().push(child.id().unwrap());
+        let (a, b) = duplex(1 << 20);
+        let (ar, aw) = tokio::io::split(a);
+        let (br, bw) = tokio::io::split(b);
+        // `connect_with_child` frames with Content-Length.
+        fake.servers.lock().push(Peer::connect(br, bw, fake.clone()));
+        Ok(Peer::connect_with_child(ar, aw, client, child))
+    });
+    let mgr = AgentManager::with_connector(
+        AgentPaths {
+            project_root: root.clone(),
+            store_dir: root.join("store"),
+            worktrees_dir: root.join("worktrees"),
+            models_file: root.join("models.json"),
+            custom_agents_dir: None,
+            home_dir: None,
+        },
+        tokio::runtime::Handle::current(),
+        connector,
+    );
+    let task = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text(if no_load { "again" } else { "Fix the lexer" }),
+            provider: "claude".into(),
+            config: vec![],
+            isolation: Isolation::Worktree,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &task.id, if no_load { AgentStatus::Ready } else { AgentStatus::NeedsInput }).await;
+    let pid = *pids.lock().last().expect("the agent was started");
+
+    #[cfg(windows)]
+    {
+        tokio::time::timeout(Duration::from_secs(5), async {
+            while !task.cwd.0.join("agent-ready").exists() {
+                tokio::time::sleep(Duration::from_millis(10)).await;
+            }
+        })
+        .await
+        .unwrap();
+        assert_eq!(
+            std::fs::rename(&task.cwd.0, task.cwd.0.with_extension("moved")).unwrap_err().raw_os_error(),
+            Some(32),
+            "the running agent really locks its worktree"
+        );
+    }
+
+    mgr.delete(&task.id, true).await.unwrap();
+    assert!(!task.cwd.0.exists());
+    // Killed and reaped: not even a zombie is left.
+    #[cfg(unix)]
+    let alive = std::process::Command::new("kill").args(["-0", &pid.to_string()]).status().unwrap().success();
+    #[cfg(windows)]
+    let alive = {
+        let mut cmd = std::process::Command::new("tasklist");
+        ide_core::process::prepare(&mut cmd).args(["/FI", &format!("PID eq {pid}"), "/FO", "CSV", "/NH"]);
+        String::from_utf8_lossy(&cmd.output().unwrap().stdout).contains(&format!("\"{pid}\""))
+    };
+    assert!(!alive, "the agent (pid {pid}) is still running");
+}

crates/ide-agent/src/worktree.rs

@@ -5,7 +5,7 @@ use ide_core::{IdeError, IdeResult, IpcPath};
 use ide_vcs::{ChangeKind, Repo};
 use std::collections::BTreeMap;
 use std::path::{Path, PathBuf};
-use std::time::UNIX_EPOCH;
+use std::time::{Duration, UNIX_EPOCH};
 
 pub(crate) struct Created {
     pub path: PathBuf,
@@ -48,8 +48,44 @@ 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);
+    }
+    retrying(REMOVE_ATTEMPTS, REMOVE_PAUSE, || std::fs::remove_dir_all(path))
+        .map_err(|e| IdeError::internal(format!("{}: {e}", path.display())))
+}
+
+/// On Windows a folder can't be deleted while a process still has a file in it open
+/// (os error 32): an agent's helper that outlived it, an antivirus scan, the search indexer.
+/// Those let go within moments, so removing is retried for a few seconds.
+const REMOVE_ATTEMPTS: u32 = 10;
+const REMOVE_PAUSE: Duration = Duration::from_millis(300);
+
+fn retrying(attempts: u32, pause: Duration, mut op: impl FnMut() -> std::io::Result<()>) -> std::io::Result<()> {
+    for _ in 1..attempts {
+        match op() {
+            Err(e) if e.kind() != std::io::ErrorKind::NotFound => std::thread::sleep(pause),
+            _ => return Ok(()),
+        }
+    }
+    match op() {
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(()),
+        r => r,
+    }
 }
 
 /// Files under `cwd` that differ from `base` (untracked files included), with line counts.
@@ -133,6 +169,54 @@ fn unique_slug(base: &str, taken: impl Fn(&str) -> bool) -> String {
 mod tests {
     use super::*;
 
+    #[test]
+    fn removing_is_retried_while_a_file_is_still_in_use() {
+        use std::io::{Error, ErrorKind};
+        // A sharing violation as Windows reports it (os error 32), a vanished folder, other errors.
+        let in_use = || Error::from_raw_os_error(32);
+        for (fails, outcome) in [(0, true), (3, true), (REMOVE_ATTEMPTS - 1, true), (REMOVE_ATTEMPTS, false)] {
+            let mut calls = 0;
+            let r = retrying(REMOVE_ATTEMPTS, Duration::ZERO, || {
+                calls += 1;
+                if calls <= fails { Err(in_use()) } else { Ok(()) }
+            });
+            assert_eq!(r.is_ok(), outcome, "{fails} failures");
+            assert_eq!(calls, (fails + 1).min(REMOVE_ATTEMPTS));
+        }
+        let mut calls = 0;
+        let gone = retrying(REMOVE_ATTEMPTS, Duration::ZERO, || {
+            calls += 1;
+            if calls == 1 { Err(in_use()) } else { Err(Error::from(ErrorKind::NotFound)) }
+        });
+        assert!(gone.is_ok(), "deleted meanwhile: done");
+        assert_eq!(calls, 2);
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn removing_waits_for_a_windows_file_lock_to_be_released() {
+        use std::os::windows::fs::OpenOptionsExt;
+        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"]);
+        let worktrees = tmp.path().join("wt");
+        let created = create(&repo, &worktrees, "Locked file", None).unwrap();
+        let file = std::fs::OpenOptions::new().read(true).share_mode(0).open(created.path.join("a.txt")).unwrap();
+        assert_eq!(std::fs::remove_file(created.path.join("a.txt")).unwrap_err().raw_os_error(), Some(32));
+        let release = std::thread::spawn(move || {
+            std::thread::sleep(Duration::from_millis(800));
+            drop(file);
+        });
+        let result = remove(&repo, &worktrees, &created.path);
+        release.join().unwrap();
+        result.unwrap();
+        assert!(!created.path.exists());
+    }
+
     #[test]
     fn slugs_are_branch_safe() {
         assert_eq!(slugify("Fix lexer UTF-16 columns!"), "fix-lexer-utf-16-columns");
@@ -153,7 +237,7 @@ 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 +286,38 @@ 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/compile/mod.rs

@@ -10,6 +10,7 @@ pub use fingerprint::{LaunchFingerprint, launch_fingerprint};
 
 use crate::process::{self, Stream};
 use crate::{BuildModel, maven};
+use ide_core::settings::CMakeProfile;
 use ide_core::{CancellationToken, Diagnostic, IdeError, IdeResult, Pos, Range, Severity};
 use parse::{ColUnit, Format, OutputParser, RawMessage};
 use serde::{Deserialize, Serialize};
@@ -41,6 +42,8 @@ pub enum BuildSystem {
     Go,
     #[serde(rename = "typescript")]
     TypeScript,
+    #[serde(rename = "cmake")]
+    CMake,
 }
 
 /// One command of a build.
@@ -152,14 +155,19 @@ fn detect_dir(dir: &Path, model: &BuildModel, root: &Path) -> Option<BuildSystem
         Some(BuildSystem::Go)
     } else if has(dir, &["tsconfig.json", "package.json"]) {
         Some(BuildSystem::TypeScript)
+    } else if has(dir, &["CMakeLists.txt"]) {
+        Some(BuildSystem::CMake)
     } else {
         None
     }
 }
 
 /// `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 {
@@ -173,7 +181,14 @@ fn ancestors_within<'a>(root: &'a Path, file: &'a Path) -> impl Iterator<Item =
 }
 
 /// The build of `root`, or of the module containing `file` (Build Module / Recompile).
-pub fn plan(root: &Path, model: &BuildModel, kind: BuildKind, file: Option<&Path>) -> IdeResult<BuildPlan> {
+/// `cmake`: the CMake profiles of the settings (the first one is built), if any.
+pub fn plan(
+    root: &Path,
+    model: &BuildModel,
+    kind: BuildKind,
+    file: Option<&Path>,
+    cmake: Option<&[CMakeProfile]>,
+) -> IdeResult<BuildPlan> {
     let project_name = root.file_name().map_or_else(|| "project".to_owned(), |n| n.to_string_lossy().into_owned());
     let module_dir = match file {
         Some(f) => {
@@ -185,9 +200,13 @@ 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 })
-        .ok_or_else(|| IdeError::not_found("no supported build system (Maven, Gradle, Cargo, Go, TypeScript) found"))?;
+        .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, CMake) found")
+        })?;
     let module = module_dir.as_deref().filter(|d| *d != root);
     let title = match module {
         Some(d) => format!(
@@ -204,6 +223,7 @@ pub fn plan(root: &Path, model: &BuildModel, kind: BuildKind, file: Option<&Path
         // Go builds the file's package (a module holds many).
         BuildSystem::Go => go_steps(file.and_then(Path::parent).unwrap_or(&dir), kind),
         BuildSystem::TypeScript => ts_steps(&dir, kind),
+        BuildSystem::CMake => cmake_steps(&dir, kind, cmake.and_then(<[_]>::first)),
     };
     Ok(BuildPlan { system, title, steps })
 }
@@ -297,6 +317,50 @@ fn cargo_steps(dir: &Path, kind: BuildKind) -> Vec<BuildStep> {
     }
 }
 
+/// CLion's Build Project for a CMake project: configures the build directory when it has no
+/// `CMakeCache.txt` yet, then `cmake --build` (`--clean-first` to rebuild). The directory and
+/// options come from the CMake profile; without one, a configured directory of the project
+/// (the first by name), else `build`, as the generated run configurations use.
+fn cmake_steps(dir: &Path, kind: BuildKind, profile: Option<&CMakeProfile>) -> Vec<BuildStep> {
+    let build_dir = match profile {
+        Some(p) if !p.build_dir.trim().is_empty() => p.build_dir.trim().to_owned(),
+        Some(p) => format!("cmake-build-{}", p.build_type.to_lowercase()),
+        None => {
+            let mut configured: Vec<String> = std::fs::read_dir(dir)
+                .into_iter()
+                .flatten()
+                .flatten()
+                .filter(|e| e.path().join("CMakeCache.txt").is_file())
+                .map(|e| e.file_name().to_string_lossy().into_owned())
+                .collect();
+            configured.sort();
+            configured.into_iter().next().unwrap_or_else(|| "build".into())
+        }
+    };
+    let build_type = profile.map_or("Debug", |p| p.build_type.as_str());
+    let env = profile.map(|p| p.env.clone()).unwrap_or_default();
+    let mut steps = Vec::new();
+    if !dir.join(&build_dir).join("CMakeCache.txt").is_file() {
+        let mut configure = BuildStep::new("cmake", &["-S", ".", "-B", &build_dir], dir, Format::Gcc);
+        if let Some(p) = profile.filter(|p| !p.generator.trim().is_empty()) {
+            configure.args.extend(["-G".into(), p.generator.clone()]);
+        }
+        configure.args.push(format!("-DCMAKE_BUILD_TYPE={build_type}"));
+        configure.args.push("-DCMAKE_EXPORT_COMPILE_COMMANDS=ON".into());
+        configure.args.extend(profile.map(|p| p.cmake_args.clone()).unwrap_or_default());
+        configure.env = env.clone();
+        steps.push(configure);
+    }
+    let mut build = BuildStep::new("cmake", &["--build", &build_dir, "--config", build_type], dir, Format::Gcc);
+    if kind == BuildKind::Rebuild {
+        build.args.push("--clean-first".into());
+    }
+    build.args.extend(profile.map(|p| p.build_args.clone()).unwrap_or_default());
+    build.env = env;
+    steps.push(build);
+    steps
+}
+
 fn go_steps(dir: &Path, kind: BuildKind) -> Vec<BuildStep> {
     let module_root = dir.ancestors().find(|d| d.join("go.mod").is_file()).unwrap_or(dir);
     let target = if module_root == dir { "./...".to_owned() } else { format!("./{}/...", rel_str(module_root, dir)) };
@@ -682,7 +746,7 @@ fn launch_plan(root: &Path, model: &BuildModel, module: &Path, test: bool) -> Id
     } else {
         BuildKind::Build
     };
-    let mut plan = plan(root, model, kind, Some(module))?;
+    let mut plan = plan(root, model, kind, Some(module), None)?;
     if plan.system == BuildSystem::Maven && !test {
         for step in &mut plan.steps {
             if let Some(goal) = step.args.last_mut() {
@@ -735,11 +799,11 @@ 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()
@@ -749,6 +813,30 @@ 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();
@@ -767,12 +855,12 @@ mod tests {
         write(&root, "core/pom.xml", "<project><artifactId>core</artifactId></project>");
         write(&root, "core/src/main/java/A.java", "class A {}");
         let model = crate::load(&root, &tmp.path().join("cache"), None);
-        let p = plan(&root, &model, BuildKind::Build, None).unwrap();
+        let p = plan(&root, &model, BuildKind::Build, None, None).unwrap();
         assert_eq!(p.system, BuildSystem::Maven);
         assert_eq!(p.title, "demo");
         assert_eq!(p.steps.len(), 1);
         assert_eq!(p.steps[0].args, ["-B", "-Dstyle.color=never", "test-compile"]);
-        let p = plan(&root, &model, BuildKind::Rebuild, Some(&root.join("core/src/main/java/A.java"))).unwrap();
+        let p = plan(&root, &model, BuildKind::Rebuild, Some(&root.join("core/src/main/java/A.java")), None).unwrap();
         assert_eq!(p.steps[0].args, ["-B", "-Dstyle.color=never", "-pl", "core", "-am", "clean", "test-compile"]);
         assert_eq!(p.steps[0].cwd, root);
         assert_eq!(p.title, "demo: build module 'core'");
@@ -781,24 +869,24 @@ mod tests {
         write(&g, "settings.gradle", "include 'app'");
         write(&g, "app/build.gradle", "apply plugin: 'java'");
         let model = crate::load(&g, &tmp.path().join("cache2"), None);
-        let p = plan(&g, &model, BuildKind::Build, Some(&g.join("app/src/A.java"))).unwrap();
+        let p = plan(&g, &model, BuildKind::Build, Some(&g.join("app/src/A.java")), None).unwrap();
         assert_eq!(p.system, BuildSystem::Gradle);
         assert_eq!(p.steps[0].args, ["--console=plain", ":app:classes", ":app:testClasses"]);
         assert_eq!(
-            plan(&g, &model, BuildKind::Artifacts, None).unwrap().steps[0].args,
+            plan(&g, &model, BuildKind::Artifacts, None, None).unwrap().steps[0].args,
             ["--console=plain", "assemble"]
         );
 
         let c = tmp.path().join("c");
         write(&c, "Cargo.toml", "[package]\nname='c'");
-        let p = plan(&c, &BuildModel::default(), BuildKind::Rebuild, None).unwrap();
+        let p = plan(&c, &BuildModel::default(), BuildKind::Rebuild, None, None).unwrap();
         assert_eq!(p.system, BuildSystem::Cargo);
         assert_eq!(p.steps.len(), 2);
         assert_eq!(p.steps[0].args[0], "clean");
 
         let go = tmp.path().join("go");
         write(&go, "go.mod", "module x");
-        let p = plan(&go, &BuildModel::default(), BuildKind::Build, Some(&go.join("pkg/a/a.go"))).unwrap();
+        let p = plan(&go, &BuildModel::default(), BuildKind::Build, Some(&go.join("pkg/a/a.go")), None).unwrap();
         assert_eq!(p.steps[0].args, ["build", "./pkg/a/..."]);
         assert_eq!(p.steps[0].cwd, go);
 
@@ -806,17 +894,60 @@ mod tests {
         write(&ts, "package.json", r#"{"scripts":{"build":"vite build"}}"#);
         write(&ts, "tsconfig.json", "{}");
         write(&ts, "pnpm-lock.yaml", "");
-        let p = plan(&ts, &BuildModel::default(), BuildKind::Build, None).unwrap();
+        let p = plan(&ts, &BuildModel::default(), BuildKind::Build, None, None).unwrap();
         assert_eq!(p.steps[0].args, ["--noEmit", "--pretty", "false", "-p", "."]);
-        let p = plan(&ts, &BuildModel::default(), BuildKind::Artifacts, None).unwrap();
+        let p = plan(&ts, &BuildModel::default(), BuildKind::Artifacts, None, None).unwrap();
         assert_eq!(
             (p.steps[0].program.as_str(), p.steps[0].args.as_slice()),
             ("pnpm", &["run".to_owned(), "build".to_owned()][..])
         );
 
+        let cm = tmp.path().join("cm");
+        write(&cm, "CMakeLists.txt", "project(app)");
+        let args = |p: &BuildPlan| p.steps.iter().map(|s| s.args.join(" ")).collect::<Vec<_>>();
+        let p = plan(&cm, &BuildModel::default(), BuildKind::Build, None, None).unwrap();
+        assert_eq!(p.system, BuildSystem::CMake);
+        assert_eq!(
+            args(&p),
+            [
+                "-S . -B build -DCMAKE_BUILD_TYPE=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS=ON",
+                "--build build --config Debug"
+            ],
+            "an unconfigured project is configured first"
+        );
+        write(&cm, "cmake-build-release/CMakeCache.txt", "");
+        let p = plan(&cm, &BuildModel::default(), BuildKind::Rebuild, None, None).unwrap();
+        assert_eq!(
+            args(&p),
+            ["--build cmake-build-release --config Debug --clean-first"],
+            "a configured directory is reused"
+        );
+        let profile = CMakeProfile {
+            build_type: "Release".into(),
+            generator: "Ninja".into(),
+            build_args: vec!["-j".into(), "8".into()],
+            ..CMakeProfile::default()
+        };
+        let p =
+            plan(&cm, &BuildModel::default(), BuildKind::Build, None, Some(std::slice::from_ref(&profile))).unwrap();
+        assert_eq!(args(&p), ["--build cmake-build-release --config Release -j 8"]);
+        let p = plan(&cm, &BuildModel::default(), BuildKind::Build, None, Some(&[CMakeProfile::default()])).unwrap();
+        assert_eq!(p.steps[0].args[..4], ["-S", ".", "-B", "cmake-build-debug"]);
+
+        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, 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());
+        assert!(plan(&none, &BuildModel::default(), BuildKind::Build, None, None).is_err());
     }
 
     #[test]

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

@@ -22,6 +22,8 @@ pub(crate) enum Format {
     Tsc,
     /// `go build`: `./a.go:12:5: msg`.
     Go,
+    /// GCC / Clang (through `cmake --build`): `src/a.cpp:12:5: error: msg`.
+    Gcc,
 }
 
 /// What a printed column counts.
@@ -296,6 +298,17 @@ fn go_line(line: &str) -> Option<RawMessage> {
     (!msg.is_empty()).then(|| RawMessage::new(Severity::Error, msg, ColUnit::Byte).at(path, ln, col))
 }
 
+/// A GCC / Clang diagnostic line; notes and the context lines after it are left as output.
+fn gcc_line(line: &str) -> Option<RawMessage> {
+    let (path, ln, col, rest) = path_line_col(line)?;
+    let rest = rest.strip_prefix(':')?.trim_start();
+    let (severity, msg) =
+        [("fatal error:", Severity::Error), ("error:", Severity::Error), ("warning:", Severity::Warning)]
+            .into_iter()
+            .find_map(|(prefix, severity)| rest.strip_prefix(prefix).map(|m| (severity, m.trim())))?;
+    (!msg.is_empty()).then(|| RawMessage::new(severity, msg, ColUnit::Byte).at(path, ln, col))
+}
+
 /// rustc's JSON diagnostic (`reason: compiler-message`) → message and its rendered text.
 fn cargo_json(v: &Value) -> Option<(Option<RawMessage>, String)> {
     if v.get("reason")?.as_str()? != "compiler-message" {
@@ -410,6 +423,7 @@ impl OutputParser {
             Format::Gradle => javac_header(&line).or_else(|| kotlin_line(&line)),
             Format::Tsc => tsc_line(&line),
             Format::Go => go_line(&line),
+            Format::Gcc => gcc_line(&line),
             Format::Cargo => None,
         };
         if let Some(msg) = parsed {
@@ -563,6 +577,24 @@ mod tests {
         assert_eq!(out[2].text, "Cannot find name 'foo'.");
     }
 
+    #[test]
+    fn gcc_errors_and_warnings() {
+        let out = parse(
+            Format::Gcc,
+            "[1/2] Building CXX object CMakeFiles/app.dir/main.cpp.o\n\
+             /p/src/main.cpp:12:5: error: use of undeclared identifier 'foo'\n\
+             \x20  12 |     foo();\n\
+             /p/src/util.h:3:10: warning: unused variable 'x' [-Wunused-variable]\n\
+             /p/src/main.cpp:4:10: fatal error: 'missing.h' file not found\n\
+             /p/src/main.cpp:2:1: note: in file included from here\n",
+        );
+        assert_eq!(out.len(), 3, "{out:?}");
+        assert_eq!(out[0].severity, Severity::Error);
+        assert_eq!(out[0].text, "use of undeclared identifier 'foo'");
+        assert_eq!(out[1].severity, Severity::Warning);
+        assert_eq!(out[2].text, "'missing.h' file not found");
+    }
+
     #[test]
     fn go_errors() {
         let out = parse(

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/gradle_deps.rs

@@ -0,0 +1,257 @@
+//! A Gradle project's resolved dependencies for the Dependency Analyzer:
+//! `gradle <project>:dependencies --configuration <name>`, parsed from its tree report.
+
+use crate::gradle;
+use crate::process;
+use crate::sync::{SyncOptions, error_summary};
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::path::Path;
+
+/// One line of the report: an occurrence of a dependency where it is requested.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct GradleDependency {
+    /// `group`, empty for a project dependency.
+    pub group: String,
+    /// Artifact name, or the project path (`:core`) of a project dependency.
+    pub name: String,
+    /// The version asked for here; `None` when a platform or constraint supplies it.
+    pub requested: Option<String>,
+    /// The version Gradle selected (`-> 1.2`), when it differs from the request.
+    pub selected: Option<String>,
+    /// A project of the build (`project :core`, or a module substituted by one).
+    pub project: bool,
+    /// `(*)`: listed with its dependencies earlier in the tree.
+    pub repeated: bool,
+    /// `(c)`: a dependency constraint rather than a dependency.
+    pub constraint: bool,
+    /// `(n)` / `FAILED`: not resolved.
+    pub unresolved: bool,
+    pub children: Vec<GradleDependency>,
+}
+
+/// Parses the tree of a `dependencies --configuration` report (lines `+--- g:a:1.0 -> 1.1 (*)`).
+pub fn parse_report(output: &str) -> Vec<GradleDependency> {
+    let mut roots: Vec<GradleDependency> = Vec::new();
+    // Path of child indexes from the roots to the last node of each depth.
+    let mut path: Vec<usize> = Vec::new();
+    for line in output.lines() {
+        let Some((depth, text)) = tree_line(line) else { continue };
+        let node = parse_entry(text);
+        path.truncate(depth);
+        if depth > path.len() {
+            continue; // A line deeper than its parent allows: not part of a well-formed tree.
+        }
+        let siblings = if depth == 0 {
+            &mut roots
+        } else {
+            let mut list = &mut roots;
+            for &i in &path[..depth - 1] {
+                list = &mut list[i].children;
+            }
+            let Some(parent) = list.get_mut(path[depth - 1]) else { continue };
+            &mut parent.children
+        };
+        siblings.push(node);
+        path.push(siblings.len() - 1);
+    }
+    roots
+}
+
+/// `|    \--- g:a:1.0` → (1, "g:a:1.0").
+fn tree_line(line: &str) -> Option<(usize, &str)> {
+    let mut rest = line;
+    let mut depth = 0;
+    loop {
+        if let Some(r) = rest.strip_prefix("+--- ").or_else(|| rest.strip_prefix("\\--- ")) {
+            return Some((depth, r.trim()));
+        }
+        rest = rest.strip_prefix("|    ").or_else(|| rest.strip_prefix("     "))?;
+        depth += 1;
+    }
+}
+
+fn parse_entry(text: &str) -> GradleDependency {
+    let mut d = GradleDependency::default();
+    let mut text = text.trim();
+    loop {
+        if let Some(t) = text.strip_suffix(" (*)") {
+            d.repeated = true;
+            text = t;
+        } else if let Some(t) = text.strip_suffix(" (c)") {
+            d.constraint = true;
+            text = t;
+        } else if let Some(t) = text.strip_suffix(" (n)").or_else(|| text.strip_suffix(" FAILED")) {
+            d.unresolved = true;
+            text = t;
+        } else {
+            break;
+        }
+        text = text.trim_end();
+    }
+    let (left, right) = match text.split_once(" -> ") {
+        Some((l, r)) => (l.trim(), Some(r.trim())),
+        None => (text, None),
+    };
+    if let Some(project) = left.strip_prefix("project ") {
+        d.project = true;
+        d.name = project_path(project);
+    } else {
+        let mut parts = left.splitn(3, ':');
+        d.group = parts.next().unwrap_or_default().to_owned();
+        d.name = parts.next().unwrap_or_default().to_owned();
+        d.requested = parts.next().filter(|v| !v.is_empty()).map(str::to_owned);
+    }
+    if let Some(right) = right {
+        if let Some(project) = right.strip_prefix("project ") {
+            // A module substituted by a project of the build.
+            d.project = true;
+            d.selected = Some(project_path(project));
+        } else {
+            d.selected = Some(right.to_owned());
+        }
+    }
+    d
+}
+
+/// `:core`, or `':core'` as Gradle 9 quotes it.
+fn project_path(text: &str) -> String {
+    let t = text.trim();
+    t.strip_prefix('\'').and_then(|t| t.strip_suffix('\'')).unwrap_or(t).to_owned()
+}
+
+/// Runs the `dependencies` report of `project` (a Gradle path, `:` for the root) for
+/// `configuration` and returns its tree.
+pub fn gradle_dependencies(
+    root: &Path,
+    options: &SyncOptions,
+    project: &str,
+    configuration: &str,
+    cancel: &CancellationToken,
+) -> IdeResult<Vec<GradleDependency>> {
+    if !configuration.chars().all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '-') || configuration.is_empty() {
+        return Err(IdeError::invalid(format!("not a configuration name: {configuration}")));
+    }
+    if !project.starts_with(':') || project.chars().any(char::is_whitespace) {
+        return Err(IdeError::invalid(format!("not a Gradle project path: {project}")));
+    }
+    let model = gradle::load(root).ok_or_else(|| IdeError::not_found("no Gradle build in this project"))?;
+    let task = if project == ":" { ":dependencies".to_owned() } else { format!("{project}:dependencies") };
+    let mut args: Vec<String> =
+        vec!["--console=plain".into(), "-q".into(), task, "--configuration".into(), configuration.into()];
+    if options.offline {
+        args.push("--offline".into());
+    }
+    let out = process::run(
+        options.gradle_command.as_deref().unwrap_or(&model.command),
+        &args,
+        &root.join(&model.dir),
+        &options.env,
+        cancel,
+        |_, _| {},
+    )?;
+    if !out.success {
+        return Err(IdeError::unavailable(error_summary(&out.text)));
+    }
+    Ok(parse_report(&out.text))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn dep(group: &str, name: &str, requested: Option<&str>) -> GradleDependency {
+        GradleDependency {
+            group: group.into(),
+            name: name.into(),
+            requested: requested.map(Into::into),
+            ..Default::default()
+        }
+    }
+
+    #[test]
+    fn parses_the_tree_with_selected_versions_and_markers() {
+        let report = "\
+------------------------------------------------------------
+Project ':app'
+------------------------------------------------------------
+
+runtimeClasspath - Runtime classpath of source set 'main'.
++--- org.springframework.boot:spring-boot-starter-web -> 3.2.0
+|    +--- org.springframework.boot:spring-boot-starter:3.2.0
+|    |    \\--- org.yaml:snakeyaml:2.2
+|    \\--- com.fasterxml.jackson.core:jackson-databind:2.15.0 -> 2.15.3 (*)
++--- project ':core'
+|    \\--- com.google.guava:guava:{strictly 32.1.3-jre} -> 32.1.3-jre (c)
++--- org.example:legacy:1.0 -> project :legacy
+\\--- org.missing:gone:9 FAILED
+
+(c) - A dependency constraint, not a dependency. The dependency affected by the constraint occurs elsewhere in the tree.
+(*) - Indicates repeated occurrences of a transitive dependency subtree. Gradle expands transitive dependency subtrees only once per project; repeat occurrences only display the root of the subtree, followed by this annotation.
+";
+        let tree = parse_report(report);
+        assert_eq!(tree.len(), 4);
+        let web = &tree[0];
+        assert_eq!((web.group.as_str(), web.name.as_str()), ("org.springframework.boot", "spring-boot-starter-web"));
+        assert_eq!((web.requested.as_deref(), web.selected.as_deref()), (None, Some("3.2.0")));
+        assert_eq!(web.children.len(), 2);
+        assert_eq!(web.children[0].children, vec![dep("org.yaml", "snakeyaml", Some("2.2"))]);
+        let databind = &web.children[1];
+        assert_eq!((databind.requested.as_deref(), databind.selected.as_deref()), (Some("2.15.0"), Some("2.15.3")));
+        assert!(databind.repeated);
+        let core = &tree[1];
+        assert!(core.project && core.group.is_empty());
+        assert_eq!(core.name, ":core");
+        let guava = &core.children[0];
+        assert!(guava.constraint);
+        assert_eq!(guava.requested.as_deref(), Some("{strictly 32.1.3-jre}"));
+        let legacy = &tree[2];
+        assert!(legacy.project);
+        assert_eq!((legacy.name.as_str(), legacy.selected.as_deref()), ("legacy", Some(":legacy")));
+        assert!(tree[3].unresolved);
+        assert_eq!(tree[3].requested.as_deref(), Some("9"));
+    }
+
+    #[test]
+    fn an_empty_configuration_has_no_dependencies() {
+        assert!(
+            parse_report("compileClasspath - Compile classpath for source set 'main'.\nNo dependencies\n").is_empty()
+        );
+    }
+
+    #[test]
+    fn rejects_names_that_are_not_configurations_or_projects() {
+        let tmp = tempfile::tempdir().unwrap();
+        let options = SyncOptions::default();
+        let cancel = CancellationToken::new();
+        assert!(gradle_dependencies(tmp.path(), &options, ":", "x --init-script y", &cancel).is_err());
+        assert!(gradle_dependencies(tmp.path(), &options, "app", "runtimeClasspath", &cancel).is_err());
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn runs_the_report_of_the_project_and_configuration() {
+        use std::os::unix::fs::PermissionsExt;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        std::fs::write(root.join("settings.gradle"), "include 'app'").unwrap();
+        std::fs::write(root.join("build.gradle"), "").unwrap();
+        let launcher = root.join("fake-gradle");
+        std::fs::write(&launcher, "#!/bin/sh\necho \"$@\" > args\necho '\\--- org.a:b:1.0'\n").unwrap();
+        std::fs::set_permissions(&launcher, std::fs::Permissions::from_mode(0o755)).unwrap();
+        let options = SyncOptions {
+            gradle_command: Some(launcher.to_string_lossy().into_owned()),
+            offline: true,
+            ..Default::default()
+        };
+        let tree =
+            gradle_dependencies(root, &options, ":app", "testRuntimeClasspath", &CancellationToken::new()).unwrap();
+        assert_eq!(tree, vec![dep("org.a", "b", Some("1.0"))]);
+        assert_eq!(
+            std::fs::read_to_string(root.join("args")).unwrap().trim(),
+            "--console=plain -q :app:dependencies --configuration testRuntimeClasspath --offline"
+        );
+    }
+}

