feat(cursor): unify tracing with existing extension plugin

.github/workflows/ci.yml

@@ -49,6 +49,11 @@ jobs:
           fi
       - name: Build and validate plugins
         run: make test
+      - name: Build Cursor extension
+        working-directory: dist/cursor
+        run: |
+          npm ci --ignore-scripts --no-audit --no-fund
+          npm run build
 
   # Pi and OpenCode run inside the user's agent process, so their unit tests
   # run on every host OS. Packaging and validation stay in `plugins`.

.github/workflows/release.yml

@@ -61,7 +61,7 @@ jobs:
             antigravity) dist_repo=braintrustdata/braintrust-antigravity-plugin ;;
             claude) dist_repo=braintrustdata/braintrust-claude-plugin ;;
             codex) dist_repo=braintrustdata/braintrust-codex-plugin ;;
-            cursor) dist_repo=braintrustdata/braintrust-cursor-plugin ;;
+            cursor) dist_repo=braintrustdata/braintrust-cursor-extension ;;
             grok) dist_repo=braintrustdata/braintrust-grok-plugin ;;
             *) echo "::error::Unsupported release plugin."; exit 1 ;;
           esac
@@ -73,7 +73,7 @@ jobs:
             case "$PLUGIN" in
               claude) printf '%s\n' 'src/plugins/claude/content/plugins/*/.claude-plugin/plugin.json' ;;
               codex) printf '%s\n' 'src/plugins/codex/content/plugins/*/.codex-plugin/plugin.json' ;;
-              cursor) printf '%s\n' 'src/plugins/cursor/content/.cursor-plugin/plugin.json' ;;
+              cursor) printf '%s\n' 'src/plugins/cursor/content/.cursor-plugin/plugin.json' 'src/plugins/cursor/content/package.json' 'src/plugins/cursor/content/package-lock.json' ;;
               grok) printf '%s\n' 'src/plugins/grok/content/.grok-plugin/plugin.json' 'src/plugins/grok/content/hooks/hooks.json' ;;
             esac
             printf 'EOF\n'
@@ -204,7 +204,7 @@ jobs:
             antigravity) dist_repo=braintrustdata/braintrust-antigravity-plugin ;;
             claude) dist_repo=braintrustdata/braintrust-claude-plugin ;;
             codex) dist_repo=braintrustdata