crates/ide-build/src/kotlin_bridge.rs

@@ -81,7 +81,7 @@ pub fn build(
     cancel: &CancellationToken,
 ) -> IdeResult<Outcome> {
     std::fs::create_dir_all(generation)?;
-    let mut plan = compile::plan(root, model, BuildKind::Build, None)?;
+    let mut plan = compile::plan(root, model, BuildKind::Build, None, None)?;
     if plan.system != compile::BuildSystem::Maven {
         return Err(IdeError::invalid("Kotlin bridge requires a Maven build root"));
     }

crates/ide-build/src/lib.rs

@@ -8,6 +8,7 @@
 pub mod application_update;
 pub mod compile;
 pub mod gradle;
+mod gradle_deps;
 pub mod kotlin_bridge;
 pub mod maven;
 pub mod pom_edit;
@@ -17,8 +18,9 @@ pub mod web;
 mod xml;
 
 pub use gradle::{GradleModel, GradleProject, GradleTask};
+pub use gradle_deps::{GradleDependency, gradle_dependencies};
 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;
@@ -53,7 +55,8 @@ pub fn load_linked(
     settings: &ide_core::settings::MavenSettings,
 ) -> BuildModel {
     let maven = maven::is_maven_project(root).then(|| {
-        let mut m = maven::load_with_repo(root, maven_repo.or_else(maven::default_local_repo));
+        let profiles = sync::maven_profiles(cache_dir);
+        let mut m = maven::load_with(root, maven_repo.or_else(maven::default_local_repo), &profiles);
         maven::UnlinkedProjects::from_model(&m, settings).filter(&mut m);
         sync::apply_maven_cache(root, cache_dir, &mut m);
         m
@@ -65,6 +68,18 @@ 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)>,
@@ -441,6 +460,8 @@ const MAX_PARENT_DEPTH: usize = 10;
 
 struct Resolver {
     local_repo: Option<PathBuf>,
+    /// The chosen profiles (`-P` entries; `!id` / `-id` deactivates).
+    profiles: Vec<String>,
     poms: HashMap<PathBuf, Option<RawPom>>,
     contexts: HashMap<PathBuf, Inherited>,
 }
@@ -448,18 +469,33 @@ 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 {
-    fn new(local_repo: Option<PathBuf>) -> Self {
-        Self { local_repo, poms: HashMap::new(), contexts: HashMap::new() }
+    fn new(local_repo: Option<PathBuf>, profiles: &[String]) -> Self {
+        Self { local_repo, profiles: profiles.to_vec(), poms: HashMap::new(), contexts: HashMap::new() }
+    }
+
+    /// The active profiles of a POM: the chosen ones, and the `activeByDefault` ones not turned
+    /// off while none of the POM's other profiles is chosen (Maven's rule).
+    fn active<'a>(&self, profiles: &'a [RawProfile]) -> impl Iterator<Item = &'a RawProfile> {
+        let chosen = |id: &str| profile_choice(&self.profiles, id);
+        let any_chosen = profiles.iter().any(|p| chosen(&p.id) == Some(true));
+        profiles.iter().filter(move |p| chosen(&p.id).unwrap_or(p.active_by_default && !any_chosen))
     }
 
     fn pom(&mut self, path: &Path) -> Option<RawPom> {
@@ -521,7 +557,10 @@ 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);
-        for p in pom.profiles.iter().filter(|p| p.active_by_default) {
+        if pom.compiler_release.is_some() {
+            ctx.compiler_release = pom.compiler_release.clone();
+        }
+        for p in self.active(&pom.profiles) {
             merge_by(&mut ctx.properties, &p.properties, |(k, _)| k.clone());
             merge_by(&mut ctx.deps, &p.deps, RawDep::key);
             merge_plugins(&mut ctx.plugins, &p.plugins);
@@ -637,7 +676,7 @@ pub(crate) fn launch_inputs(
         }
         Some(())
     }
-    let mut resolver = Resolver::new(local_repo.or_else(default_local_repo));
+    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);
@@ -680,7 +719,76 @@ 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"],
@@ -832,9 +940,27 @@ 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());
@@ -862,13 +988,19 @@ 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 };
@@ -882,9 +1014,16 @@ 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));
             }
         }
@@ -926,8 +1065,32 @@ pub fn load(root: &Path) -> MavenModel {
     load_with_repo(root, default_local_repo())
 }
 
+/// [`load`] with the chosen `profiles` (`-P` entries; `!id` deactivates): their modules,
+/// dependencies and properties are part of the model, those turned off are not.
+pub fn load_with_profiles(root: &Path, profiles: &[String]) -> MavenModel {
+    load_with(root, default_local_repo(), profiles)
+}
+
 pub(crate) fn load_with_repo(root: &Path, local_repo: Option<PathBuf>) -> MavenModel {
-    let mut resolver = Resolver::new(local_repo);
+    load_with(root, local_repo, &[])
+}
+
+/// The `-P` entries' choice for profile `id`: on, off (`!id` / `-id`), or none (the last wins).
+fn profile_choice(chosen: &[String], id: &str) -> Option<bool> {
+    chosen.iter().rev().find_map(|c| {
+        let c = c.trim();
+        if c == id {
+            Some(true)
+        } else if c.strip_prefix('!').or_else(|| c.strip_prefix('-')) == Some(id) {
+            Some(false)
+        } else {
+            None
+        }
+    })
+}
+
+pub(crate) fn load_with(root: &Path, local_repo: Option<PathBuf>, profiles: &[String]) -> MavenModel {
+    let mut resolver = Resolver::new(local_repo, profiles);
     let mut model = MavenModel::default();
     let mut seen: HashSet<PathBuf> = HashSet::new();
     // (pom, aggregated)
@@ -947,7 +1110,7 @@ pub(crate) fn load_with_repo(root: &Path, local_repo: Option<PathBuf>) -> MavenM
         let i = |s: &str| interpolate(s, &props);
 
         let mut module_names: Vec<String> = pom.modules.clone();
-        for p in pom.profiles.iter().filter(|p| p.active_by_default) {
+        for p in resolver.active(&pom.profiles) {
             module_names.extend(p.modules.iter().cloned());
         }
         let mut modules: Vec<PathBuf> = Vec::new();
@@ -999,14 +1162,14 @@ 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'.
@@ -1079,6 +1242,40 @@ 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 {
@@ -1111,6 +1308,16 @@ 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] };
@@ -1122,7 +1329,7 @@ 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
@@ -1253,6 +1460,107 @@ 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();
@@ -1276,6 +1584,72 @@ 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();
@@ -1359,6 +1733,52 @@ mod tests {
         assert!(model.projects.iter().all(|p| p.command == if cfg!(windows) { "mvn.cmd" } else { "mvn" }));
     }
 
+    #[test]
+    fn chosen_profiles_bring_their_modules_and_dependencies() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        write(
+            root,
+            "pom.xml",
+            r#"<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1.0</version><packaging>pom</packaging>
+              <modules><module>core</module></modules>
+              <profiles>
+                <profile><id>flink-1.17</id><activation><activeByDefault>true</activeByDefault></activation>
+                  <modules><module>flink-1.17</module></modules></profile>
+                <profile><id>flink-1.20</id><modules><module>flink-1.20</module></modules>
+                  <dependencies><dependency><groupId>org.apache.flink</groupId><artifactId>flink-core</artifactId><version>1.20.0</version></dependency></dependencies>
+                </profile>
+              </profiles>
+            </project>"#,
+        );
+        for m in ["core", "flink-1.17", "flink-1.20"] {
+            write(
+                root,
+                &format!("{m}/pom.xml"),
+                &format!(
+                    "<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1.0</version></parent><artifactId>{m}</artifactId></project>"
+                ),
+            );
+        }
+        let dirs = |m: &MavenModel| m.projects.iter().map(|p| p.dir.clone()).collect::<Vec<_>>();
+        let flink = |m: &MavenModel, dir: &str| {
+            m.projects.iter().find(|p| p.dir == dir).unwrap().dependencies.iter().any(|d| d.artifact_id == "flink-core")
+        };
+
+        let default = load_with(root, None, &[]);
+        assert_eq!(dirs(&default), ["", "core", "flink-1.17"]);
+        assert!(!flink(&default, "core"));
+
+        // Choosing another profile of the POM turns its activeByDefault one off (as `-P` does).
+        let chosen = load_with(root, None, &["flink-1.20".into()]);
+        assert_eq!(dirs(&chosen), ["", "core", "flink-1.20"]);
+        assert!(flink(&chosen, "core"), "a module inherits the chosen profile's dependencies");
+
+        let both = load_with(root, None, &["flink-1.20".into(), "flink-1.17".into()]);
+        assert_eq!(dirs(&both), ["", "core", "flink-1.17", "flink-1.20"]);
+        assert_eq!(dirs(&load_with(root, None, &["!flink-1.17".into()])), ["", "core"]);
+    }
+
     #[test]
     fn profiles_of_a_parent_pom_are_inherited() {
         let tmp = tempfile::tempdir().unwrap();
@@ -1471,6 +1891,25 @@ 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> =
@@ -1668,4 +2107,51 @@ 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;
 
@@ -22,18 +23,6 @@ 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.
@@ -80,12 +69,8 @@ pub(crate) fn run_with_env(
     let mut command = Command::new(&program);
     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);
-    }
-    ide_core::process::prepare(&mut command);
+    // 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);
     }

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
@@ -208,16 +283,42 @@ pub fn sync_maven(
     cancel: &CancellationToken,
     progress: &dyn Fn(SyncProgress),
 ) -> IdeResult<()> {
-    let mut model = maven::load(root);
+    let mut model = maven::load_with_profiles(root, &options.profiles);
     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"));
         let _ = std::fs::remove_file(&effective);
-        let mut args: Vec<String> = vec!["-B".into(), "-fae".into(), "-Dstyle.color=never".into()];
+        // `-T1` keeps mvnd serial: its default parallel build interleaves the
+        // `dependency:tree` output of concurrent modules, which the sync parses
+        // as one stream. mvn is serial anyway, so this only pins the daemon.
+        let mut args: Vec<String> = vec!["-B".into(), "-fae".into(), "-Dstyle.color=never".into(), "-T1".into()];
         args.extend(options.maven_options.iter().cloned());
         if options.offline {
             args.push("-o".into());
@@ -241,8 +342,9 @@ 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 +373,18 @@ 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 +397,15 @@ 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 +448,7 @@ 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 +460,7 @@ mod tests {
                     "maven-clean-plugin",
                     Some("3.2.0".into()),
                     &[],
+                    None,
                 )],
                 dependencies: vec![MavenDependency { artifact_id: "dep".into(), ..MavenDependency::default() }],
             }],
@@ -368,6 +486,128 @@ 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 +618,39 @@ 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]
@@ -420,4 +683,25 @@ mod tests {
         assert_eq!(error_summary(text), "Failed to execute goal");
         assert_eq!(error_summary("one\nlast line\n\n"), "last line");
     }
+
+    #[cfg(unix)]
+    #[test]
+    fn maven_sync_runs_the_daemon_command_serially() {
+        use std::os::unix::fs::PermissionsExt;
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path().join("p");
+        std::fs::create_dir_all(&root).unwrap();
+        std::fs::write(root.join("pom.xml"), "<project><groupId>g</groupId><artifactId>a</artifactId></project>")
+            .unwrap();
+        let launcher = tmp.path().join("fake-mvnd");
+        std::fs::write(&launcher, "#!/bin/sh\nprintf '%s\\n' \"$@\" > mvnd-args\n").unwrap();
+        std::fs::set_permissions(&launcher, std::fs::Permissions::from_mode(0o755)).unwrap();
+        let options =
+            SyncOptions { maven_command: Some(launcher.to_string_lossy().into_owned()), ..Default::default() };
+        sync_maven(&root, &tmp.path().join("cache"), &options, &CancellationToken::new(), &|_| {}).unwrap();
+        let args = std::fs::read_to_string(root.join("mvnd-args")).unwrap();
+        // `-T1` pins the daemon serial so the dependency trees stay parseable.
+        assert!(args.contains("-T1"), "args: {args}");
+        assert!(args.contains("help:effective-pom"), "args: {args}");
+    }
 }

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", "Win32_System_Registry", "Win32_Foundation"] }
+windows-sys = { version = "0.61", features = ["Win32_Globalization", "Win32_Security", "Win32_System_Registry", "Win32_Foundation", "Win32_System_Diagnostics_ToolHelp", "Win32_System_Threading"] }

crates/ide-core/src/editor_settings.rs

@@ -371,6 +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")]

crates/ide-core/src/event.rs

@@ -36,12 +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 {
@@ -82,6 +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/ignored.rs

@@ -2,6 +2,18 @@
 //! treats as nonexistent — hidden from the project view and navigation, never
 //! indexed or searched, never offered as unversioned changes.
 
+use std::path::Path;
+
+/// Whether `dir` lies in a Git (or jj) working tree: it or an ancestor holds `.git` / `.jj`.
+///
+/// Walkers pass it to `ignore::WalkBuilder::require_git`: inside a repository, `.gitignore`
+/// rules then stop at a nested repository's root as in git, so an outer repository's
+/// `.gitignore` does not hide a project that is its own repository. A folder outside any
+/// repository still honours its `.gitignore`.
+pub fn inside_git_repo(dir: &Path) -> bool {
+    dir.ancestors().any(|d| d.join(".git").exists() || d.join(".jj").exists())
+}
+
 /// IDEA's default list, plus `.jj` and the Windows shell files.
 pub const DEFAULT_IGNORED_NAMES: &[&str] = &[
     "*.pyc",
@@ -103,4 +115,15 @@ mod tests {
         assert!(m.is_ignored_path("pkg/__pycache__/mod.cpython-312.pyc"));
         assert!(!m.is_ignored_path("src/main.rs"));
     }
+
+    #[test]
+    fn finds_the_repository_at_or_above_a_directory() {
+        let dir = tempfile::tempdir().unwrap();
+        let sub = dir.path().join("a/b");
+        std::fs::create_dir_all(&sub).unwrap();
+        assert!(!inside_git_repo(&sub));
+        std::fs::create_dir(dir.path().join("a/.git")).unwrap();
+        assert!(inside_git_repo(&sub));
+        assert!(inside_git_repo(&dir.path().join("a")));
+    }
 }

crates/ide-core/src/inspection_settings.rs

@@ -36,6 +36,23 @@ impl Default for InspectionSettings {
     }
 }
 
+impl InspectionSettings {
+    /// Overrides of the profile in effect; `Default`'s when `profile` names none that exists.
+    pub fn active(&self) -> &BTreeMap<String, InspectionOverride> {
+        let custom = |level: &str, key: &str| match level {
+            "ide" => self.ide_profiles.get(key),
+            "project" => self.project_profiles.get(key),
+            _ => None,
+        };
+        match self.profile.as_str() {
+            "project" => &self.project,
+            id => {
+                id.split_once(':').and_then(|(level, key)| custom(level, key)).map_or(&self.default, |p| &p.overrides)
+            }
+        }
+    }
+}
+
 /// A named profile made with Copy.
 #[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
@@ -111,4 +128,20 @@ mod tests {
         let back: InspectionSettings = serde_json::from_str(&serde_json::to_string(&s).unwrap()).unwrap();
         assert_eq!(back, s);
     }
+
+    #[test]
+    fn active_profile_falls_back_to_default() {
+        let off = |id: &str| {
+            BTreeMap::from([(id.to_owned(), InspectionOverride { enabled: Some(false), ..Default::default() })])
+        };
+        let mut s = InspectionSettings { default: off("a"), project: off("b"), ..Default::default() };
+        s.ide_profiles.insert("strict".into(), CustomInspectionProfile { name: "Strict".into(), overrides: off("c") });
+        assert!(s.active().contains_key("a"));
+        s.profile = "project".into();
+        assert!(s.active().contains_key("b"));
+        s.profile = "ide:strict".into();
+        assert!(s.active().contains_key("c"));
+        s.profile = "project:gone".into();
+        assert!(s.active().contains_key("a"));
+    }
 }

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.
@@ -25,18 +28,195 @@ 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, then a
+///   wait for what the child started to be gone.
+pub fn kill_tree(child: &mut Child) {
+    #[cfg(unix)]
+    signal_group(child, libc::SIGKILL);
+    #[cfg(windows)]
+    taskkill_tree_of(child.id());
+    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` and a wait for what the
+/// child started to be gone. 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)]
+    taskkill_tree_of(pid);
+    #[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);
+        }
+    }
+}
+
+/// How long killing a tree waits for the processes the child started to be gone.
+#[cfg(windows)]
+const TREE_EXIT_WAIT: Duration = Duration::from_secs(5);
+
+/// `taskkill /T /F` from `pid`, then waits (up to [`TREE_EXIT_WAIT`]) until what the child
+/// started is gone: termination is asynchronous, and until a process is gone the files it
+/// holds open can't be opened or deleted. The child itself is left to its owner to reap.
+#[cfg(windows)]
+fn taskkill_tree_of(pid: u32) {
+    let started = windows_tree::descendants(pid);
+    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();
+    windows_tree::wait_all(&started, TREE_EXIT_WAIT);
+}
+
+#[cfg(windows)]
+mod windows_tree {
+    use std::collections::HashSet;
+    use std::os::windows::io::{AsRawHandle, FromRawHandle, OwnedHandle};
+    use std::time::{Duration, Instant};
+    use windows_sys::Win32::Foundation::{FILETIME, INVALID_HANDLE_VALUE};
+    use windows_sys::Win32::System::Diagnostics::ToolHelp::{
+        CreateToolhelp32Snapshot, PROCESSENTRY32W, Process32FirstW, Process32NextW, TH32CS_SNAPPROCESS,
+    };
+    use windows_sys::Win32::System::Threading::{
+        GetProcessTimes, OpenProcess, PROCESS_QUERY_LIMITED_INFORMATION, PROCESS_SYNCHRONIZE, WaitForSingleObject,
+    };
+
+    /// Every process `root` started, directly or not, opened so it can be waited for. A
+    /// parent's id is reused once it is gone, so a process counts only if it started after
+    /// its parent.
+    pub(super) fn descendants(root: u32) -> Vec<OwnedHandle> {
+        let Some(root_started) = open(root).as_ref().and_then(started) else { return Vec::new() };
+        let processes = processes();
+        let mut seen = HashSet::from([root]);
+        let mut parents = vec![(root, root_started)];
+        let mut found = Vec::new();
+        while let Some((parent, parent_started)) = parents.pop() {
+            for &(pid, ppid) in &processes {
+                if ppid != parent || !seen.insert(pid) {
+                    continue;
+                }
+                let Some(handle) = open(pid) else { continue };
+                if let Some(at) = started(&handle).filter(|&at| at >= parent_started) {
+                    parents.push((pid, at));
+                    found.push(handle);
+                }
+            }
+        }
+        found
+    }
+
+    pub(super) fn wait_all(processes: &[OwnedHandle], within: Duration) {
+        let until = Instant::now() + within;
+        for process in processes {
+            let left = until.saturating_duration_since(Instant::now());
+            // SAFETY: a live process handle opened with SYNCHRONIZE access.
+            unsafe { WaitForSingleObject(process.as_raw_handle(), left.as_millis().min(u32::MAX as u128 - 1) as u32) };
+        }
+    }
+
+    /// (process id, parent process id) of every running process.
+    fn processes() -> Vec<(u32, u32)> {
+        let mut out = Vec::new();
+        // SAFETY: a snapshot handle owned here and an entry sized as the API requires.
+        unsafe {
+            let snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
+            if snapshot.is_null() || snapshot == INVALID_HANDLE_VALUE {
+                return out;
+            }
+            let snapshot = OwnedHandle::from_raw_handle(snapshot);
+            let mut entry = PROCESSENTRY32W { dwSize: size_of::<PROCESSENTRY32W>() as u32, ..Default::default() };
+            let mut more = Process32FirstW(snapshot.as_raw_handle(), &mut entry);
+            while more != 0 {
+                out.push((entry.th32ProcessID, entry.th32ParentProcessID));
+                more = Process32NextW(snapshot.as_raw_handle(), &mut entry);
+            }
+        }
+        out
+    }
+
+    fn open(pid: u32) -> Option<OwnedHandle> {
+        // SAFETY: plain call; a non-null result is a process handle owned by the caller.
+        let handle = unsafe { OpenProcess(PROCESS_SYNCHRONIZE | PROCESS_QUERY_LIMITED_INFORMATION, 0, pid) };
+        // SAFETY: as above.
+        (!handle.is_null()).then(|| unsafe { OwnedHandle::from_raw_handle(handle) })
+    }
+
+    /// When the process started, in 100 ns ticks since 1601.
+    fn started(process: &OwnedHandle) -> Option<u64> {
+        let (mut created, mut exited, mut kernel, mut user) =
+            (FILETIME::default(), FILETIME::default(), FILETIME::default(), FILETIME::default());
+        // SAFETY: a live process handle opened with query access; four out-parameters.
+        let ok = unsafe { GetProcessTimes(process.as_raw_handle(), &mut created, &mut exited, &mut kernel, &mut user) };
+        (ok != 0).then(|| (u64::from(created.dwHighDateTime) << 32) | u64::from(created.dwLowDateTime))
+    }
+}
+
 /// 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
 /// inherits them loads the image's (older) libraries and plugins next to its own, e.g.
 /// `curl: symbol lookup error ... nghttp2_...`. The IDE process keeps its environment
 /// (WebKit and GTK still need it). Then applies the [`set_env_overlay`] variables and
-/// those of a manual HTTP proxy ([`crate::proxy_settings::ProxySettings::child_env`]).
-/// Variables the call site has already set are kept. A no-op outside an AppImage
-/// without an overlay.
+/// those of a manual HTTP proxy ([`crate::proxy_settings::ProxySettings::child_env`]),
+/// and the login shell's variables this process lacks ([`shell_env`]: an app started from
+/// Finder/Dock doesn't have what rc files export, such as `GOPATH`, `JAVA_HOME` or
+/// `MAVEN_OPTS`). Variables the call site has already set are kept.
 pub fn host_env(cmd: &mut Command) -> &mut Command {
     let fixes = child_env_changes();
-    if fixes.is_empty() {
+    let shell: Vec<_> = shell_env().collect();
+    if fixes.is_empty() && shell.is_empty() {
         return cmd;
     }
     let explicit: Vec<OsString> = cmd.get_envs().map(|(k, _)| k.to_owned()).collect();
@@ -46,6 +226,9 @@ pub fn host_env(cmd: &mut Command) -> &mut Command {
             None => cmd.env_remove(key),
         };
     }
+    for (key, value) in shell.into_iter().filter(|(k, _)| !explicit.contains(k)) {
+        cmd.env(key, value);
+    }
     cmd
 }
 
@@ -62,12 +245,13 @@ pub fn host_vars() -> impl Iterator<Item = (OsString, OsString)> {
     apply_changes(std::env::vars_os().collect(), &child_env_changes()).into_iter()
 }
 
-/// [`std::env::var_os`] as a child should see it (see [`host_env`]).
+/// [`std::env::var_os`] as a child should see it (see [`host_env`]), the login shell's value
+/// included when this process lacks the variable.
 pub fn host_var_os(key: impl AsRef<OsStr>) -> Option<OsString> {
     let key = key.as_ref();
     match child_env_changes().into_iter().find(|(k, _)| k == key) {
         Some((_, fixed)) => fixed,
-        None => std::env::var_os(key),
+        None => std::env::var_os(key).or_else(|| shell_env().find(|(k, _)| k == key).map(|(_, v)| v)),
     }
 }
 
@@ -245,10 +429,7 @@ pub fn find_executable(name: &str, search: &OsStr) -> Option<std::path::PathBuf>
 #[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, RRF_RT_REG_EXPAND_SZ, RRF_RT_REG_SZ, RegCloseKey, RegGetValueW,
-        RegOpenKeyExW,
-    };
+    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()
@@ -259,45 +440,53 @@ pub fn user_path() -> Option<OsString> {
         if RegOpenKeyExW(HKEY_CURRENT_USER, wide("Environment").as_ptr(), 0, KEY_READ, &mut key) != ERROR_SUCCESS {
             return None;
         }
-        let read = || {
-            // Only `Path`; `REG_EXPAND_SZ` is accepted so `%USERPROFILE%\…` entries expand.
-            let mut kind = 0u32;
-            let mut len = 0u32;
-            let name = wide("Path");
-            let status = RegGetValueW(
-                key,
-                std::ptr::null(),
-                name.as_ptr(),
-                RRF_RT_REG_SZ | RRF_RT_REG_EXPAND_SZ,
-                &mut kind,
-                std::ptr::null_mut(),
-                &mut len,
-            );
-            if status != ERROR_SUCCESS || len == 0 {
-                return None;
-            }
-            let mut buf = vec![0u16; (len as usize).div_ceil(2)];
-            let status = RegGetValueW(
-                key,
-                std::ptr::null(),
-                name.as_ptr(),
-                RRF_RT_REG_SZ | RRF_RT_REG_EXPAND_SZ,
-                &mut kind,
-                buf.as_mut_ptr() as *mut _,
-                &mut len,
-            );
-            if status != ERROR_SUCCESS {
-                return None;
-            }
-            let text = String::from_utf16_lossy(&buf);
-            Some(text.trim_end_matches('\0').to_owned())
-        };
-        let value = read();
+        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> {
@@ -323,6 +512,28 @@ fn append_path_entries(path: &OsStr, extra: &OsStr) -> OsString {
 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() {
@@ -334,6 +545,96 @@ mod tests {
         }
     }
 
+    #[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();
@@ -363,6 +664,15 @@ mod tests {
         assert_eq!(get("HOME"), Some(None));
         let shell: Vec<_> = shell_env().map(|(k, _)| k).collect();
         assert_eq!(shell, [OsString::from("OPENIDEA_OVERLAY_B")]);
+        // Every child gets what the login shell exports and the IDE process lacks (a Finder
+        // launch: `GOPATH`, `JAVA_HOME`...), unless the call site sets it.
+        assert_eq!(get("OPENIDEA_OVERLAY_B"), Some(Some("b".into())));
+        let mut own = Command::new("true");
+        own.env("OPENIDEA_OVERLAY_B", "call site");
+        host_env(&mut own);
+        let value = own.get_envs().find(|(n, _)| *n == "OPENIDEA_OVERLAY_B").and_then(|(_, v)| v);
+        assert_eq!(value, Some(OsStr::new("call site")));
+        assert_eq!(host_var_os("OPENIDEA_OVERLAY_B"), Some("b".into()));
         assert_eq!(host_var_os("PATH"), Some("/reloaded".into()));
         assert!(host_vars().all(|(k, _)| k != "HOME"));
         assert!(host_vars().any(|(k, v)| k == "OPENIDEA_OVERLAY_A" && v == "project"));
@@ -502,3 +812,71 @@ 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

@@ -132,7 +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,

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)]
@@ -95,6 +157,16 @@ pub struct LanguageServerSettings {
     pub languages: Vec<String>,
     /// Files marking a workspace root for a server defined here (`pyproject.toml`).
     pub root_markers: Vec<String>,
+    /// Replaces the definition's `features`: what the server is used for
+    /// (`code-action`, `hover`, …); an empty list means everything.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[specta(optional)]
+    pub features: Option<Vec<String>>,
+    /// Replaces the definition's `code-action-kinds` (`refactor`); an empty
+    /// list keeps every kind.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[specta(optional)]
+    pub code_action_kinds: Option<Vec<String>>,
 }
 
 impl Default for LanguageServerSettings {
@@ -108,6 +180,8 @@ impl Default for LanguageServerSettings {
             settings: None,
             languages: Vec::new(),
             root_markers: Vec::new(),
+            features: None,
+            code_action_kinds: None,
         }
     }
 }
@@ -154,6 +228,9 @@ 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 +274,7 @@ 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 +339,8 @@ 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,
@@ -271,6 +349,9 @@ 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,
+    pub file_icon_theme_options: BTreeMap<String, FileIconThemeOptions>,
     /// IDE zoom in percent (50–300).
     pub zoom: u32,
     /// Apply `ui_font_family` / `ui_font_size` (otherwise the theme's).
@@ -306,6 +387,24 @@ pub struct AppearanceSettings {
 /// Main toolbar entries per side, in order: title widget ids (`project`,
 /// `vcs.branch`…) or `action:<id>`. Widgets in neither list nor `hidden`
 /// (registered later) keep their default place.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct FileIconThemeOptions {
+    pub groups: BTreeMap<String, bool>,
+    pub choices: BTreeMap<String, String>,
+    pub hide_files: bool,
+    pub hide_folders: bool,
+    pub hollow_folders: bool,
+    pub hide_ui_icons: bool,
+    pub hide_psi_icons: bool,
+    pub monochrome: Option<String>,
+    pub saturation: Option<u8>,
+    pub opacity: Option<u8>,
+    pub icon_size: Option<u8>,
+    pub row_height: Option<u8>,
+    pub accent: Option<String>,
+}
+
 #[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct MainToolbarSettings {
@@ -325,6 +424,8 @@ impl Default for AppearanceSettings {
             sync_with_os: false,
             preferred_light_theme: "light".into(),
             preferred_dark_theme: "dark".into(),
+            file_icon_theme: String::new(),
+            file_icon_theme_options: BTreeMap::new(),
             zoom: 100,
             use_custom_font: false,
             ui_font_family: "Inter".into(),
@@ -505,25 +606,65 @@ 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: PrettierSettings,
+    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 PrettierSettings {
+pub struct ExternalFormatterSettings {
     /// Empty path: project node_modules, managed installation, then PATH.
     pub path: String,
     pub languages: Vec<String>,
-    /// Prefer Prettier even when a language server offers formatting.
+    /// Prefer this formatter even when a language server offers formatting.
     pub prefer: bool,
     pub run_on_save: bool,
 }
 
-impl Default for PrettierSettings {
+impl Default for ExternalFormatterSettings {
     fn default() -> Self {
         Self {
             path: String::new(),
@@ -567,6 +708,29 @@ 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,
+    /// PHP version the language server checks the code against (`7.4`); empty = from
+    /// `composer.json` (`config.platform.php`, else the lowest version `require.php` allows).
+    pub language_level: String,
+    /// Folders outside the project whose code the language server indexes too (a platform a
+    /// module extends); absolute, `~/`, or relative to the project.
+    pub include_paths: Vec<String>,
+    /// Intelephense stub sets loaded on top of its defaults and the `ext-*` entries of
+    /// `composer.json` (`wordpress`).
+    pub stubs: Vec<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 {
@@ -671,6 +835,19 @@ 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)]
@@ -693,6 +870,12 @@ pub struct MavenSettings {
     pub user_settings: String,
     /// Local repository (`-Dmaven.repo.local`); empty = from `settings.xml`.
     pub local_repository: String,
+    /// Run Maven through the Maven Daemon (`mvnd`) for faster builds. mvnd embeds
+    /// its own Maven, so `home` and the project's `mvnw` are bypassed when it is on.
+    pub daemon: bool,
+    /// Maven Daemon home (or its `mvnd` executable); empty = `$MVND_HOME`, else
+    /// `mvnd` on `PATH` / common install dirs. Only used when `daemon` is on.
+    pub mvnd_home: String,
 }
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
@@ -765,6 +948,54 @@ 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 file_icon_theme_options_default_empty_and_round_trip() {
+        let old: Settings = serde_json::from_str(r#"{"appearance":{"fileIconTheme":"p/t"}}"#).unwrap();
+        assert!(old.appearance.file_icon_theme_options.is_empty());
+        let json = serde_json::json!({"appearance":{"fileIconThemeOptions":{"p/t":{
+            "groups":{"tests":true},"choices":{"arrows":"plusminus"},"hideFiles":true,"hideFolders":false,"hollowFolders":true,"hideUiIcons":true,"hidePsiIcons":false,
+            "monochrome":"#546e7a","saturation":5,"opacity":80,"iconSize":20,"rowHeight":30,"accent":"#009688"}}}});
+        let settings: Settings = serde_json::from_value(json.clone()).unwrap();
+        let options = &settings.appearance.file_icon_theme_options["p/t"];
+        assert!(options.hide_files && options.hollow_folders && !options.hide_folders);
+        assert!(options.hide_ui_icons && !options.hide_psi_icons);
+        assert!(options.groups["tests"]);
+        assert_eq!(options.choices["arrows"], "plusminus");
+        assert_eq!(
+            (options.saturation, options.opacity, options.icon_size, options.row_height),
+            (Some(5), Some(80), Some(20), Some(30))
+        );
+        assert_eq!(options.monochrome.as_deref(), Some("#546e7a"));
+        assert_eq!(options.accent.as_deref(), Some("#009688"));
+        let value = serde_json::to_value(&settings).unwrap();
+        let restored: Settings = serde_json::from_value(value).unwrap();
+        assert_eq!(restored, settings);
+        let plain = serde_json::to_value(FileIconThemeOptions::default()).unwrap();
+        assert_eq!(plain["hideFiles"], false);
+        assert_eq!(plain["hideUiIcons"], false);
+        assert_eq!(plain["hidePsiIcons"], false);
+        assert_eq!(plain["monochrome"], serde_json::Value::Null);
+        assert_eq!(plain["groups"], serde_json::json!({}));
+    }
+
     #[test]
     fn ui_font_fallback_defaults_empty_and_round_trips() {
         let old: Settings = serde_json::from_str(r#"{"appearance":{"useCustomFont":true}}"#).unwrap();
@@ -794,6 +1025,20 @@ mod tests {
         }
     }
 
+    #[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();
@@ -862,6 +1107,17 @@ mod maven_linkage_tests {
         assert!(encoded.contains("unlinkedProjects"));
         assert_eq!(serde_json::from_str::<MavenSettings>(&encoded).unwrap(), settings);
     }
+
+    #[test]
+    fn daemon_settings_round_trip() {
+        // Old settings files predate the daemon fields; `serde(default)` keeps them loadable.
+        let old: MavenSettings = serde_json::from_str(r#"{"home":"/opt/maven"}"#).unwrap();
+        assert!(!old.daemon && old.mvnd_home.is_empty());
+        let settings = MavenSettings { daemon: true, mvnd_home: "/opt/mvnd".into(), ..old };
+        let encoded = serde_json::to_string(&settings).unwrap();
+        assert!(encoded.contains("\"daemon\":true") && encoded.contains("mvndHome"));
+        assert_eq!(serde_json::from_str::<MavenSettings>(&encoded).unwrap(), settings);
+    }
 }
 
 #[cfg(test)]
@@ -879,6 +1135,7 @@ 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);

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

@@ -97,6 +97,16 @@ 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 {
@@ -108,17 +118,26 @@ impl WorkspaceEdit {
         let mut resolve_aliases = true;
         for file in std::mem::take(&mut self.files) {
             match file {
-                FileEdit::Edit { path, edits } => {
+                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.into(), edits: Vec::new() });
+                        files.push(FileEdit::Edit { path: path.clone().into(), edits: Vec::new(), version });
                         files.len() - 1
                     });
-                    let FileEdit::Edit { edits: own, .. } = &mut files[index] else { unreachable!() };
+                    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);
@@ -140,10 +159,26 @@ impl WorkspaceEdit {
 #[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)]
@@ -254,7 +289,7 @@ mod workspace_edit_tests {
         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()] };
+        let edit = |path: PathBuf| FileEdit::Edit { path: path.into(), edits: vec![change.clone()], version: None };
         let mut workspace = WorkspaceEdit {
             files: vec![
                 edit(real.clone()),
@@ -262,6 +297,7 @@ mod workspace_edit_tests {
                 FileEdit::Create { path: dir.path().join("other").into(), overwrite: false },
                 edit(real),
             ],
+            ..Default::default()
         };
         workspace.deduplicate();
         assert_eq!(workspace.files.len(), 3);

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(),
     }
 }
 
@@ -426,12 +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 {

crates/ide-dap/src/lib.rs

@@ -212,6 +212,19 @@ pub struct Variable {
     pub evaluate_name: Option<String>,
 }
 
+/// A completion the adapter offers for an expression (DAP `completions`).
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct DebugCompletion {
+    pub label: String,
+    /// What to insert, when it differs from `label`.
+    pub text: Option<String>,
+    /// DAP item type: `method`, `field`, `variable`, `class`, `keyword`, …
+    pub kind: Option<String>,
+    pub detail: Option<String>,
+    pub sort_text: Option<String>,
+}
+
 #[derive(Clone, Copy, Debug, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 pub enum StepKind {
@@ -576,11 +589,12 @@ impl DebugManager {
         if let Some(command) = custom_command(&spec.command) {
             spec.command = command;
         }
-        // debugpy: run the adapter with the debuggee's interpreter (venvs carry their own debugpy).
+        // debugpy: run the adapter with the debuggee's interpreter (venvs carry their own debugpy),
+        // or with the launcher's when the debuggee runs through a manager (`uv run python`).
         if config.adapter == "debugpy" {
-            let python = match arguments.get("python") {
-                Some(Value::String(p)) => Some(p.clone()),
-                Some(Value::Array(a)) => a.first().and_then(Value::as_str).map(str::to_owned),
+            let python = match (arguments.get("debugLauncherPython"), arguments.get("python")) {
+                (Some(Value::String(p)), _) | (_, Some(Value::String(p))) => Some(p.clone()),
+                (_, Some(Value::Array(a))) => a.first().and_then(Value::as_str).map(str::to_owned),
                 _ => None,
             };
             if let Some(python) = python {
@@ -638,8 +652,19 @@ impl DebugManager {
         {
             arguments["project"] = json!(real);
         }
-        if config.adapter == "codelldb" && arguments.get("sourceLanguages").is_none() {
-            arguments["sourceLanguages"] = json!(["rust"]);
+        if config.adapter == "codelldb" {
+            if arguments.get("sourceLanguages").is_none() {
+                arguments["sourceLanguages"] = json!(["rust"]);
+            }
+            // The Debug Console and Evaluate Expression take expressions, as with every other
+            // debugger; LLDB commands still run with a leading backtick.
+            match arguments.get_mut("_adapterSettings") {
+                None => arguments["_adapterSettings"] = json!({"consoleMode": "evaluate"}),
+                Some(Value::Object(settings)) => {
+                    settings.entry("consoleMode").or_insert_with(|| json!("evaluate"));
+                }
+                Some(_) => {}
+            }
         }
         let port = debug_server.map(|s| s.port);
         self.start_session(id, owner, config.name, config.adapter, None, config.request, arguments, spec, port).await
@@ -1157,6 +1182,47 @@ impl DebugManager {
         })
     }
 
+    /// Completions for `text` at `line` / `column` (0-based, UTF-16) in the frame's scope; none
+    /// when the adapter doesn't offer them.
+    pub async fn completions(
+        &self,
+        s: DebugSessionId,
+        frame_id: Option<i64>,
+        text: String,
+        line: u32,
+        column: u32,
+    ) -> IdeResult<Vec<DebugCompletion>> {
+        let session = self.session(s)?;
+        if !session.supports("supportsCompletionsRequest") {
+            return Ok(Vec::new());
+        }
+        let mut args = json!({ "text": text, "line": line + 1, "column": column + 1 });
+        if let Some(f) = frame_id {
+            args["frameId"] = f.into();
+        }
+        let body = session.conn.request_timeout("completions", args, REQUEST_TIMEOUT).await?;
+        let text =
+            |v: &Value, key: &str| v.get(key).and_then(Value::as_str).filter(|t| !t.is_empty()).map(str::to_owned);
+        Ok(body
+            .get("targets")
+            .and_then(Value::as_array)
+            .map(|targets| {
+                targets
+                    .iter()
+                    .filter_map(|t| {
+                        Some(DebugCompletion {
+                            label: text(t, "label")?,
+                            text: text(t, "text"),
+                            kind: text(t, "type"),
+                            detail: text(t, "detail"),
+                            sort_text: text(t, "sortText"),
+                        })
+                    })
+                    .collect()
+            })
+            .unwrap_or_default())
+    }
+
     pub async fn resume(&self, s: DebugSessionId, thread_id: i64) -> IdeResult<()> {
         let session = self.session(s)?;
         let body = session.conn.request_timeout("continue", json!({ "threadId": thread_id }), REQUEST_TIMEOUT).await?;
@@ -1389,6 +1455,16 @@ 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

@@ -73,6 +73,7 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                 msg,
                 json!({
                     "supportsConfigurationDoneRequest": true,
+                    "supportsCompletionsRequest": true,
                     "supportsTerminateRequest": true,
                     "supportsSetVariable": true,
                     "supportsFunctionBreakpoints": true,
@@ -172,6 +173,14 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                 ]})
             ),
             "evaluate" => ok!(msg, json!({"result": "42", "type": "int", "variablesReference": 0})),
+            "completions" => ok!(
+                msg,
+                json!({"targets": [
+                    {"label": "getName()", "text": "getName", "type": "method", "detail": "String"},
+                    {"label": "name", "type": "field"},
+                    {"label": ""},
+                ]})
+            ),
             "continue" => {
                 ok!(msg, json!({"allThreadsContinued": true}));
                 send!(json!({"type": "event", "event": "exited", "body": {"exitCode": 3}}));
@@ -368,6 +377,14 @@ async fn full_protocol_flow() {
     let eval = h.request("evaluate");
     assert_eq!(eval["arguments"]["context"], "watch");
     assert_eq!(eval["arguments"]["frameId"], 10);
+    let items = h.manager.completions(id, Some(10), "req.na".into(), 0, 6).await.unwrap();
+    assert_eq!(
+        items.iter().map(|c| (c.label.as_str(), c.text.as_deref(), c.kind.as_deref())).collect::<Vec<_>>(),
+        [("getName()", Some("getName"), Some("method")), ("name", None, Some("field"))]
+    );
+    let asked = h.request("completions");
+    assert_eq!((asked["arguments"]["line"].clone(), asked["arguments"]["column"].clone()), (json!(1), json!(7)));
+    assert_eq!(asked["arguments"]["frameId"], 10);
 
     // Live breakpoint updates reach the session.
     let states = h.manager.set_breakpoints(path.clone(), vec![bp(0)]).await.unwrap();
@@ -681,6 +698,37 @@ async fn js_debug_launch_gets_port_and_workspace_folder() {
     assert_eq!(launch["type"], "pwa-node");
 }
 
+/// CodeLLDB treats console input as LLDB commands unless told otherwise: Evaluate Expression
+/// and the Debug Console send expressions, so its console evaluates them. A launch
+/// configuration that picks a console mode keeps it.
+#[tokio::test]
+async fn codelldb_console_evaluates_expressions() {
+    let launch_with = |extra: Value| async move {
+        let h = harness(Script::default());
+        let config = LaunchConfig {
+            name: "demo".into(),
+            adapter: "codelldb".into(),
+            request: "launch".into(),
+            program: Some("/p/target/debug/demo".into()),
+            args: vec![],
+            cwd: Some("/p".into()),
+            env: BTreeMap::new(),
+            extra_json: Some(extra.to_string()),
+        };
+        h.start(config).await.unwrap();
+        h.request("launch")["arguments"].clone()
+    };
+    let launch = launch_with(json!({})).await;
+    assert_eq!(launch["_adapterSettings"]["consoleMode"], "evaluate");
+    assert_eq!(launch["sourceLanguages"], json!(["rust"]));
+
+    let launch =
+        launch_with(json!({"_adapterSettings": {"consoleMode": "commands", "showDisassembly": "never"}})).await;
+    assert_eq!(launch["_adapterSettings"], json!({"consoleMode": "commands", "showDisassembly": "never"}));
+    let launch = launch_with(json!({"_adapterSettings": {"showDisassembly": "never"}})).await;
+    assert_eq!(launch["_adapterSettings"], json!({"consoleMode": "evaluate", "showDisassembly": "never"}));
+}
+
 /// An adapter that is already listening (java-debug inside jdtls): the client
 /// connects over TCP to the `debugServer` port instead of spawning anything.
 #[tokio::test]
@@ -906,6 +954,7 @@ fn godot_registry(port: u16, command: &str, args: &[&str]) -> Arc<LanguageRegist
         ui_mode: None,
         framework_ui_modes: Vec::new(),
         formatter: None,
+        scratch_template: None,
         tree_sitter: None,
         language_servers: vec![],
         debugger: Some(ide_language::DebuggerConfig {
@@ -915,6 +964,7 @@ 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]))
@@ -1147,3 +1197,58 @@ 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-db/Cargo.toml

@@ -8,7 +8,7 @@ license.workspace = true
 [dependencies]
 ide-core.workspace = true
 serde.workspace = true
-serde_json.workspace = true
+serde_json = { workspace = true, features = ["raw_value"] }
 specta.workspace = true
 toml.workspace = true
 tokio.workspace = true
@@ -21,6 +21,10 @@ bb8.workspace = true
 tokio-util = { workspace = true, features = ["compat"] }
 dirs.workspace = true
 ide-ssh.workspace = true
+ide-http.workspace = true
+reqwest = { workspace = true, features = ["query"] }
+rustls.workspace = true
+uuid.workspace = true
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["rt-multi-thread", "macros"] }

crates/ide-db/src/clickhouse.rs

@@ -0,0 +1,844 @@
+use crate::conn::{QueryResult, ResultColumn, Setup};
+use crate::source::{DataSource, DbSslMode, DbTxMode};
+use ide_core::{CancellationToken, IdeError, IdeResult, error::ErrorKind};
+use parking_lot::RwLock;
+use reqwest::{Client, RequestBuilder, StatusCode, Url};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+use tokio::sync::Mutex;
+
+#[derive(Clone)]
+pub struct ClickhousePool(Arc<State>);
+
+struct State {
+    client: RwLock<Option<Client>>,
+    endpoint: Url,
+    user: String,
+    password: String,
+    database: String,
+    settings: Vec<(String, String)>,
+    read_only: bool,
+    session_id: String,
+    session: Mutex<bool>,
+    closed: CancellationToken,
+}
+
+/// The response format: a names line, a types line, then one JSON array per row, so rows past
+/// the grid's limit are skipped without being parsed.
+const FORMAT: &str = "JSONCompactEachRowWithNamesAndTypes";
+
+pub(crate) fn transaction_error() -> IdeError {
+    IdeError::invalid("ClickHouse HTTP does not support SQL transactions; use auto-commit and run writes directly")
+}
+
+impl ClickhousePool {
+    pub(crate) async fn connect(source: &DataSource, password: Option<&str>, setup: Setup) -> IdeResult<Self> {
+        if source.options.transaction == DbTxMode::Manual {
+            return Err(transaction_error());
+        }
+        for (name, _) in &setup.params {
+            if reserved_setting(name) {
+                return Err(IdeError::invalid(format!("ClickHouse HTTP manages the {name} setting")));
+            }
+        }
+        let secure = matches!(source.ssl, DbSslMode::Require | DbSslMode::VerifyCa | DbSslMode::VerifyFull);
+        let tls_files = [&source.ssl_ca_file, &source.ssl_cert_file, &source.ssl_key_file];
+        if !secure && tls_files.iter().any(|p| !p.trim().is_empty()) {
+            return Err(IdeError::invalid(
+                "ClickHouse TLS certificate files require an SSL mode of Require, Verify CA, or Verify Full",
+            ));
+        }
+        let host = source.host.trim();
+        if host.is_empty() || host.contains(['/', '@', '?', '#']) {
+            return Err(IdeError::invalid("ClickHouse host must contain only a hostname or IP address"));
+        }
+        let host = if host.contains(':') && !host.starts_with('[') { format!("[{host}]") } else { host.to_owned() };
+        let scheme = if secure { "https" } else { "http" };
+        let port = source.port.unwrap_or(if secure { 8443 } else { 8123 });
+        let endpoint = Url::parse(&format!("{scheme}://{host}:{port}/"))
+            .map_err(|_| IdeError::invalid("invalid ClickHouse HTTP host or port"))?;
+        let timeout = setup.connect_timeout.unwrap_or(Duration::from_secs(30));
+        let _ = rustls::crypto::ring::default_provider().install_default();
+        let mut builder = Client::builder()
+            .connect_timeout(timeout)
+            .pool_max_idle_per_host(4)
+            .redirect(reqwest::redirect::Policy::none())
+            .user_agent(concat!("OpenIDEA/", env!("CARGO_PKG_VERSION")));
+        let ca = source.ssl_ca_file.trim();
+        if !ca.is_empty() {
+            let pem = read_pem(ca, "CA certificate")?;
+            let certificates = reqwest::Certificate::from_pem_bundle(&pem)
+                .map_err(|_| IdeError::invalid("invalid ClickHouse CA certificate PEM"))?;
+            if certificates.is_empty() {
+                return Err(IdeError::invalid("ClickHouse CA certificate PEM contains no certificates"));
+            }
+            builder = builder.tls_certs_only(certificates);
+        }
+        if source.ssl == DbSslMode::VerifyCa {
+            if ca.is_empty() {
+                return Err(IdeError::invalid("ClickHouse Verify CA requires a CA certificate file"));
+            }
+            builder = builder.tls_danger_accept_invalid_hostnames(true);
+        }
+        let cert = source.ssl_cert_file.trim();
+        let key = source.ssl_key_file.trim();
+        if cert.is_empty() != key.is_empty() {
+            return Err(IdeError::invalid("ClickHouse client TLS requires both certificate and key files"));
+        }
+        if !cert.is_empty() {
+            let mut pem = read_pem(cert, "client certificate")?;
+            pem.push(b'\n');
+            pem.extend(read_pem(key, "client key")?);
+            let identity = reqwest::Identity::from_pem(&pem)
+                .map_err(|_| IdeError::invalid("invalid ClickHouse client certificate or key PEM"))?;
+            builder = builder.identity(identity);
+        }
+        let proxy = ide_core::proxy_settings::proxy();
+        let client = ide_http::client::with_proxy(builder, &proxy).build().map_err(http_error)?;
+        let database = if source.options.default_schema.trim().is_empty() {
+            source.database.trim()
+        } else {
+            source.options.default_schema.trim()
+        };
+        let pool = Self(Arc::new(State {
+            client: RwLock::new(Some(client)),
+            endpoint,
+            user: if source.user.is_empty() { "default".into() } else { source.user.clone() },
+            password: password.unwrap_or_default().to_owned(),
+            database: if database.is_empty() { "default".into() } else { database.into() },
+            settings: setup.params,
+            read_only: source.read_only,
+            session_id: uuid::Uuid::new_v4().to_string(),
+            session: Mutex::new(false),
+            closed: CancellationToken::new(),
+        }));
+        let cancel = CancellationToken::new();
+        let initialize = async {
+            pool.execute("SELECT 1", 1, &cancel).await?;
+            for sql in setup.statements {
+                pool.execute(&sql, 0, &cancel).await?;
+            }
+            Ok(pool.clone())
+        };
+        tokio::pin!(initialize);
+        tokio::select! {
+            result = &mut initialize => {
+                if result.is_err() {
+                    pool.close();
+                }
+                result
+            },
+            () = tokio::time::sleep(timeout) => {
+                cancel.cancel();
+                let _ = initialize.await;
+                pool.close();
+                Err(IdeError::new(ErrorKind::TimedOut, "timed out connecting to ClickHouse HTTP"))
+            }
+        }
+    }
+
+    pub fn close(&self) {
+        self.0.closed.cancel();
+        self.0.client.write().take();
+    }
+
+    pub fn is_closed(&self) -> bool {
+        self.0.closed.is_cancelled()
+    }
+
+    fn client(&self) -> IdeResult<Client> {
+        self.0.client.read().clone().ok_or_else(|| IdeError::new(ErrorKind::Io, "ClickHouse connection is closed"))
+    }
+
+    fn request(&self, client: &Client, query_id: &str, max_rows: usize, initialized: bool) -> RequestBuilder {
+        let mut request = client
+            .post(self.0.endpoint.clone())
+            .basic_auth(&self.0.user, Some(&self.0.password))
+            .header(reqwest::header::CONTENT_TYPE, "text/plain; charset=utf-8")
+            .query(&self.0.settings)
+            .query(&[
+                ("session_id", self.0.session_id.clone()),
+                ("session_timeout", "3600".into()),
+                ("query_id", query_id.to_owned()),
+                ("default_format", FORMAT.into()),
+                ("output_format_json_quote_denormals", "1".into()),
+                ("max_result_rows", max_rows.saturating_add(1).to_string()),
+                ("result_overflow_mode", "break".into()),
+            ]);
+        if initialized {
+            request = request.query(&[("session_check", "1")]);
+        } else {
+            request = request.query(&[("database", &self.0.database)]);
+        }
+        if self.0.read_only {
+            request = request.query(&[("readonly", "1")]);
+        }
+        request
+    }
+
+    pub async fn execute(&self, sql: &str, max_rows: usize, cancel: &CancellationToken) -> IdeResult<QueryResult> {
+        if transaction_statement(sql) {
+            return Err(transaction_error());
+        }
+        let mut session = tokio::select! {
+            biased;
+            () = cancel.cancelled() => return Err(IdeError::cancelled()),
+            () = self.0.closed.cancelled() => return Err(IdeError::new(ErrorKind::Io, "ClickHouse connection is closed")),
+            session = self.0.session.lock() => session,
+        };
+        let client = self.client()?;
+        let query_id = uuid::Uuid::new_v4().to_string();
+        let request = self.request(&client, &query_id, max_rows, *session).body(sql.to_owned());
+        let started = Instant::now();
+        let fetch = async {
+            let mut response = request.send().await.map_err(http_error)?;
+            let execution_ms = started.elapsed().as_secs_f64() * 1000.0;
+            let status = response.status();
+            let header = |name: &str| response.headers().get(name).and_then(|v| v.to_str().ok()).map(str::to_owned);
+            let exception_code = header("X-ClickHouse-Exception-Code");
+            let format = header("X-ClickHouse-Format");
+            let affected = header("X-ClickHouse-Summary")
+                .and_then(|v| serde_json::from_str::<serde_json::Value>(&v).ok())
+                .and_then(|v| {
+                    v.get("written_rows")
+                        .and_then(|n| n.as_str().and_then(|n| n.parse::<u64>().ok()).or_else(|| n.as_u64()))
+                });
+            if !status.is_success() || exception_code.as_deref().is_some_and(|code| code != "0") {
+                let body = response.bytes().await.map_err(http_error)?;
+                return Err(self.server_error(status, exception_code.as_deref(), &body));
+            }
+            let (columns, rows, has_more) = if format.as_deref().is_some_and(|f| f != FORMAT) {
+                let body = response.bytes().await.map_err(http_error)?;
+                if !body.iter().all(u8::is_ascii_whitespace) {
+                    return Err(IdeError::invalid(
+                        "ClickHouse result grids need the default output format; remove the query's FORMAT clause",
+                    ));
+                }
+                (Vec::new(), Vec::new(), false)
+            } else {
+                let mut reader = RowReader::new(max_rows);
+                while let Some(chunk) = response.chunk().await.map_err(http_error)? {
+                    reader.push(&chunk)?;
+                }
+                reader.finish().map_err(|error| self.redact_error(error))?
+            };
+            let affected = if columns.is_empty() { affected.map(|n| n as f64) } else { None };
+            Ok(QueryResult {
+                statement: sql.to_owned(),
+                columns,
+                rows,
+                affected,
+                has_more,
+                elapsed_ms: started.elapsed().as_secs_f64() * 1000.0,
+                execution_ms,
+            })
+        };
+        let result = tokio::select! {
+            biased;
+            () = cancel.cancelled() => None,
+            () = self.0.closed.cancelled() => None,
+            result = fetch => Some(result),
+        };
+        match result {
+            Some(result) => {
+                if result.is_ok() {
+                    *session = true;
+                }
+                result
+            }
+            None => {
+                let killed = self.kill(&client, &query_id).await;
+                match killed {
+                    Ok(()) => Err(IdeError::cancelled()),
+                    Err(error) => Err(IdeError::new(
+                        ErrorKind::Cancelled,
+                        format!("cancelled locally; ClickHouse server cancellation failed: {}", error.message),
+                    )),
+                }
+            }
+        }
+    }
+
+    async fn kill(&self, client: &Client, query_id: &str) -> IdeResult<()> {
+        let response = client
+            .post(self.0.endpoint.clone())
+            .basic_auth(&self.0.user, Some(&self.0.password))
+            .timeout(Duration::from_secs(3))
+            .body(format!("KILL QUERY WHERE query_id = '{query_id}' SYNC"))
+            .send()
+            .await
+            .map_err(http_error)?;
+        let status = response.status();
+        let code = response
+            .headers()
+            .get("X-ClickHouse-Exception-Code")
+            .and_then(|value| value.to_str().ok())
+            .map(str::to_owned);
+        let body = response.bytes().await.map_err(http_error)?;
+        if status.is_success() && !code.as_deref().is_some_and(|code| code != "0") && !body.starts_with(b"Code:") {
+            Ok(())
+        } else {
+            Err(self.server_error(status, code.as_deref(), &body))
+        }
+    }
+
+    fn redact_error(&self, mut error: IdeError) -> IdeError {
+        if !self.0.password.is_empty() {
+            error.message = error.message.replace(&self.0.password, "[redacted]");
+        }
+        error
+    }
+
+    fn server_error(&self, status: StatusCode, code: Option<&str>, body: &[u8]) -> IdeError {
+        let message = String::from_utf8_lossy(body);
+        let message: String = exception_text(&message).chars().take(16_384).collect();
+        let auth = matches!(status, StatusCode::UNAUTHORIZED | StatusCode::FORBIDDEN)
+            || matches!(code, Some("193" | "194" | "195" | "516" | "497"));
+        let detail = if message.is_empty() { status.canonical_reason().unwrap_or("request failed") } else { &message };
+        let detail = if detail.contains("SESSION_NOT_FOUND") || detail.contains("Session not found") {
+            "ClickHouse HTTP session expired; reconnect to restore session settings"
+        } else {
+            detail
+        };
+        self.redact_error(IdeError::new(
+            if auth { ErrorKind::PermissionDenied } else { ErrorKind::InvalidInput },
+            format!("ClickHouse HTTP {}: {detail}", status.as_u16()),
+        ))
+    }
+}
+
+type DecodedResult = (Vec<ResultColumn>, Vec<Vec<Option<String>>>, bool);
+
+/// Decodes a streamed [`FORMAT`] body. Keeps the first `max_rows` rows; later rows only set
+/// `has_more` and are read past unparsed, so a grid limit bounds memory however large the
+/// block `result_overflow_mode=break` lets the server send. A line that is not a JSON array
+/// starts the exception ClickHouse writes when a query fails mid-stream.
+struct RowReader {
+    max_rows: usize,
+    pending: Vec<u8>,
+    names: Option<Vec<String>>,
+    types: Option<Vec<String>>,
+    rows: Vec<Vec<Option<String>>>,
+    more: bool,
+    exception: Option<String>,
+}
+
+impl RowReader {
+    fn new(max_rows: usize) -> Self {
+        Self { max_rows, pending: Vec::new(), names: None, types: None, rows: Vec::new(), more: false, exception: None }
+    }
+
+    fn push(&mut self, chunk: &[u8]) -> IdeResult<()> {
+        self.pending.extend_from_slice(chunk);
+        let buffer = std::mem::take(&mut self.pending);
+        let mut start = 0;
+        while let Some(end) = buffer[start..].iter().position(|&b| b == b'\n') {
+            self.line(&buffer[start..start + end])?;
+            start += end + 1;
+        }
+        self.pending = buffer[start..].to_vec();
+        Ok(())
+    }
+
+    fn line(&mut self, line: &[u8]) -> IdeResult<()> {
+        if let Some(exception) = &mut self.exception {
+            if exception.len() < 16_384 {
+                exception.push_str(&String::from_utf8_lossy(line));
+                exception.push('\n');
+            }
+            return Ok(());
+        }
+        let text = line.trim_ascii();
+        if text.is_empty() {
+            return Ok(());
+        }
+        if text[0] != b'[' {
+            self.exception = Some(format!("{}\n", String::from_utf8_lossy(line)));
+            return Ok(());
+        }
+        if self.names.is_some() && self.types.is_some() && self.rows.len() >= self.max_rows {
+            self.more = true;
+            return Ok(());
+        }
+        let Ok(values) = serde_json::from_slice::<Vec<Box<serde_json::value::RawValue>>>(text) else {
+            self.exception = Some(format!("{}\n", String::from_utf8_lossy(line)));
+            return Ok(());
+        };
+        let protocol = |message: String| IdeError::new(ErrorKind::Protocol, message);
+        let header = |values: Vec<Box<serde_json::value::RawValue>>| {
+            values
+                .iter()
+                .map(|v| serde_json::from_str::<String>(v.get()))
+                .collect::<Result<Vec<_>, _>>()
+                .map_err(|e| protocol(format!("invalid ClickHouse result header: {e}")))
+        };
+        let Some(names) = &self.names else {
+            self.names = Some(header(values)?);
+            return Ok(());
+        };
+        if self.types.is_none() {
+            self.types = Some(header(values)?);
+            return Ok(());
+        }
+        if values.len() != names.len() {
+            return Err(protocol("ClickHouse result row width does not match its metadata".into()));
+        }
+        let row = values
+            .into_iter()
+            .map(|value| {
+                let text = value.get();
+                if text == "null" {
+                    Ok(None)
+                } else if text.starts_with('"') {
+                    serde_json::from_str::<String>(text).map(Some).map_err(|e| protocol(e.to_string()))
+                } else {
+                    Ok(Some(text.to_owned()))
+                }
+            })
+            .collect::<IdeResult<_>>()?;
+        self.rows.push(row);
+        Ok(())
+    }
+
+    fn finish(mut self) -> IdeResult<DecodedResult> {
+        let rest = std::mem::take(&mut self.pending);
+        self.line(&rest)?;
+        if let Some(exception) = self.exception {
+            return Err(IdeError::invalid(format!("ClickHouse: {}", exception_text(&exception))));
+        }
+        let Some(names) = self.names else { return Ok((Vec::new(), Vec::new(), false)) };
+        let types = self.types.unwrap_or_default();
+        if types.len() != names.len() {
+            return Err(IdeError::new(ErrorKind::Protocol, "ClickHouse result types do not match its columns"));
+        }
+        let columns = names.into_iter().zip(types).map(|(name, type_name)| ResultColumn { name, type_name }).collect();
+        Ok((columns, self.rows, self.more))
+    }
+}
+
+/// The server's message in a failed response: rows already streamed and the
+/// `__exception__` block markers ClickHouse wraps a mid-stream error in are dropped.
+fn exception_text(body: &str) -> &str {
+    let Some(at) = body.find("Code:") else { return body.trim() };
+    let text = &body[at..];
+    match text.find("\n__exception__") {
+        // The line before the closing marker is `<length> <tag>`.
+        Some(end) => text[..end].trim_end().rsplit_once('\n').map_or(text[..end].trim(), |(message, _)| message.trim()),
+        None => text.trim(),
+    }
+}
+
+fn http_error(error: reqwest::Error) -> IdeError {
+    use std::error::Error;
+    let kind = if error.is_timeout() { ErrorKind::TimedOut } else { ErrorKind::Io };
+    let error = error.without_url();
+    let mut message = error.to_string();
+    let mut source = error.source();
+    while let Some(error) = source {
+        let detail = error.to_string();
+        if !message.contains(&detail) {
+            message.push_str(": ");
+            message.push_str(&detail);
+        }
+        source = error.source();
+    }
+    IdeError::new(kind, format!("ClickHouse HTTP: {message}"))
+}
+
+fn read_pem(path: &str, label: &str) -> IdeResult<Vec<u8>> {
+    std::fs::read(ide_ssh::expand(path))
+        .map_err(|error| IdeError::new(ErrorKind::Io, format!("cannot read ClickHouse {label}: {error}")))
+}
+
+fn reserved_setting(name: &str) -> bool {
+    let name = name.to_ascii_lowercase();
+    name.starts_with("output_format_json_")
+        || matches!(
+            name.as_str(),
+            "user"
+                | "password"
+                | "query"
+                | "database"
+                | "session_id"
+                | "session_check"
+                | "session_timeout"
+                | "query_id"
+                | "default_format"
+                | "max_result_rows"
+                | "result_overflow_mode"
+                | "readonly"
+        )
+}
+
+fn transaction_statement(sql: &str) -> bool {
+    let mut sql = sql.trim_start();
+    loop {
+        if let Some(rest) = sql.strip_prefix("--").or_else(|| sql.strip_prefix('#')) {
+            sql = rest.split_once('\n').map_or("", |(_, rest)| rest).trim_start();
+        } else if let Some(rest) = sql.strip_prefix("/*") {
+            sql = rest.split_once("*/").map_or("", |(_, rest)| rest).trim_start();
+        } else {
+            break;
+        }
+    }
+    let mut words = sql.split(|c: char| !c.is_ascii_alphanumeric() && c != '_').filter(|s| !s.is_empty());
+    let first = words.next().unwrap_or_default();
+    ["BEGIN", "COMMIT", "ROLLBACK", "SAVEPOINT", "RELEASE"].iter().any(|s| first.eq_ignore_ascii_case(s))
+        || (first.eq_ignore_ascii_case("START") && words.next().is_some_and(|s| s.eq_ignore_ascii_case("TRANSACTION")))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::conn::Pool;
+    use crate::source::{DbDriver, DbOptions, DbProperty};
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+
+    const ONE: &str = "[\"1\"]\n[\"UInt8\"]\n[1]\n";
+
+    async fn read_request(stream: &mut tokio::net::TcpStream) -> String {
+        let mut bytes = Vec::new();
+        let mut buffer = [0; 4096];
+        loop {
+            let count = tokio::time::timeout(Duration::from_secs(5), stream.read(&mut buffer)).await.unwrap().unwrap();
+            assert!(count > 0, "request ended early");
+            bytes.extend_from_slice(&buffer[..count]);
+            if let Some(end) = bytes.windows(4).position(|s| s == b"\r\n\r\n") {
+                let header = String::from_utf8_lossy(&bytes[..end]);
+                let length: usize = header
+                    .lines()
+                    .find_map(|line| {
+                        line.to_ascii_lowercase().strip_prefix("content-length:").map(|v| v.trim().parse().unwrap())
+                    })
+                    .unwrap_or(0);
+                if bytes.len() >= end + 4 + length {
+                    return String::from_utf8(bytes).unwrap();
+                }
+            }
+        }
+    }
+
+    async fn reply(stream: &mut tokio::net::TcpStream, status: &str, headers: &str, body: &str) {
+        let response =
+            format!("HTTP/1.1 {status}\r\nContent-Length: {}\r\nConnection: close\r\n{headers}\r\n{body}", body.len());
+        stream.write_all(response.as_bytes()).await.unwrap();
+    }
+
+    async fn server(
+        responses: Vec<(&'static str, &'static str, &'static str)>,
+    ) -> (u16, tokio::task::JoinHandle<Vec<String>>) {
+        let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let port = listener.local_addr().unwrap().port();
+        let task = tokio::spawn(async move {
+            let mut requests = Vec::new();
+            for (status, headers, body) in responses {
+                let (mut stream, _) =
+                    tokio::time::timeout(Duration::from_secs(5), listener.accept()).await.unwrap().unwrap();
+                requests.push(read_request(&mut stream).await);
+                reply(&mut stream, status, headers, body).await;
+            }
+            requests
+        });
+        (port, task)
+    }
+
+    fn source(port: u16) -> DataSource {
+        DataSource { driver: DbDriver::Clickhouse, host: "127.0.0.1".into(), port: Some(port), ..Default::default() }
+    }
+
+    fn decode(body: &[u8], max_rows: usize, chunk: usize) -> IdeResult<DecodedResult> {
+        let mut reader = RowReader::new(max_rows);
+        for part in body.chunks(chunk) {
+            reader.push(part)?;
+        }
+        reader.finish()
+    }
+
+    #[test]
+    fn rows_preserve_precision_nulls_and_strings_across_chunks() {
+        let body = concat!(
+            r#"["n", "d", "v", "v", "v"]"#,
+            "\n",
+            r#"["UInt64", "Decimal(38, 9)", "Nullable(String)", "Nullable(String)", "Nullable(String)"]"#,
+            "\n",
+            r#"[18446744073709551615, 12345678901234567890.123456789, null, "null", "ᴺᵁᴸᴸ"]"#,
+        );
+        for chunk in [1, 7, body.len()] {
+            let (columns, rows, more) = decode(body.as_bytes(), 1, chunk).unwrap();
+            assert_eq!(columns.len(), 5);
+            assert_eq!(columns[1].type_name, "Decimal(38, 9)");
+            assert_eq!(
+                rows[0],
+                vec![
+                    Some("18446744073709551615".into()),
+                    Some("12345678901234567890.123456789".into()),
+                    None,
+                    Some("null".into()),
+                    Some("ᴺᵁᴸᴸ".into()),
+                ]
+            );
+            assert!(!more);
+        }
+        let (columns, rows, more) = decode(b"[\"x\"]\n[\"String\"]\n", 0, 64).unwrap();
+        assert_eq!(columns[0].name, "x");
+        assert!(rows.is_empty() && !more);
+        assert_eq!(decode(b"", 5, 64).unwrap().0.len(), 0);
+        assert!(decode(b"[\"x\"]\n[\"UInt8\"]\n[1, 2]\n", 1, 64).is_err());
+    }
+
+    #[test]
+    fn rows_past_the_limit_are_skipped_but_a_later_exception_still_fails() {
+        let mut body = String::from("[\"n\"]\n[\"UInt64\"]\n");
+        for n in 0..1000 {
+            body.push_str(&format!("[{n}]\n"));
+        }
+        let (_, rows, more) = decode(body.as_bytes(), 2, 4096).unwrap();
+        assert_eq!(rows, vec![vec![Some("0".into())], vec![Some("1".into())]]);
+        assert!(more);
+        body.push_str("\n__exception__\nabcdefgh\nCode: 395. DB::Exception: Value passed to 'throwIf' is non-zero\n");
+        body.push_str("62 abcdefgh\n__exception__\n");
+        let error = decode(body.as_bytes(), 2, 4096).unwrap_err();
+        assert_eq!(error.message, "ClickHouse: Code: 395. DB::Exception: Value passed to 'throwIf' is non-zero");
+        let multiline = "Code: 62. DB::Exception: Syntax error\nat line 2";
+        assert_eq!(exception_text(multiline), multiline);
+    }
+
+    #[tokio::test]
+    async fn http_requests_use_auth_settings_limits_and_a_shared_session() {
+        let (port, requests) = server(vec![
+            ("200 OK", "X-ClickHouse-Format: JSONCompactEachRowWithNamesAndTypes\r\n", ONE),
+            ("200 OK", "", ""),
+            (
+                "200 OK",
+                "X-ClickHouse-Format: JSONCompactEachRowWithNamesAndTypes\r\n",
+                "[\"n\"]\n[\"UInt64\"]\n[\"1\"]\n[\"2\"]\n[\"3\"]\n",
+            ),
+        ])
+        .await;
+        let source = DataSource {
+            user: "reader".into(),
+            read_only: true,
+            options: DbOptions { default_schema: "analytics".into(), time_zone: "UTC".into(), ..Default::default() },
+            properties: vec![DbProperty { name: "max_threads".into(), value: "2".into() }],
+            ..source(port)
+        };
+        let pool = Pool::connect(&source, Some("mock-password"), None).await.unwrap();
+        pool.execute("USE other", 0, &CancellationToken::new()).await.unwrap();
+        let result = pool.execute("SELECT number FROM numbers(3)", 1, &CancellationToken::new()).await.unwrap();
+        assert_eq!(result.rows, vec![vec![Some("1".into())]]);
+        assert!(result.has_more && result.affected.is_none());
+        let requests = requests.await.unwrap();
+        let target = |request: &String| {
+            Url::parse(&format!(
+                "http://localhost{}",
+                request.lines().next().unwrap().split_whitespace().nth(1).unwrap()
+            ))
+            .unwrap()
+        };
+        let urls: Vec<_> = requests.iter().map(target).collect();
+        let value = |url: &Url, key: &str| url.query_pairs().find(|(k, _)| k == key).map(|(_, v)| v.into_owned());
+        assert_eq!(value(&urls[0], "database").as_deref(), Some("analytics"));
+        assert_eq!(value(&urls[1], "database"), None);
+        assert_eq!(value(&urls[1], "session_check").as_deref(), Some("1"));
+        assert_eq!(value(&urls[0], "session_id"), value(&urls[2], "session_id"));
+        assert_ne!(value(&urls[0], "query_id"), value(&urls[2], "query_id"));
+        assert_eq!(value(&urls[2], "max_result_rows").as_deref(), Some("2"));
+        for (request, url) in requests.iter().zip(&urls) {
+            assert!(request.starts_with("POST /?"));
+            assert!(request.contains("Basic cmVhZGVyOm1vY2stcGFzc3dvcmQ="));
+            assert!(!url.as_str().contains("reader") && !url.as_str().contains("mock-password"));
+            assert_eq!(value(url, "readonly").as_deref(), Some("1"));
+            assert_eq!(value(url, "session_timezone").as_deref(), Some("UTC"));
+            assert_eq!(value(url, "max_threads").as_deref(), Some("2"));
+        }
+        assert!(requests[0].ends_with("SELECT 1"));
+        assert!(pool.transaction(&[]).await.is_err());
+        let cancel = CancellationToken::new();
+        cancel.cancel();
+        assert_eq!(pool.execute("SELECT 1", 1, &cancel).await.unwrap_err().kind, ErrorKind::Cancelled);
+        pool.close().await;
+        assert!(pool.is_closed());
+        assert!(pool.execute("SELECT 1", 1, &CancellationToken::new()).await.is_err());
+    }
+
+    #[tokio::test]
+    async fn sequential_queries_reuse_the_http_connection() {
+        let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let port = listener.local_addr().unwrap().port();
+        let task = tokio::spawn(async move {
+            let (mut stream, _) = listener.accept().await.unwrap();
+            for _ in 0..2 {
+                read_request(&mut stream).await;
+                let response = format!("HTTP/1.1 200 OK\r\nContent-Length: {}\r\n\r\n{ONE}", ONE.len());
+                stream.write_all(response.as_bytes()).await.unwrap();
+            }
+        });
+        let pool = Pool::connect(&source(port), None, None).await.unwrap();
+        assert_eq!(
+            pool.execute("SELECT 1", 1, &CancellationToken::new()).await.unwrap().rows,
+            vec![vec![Some("1".into())]]
+        );
+        task.await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn server_errors_keep_details_and_hide_passwords() {
+        let (port, requests) = server(vec![(
+            "403 Forbidden",
+            "X-ClickHouse-Exception-Code: 516\r\n",
+            "Code: 516. DB::Exception: bad mock-password",
+        )])
+        .await;
+        let error = match Pool::connect(&source(port), Some("mock-password"), None).await {
+            Ok(_) => panic!("expected login failure"),
+            Err(error) => error,
+        };
+        assert_eq!(error.kind, ErrorKind::PermissionDenied);
+        assert!(error.message.contains("516") && error.message.contains("[redacted]"));
+        assert!(!error.message.contains("mock-password"));
+        requests.await.unwrap();
+        let (port, requests) = server(vec![("200 OK", "", "Code: 241. DB::Exception: memory limit")]).await;
+        let error = match Pool::connect(&source(port), None, None).await {
+            Ok(_) => panic!("expected late query failure"),
+            Err(error) => error,
+        };
+        assert!(error.message.contains("memory limit"));
+        requests.await.unwrap();
+        let (port, requests) = server(vec![(
+            "500 Internal Server Error",
+            "X-ClickHouse-Exception-Code: 395\r\n",
+            "[\"1\"]\n[\"UInt8\"]\n[1]\n\n__exception__\ntag\nCode: 395. DB::Exception: thrown\n32 tag\n__exception__\n",
+        )])
+        .await;
+        let error = match Pool::connect(&source(port), None, None).await {
+            Ok(_) => panic!("expected mid-stream failure"),
+            Err(error) => error,
+        };
+        assert_eq!(error.message, "ClickHouse HTTP 500: Code: 395. DB::Exception: thrown");
+        requests.await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn cancellation_sends_kill_outside_the_busy_session() {
+        let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let port = listener.local_addr().unwrap().port();
+        let (started, received) = tokio::sync::oneshot::channel();
+        let server = tokio::spawn(async move {
+            let (mut health, _) = listener.accept().await.unwrap();
+            read_request(&mut health).await;
+            reply(&mut health, "200 OK", "", ONE).await;
+            drop(health);
+            let (mut query, _) = listener.accept().await.unwrap();
+            let request = read_request(&mut query).await;
+            started.send(()).unwrap();
+            let (mut kill, _) = tokio::time::timeout(Duration::from_secs(5), listener.accept()).await.unwrap().unwrap();
+            let kill_request = read_request(&mut kill).await;
+            reply(&mut kill, "200 OK", "", "").await;
+            (request, kill_request)
+        });
+        let pool = Pool::connect(&source(port), None, None).await.unwrap();
+        let cancel = CancellationToken::new();
+        let query = pool.execute("SELECT sleep(30)", 1, &cancel);
+        let cancelled = async {
+            received.await.unwrap();
+            cancel.cancel();
+        };
+        let (result, ()) = tokio::join!(query, cancelled);
+        assert_eq!(result.unwrap_err().kind, ErrorKind::Cancelled);
+        let (query, kill) = server.await.unwrap();
+        let target = query.lines().next().unwrap().split_whitespace().nth(1).unwrap();
+        let url = Url::parse(&format!("http://localhost{target}")).unwrap();
+        let query_id = url.query_pairs().find(|(k, _)| k == "query_id").unwrap().1.into_owned();
+        assert!(kill.ends_with(&format!("KILL QUERY WHERE query_id = '{query_id}' SYNC")));
+        assert!(!kill.contains("session_id="));
+    }
+
+    #[tokio::test]
+    async fn unsupported_settings_and_transactions_fail_before_connecting() {
+        for statement in ["BEGIN", "-- comment\n COMMIT", "/* comment */ ROLLBACK", "START TRANSACTION", "SAVEPOINT s"]
+        {
+            assert!(transaction_statement(statement));
+        }
+        assert!(!transaction_statement("SELECT 'BEGIN'"));
+        let sources = [
+            DataSource { options: DbOptions { transaction: DbTxMode::Manual, ..Default::default() }, ..source(1) },
+            DataSource {
+                properties: vec![DbProperty { name: "statement_cache_capacity".into(), value: "4".into() }],
+                ..source(1)
+            },
+            DataSource { properties: vec![DbProperty { name: "password".into(), value: "x".into() }], ..source(1) },
+            DataSource { ssl_ca_file: "unused.pem".into(), ..source(1) },
+            DataSource { ssl: DbSslMode::VerifyCa, ..source(1) },
+            DataSource { ssl: DbSslMode::Require, ssl_cert_file: "unused.pem".into(), ..source(1) },
+        ];
+        for source in sources {
+            let error = match Pool::connect(&source, None, None).await {
+                Ok(_) => panic!("unsupported settings were accepted"),
+                Err(error) => error,
+            };
+            assert_eq!(error.kind, ErrorKind::InvalidInput);
+        }
+    }
+
+    #[tokio::test]
+    #[ignore = "requires CLICKHOUSE_TEST_HOST, CLICKHOUSE_TEST_USER, and CLICKHOUSE_TEST_PASSWORD"]
+    async fn clickhouse_cloud_transport() {
+        let source = DataSource {
+            driver: DbDriver::Clickhouse,
+            host: std::env::var("CLICKHOUSE_TEST_HOST").expect("CLICKHOUSE_TEST_HOST"),
+            port: Some(std::env::var("CLICKHOUSE_TEST_PORT").ok().and_then(|v| v.parse().ok()).unwrap_or(8443)),
+            user: std::env::var("CLICKHOUSE_TEST_USER").expect("CLICKHOUSE_TEST_USER"),
+            ssl: DbSslMode::Require,
+            options: DbOptions {
+                time_zone: "UTC".into(),
+                startup_script: "SET max_threads = 2".into(),
+                ..Default::default()
+            },
+            properties: vec![DbProperty { name: "max_block_size".into(), value: "50".into() }],
+            ..Default::default()
+        };
+        let password = std::env::var("CLICKHOUSE_TEST_PASSWORD").expect("CLICKHOUSE_TEST_PASSWORD");
+        let pool = Pool::connect(&source, Some(&password), None).await.unwrap();
+        let cancel = CancellationToken::new();
+        let settings = pool
+            .execute("SELECT getSetting('max_threads'), getSetting('max_block_size'), timezone()", 1, &cancel)
+            .await
+            .unwrap();
+        assert_eq!(settings.rows, vec![vec![Some("2".into()), Some("50".into()), Some("UTC".into())]]);
+        let result = pool.execute("SELECT toUInt64('18446744073709551615') AS n, CAST(NULL AS Nullable(String)) AS missing, CAST('ᴺᵁᴸᴸ' AS Nullable(String)) AS text, 'a\\nb' AS lines", 1, &cancel).await.unwrap();
+        assert_eq!(
+            result.rows,
+            vec![vec![Some("18446744073709551615".into()), None, Some("ᴺᵁᴸᴸ".into()), Some("a\nb".into())]]
+        );
+        assert_eq!(result.columns[1].type_name, "Nullable(String)");
+        let limited = pool.execute("SELECT number FROM numbers(100)", 2, &cancel).await.unwrap();
+        assert_eq!(limited.rows.len(), 2);
+        assert!(limited.has_more);
+        let marker = format!("transport_cancel_{}", uuid::Uuid::new_v4().simple());
+        let sql = format!("SELECT sleepEachRow(0.05) FROM numbers(50) /* {marker} */");
+        let stop = CancellationToken::new();
+        let query = pool.execute(&sql, 1, &stop);
+        let cancel_query = async {
+            tokio::time::sleep(Duration::from_millis(500)).await;
+            stop.cancel();
+        };
+        let (cancelled, ()) = tokio::join!(query, cancel_query);
+        let cancelled = cancelled.unwrap_err();
+        assert_eq!(cancelled.kind, ErrorKind::Cancelled);
+        assert_eq!(cancelled.message, "cancelled");
+        let active = pool.execute(&format!("SELECT count() FROM system.processes WHERE position(query, '{marker}') > 0 AND query_id != currentQueryID()"), 1, &cancel).await.unwrap();
+        assert_eq!(active.rows, vec![vec![Some("0".into())]]);
+        let table = format!("transport_test_{}", uuid::Uuid::new_v4().simple());
+        pool.execute(&format!("CREATE TEMPORARY TABLE {table} (n UInt8)"), 0, &cancel).await.unwrap();
+        let continuity = async {
+            pool.execute(&format!("INSERT INTO {table} VALUES (7)"), 0, &cancel).await?;
+            pool.execute(&format!("SELECT n FROM {table}"), 1, &cancel).await
+        }
+        .await;
+        let cleanup = pool.execute(&format!("DROP TEMPORARY TABLE {table}"), 0, &cancel).await;
+        assert_eq!(continuity.unwrap().rows, vec![vec![Some("7".into())]]);
+        cleanup.unwrap();
+        pool.close().await;
+        assert!(pool.is_closed());
+    }
+}

crates/ide-db/src/conn.rs

@@ -106,6 +106,7 @@ pub enum Pool {
     Postgres(PgPool),
     Mysql(MySqlPool),
     SqlServer(Bb8Pool<MssqlConnectionManager>),
+    Clickhouse(crate::clickhouse::ClickhousePool),
 }
 
 /// Runs `$body` with `$p` bound to the concrete pool of each driver.
@@ -115,7 +116,7 @@ macro_rules! with_pool {
             Pool::Sqlite($p) => $body,
             Pool::Postgres($p) => $body,
             Pool::Mysql($p) => $body,
-            Pool::SqlServer(_) => unreachable!(),
+            Pool::SqlServer(_) | Pool::Clickhouse(_) => unreachable!(),
         }
     };
 }
@@ -503,6 +504,9 @@ impl Setup {
                 value.parse::<u64>().map_err(|_| IdeError::invalid(format!("{what} must be a whole number: {value}")))
             };
             match (source.driver, name.to_ascii_lowercase().as_str()) {
+                (DbDriver::Clickhouse, "statement_cache_capacity") => {
+                    return Err(IdeError::invalid("ClickHouse HTTP does not support statement caching"));
+                }
                 (_, "statement_cache_capacity") => s.statement_cache = Some(number(&name)? as usize),
                 (_, "connect_timeout") => s.connect_timeout = Some(Duration::from_secs(number(&name)?)),
                 (DbDriver::Postgres, "application_name") => s.application_name = Some(value.to_owned()),
@@ -512,6 +516,9 @@ impl Setup {
                 _ => s.params.push((name, value.to_owned())),
             }
         }
+        if source.driver == DbDriver::Clickhouse && !o.time_zone.trim().is_empty() {
+            s.params.push(("session_timezone".into(), o.time_zone.trim().into()));
+        }
         let script = o.startup_script.trim();
         if !script.is_empty() {
             s.statements.extend(crate::split::split(script, source.driver).into_iter().map(|st| st.text));
@@ -527,6 +534,7 @@ impl Pool {
             Pool::Postgres(_) => DbDriver::Postgres,
             Pool::Mysql(_) => DbDriver::Mysql,
             Pool::SqlServer(_) => DbDriver::SqlServer,
+            Pool::Clickhouse(_) => DbDriver::Clickhouse,
         }
     }
 
@@ -534,6 +542,9 @@ impl Pool {
     pub async fn connect(source: &DataSource, password: Option<&str>, root: Option<&Path>) -> IdeResult<Self> {
         const MAX: u32 = 4;
         let setup = Setup::of(source)?;
+        if source.driver == DbDriver::Clickhouse {
+            return crate::clickhouse::ClickhousePool::connect(source, password, setup).await.map(Pool::Clickhouse);
+        }
         let timeout = setup.connect_timeout.unwrap_or(Duration::from_secs(30));
         let init = Arc::new(setup.statements);
         // Runs the session statements (startup script…) on every new connection.
@@ -695,12 +706,14 @@ impl Pool {
                 conn.query("SELECT 1", &[]).await.map_err(mssql_err)?.into_results().await.map_err(mssql_err)?;
                 Ok(Pool::SqlServer(pool))
             }
+            DbDriver::Clickhouse => unreachable!(),
         }
     }
 
     pub async fn close(&self) {
         match self {
             Pool::SqlServer(_) => {}
+            Pool::Clickhouse(p) => p.close(),
             _ => with_pool!(self, p => p.close().await),
         }
     }
@@ -708,12 +721,16 @@ impl Pool {
     pub fn is_closed(&self) -> bool {
         match self {
             Pool::SqlServer(_) => false,
+            Pool::Clickhouse(p) => p.is_closed(),
             _ => with_pool!(self, p => p.is_closed()),
         }
     }
 
     /// Runs `sql` (no row limit beyond `max`), for introspection: cells are text (see [`Cells::Text`]).
     pub async fn rows(&self, sql: &str, max: usize) -> IdeResult<Vec<Vec<Option<String>>>> {
+        if let Pool::Clickhouse(p) = self {
+            return Ok(p.execute(sql, max, &CancellationToken::new()).await?.rows);
+        }
         let fetched: IdeResult<Fetched> = match self {
             Pool::SqlServer(p) => {
                 let mut conn = p.get_owned().await.map_err(mssql_pool_err)?;
@@ -727,6 +744,9 @@ impl Pool {
     /// Runs one statement and keeps at most `max_rows` rows. Cancelling stops
     /// the statement on the server (PostgreSQL, MySQL) and drops the connection.
     pub async fn execute(&self, sql: &str, max_rows: usize, cancel: &CancellationToken) -> IdeResult<QueryResult> {
+        if let Pool::Clickhouse(p) = self {
+            return p.execute(sql, max_rows, cancel).await;
+        }
         let mut conn = Held::acquire(self).await?;
         let r = conn.execute(self, sql, max_rows, cancel).await;
         if cancel.is_cancelled() {
@@ -740,6 +760,7 @@ impl Pool {
     /// row when flagged (table editor submits).
     pub async fn transaction(&self, statements: &[(String, bool)]) -> IdeResult<u64> {
         match self {
+            Pool::Clickhouse(_) => Err(crate::clickhouse::transaction_error()),
             Pool::SqlServer(p) => {
                 let mut conn = p.get_owned().await.map_err(mssql_pool_err)?;
                 let result = async {
@@ -790,6 +811,7 @@ pub enum Held {
     Postgres(PoolConnection<Postgres>),
     Mysql(PoolConnection<MySql>),
     SqlServer(Box<bb8::PooledConnection<'static, MssqlConnectionManager>>),
+    Clickhouse(crate::clickhouse::ClickhousePool),
 }
 
 impl Held {
@@ -799,6 +821,12 @@ impl Held {
             Pool::Postgres(p) => Held::Postgres(p.acquire().await.map_err(db_err)?),
             Pool::Mysql(p) => Held::Mysql(p.acquire().await.map_err(db_err)?),
             Pool::SqlServer(p) => Held::SqlServer(Box::new(p.get_owned().await.map_err(mssql_pool_err)?)),
+            Pool::Clickhouse(p) => {
+                if p.is_closed() {
+                    return Err(IdeError::new(ErrorKind::Io, "ClickHouse connection is closed"));
+                }
+                Held::Clickhouse(p.clone())
+            }
         })
     }
 
@@ -806,13 +834,14 @@ impl Held {
     pub async fn command(&mut self, sql: &str) -> IdeResult<()> {
         match self {
             Held::SqlServer(c) => mssql_command(c, sql).await,
+            Held::Clickhouse(_) => Err(crate::clickhouse::transaction_error()),
             other => {
                 let sql = sqlx::AssertSqlSafe(sql.to_owned());
                 match other {
                     Held::Sqlite(c) => sqlx::raw_sql(sql).execute(&mut **c).await.map(drop),
                     Held::Postgres(c) => sqlx::raw_sql(sql).execute(&mut **c).await.map(drop),
                     Held::Mysql(c) => sqlx::raw_sql(sql).execute(&mut **c).await.map(drop),
-                    Held::SqlServer(_) => unreachable!(),
+                    Held::SqlServer(_) | Held::Clickhouse(_) => unreachable!(),
                 }
                 .map_err(db_err)
             }
@@ -833,6 +862,7 @@ impl Held {
             Held::SqlServer(mut c) => {
                 c.0.take();
             }
+            Held::Clickhouse(_) => {}
         }
     }
 
@@ -845,6 +875,9 @@ impl Held {
         max_rows: usize,
         cancel: &CancellationToken,
     ) -> IdeResult<QueryResult> {
+        if let Held::Clickhouse(c) = self {
+            return c.execute(sql, max_rows, cancel).await;
+        }
         let started = Instant::now();
         // `$id`: the query naming the server process, `$kill`: how another connection stops it.
         macro_rules! run {
@@ -887,6 +920,7 @@ impl Held {
                     () = cancel.cancelled() => return Err(IdeError::cancelled()),
                 }
             }
+            Held::Clickhouse(_) => unreachable!(),
         };
         let (columns, rows, affected, has_more, first) = fetched;
         let elapsed_ms = started.elapsed().as_secs_f64() * 1000.0;
@@ -907,7 +941,7 @@ pub fn begin_statement(driver: DbDriver) -> &'static str {
     match driver {
         DbDriver::Mysql => "START TRANSACTION",
         DbDriver::SqlServer => "BEGIN TRAN",
-        DbDriver::Sqlite | DbDriver::Postgres => "BEGIN",
+        DbDriver::Sqlite | DbDriver::Postgres | DbDriver::Clickhouse => "BEGIN",
     }
 }
 

crates/ide-db/src/lib.rs

@@ -2,6 +2,7 @@
 //! execution ([`conn`]), introspection, table data paging / editing ([`sql`])
 //! and statement splitting ([`split`]), for SQLite, PostgreSQL and MySQL/MariaDB.
 
+mod clickhouse;
 pub mod conn;
 pub mod history;
 pub mod plan;
@@ -547,12 +548,14 @@ impl DbManager {
         })?;
         let version = match source.driver {
             DbDriver::Sqlite => "SELECT 'SQLite ' || sqlite_version()",
-            DbDriver::Postgres => "SELECT version()",
+            DbDriver::Postgres | DbDriver::Clickhouse => "SELECT version()",
             DbDriver::Mysql => "SELECT CONCAT(@@version_comment, ' ', VERSION())",
             DbDriver::SqlServer => "SELECT @@VERSION",
         };
-        let v = pool.rows(version, 1).await.ok().and_then(|r| r.into_iter().next()?.into_iter().next()?);
+        let result = pool.rows(version, 1).await;
         pool.close().await;
+        let rows = if source.driver == DbDriver::Clickhouse { result? } else { result.unwrap_or_default() };
+        let v = rows.into_iter().next().and_then(|r| r.into_iter().next().flatten());
         Ok(v.unwrap_or_else(|| "Connected".into()))
     }
 
@@ -701,8 +704,11 @@ impl DbManager {
                 _ => indexes.push(IndexInfo { name, unique: flag(&unique), columns: vec![col] }),
             }
         }
-        let fk_rows =
-            pool.rows(&sql::table_foreign_keys(driver, schema, table), MAX_META_ROWS).await.unwrap_or_default();
+        let fk_rows = if driver == DbDriver::Clickhouse {
+            Vec::new()
+        } else {
+            pool.rows(&sql::table_foreign_keys(driver, schema, table), MAX_META_ROWS).await.unwrap_or_default()
+        };
         let mut foreign_keys = group_foreign_keys(fk_rows, &[]);
         // SQLite keys that reference the primary key implicitly: look it up.
         for k in foreign_keys.iter_mut().filter(|k| k.ref_columns.is_empty()) {
@@ -715,13 +721,15 @@ impl DbManager {
                 .collect();
         }
         foreign_keys.retain(|k| k.columns.len() == k.ref_columns.len());
-        let triggers = pool
-            .rows(&sql::triggers(driver, schema, table), MAX_META_ROWS)
-            .await
-            .unwrap_or_else(|e| {
+        let trigger_rows = if driver == DbDriver::Clickhouse {
+            Vec::new()
+        } else {
+            pool.rows(&sql::triggers(driver, schema, table), MAX_META_ROWS).await.unwrap_or_else(|e| {
                 tracing::warn!("triggers: {}", e.message);
                 Vec::new()
             })
+        };
+        let triggers = trigger_rows
             .into_iter()
             .filter_map(|r| {
                 let mut it = r.into_iter();
@@ -822,6 +830,11 @@ impl DbManager {
                 let ddl = cells(pool.rows(&q, 1).await?, 1).into_iter().next();
                 ddl.map(|d| format!("{d};\n")).ok_or_else(missing)
             }
+            DbDriver::Clickhouse => {
+                let q = format!("SHOW CREATE TABLE {}", sql::qualified(driver, schema, name));
+                let ddl = cells(pool.rows(&q, 1).await?, 0).into_iter().next();
+                ddl.map(|d| format!("{};\n", d.trim_end().trim_end_matches(';'))).ok_or_else(missing)
+            }
             DbDriver::SqlServer => {
                 let obj = format!("{}.{}", schema, name).replace('\'', "''");
                 let ddl = cells(pool.rows(&format!("SELECT OBJECT_DEFINITION(OBJECT_ID('{}'))", obj), 1).await?, 0)
@@ -902,10 +915,14 @@ impl DbManager {
             }
         }
         // Foreign keys are a nicety (JOIN completion): a server that refuses the catalog query still completes.
-        let fk_rows = pool.rows(sql::foreign_keys(driver), MAX_META_ROWS).await.unwrap_or_else(|e| {
-            tracing::warn!("foreign keys: {}", e.message);
+        let fk_rows = if driver == DbDriver::Clickhouse {
             Vec::new()
-        });
+        } else {
+            pool.rows(sql::foreign_keys(driver), MAX_META_ROWS).await.unwrap_or_else(|e| {
+                tracing::warn!("foreign keys: {}", e.message);
+                Vec::new()
+            })
+        };
         let foreign_keys = group_foreign_keys(fk_rows, &tables);
         let default_schema = match sql::current_schema(driver) {
             None => "main".to_owned(),
@@ -980,6 +997,9 @@ impl DbManager {
         let Some(session) = session else {
             return pool.execute(statement, max_rows, cancel).await;
         };
+        if pool.driver() == DbDriver::Clickhouse {
+            return Err(IdeError::invalid("ClickHouse manual transactions are unsupported"));
+        }
         let mut held = session.lock().await;
         if held.is_none() {
             let mut conn = Held::acquire(&pool).await?;
@@ -998,8 +1018,11 @@ impl DbManager {
 
     /// Switches `id` between auto-commit and manual commit. Leaving manual
     /// mode rolls back what was not committed.
-    pub async fn set_manual_commit(&self, id: &str, manual: bool) {
+    pub async fn set_manual_commit(&self, id: &str, manual: bool) -> IdeResult<()> {
         if manual {
+            if self.source(id)?.driver == DbDriver::Clickhouse {
+                return Err(IdeError::invalid("ClickHouse manual transactions are unsupported"));
+            }
             self.sessions.lock().entry(id.to_owned()).or_default();
         } else {
             let session = self.sessions.lock().remove(id);
@@ -1007,10 +1030,14 @@ impl DbManager {
                 end_session(&s).await;
             }
         }
+        Ok(())
     }
 
     /// Commits (or rolls back) the open transaction of a manual-commit data source.
     pub async fn finish_transaction(&self, id: &str, commit: bool) -> IdeResult<()> {
+        if self.source(id).is_ok_and(|s| s.driver == DbDriver::Clickhouse) {
+            return Err(IdeError::invalid("ClickHouse manual transactions are unsupported"));
+        }
         let session = self.sessions.lock().get(id).cloned();
         let Some(session) = session else { return Ok(()) };
         let mut held = session.lock().await;
@@ -1052,6 +1079,9 @@ impl DbManager {
 
     /// Applies the table editor's pending changes in one transaction.
     pub async fn apply_edits(&self, id: &str, schema: &str, table: &str, edits: &[DbRowEdit]) -> IdeResult<u64> {
+        if self.source(id)?.driver == DbDriver::Clickhouse {
+            return Err(IdeError::invalid("ClickHouse table editing is unsupported"));
+        }
         let pool = self.pool(id).await?;
         let driver = pool.driver();
         let statements = edits
@@ -1064,3 +1094,37 @@ impl DbManager {
         pool.transaction(&statements).await
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn clickhouse_rejects_manual_transactions_and_table_edits_without_connecting() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path().to_path_buf();
+        let ssh = Arc::new(SshManager::new(root.join("ssh-passwords.json")));
+        let db = DbManager::new(root.clone(), root.join("passwords.json"), root.join("history.json"), ssh);
+        db.save_sources(vec![DataSource {
+            id: "clickhouse".into(),
+            name: "clickhouse".into(),
+            driver: DbDriver::Clickhouse,
+            host: "127.0.0.1".into(),
+            port: Some(1),
+            ..Default::default()
+        }])
+        .await
+        .unwrap();
+        let error = db.set_manual_commit("clickhouse", true).await.unwrap_err();
+        assert!(error.message.contains("manual transactions are unsupported"));
+        assert!(db.sessions.lock().is_empty());
+        for commit in [false, true] {
+            let error = db.finish_transaction("clickhouse", commit).await.unwrap_err();
+            assert!(error.message.contains("manual transactions are unsupported"));
+        }
+        let error = db.apply_edits("clickhouse", "default", "events", &[]).await.unwrap_err();
+        assert!(error.message.contains("table editing is unsupported"));
+        assert!(!db.is_connected("clickhouse"));
+        db.set_manual_commit("clickhouse", false).await.unwrap();
+    }
+}

crates/ide-db/src/plan.rs

@@ -35,6 +35,7 @@ pub fn explain_statement(driver: DbDriver, statement: &str) -> String {
     match driver {
         DbDriver::Sqlite => format!("EXPLAIN QUERY PLAN {s}"),
         DbDriver::Postgres => format!("EXPLAIN (FORMAT JSON) {s}"),
+        DbDriver::Clickhouse => format!("EXPLAIN json = 1 {s}"),
         DbDriver::Mysql => format!("EXPLAIN {s}"),
         DbDriver::SqlServer => format!("SET SHOWPLAN_TEXT ON; {s}"),
     }
@@ -44,7 +45,7 @@ pub fn explain_statement(driver: DbDriver, statement: &str) -> String {
 pub fn parse(driver: DbDriver, result: &QueryResult) -> IdeResult<Vec<PlanNode>> {
     match driver {
         DbDriver::Sqlite => Ok(sqlite(&result.rows)),
-        DbDriver::Postgres => {
+        DbDriver::Postgres | DbDriver::Clickhouse => {
             let text: String =
                 result.rows.iter().filter_map(|r| r.first().cloned().flatten()).collect::<Vec<_>>().join("\n");
             let json: Value = serde_json::from_str(&text).map_err(|e| IdeError::invalid(format!("plan: {e}")))?;
@@ -199,6 +200,7 @@ mod tests {
         assert_eq!(explain_statement(DbDriver::Sqlite, "select 1;"), "EXPLAIN QUERY PLAN select 1");
         assert_eq!(explain_statement(DbDriver::Postgres, " select 1 "), "EXPLAIN (FORMAT JSON) select 1");
         assert_eq!(explain_statement(DbDriver::Mysql, "select 1"), "EXPLAIN select 1");
+        assert_eq!(explain_statement(DbDriver::Clickhouse, " select 1;"), "EXPLAIN json = 1 select 1");
         assert_eq!(explain_statement(DbDriver::SqlServer, "select 1"), "SET SHOWPLAN_TEXT ON; select 1");
     }
 
@@ -254,6 +256,21 @@ mod tests {
         assert_eq!((plan[3].parent, plan[3].operation.as_str()), (Some(2), "Seq Scan"));
     }
 
+    #[test]
+    fn reads_clickhouse_json_plans_and_rejects_invalid_json() {
+        let json = r#"[{"Plan": {"Node Type": "Expression", "Node Id": "Expression_5",
+            "Description": "Project names", "Plans": [
+                {"Node Type": "ReadFromMergeTree", "Node Id": "ReadFromMergeTree_0",
+                 "Description": "default.events"}
+            ]}}]"#;
+        let plan = parse(DbDriver::Clickhouse, &result(&["explain"], vec![vec![Some(json)]])).unwrap();
+        assert_eq!(plan.len(), 2);
+        assert_eq!((plan[0].parent, plan[0].operation.as_str()), (None, "Expression"));
+        assert_eq!((plan[1].parent, plan[1].operation.as_str()), (Some(0), "ReadFromMergeTree"));
+        assert!(plan[1].properties.iter().any(|p| p.name == "Description" && p.value == "default.events"));
+        assert!(parse(DbDriver::Clickhouse, &result(&["explain"], vec![vec![Some("invalid")]])).is_err());
+    }
+
     #[test]
     fn reads_mysql_rows() {
         let r = result(

crates/ide-db/src/source.rs

@@ -18,6 +18,7 @@ pub enum DbDriver {
     Mysql,
     /// Microsoft SQL Server.
     SqlServer,
+    Clickhouse,
 }
 
 impl DbDriver {
@@ -27,6 +28,7 @@ impl DbDriver {
             DbDriver::Postgres => Some(5432),
             DbDriver::Mysql => Some(3306),
             DbDriver::SqlServer => Some(1433),
+            DbDriver::Clickhouse => Some(8123),
         }
     }
 }
@@ -253,6 +255,7 @@ pub fn scheme_driver(scheme: &str) -> Option<DbDriver> {
         "mysql" | "mariadb" | "tidb" | "singlestore" | "memsql" | "oceanbase" => Some(DbDriver::Mysql),
         "sqlserver" | "mssql" | "mssqlserver" => Some(DbDriver::SqlServer),
         "sqlite" | "sqlite3" => Some(DbDriver::Sqlite),
+        "clickhouse" | "http" | "https" => Some(DbDriver::Clickhouse),
         _ => None,
     }
 }
@@ -260,7 +263,7 @@ pub fn scheme_driver(scheme: &str) -> Option<DbDriver> {
 /// Parses `scheme://[user[:password]@]host[:port][/database][?k=v&…]`, `jdbc:` forms
 /// included, and `sqlite:path`.
 pub fn parse_url(raw: &str) -> IdeResult<ParsedUrl> {
-    let bad = || IdeError::invalid(format!("not a database URL: {raw}"));
+    let bad = || IdeError::invalid("invalid database URL");
     let url = raw.trim();
     let url = url.strip_prefix("jdbc:").or_else(|| url.strip_prefix("JDBC:")).unwrap_or(url);
     let (scheme, rest) = url.split_once(':').ok_or_else(bad)?;
@@ -367,6 +370,15 @@ impl DataSource {
         }
         properties.append(&mut s.properties);
         s.properties = properties;
+        if s.driver == DbDriver::Clickhouse {
+            let raw_url = self.url.trim().to_ascii_lowercase();
+            let url = raw_url.strip_prefix("jdbc:").unwrap_or(&raw_url);
+            if url.starts_with("https://") {
+                s.ssl = DbSslMode::VerifyFull;
+            } else if url.starts_with("http://") {
+                s.ssl = DbSslMode::Disable;
+            }
+        }
         Ok(s)
     }
 
@@ -519,4 +531,31 @@ mod tests {
         assert!(DataSource { url: "mysql://h/db".into(), ..s.clone() }.resolved().is_err());
         assert_eq!(DataSource { url_only: false, ..s }.resolved().unwrap().host, "localhost");
     }
+
+    #[test]
+    fn clickhouse_urls_resolve_http_https_and_credentials() {
+        assert_eq!(DbDriver::Clickhouse.default_port(), Some(8123));
+        let source = DataSource {
+            driver: DbDriver::Clickhouse,
+            url_only: true,
+            url: "https://reader:s%[email protected]:8443/analytics?max_execution_time=30".into(),
+            ..Default::default()
+        };
+        let resolved = source.resolved().unwrap();
+        assert_eq!(resolved.host, "db.example");
+        assert_eq!(resolved.port, Some(8443));
+        assert_eq!(resolved.database, "analytics");
+        assert_eq!(resolved.user, "reader");
+        assert_eq!(resolved.ssl, DbSslMode::VerifyFull);
+        assert_eq!(source.url_password().as_deref(), Some("s@cret"));
+        assert_eq!(resolved.properties[0].name, "max_execution_time");
+        let http = DataSource { url: "http://localhost/default".into(), ..source.clone() }.resolved().unwrap();
+        assert_eq!(http.ssl, DbSslMode::Disable);
+        let jdbc = DataSource { url: "jdbc:clickhouse://localhost/analytics".into(), ..source.clone() };
+        assert_eq!(jdbc.resolved().unwrap().database, "analytics");
+        let secure = DataSource { url: "https://db.example/default?sslmode=disable".into(), ..source };
+        assert_eq!(secure.resolved().unwrap().ssl, DbSslMode::VerifyFull);
+        let error = parse_url("clickhouse://reader:[email protected]:invalid/default").unwrap_err();
+        assert!(!error.message.contains("secret"));
+    }
 }

crates/ide-db/src/split.rs

@@ -28,6 +28,7 @@ enum State {
 /// Every statement of `text` that contains more than whitespace and comments.
 pub fn split(text: &str, driver: DbDriver) -> Vec<SqlStatement> {
     let mysql = driver == DbDriver::Mysql;
+    let clickhouse = driver == DbDriver::Clickhouse;
     let chars: Vec<(usize, char)> = text.char_indices().collect();
     // UTF-16 offset of each char index (plus the end).
     let mut u16_at = Vec::with_capacity(chars.len() + 1);
@@ -81,7 +82,7 @@ pub fn split(text: &str, driver: DbDriver) -> Vec<SqlStatement> {
                     state = State::Double;
                     has_code = true;
                 }
-                '`' if mysql => {
+                '`' if mysql || clickhouse => {
                     state = State::Backtick;
                     has_code = true;
                 }
@@ -117,7 +118,7 @@ pub fn split(text: &str, driver: DbDriver) -> Vec<SqlStatement> {
                 _ => {}
             },
             State::Single => {
-                if mysql && c == '\\' {
+                if (mysql || clickhouse) && c == '\\' {
                     i += 1;
                 } else if c == '\'' {
                     if next == Some('\'') {
@@ -128,7 +129,9 @@ pub fn split(text: &str, driver: DbDriver) -> Vec<SqlStatement> {
                 }
             }
             State::Double => {
-                if c == '"' {
+                if clickhouse && c == '\\' {
+                    i += 1;
+                } else if c == '"' {
                     if next == Some('"') {
                         i += 1;
                     } else {
@@ -137,7 +140,9 @@ pub fn split(text: &str, driver: DbDriver) -> Vec<SqlStatement> {
                 }
             }
             State::Backtick => {
-                if c == '`' {
+                if clickhouse && (c == '\\' || (c == '`' && next == Some('`'))) {
+                    i += 1;
+                } else if c == '`' {
                     state = State::Code;
                 }
             }
@@ -224,6 +229,12 @@ mod tests {
         assert_eq!(texts(sql, DbDriver::Mysql), vec!["select `a;b`, 'it\\'s;' from t # x;y", "select 2"]);
     }
 
+    #[test]
+    fn clickhouse_backticks_and_escaped_quotes_keep_statements_intact() {
+        let query = r#"SELECT `a\`;b`, "c\";d", 'it\'s;safe'; SELECT 2"#;
+        assert_eq!(texts(query, DbDriver::Clickhouse), vec![r#"SELECT `a\`;b`, "c\";d", 'it\'s;safe'"#, "SELECT 2"]);
+    }
+
     #[test]
     fn postgres_dollar_quotes() {
         let sql =

crates/ide-db/src/sql.rs

@@ -7,6 +7,7 @@ use specta::Type;
 
 pub fn quote_ident(driver: DbDriver, name: &str) -> String {
     match driver {
+        DbDriver::Clickhouse => format!("`{}`", name.replace('\\', "\\\\").replace('`', "\\`")),
         DbDriver::Mysql => format!("`{}`", name.replace('`', "``")),
         DbDriver::SqlServer => format!("[{}]", name.replace(']', "]]")),
         _ => format!("\"{}\"", name.replace('"', "\"\"")),
@@ -15,7 +16,7 @@ pub fn quote_ident(driver: DbDriver, name: &str) -> String {
 
 pub fn quote_literal(driver: DbDriver, value: &str) -> String {
     let mut s = value.replace('\'', "''");
-    if driver == DbDriver::Mysql {
+    if matches!(driver, DbDriver::Mysql | DbDriver::Clickhouse) {
         s = s.replace('\\', "\\\\");
     }
     format!("'{s}'")
@@ -48,6 +49,10 @@ pub const INTERNAL_DATABASES: &[&str] = &["rdsadmin", "azure_maintenance", "azur
 pub fn schemas(driver: DbDriver, system: bool) -> &'static str {
     match driver {
         DbDriver::Sqlite => "SELECT name FROM pragma_database_list WHERE name <> 'temp' ORDER BY seq",
+        DbDriver::Clickhouse if system => "SELECT name FROM system.databases ORDER BY name",
+        DbDriver::Clickhouse => {
+            "SELECT name FROM system.databases WHERE lower(name) NOT IN ('system', 'information_schema') ORDER BY name"
+        }
         DbDriver::Postgres if system => {
             "SELECT schema_name FROM information_schema.schemata \
              WHERE schema_name NOT LIKE 'pg\\_toast%' AND schema_name NOT LIKE 'pg\\_temp%' ORDER BY 1"
@@ -73,6 +78,12 @@ pub fn schemas(driver: DbDriver, system: bool) -> &'static str {
 /// Rows: `name, kind` where kind is `table`, `view` or `materialized view`.
 pub fn tables(driver: DbDriver, schema: &str) -> String {
     match driver {
+        DbDriver::Clickhouse => format!(
+            "SELECT name, CASE engine WHEN 'View' THEN 'view' WHEN 'MaterializedView' THEN 'materialized view' \
+             WHEN 'WindowView' THEN 'view' ELSE 'table' END FROM system.tables \
+             WHERE database = {} AND is_temporary = 0 ORDER BY name",
+            quote_literal(driver, schema)
+        ),
         DbDriver::Sqlite => format!(
             "SELECT name, type FROM {}.sqlite_master WHERE type IN ('table', 'view') \
              AND name NOT LIKE 'sqlite\\_%' ESCAPE '\\' ORDER BY name",
@@ -101,6 +112,12 @@ pub fn tables(driver: DbDriver, schema: &str) -> String {
 pub fn columns(driver: DbDriver, schema: &str, table: &str) -> String {
     let (s, t) = (quote_literal(driver, schema), quote_literal(driver, table));
     match driver {
+        DbDriver::Clickhouse => format!(
+            "SELECT name, type, CASE WHEN startsWith(type, 'Nullable(') \
+             OR startsWith(type, 'LowCardinality(Nullable(') THEN 'YES' ELSE 'NO' END, \
+             if(default_kind = '', NULL, default_expression), is_in_primary_key \
+             FROM system.columns WHERE database = {s} AND table = {t} ORDER BY position"
+        ),
         DbDriver::Sqlite => format!(
             "SELECT name, type, CASE WHEN \"notnull\" = 0 THEN 'YES' ELSE 'NO' END, dflt_value, \
              CASE WHEN pk > 0 THEN 1 ELSE 0 END FROM pragma_table_info({t}, {s}) ORDER BY cid"
@@ -138,6 +155,12 @@ pub fn columns(driver: DbDriver, schema: &str, table: &str) -> String {
 pub fn indexes(driver: DbDriver, schema: &str, table: &str) -> String {
     let (s, t) = (quote_literal(driver, schema), quote_literal(driver, table));
     match driver {
+        DbDriver::Clickhouse => format!(
+            "SELECT * FROM (SELECT 'PRIMARY KEY' AS index_name, 0 AS is_unique, primary_key AS expression \
+             FROM system.tables WHERE database = {s} AND name = {t} AND primary_key != '' \
+             UNION ALL SELECT name, 0, expr FROM system.data_skipping_indices \
+             WHERE database = {s} AND table = {t}) ORDER BY index_name"
+        ),
         DbDriver::Sqlite => format!(
             "SELECT il.name, il.\"unique\", ii.name FROM pragma_index_list({t}, {s}) il \
              JOIN pragma_index_info(il.name, {s}) ii ORDER BY il.name, ii.seqno"
@@ -169,6 +192,15 @@ pub fn indexes(driver: DbDriver, schema: &str, table: &str) -> String {
 /// for SQL completion, grouped by table in column order.
 pub fn completion_columns(driver: DbDriver) -> &'static str {
     match driver {
+        DbDriver::Clickhouse => {
+            "SELECT c.database, c.table, CASE t.engine WHEN 'View' THEN 'view' \
+             WHEN 'MaterializedView' THEN 'materialized view' WHEN 'WindowView' THEN 'view' ELSE 'table' END, \
+             c.name, c.type, CASE WHEN startsWith(c.type, 'Nullable(') \
+             OR startsWith(c.type, 'LowCardinality(Nullable(') THEN 'YES' ELSE 'NO' END, c.is_in_primary_key, 1 \
+             FROM system.columns c JOIN system.tables t ON t.database = c.database AND t.name = c.table \
+             WHERE lower(c.database) NOT IN ('system', 'information_schema') AND t.is_temporary = 0 \
+             ORDER BY c.database, c.table, c.position LIMIT 50000"
+        }
         DbDriver::Sqlite => {
             "SELECT 'main', m.name, m.type, p.name, p.type, CASE WHEN p.\"notnull\" = 0 THEN 'YES' ELSE 'NO' END, \
              CASE WHEN p.pk > 0 THEN 1 ELSE 0 END, \
@@ -221,6 +253,7 @@ pub fn completion_columns(driver: DbDriver) -> &'static str {
 /// when the key references the primary key implicitly.
 pub fn foreign_keys(driver: DbDriver) -> &'static str {
     match driver {
+        DbDriver::Clickhouse => "SELECT '', '', '', '', '', '', '' WHERE 0",
         DbDriver::Sqlite => {
             "SELECT 'main', m.name, f.id, f.\"from\", 'main', f.\"table\", f.\"to\" \
              FROM sqlite_master m JOIN pragma_foreign_key_list(m.name) f \
@@ -258,6 +291,7 @@ pub fn foreign_keys(driver: DbDriver) -> &'static str {
 pub fn table_foreign_keys(driver: DbDriver, schema: &str, table: &str) -> String {
     let (s, t) = (quote_literal(driver, schema), quote_literal(driver, table));
     match driver {
+        DbDriver::Clickhouse => foreign_keys(driver).to_owned(),
         DbDriver::Sqlite => format!(
             "SELECT {s}, {t}, f.id, f.\"from\", {s}, f.\"table\", f.\"to\"              FROM pragma_foreign_key_list({t}, {s}) f ORDER BY f.id, f.seq"
         ),
@@ -276,6 +310,7 @@ pub fn table_foreign_keys(driver: DbDriver, schema: &str, table: &str) -> String
 /// The schema unqualified names resolve to (`None`: always `main`).
 pub fn current_schema(driver: DbDriver) -> Option<&'static str> {
     match driver {
+        DbDriver::Clickhouse => Some("SELECT currentDatabase()"),
         DbDriver::Sqlite => None,
         DbDriver::Postgres => Some("SELECT current_schema()"),
         DbDriver::Mysql => Some("SELECT DATABASE()"),
@@ -362,6 +397,9 @@ fn where_key(driver: DbDriver, key: &[CellValue]) -> String {
 /// The DML statement for `edit`. Values are written as quoted literals, which
 /// every supported database coerces to the column type.
 pub fn edit_statement(driver: DbDriver, schema: &str, table: &str, edit: &DbRowEdit) -> Result<String, String> {
+    if driver == DbDriver::Clickhouse {
+        return Err("ClickHouse table editing is unsupported: primary keys do not uniquely identify rows and edits require transactions".into());
+    }
     let target = qualified(driver, schema, table);
     match edit {
         DbRowEdit::Update { key, values } => {
@@ -450,6 +488,7 @@ pub fn postgres_ddl_indexes(oid: u32) -> String {
 pub fn triggers(driver: DbDriver, schema: &str, table: &str) -> String {
     let (s, t) = (quote_literal(driver, schema), quote_literal(driver, table));
     match driver {
+        DbDriver::Clickhouse => "SELECT '', '', '' WHERE 0".to_owned(),
         DbDriver::Sqlite => format!(
             "SELECT name, sql FROM {}.sqlite_master WHERE type = 'trigger' AND tbl_name = {t} ORDER BY name",
             quote_ident(driver, schema)
@@ -492,7 +531,7 @@ pub fn sqlite_trigger_event(sql: &str) -> (String, String) {
 pub fn routines(driver: DbDriver, schema: &str) -> Option<String> {
     let s = quote_literal(driver, schema);
     match driver {
-        DbDriver::Sqlite => None,
+        DbDriver::Sqlite | DbDriver::Clickhouse => None,
         // Functions of extensions are left out, as in IDEA.
         DbDriver::Postgres => Some(format!(
             "SELECT p.proname, CASE WHEN p.prokind = 'p' THEN 'procedure' ELSE 'function' END, \
@@ -625,6 +664,71 @@ mod tests {
         assert_eq!(quote_literal(DbDriver::Mysql, "it's \\"), "'it''s \\\\'");
     }
 
+    #[test]
+    fn clickhouse_escapes_backslashes_and_delimiters() {
+        let driver = DbDriver::Clickhouse;
+        assert_eq!(quote_literal(driver, r"path\O'Brien"), r"'path\\O''Brien'");
+        assert_eq!(quote_literal(driver, r"\' OR 1 = 1 --"), r"'\\'' OR 1 = 1 --'");
+        assert_eq!(quote_ident(driver, r"a\`b"), r"`a\\\`b`");
+        assert_eq!(qualified(driver, "data base", "event`log"), r"`data base`.`event\`log`");
+    }
+
+    #[test]
+    fn clickhouse_metadata_preserves_types_defaults_and_nonunique_keys() {
+        let driver = DbDriver::Clickhouse;
+        assert_eq!(schemas(driver, true), "SELECT name FROM system.databases ORDER BY name");
+        assert!(schemas(driver, false).contains("lower(name) NOT IN ('system', 'information_schema')"));
+        assert_eq!(current_schema(driver), Some("SELECT currentDatabase()"));
+        let relations = tables(driver, "event's\\db");
+        assert!(relations.contains("WHEN 'MaterializedView' THEN 'materialized view'"));
+        assert!(relations.contains(r"WHERE database = 'event''s\\db' AND is_temporary = 0"));
+        let fields = columns(driver, "default", "events");
+        assert!(fields.starts_with("SELECT name, type, CASE WHEN startsWith(type, 'Nullable(')"));
+        assert!(fields.contains("startsWith(type, 'LowCardinality(Nullable(')"));
+        assert!(fields.contains("if(default_kind = '', NULL, default_expression), is_in_primary_key"));
+        assert!(fields.ends_with("WHERE database = 'default' AND table = 'events' ORDER BY position"));
+        let keys = indexes(driver, "default", "events");
+        assert!(keys.contains("'PRIMARY KEY' AS index_name, 0 AS is_unique, primary_key AS expression"));
+        assert!(keys.contains("SELECT name, 0, expr FROM system.data_skipping_indices"));
+        let completion = completion_columns(driver);
+        assert!(completion.contains("c.is_in_primary_key, 1"));
+        assert!(completion.contains("ORDER BY c.database, c.table, c.position LIMIT 50000"));
+    }
+
+    #[test]
+    fn clickhouse_has_no_foreign_key_trigger_or_schema_routine_catalogs() {
+        let driver = DbDriver::Clickhouse;
+        assert_eq!(foreign_keys(driver), "SELECT '', '', '', '', '', '', '' WHERE 0");
+        assert_eq!(table_foreign_keys(driver, "default", "events"), foreign_keys(driver));
+        assert_eq!(triggers(driver, "default", "events"), "SELECT '', '', '' WHERE 0");
+        assert!(routines(driver, "default").is_none());
+        assert!(sequences(driver, "default").is_none());
+        assert!(object_ddl(driver, "default", crate::DbObjectKind::Trigger, "t").is_none());
+    }
+
+    #[test]
+    fn clickhouse_pages_quote_keys_and_fetch_one_extra_row() {
+        let sort = [SortKey { column: "event`id".into(), descending: true }];
+        assert_eq!(
+            table_page(DbDriver::Clickhouse, "default", "events", Some("WHERE id > 3"), &sort, 50, 25),
+            r"SELECT * FROM `default`.`events` WHERE id > 3 ORDER BY `event\`id` DESC LIMIT 26 OFFSET 50"
+        );
+    }
+
+    #[test]
+    fn clickhouse_keys_never_enable_transactional_table_edits() {
+        let key = vec![cv("id", Some("1"))];
+        for edit in [
+            DbRowEdit::Update { key: key.clone(), values: vec![cv("name", Some("new"))] },
+            DbRowEdit::Delete { key },
+            DbRowEdit::Insert { values: vec![cv("name", Some("new"))] },
+            DbRowEdit::Insert { values: vec![] },
+        ] {
+            let error = edit_statement(DbDriver::Clickhouse, "default", "events", &edit).unwrap_err();
+            assert!(error.contains("primary keys do not uniquely identify rows"));
+        }
+    }
+
     #[test]
     fn pages() {
         let sort = [SortKey { column: "id".into(), descending: true }];

crates/ide-db/tests/clickhouse.rs

@@ -0,0 +1,136 @@
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use ide_db::{CellValue, DataSource, DbDriver, DbManager, DbRowEdit, DbSslMode, SortKey, sql};
+use std::sync::Arc;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+fn check(condition: bool, message: &str) -> IdeResult<()> {
+    if condition { Ok(()) } else { Err(IdeError::invalid(message)) }
+}
+
+#[tokio::test]
+#[ignore = "requires CLICKHOUSE_TEST_HOST, CLICKHOUSE_TEST_USER, and CLICKHOUSE_TEST_PASSWORD"]
+async fn clickhouse_cloud_manager_catalogs_and_session_table() -> IdeResult<()> {
+    let tmp = tempfile::tempdir()?;
+    let root = tmp.path().to_path_buf();
+    let ssh = Arc::new(ide_ssh::SshManager::new(root.join("ssh-passwords.json")));
+    let db = DbManager::new(root.clone(), root.join("passwords.json"), root.join("history.json"), ssh);
+    let mut source = DataSource {
+        id: "clickhouse".into(),
+        name: "clickhouse".into(),
+        driver: DbDriver::Clickhouse,
+        host: std::env::var("CLICKHOUSE_TEST_HOST").expect("set CLICKHOUSE_TEST_HOST"),
+        port: Some(
+            std::env::var("CLICKHOUSE_TEST_PORT")
+                .map(|value| value.parse().expect("numeric CLICKHOUSE_TEST_PORT"))
+                .unwrap_or(8443),
+        ),
+        user: std::env::var("CLICKHOUSE_TEST_USER").expect("set CLICKHOUSE_TEST_USER"),
+        database: "default".into(),
+        ssl: DbSslMode::VerifyFull,
+        ..Default::default()
+    };
+    source.introspection.show_system = true;
+    let password = std::env::var("CLICKHOUSE_TEST_PASSWORD").expect("set CLICKHOUSE_TEST_PASSWORD");
+    check(!db.test(&source, Some(password.clone()), None).await?.is_empty(), "missing server version")?;
+    db.save_sources(vec![source]).await?;
+    db.set_password("clickhouse", Some(password), false).await?;
+    let cancel = CancellationToken::new();
+    let suffix = SystemTime::now().duration_since(UNIX_EPOCH).unwrap().as_nanos();
+    let name = format!("manager_test_{}_{suffix}", std::process::id());
+    let table = sql::quote_ident(DbDriver::Clickhouse, &name);
+    db.execute(
+        "clickhouse",
+        &format!(
+            "CREATE TEMPORARY TABLE {table} (id UInt64, label Nullable(String) DEFAULT NULL, \
+             category LowCardinality(Nullable(String)) DEFAULT NULL, items Array(Nullable(UInt8)), \
+             label_size UInt64 ALIAS length(ifNull(label, ''))) ENGINE = Memory"
+        ),
+        0,
+        &cancel,
+    )
+    .await?;
+    let checked: IdeResult<()> = async {
+        db.execute(
+            "clickhouse",
+            &format!("INSERT INTO {table} (id, label, items) VALUES (1, 'first', [1, NULL]), (1, NULL, [])"),
+            0,
+            &cancel,
+        )
+        .await?;
+        let schemas = db.schemas("clickhouse").await?;
+        check(schemas.iter().any(|schema| schema == "default"), "default database missing")?;
+        check(schemas.iter().any(|schema| schema == "system"), "system database missing")?;
+        let tables = db.tables("clickhouse", "system").await?;
+        check(tables.iter().any(|table| table.name == "one"), "system table listing missing one")?;
+        let details = db.table_details("clickhouse", "", &name).await?;
+        check(details.columns.len() == 5, "temporary table columns missing")?;
+        for (name, data_type, nullable) in [
+            ("id", "UInt64", false),
+            ("label", "Nullable(String)", true),
+            ("category", "LowCardinality(Nullable(String))", true),
+            ("items", "Array(Nullable(UInt8))", false),
+        ] {
+            check(
+                details
+                    .columns
+                    .iter()
+                    .any(|column| column.name == name && column.data_type == data_type && column.nullable == nullable),
+                "column type or nullability mismatch",
+            )?;
+        }
+        check(
+            details.columns.iter().any(|column| column.name == "label" && column.default.as_deref() == Some("NULL")),
+            "explicit default expression missing",
+        )?;
+        check(details.indexes.iter().all(|index| !index.unique), "ClickHouse index reported unique")?;
+        check(details.foreign_keys.is_empty() && details.triggers.is_empty(), "unsupported table objects returned")?;
+        let sort = [SortKey { column: "id".into(), descending: false }];
+        let first = db.table_page("clickhouse", "", &name, None, &sort, 0, 1, &cancel).await?;
+        check(first.result.rows.len() == 1 && first.result.has_more, "first page limit failed")?;
+        let second = db.table_page("clickhouse", "", &name, None, &sort, 1, 1, &cancel).await?;
+        check(second.result.rows.len() == 1 && !second.result.has_more, "page offset failed")?;
+        let ddl = db.ddl("clickhouse", "", &name).await?;
+        check(ddl.contains(&name) && ddl.contains("Memory"), "temporary table DDL missing")?;
+        let completion = db.completion("clickhouse").await?;
+        check(completion.default_schema == "default", "completion default database mismatch")?;
+        check(completion.foreign_keys.is_empty(), "completion returned unsupported foreign keys")?;
+        if let Some(table) = completion.tables.first() {
+            let details = db.table_details("clickhouse", &table.schema, &table.name).await?;
+            check(
+                table.columns.iter().all(|column| {
+                    details.columns.iter().any(|field| field.name == column.name && field.data_type == column.data_type)
+                }),
+                "completion columns differ from catalog",
+            )?;
+        }
+        let plan = db.explain("clickhouse", &format!("SELECT id FROM {table}"), &cancel).await?;
+        check(!plan.is_empty(), "query plan missing")?;
+        let value = r"path\O'Brien";
+        let result = db
+            .execute("clickhouse", &format!("SELECT {}", sql::quote_literal(DbDriver::Clickhouse, value)), 1, &cancel)
+            .await?;
+        check(result.rows == vec![vec![Some(value.to_owned())]], "quoted literal changed value")?;
+        let edits = [DbRowEdit::Update {
+            key: vec![CellValue { column: "id".into(), value: Some("1".into()) }],
+            values: vec![CellValue { column: "label".into(), value: Some("changed".into()) }],
+        }];
+        check(
+            db.apply_edits("clickhouse", "", &name, &edits)
+                .await
+                .err()
+                .is_some_and(|error| error.message.contains("table editing is unsupported")),
+            "supplied row key authorized table editing",
+        )?;
+        check(db.set_manual_commit("clickhouse", true).await.is_err(), "manual transactions were accepted")?;
+        for commit in [false, true] {
+            check(db.finish_transaction("clickhouse", commit).await.is_err(), "transaction control was accepted")?;
+        }
+        Ok(())
+    }
+    .await;
+    let cleanup = db.execute("clickhouse", &format!("DROP TEMPORARY TABLE {table}"), 0, &cancel).await;
+    db.disconnect("clickhouse").await;
+    checked?;
+    cleanup?;
+    Ok(())
+}

crates/ide-db/tests/sqlite.rs

@@ -197,7 +197,7 @@ async fn count(db: &DbManager) -> String {
 async fn manual_commit_keeps_a_transaction_until_commit_or_rollback() -> IdeResult<()> {
     let (_tmp, db) = setup().await;
     let c = CancellationToken::new();
-    db.set_manual_commit("s1", true).await;
+    db.set_manual_commit("s1", true).await.unwrap();
     db.execute("s1", "INSERT INTO users (name) VALUES ('dee')", 1, &c).await?;
     // The session sees its own change.
     assert_eq!(count(&db).await, "4");
@@ -208,10 +208,10 @@ async fn manual_commit_keeps_a_transaction_until_commit_or_rollback() -> IdeResu
     db.finish_transaction("s1", true).await?;
     // Leaving manual mode rolls back what is still open.
     db.execute("s1", "DELETE FROM users", 1, &c).await?;
-    db.set_manual_commit("s1", false).await;
+    db.set_manual_commit("s1", false).await.unwrap();
     assert_eq!(count(&db).await, "4");
     // Disconnecting with an open transaction does not hang.
-    db.set_manual_commit("s1", true).await;
+    db.set_manual_commit("s1", true).await.unwrap();
     db.execute("s1", "DELETE FROM users", 1, &c).await?;
     db.disconnect("s1").await;
     assert_eq!(count(&db).await, "4");

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, CATEGORIES, Capabilities, ENGINE_VERSION, EVENT_KINDS, LEGACY_API, MANIFEST_FILE, MAX_CATEGORIES,
+    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 +1,567 @@
+//! `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";
+/// Marketplace categories, in the order they are shown.
+pub const CATEGORIES: &[&str] =
+    &["languages", "themes", "icon-themes", "linters", "vcs", "ai", "frameworks", "tools", "other"];
+/// Categories a plugin is listed under; later ones are ignored.
+pub const MAX_CATEGORIES: usize = 3;
+
+#[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>,
+    /// Marketplace categories as declared (see [`Manifest::categories`]).
+    pub declared_categories: Vec<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)]
+    categories: Vec<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,
+            declared_categories: raw.categories,
+            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 c in &self.declared_categories {
+            validate_item_id(c, "category")?;
+        }
+        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))
+    }
+}
+
+impl Manifest {
+    /// Its marketplace categories, in [`CATEGORIES`] order: the first
+    /// [`MAX_CATEGORIES`] declared that this IDE knows; without any, those its
+    /// contributions imply (themes, icon themes, languages), else `other`.
+    pub fn categories(&self) -> Vec<String> {
+        let pick = |f: &dyn Fn(&str) -> bool| CATEGORIES.iter().filter(|c| f(c)).map(|c| c.to_string()).collect();
+        let mut known: Vec<&str> = Vec::new();
+        for d in &self.declared_categories {
+            if CATEGORIES.contains(&d.as_str()) && !known.contains(&d.as_str()) && known.len() < MAX_CATEGORIES {
+                known.push(d);
+            }
+        }
+        let mut out: Vec<String> = pick(&|c| known.contains(&c));
+        if out.is_empty() {
+            out = pick(&|c| match c {
+                "themes" => self.contributes.contains_key("themes"),
+                "icon-themes" => self.contributes.contains_key("iconThemes"),
+                "languages" => self.contributes.contains_key("languages"),
+                _ => false,
+            });
+        }
+        if out.is_empty() {
+            out.push("other".into());
+        }
+        out
+    }
+
+    /// Declared categories this IDE doesn't know (ignored).
+    pub fn unknown_categories(&self) -> Vec<&str> {
+        self.declared_categories.iter().map(String::as_str).filter(|c| !CATEGORIES.contains(c)).collect()
+    }
+}
+
+/// 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 categories_are_declared_or_implied() {
+        let head = "id = \"acme.x\"\nname = \"X\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.0\"\n";
+        let m = |rest: &str| Manifest::parse(&format!("{head}{rest}"));
+        // Declared, in the catalogue's order; unknown ones (a newer IDE's) are ignored.
+        let declared = m("categories = [\"tools\", \"vcs\", \"robots\"]\n").unwrap();
+        assert_eq!(declared.categories(), ["vcs", "tools"]);
+        assert_eq!(declared.unknown_categories(), ["robots"]);
+        // None declared: implied by the contributions, else `other`.
+        let theme = m("[[contributes.themes]]\nid = \"t\"\n[[contributes.languages]]\nid = \"l\"\n").unwrap();
+        assert_eq!(theme.categories(), ["languages", "themes"]);
+        let declared_wins = m("categories = [\"tools\"]\n[[contributes.languages]]\nid = \"l\"\n").unwrap();
+        assert_eq!(declared_wins.categories(), ["tools"]);
+        assert_eq!(m("").unwrap().categories(), ["other"]);
+        // At most three: the first ones declared.
+        let many = m("categories = [\"vcs\", \"ai\", \"vcs\", \"tools\", \"themes\"]\n").unwrap();
+        assert_eq!(many.categories(), ["vcs", "ai", "tools"]);
+        assert!(m("categories = [\"Bad Name\"]\n").is_err());
+    }
+
+    #[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 +1,955 @@
+//! 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 plugin versions, 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. A plugin may be
+//!   listed in several versions, each with the plugin API it needs: the IDE
+//!   offers the newest one it can load.
+//! - **Key continuity**: an installed plugin updates silently only to a
+//!   package signed with the same key, or with a key the installed one
+//!   endorsed ([`Endorsement`], a publisher rotating keys); any other signer
+//!   is the user's call. An IDE can pin a publisher to keys it was built with
+//!   ([`Index::pin_publisher`]): the index then can't replace them.
+//! - **Format**: fields are only ever added (IDEs ignore those they don't
+//!   know); `format` grows only for changes older IDEs can't read, and they
+//!   still apply such an index's revocations ([`Index::parse`]).
+
+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()
+}
+
+fn endorsement_message(publisher: &str, key: &str) -> Vec<u8> {
+    format!("openidea-key/1\n{publisher}\n{key}").into_bytes()
+}
+
+/// Whether `signature` (base64) is `key`'s (base64) Ed25519 signature of
+/// `message`; malformed keys and signatures are errors.
+fn verify_ed25519(key: &str, message: &[u8], signature: &str) -> Result<bool, String> {
+    let key: [u8; 32] = B64
+        .decode(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(signature).ok().and_then(|b| b.try_into().ok()).ok_or_else(|| "signature: malformed".to_owned())?;
+    Ok(key.verify_strict(message, &Signature::from_bytes(&sig)).is_ok())
+}
+
+/// `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())
+    }
+
+    /// Vouches for `publisher`'s new key `key` (base64), the one that follows this one.
+    pub fn endorse(&self, publisher: &str, key: &str) -> Endorsement {
+        let sig = self.0.sign(&endorsement_message(publisher, key));
+        Endorsement { key: self.public_base64(), signature: B64.encode(sig.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> {
+        if verify_ed25519(&self.key, &signed_message(id, version, digest), &self.signature)? {
+            Ok(())
+        } else {
+            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>,
+    /// The marketplace moved: its index is at this URL (relative to this
+    /// one, or absolute), and the IDE reads that one instead.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub moved: Option<String>,
+}
+
+#[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, Default, 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,
+    /// The publisher's earlier key vouching for this one.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub endorsement: Option<Endorsement>,
+}
+
+impl KeyEntry {
+    pub fn new(key: String) -> Self {
+        Self { key, ..Self::default() }
+    }
+}
+
+/// A publisher's earlier key vouching for a newer one: plugins installed from
+/// packages signed with the earlier key update to ones signed with the newer
+/// key without asking the user.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, specta::Type)]
+#[serde(rename_all = "camelCase")]
+pub struct Endorsement {
+    /// The endorsing key, base64.
+    pub key: String,
+    /// Its Ed25519 signature of `openidea-key/1\n<publisher>\n<endorsed key>`, base64.
+    pub signature: String,
+}
+
+/// 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>,
+    /// The plugin API versions it loads in (a semver requirement): its
+    /// manifest's `engines.openidea` and the API its component was built for.
+    /// Required: an entry without one is offered to no IDE.
+    #[serde(default)]
+    pub engine: String,
+    /// Marketplace categories (`CATEGORIES`); an IDE ignores those it doesn't know.
+    #[serde(default)]
+    pub categories: Vec<String>,
+}
+
+impl IndexEntry {
+    /// Whether this IDE can load the version.
+    pub fn compatible(&self) -> bool {
+        crate::engine_compatible(&self.engine, false)
+    }
+
+    fn semver(&self) -> Option<semver::Version> {
+        semver::Version::parse(&self.version).ok()
+    }
+}
+
+/// `engines.openidea` of a manifest narrowed to the API its component was built
+/// for (`major.minor`, if it has code): the requirement an index lists.
+pub fn engine_requirement(manifest_engine: &str, built_for: Option<&semver::Version>) -> String {
+    match built_for {
+        Some(v) => format!("{manifest_engine}, ^{}.{}", v.major, v.minor),
+        None => manifest_engine.to_owned(),
+    }
+}
+
+/// 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 {
+    /// Parses an index. One in a newer format keeps what must reach every IDE —
+    /// revocations, publisher keys (revoked ones) and `moved` — and lists no
+    /// plugins ([`Index::is_newer`]): the IDE needs updating to install from it.
+    pub fn parse(text: &str) -> Result<Self, String> {
+        let value: serde_json::Value = serde_json::from_str(text).map_err(|e| format!("index: {e}"))?;
+        let format = value.get("format").and_then(serde_json::Value::as_u64).ok_or("index: `format` is missing")?;
+        if format == u64::from(INDEX_FORMAT) {
+            return serde_json::from_value(value).map_err(|e| format!("index: {e}"));
+        }
+        if format < u64::from(INDEX_FORMAT) {
+            return Err(format!("index format {format} is not supported (this IDE reads {INDEX_FORMAT})"));
+        }
+        fn each<T: serde::de::DeserializeOwned>(value: &serde_json::Value, field: &str) -> Vec<T> {
+            let items = value.get(field).and_then(serde_json::Value::as_array);
+            items.into_iter().flatten().filter_map(|v| serde_json::from_value(v.clone()).ok()).collect()
+        }
+        Ok(Index {
+            format: u32::try_from(format).unwrap_or(u32::MAX),
+            publishers: each(&value, "publishers"),
+            plugins: Vec::new(),
+            revoked: each(&value, "revoked"),
+            moved: value.get("moved").and_then(serde_json::Value::as_str).map(str::to_owned),
+        })
+    }
+
+    /// Written in a format newer than this IDE reads: it lists no plugins.
+    pub fn is_newer(&self) -> bool {
+        self.format > INDEX_FORMAT
+    }
+
+    /// The version of each plugin to offer, and whether this IDE can load it:
+    /// the newest it can load, else the newest. Revoked versions are skipped;
+    /// plugins come in the order they are first listed.
+    pub fn offered(&self) -> Vec<(&IndexEntry, bool)> {
+        let mut ids: Vec<&str> = Vec::new();
+        for e in &self.plugins {
+            if !ids.contains(&e.id.as_str()) {
+                ids.push(&e.id);
+            }
+        }
+        ids.into_iter()
+            .filter_map(|id| {
+                let versions: Vec<&IndexEntry> =
+                    self.plugins.iter().filter(|e| e.id == id && self.revocation(id, &e.version).is_none()).collect();
+                let newest = |loadable: bool| {
+                    versions.iter().copied().filter(|e| !loadable || e.compatible()).max_by_key(|e| e.semver())
+                };
+                newest(true).map(|e| (e, true)).or_else(|| newest(false).map(|e| (e, false)))
+            })
+            .collect()
+    }
+
+    /// Drops the versions no IDE would pick: revoked ones, and of each plugin
+    /// all but the newest version per API requirement.
+    pub fn prune_versions(&mut self) {
+        let plugins = std::mem::take(&mut self.plugins);
+        let mut kept: Vec<IndexEntry> = Vec::new();
+        for e in plugins.into_iter().filter(|e| self.revocation(&e.id, &e.version).is_none()) {
+            match kept.iter_mut().find(|k| k.id == e.id && k.engine == e.engine) {
+                Some(k) if e.semver() > k.semver() => *k = e,
+                Some(_) => {}
+                None => kept.push(e),
+            }
+        }
+        self.plugins = kept;
+    }
+
+    /// 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())
+    }
+
+    /// Whether `to` is `from`, or a key of `publisher` that `from` endorsed,
+    /// directly or through keys it endorsed. Endorsements by revoked keys don't
+    /// count: whoever stole a key could vouch for their own.
+    pub fn succeeds(&self, publisher: &str, from: &str, to: &str) -> bool {
+        let keys = self.publishers.iter().find(|p| p.id == publisher).map_or(&[][..], |p| &p.keys[..]);
+        let mut key = to;
+        // Each step moves to an earlier key; more steps than keys is a loop.
+        for _ in 0..=keys.len() {
+            if key == from {
+                return true;
+            }
+            let Some(e) = keys.iter().find(|k| k.key == key).and_then(|k| k.endorsement.as_ref()) else {
+                return false;
+            };
+            let endorser_valid = keys.iter().any(|k| k.key == e.key && !k.revoked);
+            if !endorser_valid || verify_ed25519(&e.key, &endorsement_message(publisher, key), &e.signature) != Ok(true)
+            {
+                return false;
+            }
+            key = &e.key;
+        }
+        false
+    }
+
+    /// Makes `roots` (base64) the keys `publisher` signs with, whatever this
+    /// index says: another key it lists stays only when a root endorsed it (a
+    /// rotation the roots vouched for). Revocations of the keys are kept.
+    pub fn pin_publisher(&mut self, publisher: &str, name: &str, roots: &[String]) {
+        if roots.is_empty() {
+            return;
+        }
+        let i = match self.publishers.iter().position(|p| p.id == publisher) {
+            Some(i) => i,
+            None => {
+                self.publishers.push(Publisher { id: publisher.into(), name: name.into(), keys: Vec::new() });
+                self.publishers.len() - 1
+            }
+        };
+        for root in roots {
+            if !self.publishers[i].keys.iter().any(|k| &k.key == root) {
+                self.publishers[i].keys.push(KeyEntry::new(root.clone()));
+            }
+        }
+        let keys = self.publishers[i].keys.clone();
+        let trusted = keys
+            .into_iter()
+            .filter(|k| roots.iter().any(|r| self.succeeds(publisher, r, &k.key)))
+            .map(|k| if roots.contains(&k.key) { KeyEntry { endorsement: None, ..k } } else { k })
+            .collect();
+        self.publishers[i].keys = trusted;
+    }
+
+    /// Replaces what this index lists for every publisher but `keep` with what
+    /// `other` lists: its publishers, their plugins and their revocations
+    /// (`other`'s downloads should already be absolute). `other` may only
+    /// speak for its own publishers, and none of them may be in `keep`.
+    pub fn include(&mut self, other: Index, keep: &[&str]) -> Result<(), String> {
+        let mut theirs: Vec<&str> = Vec::new();
+        for p in &other.publishers {
+            if !publisher_id_ok(&p.id) {
+                return Err(format!("invalid publisher id {:?}: use a-z, 0-9, '-' and '_'", p.id));
+            }
+            if keep.contains(&p.id.as_str()) {
+                return Err(format!("may not list publisher {:?}", p.id));
+            }
+            if theirs.contains(&p.id.as_str()) {
+                return Err(format!("publisher {:?} is listed twice", p.id));
+            }
+            theirs.push(&p.id);
+        }
+        let owned_by = |id: &str| theirs.iter().any(|p| owns(p, id));
+        for e in &other.plugins {
+            if !theirs.contains(&e.publisher.as_str()) || !owns(&e.publisher, &e.id) {
+                return Err(format!("{}: not a plugin of publisher {:?}", e.id, e.publisher));
+            }
+            if semver::VersionReq::parse(&e.engine).is_err() {
+                return Err(format!("{} {}: `engine` must be the plugin API it needs", e.id, e.version));
+            }
+        }
+        if let Some(r) = other.revoked.iter().find(|r| !owned_by(&r.id)) {
+            return Err(format!("{}: revoked by an index that doesn't publish it", r.id));
+        }
+        let kept = |id: &str| keep.iter().any(|p| owns(p, id));
+        self.publishers.retain(|p| keep.contains(&p.id.as_str()));
+        self.plugins.retain(|e| keep.contains(&e.publisher.as_str()));
+        self.revoked.retain(|r| kept(&r.id));
+        self.publishers.extend(other.publishers);
+        self.plugins.extend(other.plugins);
+        self.revoked.extend(other.revoked);
+        Ok(())
+    }
+}
+
+/// Whether a package signed `new` (`None`: unsigned) may replace an installed
+/// one signed `installed` without asking the user: signed with the same key,
+/// or with one the installed key endorsed (per `index`). An unsigned installed
+/// copy pins nothing.
+pub fn signer_continues(
+    index: Option<&Index>,
+    installed: Option<&PackageSignature>,
+    new: Option<&PackageSignature>,
+) -> bool {
+    match (installed, new) {
+        (None, _) => true,
+        (Some(_), None) => false,
+        (Some(old), Some(new)) => {
+            old.publisher == new.publisher
+                && (old.key == new.key || index.is_some_and(|i| i.succeeds(&new.publisher, &old.key, &new.key)))
+        }
+    }
+}
+
+/// Whether the plugin `id` is in `publisher`'s namespace.
+fn owns(publisher: &str, id: &str) -> bool {
+    id.strip_prefix(publisher).is_some_and(|rest| rest.starts_with('.'))
+}
+
+/// A publisher id is a single segment of a plugin id.
+pub fn publisher_id_ok(id: &str) -> bool {
+    !id.contains('.') && crate::validate_plugin_id(id).is_ok()
+}
+
+#[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::new(key.public_base64())],
+            }],
+            plugins: Vec::new(),
+            revoked: vec![Revocation {
+                id: "acme.bad".into(),
+                versions: vec!["1.0.0".into()],
+                reason: "malware".into(),
+            }],
+            moved: None,
+        }
+    }
+
+    #[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());
+    }
+
+    fn entry(id: &str, publisher: &str) -> IndexEntry {
+        IndexEntry {
+            id: id.into(),
+            name: id.into(),
+            version: "1.0.0".into(),
+            description: String::new(),
+            authors: Vec::new(),
+            publisher: publisher.into(),
+            download: format!("https://example.com/{id}.oiplugin"),
+            digest: "d".into(),
+            capabilities: Vec::new(),
+            engine: "^1.0".into(),
+            categories: Vec::new(),
+        }
+    }
+
+    fn version(id: &str, version: &str, engine: &str) -> IndexEntry {
+        IndexEntry { version: version.into(), engine: engine.into(), ..entry(id, "acme") }
+    }
+
+    #[test]
+    fn the_ide_is_offered_the_newest_version_it_can_load() {
+        let host = crate::ENGINE_VERSION;
+        let newer = semver::Version::parse(host).unwrap().major + 1;
+        let mut index = Index {
+            format: INDEX_FORMAT,
+            plugins: vec![
+                version("acme.a", "1.0.0", &format!("^{host}")),
+                version("acme.a", "1.2.0", &format!("^{host}")),
+                version("acme.a", "2.0.0", &format!("^{newer}.0")),
+                version("acme.b", "0.1.0", &format!("^{newer}.0")),
+                version("acme.b", "0.2.0", &format!("^{newer}.1")),
+                version("acme.c", "1.0.0", ""),
+                version("acme.c", "1.1.0", ""),
+            ],
+            revoked: vec![Revocation { id: "acme.c".into(), versions: vec!["1.1.0".into()], reason: "r".into() }],
+            ..Index::default()
+        };
+        let offered = |index: &Index| {
+            index.offered().into_iter().map(|(e, ok)| (e.id.clone(), e.version.clone(), ok)).collect::<Vec<_>>()
+        };
+        let expected = [
+            ("acme.a".to_owned(), "1.2.0".to_owned(), true),
+            ("acme.b".to_owned(), "0.2.0".to_owned(), false),
+            // No `engine`: listed, but no IDE installs it.
+            ("acme.c".to_owned(), "1.0.0".to_owned(), false),
+        ];
+        assert_eq!(offered(&index), expected);
+
+        // Pruning keeps the newest version per requirement, which changes nothing offered.
+        index.prune_versions();
+        let left: Vec<_> = index.plugins.iter().map(|e| format!("{} {}", e.id, e.version)).collect();
+        assert_eq!(left, ["acme.a 1.2.0", "acme.a 2.0.0", "acme.b 0.1.0", "acme.b 0.2.0", "acme.c 1.0.0"]);
+        assert_eq!(offered(&index), expected);
+
+        let built_for = semver::Version::new(1, 3, 0);
+        assert_eq!(engine_requirement("^1.0", Some(&built_for)), "^1.0, ^1.3");
+        assert_eq!(engine_requirement("^1.0", None), "^1.0");
+        assert!(semver::VersionReq::parse(&engine_requirement("^1.0", Some(&built_for))).is_ok());
+    }
+
+    fn publisher(id: &str) -> Publisher {
+        Publisher { id: id.into(), name: id.into(), keys: vec![KeyEntry::new(format!("{id}-key"))] }
+    }
+
+    fn revocation(id: &str) -> Revocation {
+        Revocation { id: id.into(), versions: Vec::new(), reason: "r".into() }
+    }
+
+    #[test]
+    fn including_an_index_replaces_everything_but_the_kept_publishers() {
+        let mut official = Index {
+            format: INDEX_FORMAT,
+            publishers: vec![publisher("openidea"), publisher("gone")],
+            plugins: vec![entry("openidea.a", "openidea"), entry("gone.x", "gone")],
+            revoked: vec![revocation("openidea.old"), revocation("gone.x")],
+            moved: None,
+        };
+        let community = Index {
+            format: INDEX_FORMAT,
+            publishers: vec![publisher("alice")],
+            plugins: vec![entry("alice.arthas", "alice")],
+            revoked: vec![revocation("alice.bad")],
+            moved: None,
+        };
+        official.include(community.clone(), &["openidea"]).unwrap();
+        let ids = |v: &[IndexEntry]| v.iter().map(|e| e.id.clone()).collect::<Vec<_>>();
+        assert_eq!(official.publishers.iter().map(|p| p.id.as_str()).collect::<Vec<_>>(), ["openidea", "alice"]);
+        assert_eq!(ids(&official.plugins), ["openidea.a", "alice.arthas"]);
+        assert_eq!(official.revoked.iter().map(|r| r.id.as_str()).collect::<Vec<_>>(), ["openidea.old", "alice.bad"]);
+
+        // Including again is idempotent.
+        let once = official.clone();
+        official.include(community.clone(), &["openidea"]).unwrap();
+        assert_eq!(official, once);
+    }
+
+    #[test]
+    fn an_included_index_speaks_only_for_its_own_publishers() {
+        let base = Index { format: INDEX_FORMAT, publishers: vec![publisher("openidea")], ..Index::default() };
+        let with = |publishers: Vec<Publisher>, plugins: Vec<IndexEntry>, revoked: Vec<Revocation>| Index {
+            format: INDEX_FORMAT,
+            publishers,
+            plugins,
+            revoked,
+            moved: None,
+        };
+        let cases = [
+            (with(vec![publisher("openidea")], vec![], vec![]), "may not list"),
+            (with(vec![publisher("alice"), publisher("alice")], vec![], vec![]), "listed twice"),
+            (with(vec![publisher("openidea.x")], vec![], vec![]), "invalid publisher"),
+            (with(vec![publisher("alice")], vec![entry("openidea.a", "alice")], vec![]), "not a plugin of"),
+            (with(vec![publisher("alice")], vec![entry("alice.a", "bob")], vec![]), "not a plugin of"),
+            (with(vec![publisher("alice")], vec![entry("alicex.a", "alice")], vec![]), "not a plugin of"),
+            (with(vec![publisher("alice")], vec![], vec![revocation("openidea.a")]), "doesn't publish"),
+            (
+                with(
+                    vec![publisher("alice")],
+                    vec![IndexEntry { engine: String::new(), ..entry("alice.a", "alice") }],
+                    vec![],
+                ),
+                "`engine`",
+            ),
+        ];
+        for (other, error) in cases {
+            let mut index = base.clone();
+            let err = index.include(other, &["openidea"]).unwrap_err();
+            assert!(err.contains(error), "{err}");
+            assert_eq!(index, base);
+        }
+    }
+
+    #[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}"#).unwrap().is_newer());
+    }
+
+    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}");
+        }
+    }
+
+    #[test]
+    fn a_newer_index_still_revokes_and_moves() {
+        let newer = format!(
+            r#"{{"format": {}, "plugins": [{{"anything": "new"}}], "shape": "changed",
+                "publishers": [{{"id": "acme", "name": "ACME", "keys": [{{"key": "k1", "revoked": true}}]}}, {{"id": 5}}],
+                "revoked": [{{"id": "acme.bad", "reason": "malware"}}, {{"oops": 1}}],
+                "moved": "https://example.com/next.json"}}"#,
+            INDEX_FORMAT + 1
+        );
+        let index = Index::parse(&newer).unwrap();
+        assert!(index.is_newer());
+        assert!(index.plugins.is_empty() && index.offered().is_empty());
+        assert_eq!(index.revocation("acme.bad", "2.0.0").unwrap().reason, "malware");
+        assert!(index.key_revoked("k1"));
+        assert_eq!(index.moved.as_deref(), Some("https://example.com/next.json"));
+        // Fields this IDE doesn't know are ignored in its own format.
+        let current = format!(r#"{{"format": {INDEX_FORMAT}, "later": true, "plugins": []}}"#);
+        assert!(!Index::parse(&current).unwrap().is_newer());
+        assert!(Index::parse(r#"{"format": 0}"#).unwrap_err().contains("not supported"));
+        assert!(Index::parse(r#"{"plugins": []}"#).is_err());
+    }
+
+    fn keys<'a>(index: &'a mut Index, publisher: &str) -> &'a mut Vec<KeyEntry> {
+        &mut index.publishers.iter_mut().find(|p| p.id == publisher).unwrap().keys
+    }
+
+    #[test]
+    fn rotated_keys_continue_through_endorsements() {
+        let (k1, k2, k3) =
+            (PublisherKey::from_seed([1; 32]), PublisherKey::from_seed([2; 32]), PublisherKey::from_seed([3; 32]));
+        let mut index = index(&k1);
+        let endorsed = |by: &PublisherKey, key: &PublisherKey| KeyEntry {
+            endorsement: Some(by.endorse("acme", &key.public_base64())),
+            ..KeyEntry::new(key.public_base64())
+        };
+        keys(&mut index, "acme").push(endorsed(&k1, &k2));
+        keys(&mut index, "acme").push(endorsed(&k2, &k3));
+        let (p1, p2, p3) = (k1.public_base64(), k2.public_base64(), k3.public_base64());
+        assert!(index.succeeds("acme", &p1, &p1));
+        assert!(index.succeeds("acme", &p1, &p3), "through k2");
+        assert!(!index.succeeds("acme", &p3, &p1), "not backwards");
+        assert!(!index.succeeds("other", &p1, &p2));
+        // An endorsement for another publisher, or by a revoked key, doesn't count.
+        let mut foreign = index.clone();
+        keys(&mut foreign, "acme")[1].endorsement = Some(k1.endorse("evil", &p2));
+        assert!(!foreign.succeeds("acme", &p1, &p2));
+        let mut stolen = index.clone();
+        keys(&mut stolen, "acme")[0].revoked = true;
+        assert!(!stolen.succeeds("acme", &p1, &p2));
+
+        let sig = |key: &PublisherKey| key.sign("acme", "acme.tools", "1.0.0", "d");
+        assert!(signer_continues(Some(&index), Some(&sig(&k1)), Some(&sig(&k3))));
+        assert!(signer_continues(None, Some(&sig(&k1)), Some(&sig(&k1))));
+        assert!(!signer_continues(None, Some(&sig(&k1)), Some(&sig(&k2))), "no index to vouch");
+        let stranger = PublisherKey::from_seed([4; 32]);
+        assert!(!signer_continues(Some(&index), Some(&sig(&k1)), Some(&sig(&stranger))));
+        assert!(!signer_continues(Some(&index), Some(&sig(&k1)), None), "signed, then unsigned");
+        assert!(signer_continues(Some(&index), None, Some(&sig(&stranger))), "unsigned pins nothing");
+    }
+
+    #[test]
+    fn pinned_publishers_keep_their_built_in_keys() {
+        let (root, next, intruder) =
+            (PublisherKey::from_seed([1; 32]), PublisherKey::from_seed([2; 32]), PublisherKey::from_seed([5; 32]));
+        let mut index = index(&intruder);
+        index.publishers[0].id = "openidea".into();
+        keys(&mut index, "openidea").push(KeyEntry {
+            endorsement: Some(root.endorse("openidea", &next.public_base64())),
+            ..KeyEntry::new(next.public_base64())
+        });
+        let roots = [root.public_base64()];
+        let listed = |index: &Index| -> Vec<(String, bool)> {
+            let mut index = index.clone();
+            index.pin_publisher("openidea", "OpenIDEA", &roots);
+            keys(&mut index, "openidea").iter().map(|k| (k.key.clone(), k.revoked)).collect()
+        };
+        // The intruder's key goes, the successor the root endorsed stays, the root is added.
+        assert_eq!(listed(&index), [(next.public_base64(), false), (root.public_base64(), false)]);
+        let mut pinned = index.clone();
+        pinned.pin_publisher("openidea", "OpenIDEA", &roots);
+        let digest = "d";
+        let signed = |k: &PublisherKey| k.sign("openidea", "openidea.tools", "1.0.0", digest);
+        assert!(pinned.verify(&signed(&intruder), "openidea.tools", "1.0.0", digest).is_err());
+        assert!(pinned.verify(&signed(&next), "openidea.tools", "1.0.0", digest).is_ok());
+        // A revoked root stays revoked, and what it endorsed is no longer trusted.
+        keys(&mut index, "openidea").push(KeyEntry { revoked: true, ..KeyEntry::new(root.public_base64()) });
+        assert_eq!(listed(&index), [(root.public_base64(), true)]);
+
+        // A publisher missing from the index is added with its roots.
+        let mut empty = Index { format: INDEX_FORMAT, ..Index::default() };
+        empty.pin_publisher("openidea", "OpenIDEA", &[root.public_base64()]);
+        assert_eq!(empty.verify(&signed(&root), "openidea.tools", "1.0.0", digest).unwrap(), "openidea");
+        // No roots: the index decides.
+        let mut open = index.clone();
+        open.pin_publisher("openidea", "OpenIDEA", &[]);
+        assert_eq!(open, index);
+    }
+}

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/src/lib.rs

@@ -21,6 +21,18 @@ pub struct FontFamily {
     pub monospaced: bool,
 }
 
+/// PANOSE bProportion value 9 means "Monospaced"; DirectWrite's
+/// `IsMonospacedFont` alone misses fonts that only carry this classification.
+const PANOSE_MONOSPACED: u8 = 9;
+
+/// One face counts as monospaced when the font system flags it fixed pitch, its
+/// PANOSE proportion is "Monospaced", or its glyph advances are uniform
+/// (fonts with wrong/missing metadata, e.g. bitmap-style TTFs).
+#[cfg_attr(not(windows), allow(dead_code))]
+fn face_is_mono(is_monospaced_font: bool, panose_proportion: u8, advances_equal: bool) -> bool {
+    is_monospaced_font || panose_proportion == PANOSE_MONOSPACED || advances_equal
+}
+
 type Cache = Mutex<Option<Arc<[FontFamily]>>>;
 
 /// The installed families, sorted case-insensitively, read on first use and
@@ -195,7 +207,9 @@ mod imp {
         // 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 Some(descriptors) = collection.matching_font_descriptors() else {
+                return Vec::new();
+            };
             let mut seen = std::collections::BTreeSet::new();
             descriptors
                 .cast_unchecked::<CTFontDescriptor>()
@@ -271,14 +285,16 @@ mod imp {
 
 #[cfg(windows)]
 mod imp {
+    use std::os::windows::ffi::OsStrExt;
+    use windows::Win32::Graphics::DirectWrite::IDWriteFontFace1;
     use windows::Win32::Graphics::DirectWrite::{
-        DWRITE_FACTORY_TYPE_SHARED, DWRITE_FONT_STRETCH_NORMAL, DWRITE_FONT_STYLE_NORMAL, DWRITE_FONT_WEIGHT_NORMAL,
-        DWriteCreateFactory, IDWriteFactory, IDWriteFont1, IDWriteLocalizedStrings,
+        DWRITE_FACTORY_TYPE_SHARED, DWriteCreateFactory, IDWriteFactory, IDWriteFactory3, IDWriteFactory5, IDWriteFont,
+        IDWriteFont1, IDWriteFontCollection, IDWriteFontFamily, IDWriteLocalizedStrings,
     };
-    use windows::core::{BOOL, Interface, w};
+    use windows::core::{BOOL, Interface, PCWSTR, w};
 
-    /// The system font collection's families, named in English when the
-    /// family has an English name (what CSS matches), else its first name.
+    /// The installed families, named in English when the family has an
+    /// English name (what CSS matches), else its first name.
     pub(crate) fn list(refresh: bool) -> Vec<(String, bool)> {
         // SAFETY: plain DirectWrite COM calls on interfaces we own.
         unsafe { read(refresh) }.unwrap_or_default()
@@ -286,11 +302,85 @@ mod imp {
 
     unsafe fn read(refresh: bool) -> windows::core::Result<Vec<(String, bool)>> {
         let factory: IDWriteFactory = unsafe { DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED) }?;
+        let mut faces = Vec::new();
+        // Windows 10+: the newer collection covers registered per-user fonts.
+        // Exclude downloadable fonts that are not installed on this machine.
+        // Bitmap .FON fonts (e.g. the stock raster Fixedsys) are invisible to
+        // DirectWrite either way: it only reads TrueType/OpenType files.
         let mut collection = None;
-        unsafe { factory.GetSystemFontCollection(&mut collection, refresh) }?;
-        let Some(collection) = collection else {
-            return Ok(Vec::new());
+        if let Ok(factory3) = factory.cast::<IDWriteFactory3>() {
+            let mut local = None;
+            if unsafe { factory3.GetSystemFontCollection(false, &mut local, refresh) }.is_ok() {
+                collection = local.map(Into::into);
+            }
+        }
+        if collection.is_none() {
+            unsafe { factory.GetSystemFontCollection(&mut collection, refresh) }?;
+        }
+        if let Some(collection) = collection {
+            faces.extend(collect(&collection));
+        }
+        // DirectWrite enumerates via the font registry, so font files copied
+        // into the per-user directory without registering (no HKCU entry)
+        // are invisible to the calls above; scan the directory directly.
+        faces.extend(unsafe { user_dir_faces(&factory) });
+        Ok(faces)
+    }
+
+    /// Families from `%LOCALAPPDATA%\Microsoft\Windows\Fonts` files, registered
+    /// or not, via a font set built from the files on disk.
+    unsafe fn user_dir_faces(factory: &IDWriteFactory) -> Vec<(String, bool)> {
+        let Some(local_app_data) = std::env::var_os("LOCALAPPDATA") else {
+            return Vec::new();
         };
+        let dir = std::path::Path::new(&local_app_data).join(r"Microsoft\Windows\Fonts");
+        let Ok(entries) = std::fs::read_dir(&dir) else {
+            return Vec::new();
+        };
+        let files: Vec<_> = entries
+            .filter_map(|e| e.ok())
+            .map(|e| e.path())
+            .filter(|p| {
+                matches!(
+                    p.extension().and_then(|e| e.to_str()).map(|e| e.to_ascii_lowercase()).as_deref(),
+                    Some("ttf" | "otf" | "ttc" | "otc")
+                )
+            })
+            .collect();
+        unsafe { file_faces(factory, &files) }
+    }
+
+    unsafe fn file_faces(factory: &IDWriteFactory, files: &[std::path::PathBuf]) -> Vec<(String, bool)> {
+        if files.is_empty() {
+            return Vec::new();
+        }
+        let Ok(factory3) = factory.cast::<IDWriteFactory3>() else {
+            return Vec::new();
+        };
+        let Ok(factory5) = factory.cast::<IDWriteFactory5>() else {
+            return Vec::new();
+        };
+        let Ok(builder) = (unsafe { factory5.CreateFontSetBuilder() }) else {
+            return Vec::new();
+        };
+        for path in files {
+            let wide: Vec<u16> = path.as_os_str().encode_wide().chain(Some(0)).collect();
+            // SAFETY: wide is a valid NUL-terminated string for the calls.
+            let Ok(file) = (unsafe { factory.CreateFontFileReference(PCWSTR(wide.as_ptr()), None) }) else {
+                continue;
+            };
+            let _ = unsafe { builder.AddFontFile(&file) };
+        }
+        let Ok(set) = (unsafe { builder.CreateFontSet() }) else {
+            return Vec::new();
+        };
+        let Ok(collection) = (unsafe { factory3.CreateFontCollectionFromFontSet(&set) }) else {
+            return Vec::new();
+        };
+        collect(&collection)
+    }
+
+    fn collect(collection: &IDWriteFontCollection) -> Vec<(String, bool)> {
         let mut out = Vec::new();
         for i in 0..unsafe { collection.GetFontFamilyCount() } {
             let Ok(family) = (unsafe { collection.GetFontFamily(i) }) else {
@@ -299,19 +389,120 @@ mod imp {
             let Some(name) = unsafe { family.GetFamilyNames() }.ok().and_then(|n| unsafe { english(&n) }) else {
                 continue;
             };
-            let mono = unsafe {
-                family.GetFirstMatchingFont(
-                    DWRITE_FONT_WEIGHT_NORMAL,
-                    DWRITE_FONT_STRETCH_NORMAL,
-                    DWRITE_FONT_STYLE_NORMAL,
-                )
-            }
-            .ok()
-            .and_then(|f| f.cast::<IDWriteFont1>().ok())
-            .is_some_and(|f| unsafe { f.IsMonospacedFont() }.as_bool());
-            out.push((name, mono));
+            out.push((name, unsafe { family_is_mono(&family) }));
+        }
+        out
+    }
+
+    /// A family is monospaced when any face reports fixed pitch, PANOSE
+    /// proportion 9, or uniform glyph advances; probing every face matches
+    /// `normalize`'s any-face merge (macOS and Linux already flag every face,
+    /// not just the regular one).
+    unsafe fn family_is_mono(family: &IDWriteFontFamily) -> bool {
+        (0..unsafe { family.GetFontCount() }).any(|i| {
+            let Ok(font) = (unsafe { family.GetFont(i) }) else {
+                return false;
+            };
+            if let Ok(font1) = font.cast::<IDWriteFont1>() {
+                let is_monospaced = unsafe { font1.IsMonospacedFont() }.as_bool();
+                // The proportion byte is defined for text/display fonts only.
+                let panose = unsafe { font1.GetPanose().values };
+                let panose_proportion = if panose[0] == 2 { panose[3] } else { 0 };
+                if super::face_is_mono(is_monospaced, panose_proportion, false) {
+                    return true;
+                }
+            }
+            unsafe { advances_equal(&font) }
+        })
+    }
+
+    /// Some monospaced fonts carry no fixed-pitch metadata at all (bitmap-style
+    /// TTFs like Fixedsys Excelsior): compare the advance widths of 'i' and
+    /// 'W'. Dual-width CJK monospace fonts pass too (both half-width).
+    unsafe fn advances_equal(font: &IDWriteFont) -> bool {
+        let Ok(face) = (unsafe { font.CreateFontFace() }) else {
+            return false;
+        };
+        let Ok(face1) = face.cast::<IDWriteFontFace1>() else {
+            return false;
+        };
+        let codepoints = ['i' as u32, 'W' as u32];
+        let mut indices = [0u16; 2];
+        if unsafe { face.GetGlyphIndices(codepoints.as_ptr(), 2, indices.as_mut_ptr()) }.is_err()
+            || indices.contains(&0)
+        {
+            return false;
+        }
+        let mut advances = [0i32; 2];
+        unsafe { face1.GetDesignGlyphAdvances(2, indices.as_ptr(), advances.as_mut_ptr(), false) }.is_ok()
+            && advances[0] > 0
+            && advances[0] == advances[1]
+    }
+
+    #[test]
+    fn glyph_probe_distinguishes_monospace_proportional_and_symbol_fonts() {
+        unsafe {
+            let factory: IDWriteFactory = DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED).unwrap();
+            let mut collection = None;
+            factory.GetSystemFontCollection(&mut collection, false).unwrap();
+            let collection = collection.unwrap();
+            for (name, expected) in [
+                ("Consolas", true),
+                ("Arial", false),
+                ("Times New Roman", false),
+                ("Wingdings", false),
+                ("Webdings", false),
+                ("Segoe MDL2 Assets", false),
+            ] {
+                let wide: Vec<_> = name.encode_utf16().chain(Some(0)).collect();
+                let mut index = 0;
+                let mut exists = BOOL(0);
+                collection.FindFamilyName(PCWSTR(wide.as_ptr()), &mut index, &mut exists).unwrap();
+                assert!(exists.as_bool(), "{name} ships with Windows");
+                let family = collection.GetFontFamily(index).unwrap();
+                for i in 0..family.GetFontCount() {
+                    let font = family.GetFont(i).unwrap();
+                    assert_eq!(advances_equal(&font), expected, "{name} face {i}");
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn font_files_include_every_family_in_a_collection() {
+        let path = std::path::PathBuf::from(std::env::var_os("WINDIR").unwrap()).join(r"Fonts\cambria.ttc");
+        unsafe {
+            let factory: IDWriteFactory = DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED).unwrap();
+            let faces = file_faces(&factory, &[path]);
+            for name in ["Cambria", "Cambria Math"] {
+                assert!(faces.iter().any(|(family, _)| family == name), "missing {name}: {faces:?}");
+            }
+        }
+    }
+
+    #[test]
+    fn excludes_families_available_only_as_downloads() {
+        use windows::Win32::Graphics::DirectWrite::{DWRITE_E_REMOTEFONT, DWRITE_LOCALITY_LOCAL, IDWriteFont3};
+
+        unsafe {
+            let factory: IDWriteFactory = DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED).unwrap();
+            let factory3: IDWriteFactory3 = factory.cast().unwrap();
+            let set = factory3.GetSystemFontSet().unwrap();
+            let collection = factory3.CreateFontCollectionFromFontSet(&set).unwrap();
+            let listed = super::normalize(read(false).unwrap());
+            let user = super::normalize(user_dir_faces(&factory));
+            for i in 0..collection.GetFontFamilyCount() {
+                let family = collection.GetFontFamily(i).unwrap();
+                let name = english(&family.GetFamilyNames().unwrap()).unwrap();
+                let remote_only = (0..family.GetFontCount()).all(|j| match family.GetFont(j) {
+                    Ok(font) => font.cast::<IDWriteFont3>().unwrap().GetLocality() != DWRITE_LOCALITY_LOCAL,
+                    Err(error) => error.code() == DWRITE_E_REMOTEFONT,
+                });
+                if remote_only && !user.iter().any(|f| f.name == name) {
+                    assert!(!listed.iter().any(|f| f.name == name), "{name} is not installed locally");
+                }
+            }
         }
-        Ok(out)
     }
 
     unsafe fn english(names: &IDWriteLocalizedStrings) -> Option<String> {
@@ -476,6 +667,15 @@ mod tests {
         );
     }
 
+    #[test]
+    fn panose_monospaced_proportion_counts_as_mono() {
+        assert!(face_is_mono(true, 0, false));
+        assert!(face_is_mono(false, PANOSE_MONOSPACED, false));
+        assert!(face_is_mono(false, 0, true));
+        assert!(!face_is_mono(false, 0, false));
+        assert!(!face_is_mono(false, 3, false));
+    }
+
     #[test]
     fn fc_list_spacing_marks_monospace() {
         let out = "DejaVu Sans Mono\t100\nDejaVu Sans\t\nNoto Sans Mono CJK SC\t90\nTerminus\t110\nCantarell\nFira\\-Code\tmono\n\t100\n";

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/account.rs

@@ -0,0 +1,145 @@
+//! The signed-in GitHub account, independent of any project: its repositories for
+//! "Get from Version Control" › GitHub.
+
+use crate::{GhAvailability, QUICK, classify_failure, command, gh_executable, process};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+
+/// A repository of the signed-in account (owned, collaborator, or organization member).
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct GhAccountRepo {
+    /// `owner/name`.
+    pub name_with_owner: String,
+    pub description: Option<String>,
+    pub private: bool,
+    pub fork: bool,
+    pub archived: bool,
+    /// What `git clone` takes: HTTPS, or SSH when gh's `git_protocol` is `ssh`.
+    pub clone_url: String,
+}
+
+/// The account's repositories, or why they can't be listed.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase", tag = "kind")]
+pub enum GhAccountRepos {
+    Ready {
+        login: String,
+        repos: Vec<GhAccountRepo>,
+    },
+    /// No `gh` executable was found.
+    NotInstalled,
+    /// `gh auth login` has not been run (or the token expired).
+    NotLoggedIn {
+        message: String,
+    },
+    Error {
+        message: String,
+    },
+}
+
+#[derive(Deserialize)]
+struct RestRepo {
+    full_name: String,
+    description: Option<String>,
+    #[serde(default)]
+    private: bool,
+    #[serde(default)]
+    fork: bool,
+    #[serde(default)]
+    archived: bool,
+    clone_url: String,
+    ssh_url: String,
+}
+
+/// `gh api --paginate --slurp user/repos` output: one array per page.
+pub fn parse_account_repos(slurped: &str, ssh: bool) -> Result<Vec<GhAccountRepo>, serde_json::Error> {
+    let pages: Vec<Vec<RestRepo>> = serde_json::from_str(slurped)?;
+    Ok(pages
+        .into_iter()
+        .flatten()
+        .map(|r| GhAccountRepo {
+            name_with_owner: r.full_name,
+            description: r.description.filter(|d| !d.trim().is_empty()),
+            private: r.private,
+            fork: r.fork,
+            archived: r.archived,
+            clone_url: if ssh { r.ssh_url } else { r.clone_url },
+        })
+        .collect())
+}
+
+/// Lists the repositories of the account gh is signed in to, most recently pushed first.
+pub fn account_repositories() -> GhAccountRepos {
+    if gh_executable().is_none() {
+        return GhAccountRepos::NotInstalled;
+    }
+    let dir = std::env::temp_dir();
+    let gh = |args: &[&str]| -> Result<String, GhAccountRepos> {
+        let out = command(&dir, args)
+            .and_then(|cmd| process::run(cmd, QUICK, None))
+            .map_err(|e| GhAccountRepos::Error { message: e.message })?;
+        if out.success {
+            return Ok(out.stdout);
+        }
+        let message = if out.stderr.trim().is_empty() { out.stdout } else { out.stderr };
+        Err(match classify_failure(&message) {
+            GhAvailability::NotLoggedIn { message } => GhAccountRepos::NotLoggedIn { message },
+            _ => GhAccountRepos::Error { message: message.trim().to_owned() },
+        })
+    };
+    let result = (|| {
+        let login = gh(&["api", "user", "--jq", ".login"])?.trim().to_owned();
+        let ssh = gh(&["config", "get", "git_protocol", "--host", "github.com"]).is_ok_and(|p| p.trim() == "ssh");
+        let pages = gh(&[
+            "api",
+            "user/repos?per_page=100&sort=pushed&affiliation=owner,collaborator,organization_member",
+            "--paginate",
+            "--slurp",
+        ])?;
+        let repos = parse_account_repos(&pages, ssh)
+            .map_err(|e| GhAccountRepos::Error { message: format!("unexpected gh output: {e}") })?;
+        Ok(GhAccountRepos::Ready { login, repos })
+    })();
+    result.unwrap_or_else(|e| e)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn reads_every_page_and_picks_the_configured_protocol() {
+        let pages = r#"[
+          [{"full_name":"me/app","description":"An app","private":true,"fork":false,"archived":false,
+            "clone_url":"https://github.com/me/app.git","ssh_url":"[email protected]:me/app.git"}],
+          [{"full_name":"org/lib","description":"","fork":true,
+            "clone_url":"https://github.com/org/lib.git","ssh_url":"[email protected]:org/lib.git"}]
+        ]"#;
+        let https = parse_account_repos(pages, false).unwrap();
+        assert_eq!(
+            https,
+            vec![
+                GhAccountRepo {
+                    name_with_owner: "me/app".into(),
+                    description: Some("An app".into()),
+                    private: true,
+                    fork: false,
+                    archived: false,
+                    clone_url: "https://github.com/me/app.git".into(),
+                },
+                GhAccountRepo {
+                    name_with_owner: "org/lib".into(),
+                    description: None,
+                    private: false,
+                    fork: true,
+                    archived: false,
+                    clone_url: "https://github.com/org/lib.git".into(),
+                },
+            ]
+        );
+        let ssh = parse_account_repos(pages, true).unwrap();
+        assert_eq!(ssh[1].clone_url, "[email protected]:org/lib.git");
+        assert!(parse_account_repos("[]", false).unwrap().is_empty());
+    }
+}

crates/ide-github/src/lib.rs

@@ -3,9 +3,11 @@
 //!
 //! Every function blocks; callers run them off the UI / command threads.
 
+mod account;
 mod model;
 mod process;
 
+pub use account::{GhAccountRepo, GhAccountRepos, account_repositories, parse_account_repos};
 pub use model::*;
 
 use ide_core::{CancellationToken, IdeError, IdeResult};

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();
@@ -92,11 +74,11 @@ 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("gh did not respond in time"));
         }
         std::thread::sleep(Duration::from_millis(10));
@@ -170,7 +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)) {
@@ -193,7 +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-host/Cargo.toml

@@ -14,6 +14,7 @@ encoding_rs.workspace = true
 ide-core.workspace = true
 ide-text.workspace = true
 ide-vfs.workspace = true
+regex-syntax.workspace = true
 ide-workspace.workspace = true
 ide-language.workspace = true
 ide-index.workspace = true
@@ -30,15 +31,25 @@ 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" }
+ide-docker = { path = "../ide-docker" }
+semver = "1"
 serde.workspace = true
 serde_json.workspace = true
+toml.workspace = true
 specta.workspace = true
 specta-typescript.workspace = true
 tokio = { workspace = true, features = ["io-std"] }
@@ -49,6 +60,20 @@ dunce.workspace = true
 dirs.workspace = true
 uuid.workspace = true
 tempfile.workspace = true
+zip.workspace = true
+quick-xml = "0.42"
 
 [dev-dependencies]
+ide-ssh = { workspace = true, features = ["testing"] }
 tokio = { workspace = true, features = ["rt-multi-thread", "macros", "io-util", "test-util"] }
+criterion = { version = "0.5", default-features = false }
+
+[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 +1,988 @@
+//! `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|package]     # 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 endorse <new-public-key> --key OLD --publisher ID   # vouch for a new key
+//! openidea-plugin pack [dir] [--key F --publisher ID] [--out FILE]   # <id>-<version>.oiplugin
+//! openidea-plugin index <dir> [--publisher ID --name NAME --key F [--previous-key F]]   # marketplace index.json
+//! openidea-plugin merge <index> <other-index> --keep ID               # list another index's publishers
+//! ```
+//!
+//! `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, read_market_url, resolve_market_href};
+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. A Rust
+        plugin depends on the SDK of this tool's release (git); --sdk PATH uses a
+        local sdk/rust/openidea-plugin instead
+  build [dir] [--debug]   compile a Rust plugin to dist/plugin.wasm and check it
+  check [dir|package]     validate the package (folder or .oiplugin) 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)
+  endorse <new-public-key> --key F --publisher ID
+                          print an earlier key's endorsement of a new one (JSON), for an
+                          index the publisher doesn't write with `index --previous-key`
+  pack [dir] [--key F --publisher ID] [--out FILE]
+                          write <id>-<version>.oiplugin, signed with the key
+  index <dir> [--publisher ID --name NAME --key F [--previous-key F]] [--out FILE]
+        [--download-base URL]
+                          write the marketplace index.json for the packages in dir: with a
+                          key, register it and list that publisher's plugins (earlier
+                          versions stay for older IDEs); without, list only these packages,
+                          each checked against the index's publishers. A new key replacing
+                          an earlier one is endorsed with --previous-key, so installed
+                          plugins update to it without asking
+  merge <index> <other-index> --keep ID [--out FILE]
+                          replace every publisher but ID in index with those of other-index
+                          (a path or URL), their plugins and revocations
+
+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_path(&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("endorse") => cmd_endorse(&args[1..]),
+        Some("pack") => cmd_pack(&args[1..]),
+        Some("index") => cmd_index(&args[1..]),
+        Some("merge") => cmd_merge(&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_dependency(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 written into a new plugin's Cargo.toml: by path with `--sdk`, or
+/// when the plugin is inside the source tree this tool was built from; otherwise the
+/// repository at this tool's release tag.
+fn sdk_dependency(explicit: Option<&str>, plugin_dir: &Path) -> Result<String, String> {
+    let sdk = match explicit {
+        Some(p) => PathBuf::from(p),
+        None => match dunce::canonicalize(concat!(env!("CARGO_MANIFEST_DIR"), "/../..")) {
+            Ok(tree) if plugin_dir.starts_with(&tree) => tree.join("sdk/rust/openidea-plugin"),
+            _ => return Ok(format!("{{ git = \"{REPOSITORY}\", tag = \"v{}\" }}", env!("CARGO_PKG_VERSION"))),
+        },
+    };
+    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(format!("{{ path = \"{}\" }}", path.to_string_lossy().replace('\\', "/")))
+}
+
+const REPOSITORY: &str = "https://github.com/l0ng-ai/openidea";
+
+/// `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.
+/// [`check`] of a folder, or of a package file unpacked as installing would.
+fn check_path(path: &Path) -> Result<(), String> {
+    if !path.is_file() {
+        return check(path);
+    }
+    let tmp = scratch_dir("unpack")?;
+    let dir = tmp.path().join("package");
+    package::unpack(path, &dir).and_then(|_| check(&dir))
+}
+
+fn check(dir: &Path) -> Result<(), String> {
+    let dir = canonical(dir)?;
+    let tmp = scratch_dir("check")?;
+    let scratch = tmp.path().join("host");
+    (|| {
+        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)");
+        }
+        println!("  categories: {}", manifest.categories().join(", "));
+        for c in manifest.unknown_categories() {
+            println!("  warning: unknown category {c:?} (ignored); use {}", ide_extension::CATEGORIES.join(", "));
+        }
+        if manifest.declared_categories.len() > ide_extension::MAX_CATEGORIES {
+            println!(
+                "  warning: only the first {} known categories are used; {} are declared",
+                ide_extension::MAX_CATEGORIES,
+                manifest.declared_categories.len()
+            );
+        }
+        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(())
+    })()
+}
+
+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(())
+}
+
+fn cmd_endorse(args: &[String]) -> Result<(), String> {
+    let a = Args::parse(args, &[], &["key", "publisher"])?;
+    let usage = "usage: openidea-plugin endorse <new-public-key> --key <earlier-key-file> --publisher ID";
+    let ([new], Some(key), Some(publisher)) = (a.positional.as_slice(), a.value("key"), a.value("publisher")) else {
+        return Err(usage.into());
+    };
+    if !package::publisher_id_ok(publisher) {
+        return Err(format!("invalid publisher id {publisher:?}"));
+    }
+    let endorsement = read_key(key)?.endorse(publisher, new.trim());
+    println!("{}", serde_json::to_string_pretty(&endorsement).map_err(|e| e.to_string())?);
+    Ok(())
+}
+
+/// A fresh scratch directory, removed when dropped.
+fn scratch_dir(what: &str) -> Result<tempfile::TempDir, String> {
+    tempfile::Builder::new().prefix(&format!("openidea-plugin-{what}-")).tempdir().map_err(|e| e.to_string())
+}
+
+/// 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 tmp = scratch_dir("host")?;
+    PluginHost::new(tmp.path().join("host"), Arc::new(|_: Option<&str>, _| {}), Limits::default())
+        .map_err(|e| e.to_string())
+        .and_then(|h| f(&h))
+}
+
+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", "previous-key", "out", "download-base"])?;
+    let dir = canonical(&a.dir()?)?;
+    let out = a.value("out").map(PathBuf::from).unwrap_or_else(|| dir.join("index.json"));
+    let base = a.value("download-base").map(|b| b.trim_end_matches('/'));
+    // Revocations and other publishers of an existing index are kept.
+    let mut index = match std::fs::read_to_string(&out) {
+        Ok(text) => current_format(Index::parse(&text)?, &out.to_string_lossy())?,
+        Err(_) => Index { format: package::INDEX_FORMAT, ..Index::default() },
+    };
+    let publisher = match (a.value("publisher"), a.value("key")) {
+        (Some(publisher), Some(key)) => {
+            let key = read_key(key)?;
+            let name = a.value("name").unwrap_or(publisher);
+            let previous = a.value("previous-key").map(read_key).transpose()?;
+            index.publishers =
+                register_key(std::mem::take(&mut index.publishers), publisher, name, &key, previous.as_ref())?;
+            Some(publisher)
+        }
+        (None, None) if a.has("previous-key") => return Err("--previous-key goes with --publisher and --key".into()),
+        (None, None) => None,
+        _ => return Err("--publisher and --key go together".into()),
+    };
+    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();
+    let engine = PluginEngine::new()?;
+    let mut added: Vec<IndexEntry> = Vec::new();
+    for path in packages {
+        let tmp = scratch_dir("index")?;
+        let scratch = tmp.path().join("package");
+        let entry = (|| {
+            let unpacked = package::unpack(&path, &scratch)?;
+            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("not signed")?;
+            let signer = index.verify(sig, &m.id, &m.version, &digest)?;
+            if publisher.is_some_and(|p| p != signer) {
+                return Err(format!("signed by {signer}, not {}", publisher.unwrap_or_default()));
+            }
+            if added.iter().any(|e| (&e.id, &e.version) == (&m.id, &m.version)) {
+                return Err(format!("another package of {} {} is in the folder", m.id, m.version));
+            }
+            if m.legacy {
+                return Err("plugin.toml uses the 0.1 format; see plugins/README.md".into());
+            }
+            let built_for = match &m.wasm {
+                Some(wasm) => engine.check_component(&engine.compile(&scratch.join(wasm))?)?,
+                None => None,
+            };
+            let file = path.file_name().map(|n| n.to_string_lossy().into_owned()).unwrap_or_default();
+            Ok::<_, String>(IndexEntry {
+                id: m.id.clone(),
+                name: m.name.clone(),
+                version: m.version.clone(),
+                description: m.description.clone(),
+                authors: m.authors.clone(),
+                publisher: signer,
+                download: base.map_or_else(|| file.clone(), |b| format!("{b}/{file}")),
+                digest,
+                capabilities: m.capabilities.all().map(|c| c.to_string()).collect(),
+                engine: package::engine_requirement(&m.engine, built_for.as_ref()),
+                categories: m.categories(),
+            })
+        })();
+        let entry = entry.map_err(|e| format!("{}: {e}", path.display()))?;
+        println!("  {} {} (plugin API {})", entry.id, entry.version, entry.engine);
+        added.push(entry);
+    }
+    // A publisher's earlier versions of these plugins stay for IDEs that can't load the new
+    // ones (pruned below); plugins no longer in the folder go.
+    index.plugins.retain(|e| match publisher {
+        Some(p) => {
+            e.publisher != p
+                || (added.iter().any(|n| n.id == e.id)
+                    && !added.iter().any(|n| (&n.id, &n.version) == (&e.id, &e.version)))
+        }
+        None => false,
+    });
+    index.plugins.extend(added);
+    index.prune_versions();
+    write_index(&index, &out)
+}
+
+/// `publishers` with `key` as `publisher`'s current key. Earlier keys stay listed
+/// (packages they signed remain valid until revoked); a key new to the
+/// publisher is endorsed by `previous`, one of them, so installed plugins
+/// signed with it update without asking.
+fn register_key(
+    mut publishers: Vec<package::Publisher>,
+    publisher: &str,
+    name: &str,
+    key: &PublisherKey,
+    previous: Option<&PublisherKey>,
+) -> Result<Vec<package::Publisher>, String> {
+    let current = key.public_base64();
+    let earlier: Vec<KeyEntry> = publishers.iter().filter(|p| p.id == publisher).flat_map(|p| p.keys.clone()).collect();
+    let entry = match earlier.iter().find(|k| k.key == current) {
+        Some(listed) => listed.clone(),
+        None => {
+            let endorsement = match previous {
+                Some(prev) => {
+                    let prev_key = prev.public_base64();
+                    if !earlier.iter().any(|k| k.key == prev_key && !k.revoked) {
+                        return Err(format!("--previous-key is not one of {publisher}'s valid keys in the index"));
+                    }
+                    Some(prev.endorse(publisher, &current))
+                }
+                None => {
+                    if earlier.iter().any(|k| !k.revoked) {
+                        println!(
+                            "  warning: {publisher}'s new key is not endorsed (--previous-key): users who installed \
+                             its plugins will be asked to confirm the change when they update"
+                        );
+                    }
+                    None
+                }
+            };
+            KeyEntry { endorsement, ..KeyEntry::new(current.clone()) }
+        }
+    };
+    let keys = std::iter::once(entry).chain(earlier.into_iter().filter(|k| k.key != current)).collect();
+    publishers.retain(|p| p.id != publisher);
+    publishers.push(package::Publisher { id: publisher.into(), name: name.into(), keys });
+    Ok(publishers)
+}
+
+/// `index`, unless a newer `openidea-plugin` wrote it (rewriting it would drop what this one can't read).
+fn current_format(index: Index, file: &str) -> Result<Index, String> {
+    if index.is_newer() {
+        return Err(format!(
+            "{file}: index format {} is newer than this tool writes; update openidea-plugin",
+            index.format
+        ));
+    }
+    Ok(index)
+}
+
+fn cmd_merge(args: &[String]) -> Result<(), String> {
+    let a = Args::parse(args, &[], &["keep", "out"])?;
+    let [base, other] = a.positional.as_slice() else {
+        return Err("usage: openidea-plugin merge <index> <other-index> --keep ID [--out FILE]".into());
+    };
+    let keep = a.value("keep").ok_or("--keep is required")?;
+    let out = a.value("out").unwrap_or(base);
+    let mut index =
+        current_format(Index::parse(&std::fs::read_to_string(base).map_err(|e| format!("{base}: {e}"))?)?, base)?;
+    let bytes = read_market_url(other, 16 << 20)?;
+    let theirs = Index::parse(&String::from_utf8(bytes).map_err(|_| format!("{other}: not UTF-8"))?)?;
+    let mut theirs = current_format(theirs, other)?;
+    // Their downloads are relative to their index, not to ours.
+    for e in &mut theirs.plugins {
+        e.download = resolve_market_href(other, &e.download);
+    }
+    let count = theirs.plugins.len();
+    index.include(theirs, &[keep]).map_err(|e| format!("{other}: {e}"))?;
+    println!("  {count} plugins from {other}");
+    write_index(&index, Path::new(out))
+}
+
+fn write_index(index: &Index, out: &Path) -> Result<(), String> {
+    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 a_new_key_is_endorsed_by_the_previous_one() {
+        let (k1, k2, k3) =
+            (PublisherKey::from_seed([1; 32]), PublisherKey::from_seed([2; 32]), PublisherKey::from_seed([3; 32]));
+        let first = register_key(Vec::new(), "acme", "ACME", &k1, None).unwrap();
+        let rotated = register_key(first.clone(), "acme", "ACME", &k2, Some(&k1)).unwrap();
+        let index = Index { format: package::INDEX_FORMAT, publishers: rotated.clone(), ..Index::default() };
+        assert!(index.succeeds("acme", &k1.public_base64(), &k2.public_base64()));
+        assert_eq!(rotated[0].keys.len(), 2, "the earlier key stays listed");
+        // Registering the current key again keeps its endorsement.
+        let again = register_key(rotated.clone(), "acme", "ACME", &k2, None).unwrap();
+        assert_eq!(again, rotated);
+        // Only a key the publisher has can endorse.
+        assert!(register_key(first.clone(), "acme", "ACME", &k2, Some(&k3)).unwrap_err().contains("--previous-key"));
+        // Without one the new key is listed unendorsed.
+        let unendorsed = register_key(first, "acme", "ACME", &k3, None).unwrap();
+        assert!(unendorsed[0].keys[0].endorsement.is_none());
+    }
+
+    #[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 new_plugins_depend_on_the_sdk_by_path_only_in_its_source_tree() {
+        let tree = dunce::canonicalize(concat!(env!("CARGO_MANIFEST_DIR"), "/../..")).unwrap();
+        assert_eq!(
+            sdk_dependency(None, &tree.join("plugins/official/new")).unwrap(),
+            "{ path = \"../../../sdk/rust/openidea-plugin\" }"
+        );
+        let outside = dunce::canonicalize(std::env::temp_dir()).unwrap().join("my-plugin");
+        assert_eq!(
+            sdk_dependency(None, &outside).unwrap(),
+            format!("{{ git = \"https://github.com/l0ng-ai/openidea\", tag = \"v{}\" }}", env!("CARGO_PKG_VERSION"))
+        );
+        let sdk = tree.join("sdk/rust/openidea-plugin");
+        assert!(sdk_dependency(Some(sdk.to_str().unwrap()), &outside).unwrap().starts_with("{ path = "));
+        assert!(
+            sdk_dependency(Some(tree.join("wit").to_str().unwrap()), &outside)
+                .unwrap_err()
+                .contains("not the openidea-plugin SDK")
+        );
+    }
+
+    /// A theme package `id` signed by `publisher` with `key`, packed into `out`.
+    fn signed_theme(tmp: &Path, id: &str, publisher: &str, key: &str, out: &Path) {
+        signed_theme_version(tmp, id, "0.1.0", "^1.0", publisher, key, out);
+    }
+
+    fn signed_theme_version(tmp: &Path, id: &str, version: &str, engine: &str, publisher: &str, key: &str, out: &Path) {
+        let src = tmp.join("src").join(format!("{id}-{version}"));
+        let vars = templates::Vars { id, name: id, sdk: None };
+        for (rel, content) in templates::render(templates::Template::Theme, &vars) {
+            let path = src.join(rel);
+            std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+            let content = content
+                .replace("version = \"0.1.0\"", &format!("version = \"{version}\""))
+                .replace("engines.openidea = \"^1.0\"", &format!("engines.openidea = \"{engine}\""));
+            std::fs::write(path, content).unwrap();
+        }
+        std::fs::create_dir_all(out).unwrap();
+        let args = [src.to_str().unwrap(), "--key", key, "--publisher", publisher, "--out"]
+            .into_iter()
+            .map(String::from)
+            .chain([out.join(format!("{id}-{version}.oiplugin")).to_string_lossy().into_owned()])
+            .collect::<Vec<_>>();
+        cmd_pack(&args).unwrap();
+    }
+
+    #[test]
+    fn a_release_keeps_the_versions_older_ides_need() {
+        let tmp = tempfile::tempdir().unwrap();
+        let t = tmp.path();
+        let key = t.join("acme.key");
+        std::fs::write(&key, PublisherKey::from_seed([5; 32]).seed_base64()).unwrap();
+        let key = key.to_string_lossy().into_owned();
+        let index_file = t.join("index.json");
+        let release = |n: usize, packages: &[(&str, &str, &str)]| {
+            let dir = t.join(format!("release-{n}"));
+            for (id, version, engine) in packages {
+                signed_theme_version(t, id, version, engine, "acme", &key, &dir);
+            }
+            let base = format!("https://example.com/download/v{n}");
+            let args = [dir.to_str().unwrap(), "--publisher", "acme", "--key", &key, "--download-base", &base];
+            cmd_index(&strings(&[&args[..], &["--out", index_file.to_str().unwrap()]].concat())).unwrap();
+            let index = Index::parse(&std::fs::read_to_string(&index_file).unwrap()).unwrap();
+            index.plugins.iter().map(|e| format!("{} {} {}", e.id, e.version, e.download)).collect::<Vec<_>>()
+        };
+        release(1, &[("acme.a", "1.0.0", "^1.0"), ("acme.b", "1.0.0", "^1.0")]);
+        // Same requirement: the newer version replaces it; acme.b is gone from the release.
+        assert_eq!(
+            release(2, &[("acme.a", "1.1.0", "^1.0")]),
+            ["acme.a 1.1.0 https://example.com/download/v2/acme.a-1.1.0.oiplugin"]
+        );
+        // Another API requirement: the last version for the earlier one stays, where it was published.
+        assert_eq!(
+            release(3, &[("acme.a", "2.0.0", ">=1.0, <2")]),
+            [
+                "acme.a 1.1.0 https://example.com/download/v2/acme.a-1.1.0.oiplugin",
+                "acme.a 2.0.0 https://example.com/download/v3/acme.a-2.0.0.oiplugin",
+            ]
+        );
+        let index = Index::parse(&std::fs::read_to_string(&index_file).unwrap()).unwrap();
+        assert_eq!(index.offered()[0].0.version, "2.0.0", "the newest this IDE can load");
+    }
+
+    fn strings(args: &[&str]) -> Vec<String> {
+        args.iter().map(|a| a.to_string()).collect()
+    }
+
+    #[test]
+    fn official_and_community_indexes_merge() {
+        let tmp = tempfile::tempdir().unwrap();
+        let t = tmp.path();
+        let mut keys = Vec::new();
+        for (name, seed) in [("openidea", 1), ("alice", 2), ("carol", 3)] {
+            let file = t.join(format!("{name}.key"));
+            let key = PublisherKey::from_seed([seed; 32]);
+            std::fs::write(&file, key.seed_base64()).unwrap();
+            keys.push((file.to_string_lossy().into_owned(), key.public_base64()));
+        }
+        let (official, community) = (t.join("official"), t.join("community"));
+        signed_theme(t, "openidea.night", "openidea", &keys[0].0, &official);
+        signed_theme(t, "alice.dawn", "alice", &keys[1].0, &community);
+        let official_index = official.join("index.json");
+        let community_index = community.join("index.json");
+        let release = strings(&[official.to_str().unwrap(), "--publisher", "openidea", "--key", &keys[0].0]);
+        cmd_index(&release).unwrap();
+
+        // The community index lists its publishers; `index` without a key checks packages against them.
+        let skeleton = Index {
+            format: package::INDEX_FORMAT,
+            publishers: vec![package::Publisher {
+                id: "alice".into(),
+                name: "Alice".into(),
+                keys: vec![KeyEntry::new(keys[1].1.clone())],
+            }],
+            ..Index::default()
+        };
+        write_index(&skeleton, &community_index).unwrap();
+        cmd_index(&strings(&[community.to_str().unwrap()])).unwrap();
+
+        cmd_merge(&strings(&[
+            official_index.to_str().unwrap(),
+            community_index.to_str().unwrap(),
+            "--keep",
+            "openidea",
+        ]))
+        .unwrap();
+        // A release rebuilds the official plugins and keeps the community's.
+        cmd_index(&release).unwrap();
+        let index = Index::parse(&std::fs::read_to_string(&official_index).unwrap()).unwrap();
+        let listed: Vec<_> = index.plugins.iter().map(|e| (e.id.as_str(), e.publisher.as_str())).collect();
+        assert_eq!(listed, [("alice.dawn", "alice"), ("openidea.night", "openidea")]);
+        assert_eq!(index.plugins[1].categories, ["themes"], "implied by the theme");
+        assert_eq!(index.plugins[1].download, "openidea.night-0.1.0.oiplugin");
+        assert!(Path::new(&index.plugins[0].download).is_absolute(), "{}", index.plugins[0].download);
+
+        // A package by a publisher the index doesn't know is refused.
+        signed_theme(t, "carol.noon", "carol", &keys[2].0, &community);
+        let err = cmd_index(&strings(&[community.to_str().unwrap()])).unwrap_err();
+        assert!(err.contains("unknown publisher"), "{err}");
+    }
+
+    /// `cargo test` of a new Rust plugin (its own tests against the mock host) with this SDK.
+    #[test]
+    fn the_command_template_builds_against_the_sdk() {
+        let dir = std::env::temp_dir().join(format!("openidea-plugin-template-build-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+        let dir = dunce::canonicalize(&dir).unwrap();
+        let plugin = dir.join("plugin");
+        let sdk = concat!(env!("CARGO_MANIFEST_DIR"), "/../../sdk/rust/openidea-plugin");
+        let sdk = sdk_dependency(Some(sdk), &plugin).unwrap();
+        let vars = templates::Vars { id: "acme.sample", name: "Sample", sdk: Some(&sdk) };
+        for (rel, content) in templates::render(templates::Template::Command, &vars) {
+            let path = plugin.join(rel);
+            std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+            std::fs::write(path, content).unwrap();
+        }
+        // The SDK's lockfile keeps the versions its own CI builds with (the resolver also
+        // looks up the wasm-only dependencies, which may not be downloaded yet).
+        let sdk_lock = concat!(env!("CARGO_MANIFEST_DIR"), "/../../sdk/rust/openidea-plugin/Cargo.lock");
+        std::fs::copy(sdk_lock, plugin.join("Cargo.lock")).unwrap();
+        let out = Command::new(std::env::var("CARGO").unwrap_or_else(|_| "cargo".into()))
+            .args(["test", "--manifest-path"])
+            .arg(plugin.join("Cargo.toml"))
+            .env("CARGO_TARGET_DIR", dir.join("target"))
+            .output()
+            .unwrap();
+        assert!(
+            out.status.success(),
+            "{}{}",
+            String::from_utf8_lossy(&out.stdout),
+            String::from_utf8_lossy(&out.stderr)
+        );
+        std::fs::remove_dir_all(&dir).unwrap();
+    }
+
+    #[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("{ path = \"../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 +1,282 @@
+//! 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,
+    /// The SDK dependency, as a TOML value (`{ path = "…" }`).
+    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 = []
+# Marketplace categories (up to 3): languages, themes, icon-themes, linters,
+# vcs, ai, frameworks, tools, other.
+categories = ["tools"]
+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 = __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::{Error, 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>, Error> {
+        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}").into()),
+        }
+    }
+}
+
+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/formatter.rs

@@ -2,16 +2,48 @@
 
 use crate::Host;
 use ide_core::event::NotifyLevel;
-use ide_core::settings::PrettierSettings;
+use ide_core::settings::{ExternalFormatter, LanguagesSettings};
 use ide_core::{DocId, IdeError, IdeEvent, IdeResult, Range, TextEdit};
-use ide_language::FormatterConfig;
+use ide_language::LanguageConfig;
 use ide_lsp::types::FormatOptions;
 use ide_tools::{Tools, formatter};
+use std::path::Path;
 
-fn external_selected(config: Option<&FormatterConfig>, language: &str, settings: &PrettierSettings, lsp: bool) -> bool {
-    config.is_some_and(|c| c.tool == "prettier")
-        && settings.languages.iter().any(|l| l == language)
-        && (settings.prefer || !lsp)
+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(
@@ -24,36 +56,43 @@ pub async fn format(
     let project = host.project(window)?;
     let snap = project.documents.snapshot(doc)?;
     let settings = project.settings.effective();
-    let prettier = &settings.languages.prettier;
     let language = project.languages.get(&snap.language);
-    let config = language.as_ref().and_then(|l| l.formatter.as_ref());
-    let candidate =
-        config.is_some_and(|c| c.tool == "prettier") && prettier.languages.iter().any(|l| l == snap.language.as_str());
-    let lsp = if candidate && !prettier.prefer { project.lsp.can_format(doc).await? } else { false };
-    if !external_selected(config, snap.language.as_str(), prettier, lsp) {
+    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;
-    }
-    if options.on_save && !prettier.run_on_save {
+    };
+    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 = config.unwrap().clone();
-    let custom = ide_sdk::apply::setting_path(&project.root, &prettier.path);
-    let tools = Tools::new(&host.data_dir);
-    let whole_selection = range.is_some() && !config.range;
+    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(&config.tool, &snap.path, custom.as_deref())?;
-        command.current_dir(snap.path.parent().ok_or_else(|| IdeError::invalid("Prettier: file has no directory"))?);
-        command.args(formatter::arguments(&config, &snap.path, options.tab_size, options.insert_spaces, offsets));
-        let formatted = formatter::run(command, &snap.text, &Default::default())?;
+        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
@@ -69,39 +108,88 @@ pub async fn format(
     if edits.is_ok() && whole_selection {
         project.sink.emit(IdeEvent::Notify {
             level: NotifyLevel::Info,
-            title: "Prettier".into(),
-            body: Some(
-                "Prettier does not support selection formatting for this language; formatted the whole file".into(),
-            ),
+            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("prettier"))
+    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 language_enablement_and_preference_preserve_lsp_formatters() {
-        let languages = ide_language::LanguageRegistry::load(None).unwrap();
-        let mut settings = PrettierSettings::default();
-        for lang in languages.all() {
-            for lsp in [false, true] {
-                let configured = lang.formatter.as_ref().is_some_and(|f| f.tool == "prettier");
-                assert_eq!(
-                    external_selected(lang.formatter.as_ref(), lang.id.as_str(), &settings, lsp),
-                    configured && !lsp,
-                    "{}",
-                    lang.id
-                );
-            }
+    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);
         }
-        let ts = languages.get(&ide_core::LanguageId::new("typescript")).unwrap();
-        settings.prefer = true;
-        assert!(external_selected(ts.formatter.as_ref(), "typescript", &settings, true));
-        settings.languages.clear();
-        assert!(!external_selected(ts.formatter.as_ref(), "typescript", &settings, false));
-        assert!(!external_selected(None, "rust", &settings, false));
+        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/lib.rs

@@ -1,14 +1,16 @@
 //! 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;
@@ -33,7 +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>>>,
@@ -49,10 +54,14 @@ 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).
@@ -70,14 +79,24 @@ pub struct Host {
     pub runtime: tokio::runtime::Handle,
     /// One project per window, keyed by window label.
     projects: RwLock<HashMap<String, Arc<Project>>>,
+    pub(crate) external_logs: RwLock<HashMap<String, Vec<Arc<ide_vcs::Repo>>>>,
     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);
@@ -86,8 +105,11 @@ impl Host {
             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(),
@@ -96,10 +118,12 @@ impl Host {
             syntax,
             config_dir,
             data_dir,
+            local_data_dir,
             sink_for,
             owner,
             runtime,
             projects: RwLock::default(),
+            external_logs: RwLock::default(),
             requests: Default::default(),
             project_requests: RwLock::default(),
         };
@@ -112,6 +136,17 @@ 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()
@@ -145,6 +180,10 @@ impl Host {
     }
 
     pub fn close_project(&self, window: &str) {
+        self.external_logs.write().remove(self.owner_window(window));
+        for request in self.project_requests.write().remove(self.owner_window(window)).unwrap_or_default() {
+            self.cancel_request(request);
+        }
         let project = self.projects.write().remove(window);
         if let Some(project) = project {
             if !project.light {
@@ -153,14 +192,21 @@ impl Host {
             if let Some(bridge) = &project.kotlin_bridge {
                 bridge.stop();
             }
+            project.documents.clear_workspace_edit_history();
             project.agents.shutdown();
             project.notebooks.stop_admission();
+            // 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.
+            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())),
             );
-            let lsp = project.lsp.clone();
-            self.runtime.spawn(async move { lsp.shutdown_all().await });
         }
     }
 
@@ -170,6 +216,8 @@ impl Host {
         &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();
@@ -187,6 +235,12 @@ impl Host {
                     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() {
@@ -208,9 +262,18 @@ impl Host {
         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.
     /// For a process that exits without dropping the host (the remote server).
     pub async fn shutdown(&self) {
@@ -222,6 +285,7 @@ impl Host {
             if let Some(bridge) = &project.kotlin_bridge {
                 bridge.stop();
             }
+            project.documents.clear_workspace_edit_history();
             project.notebooks.stop_admission();
             project.agents.shutdown();
         }
@@ -250,14 +314,20 @@ impl Host {
     }
 
     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);
+        let token = self.begin_project_read_request(window, id);
         if self.project(window).is_ok_and(|p| !p.is_trusted()) {
             token.cancel();
         }
         token
     }
 
+    /// Read-only work remains cancellable/disposed with its window in restricted projects.
+    pub fn begin_project_read_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);
+        token
+    }
+
     pub fn end_request(&self, id: RequestId) {
         for ids in self.project_requests.write().values_mut() {
             ids.retain(|entry| *entry != id);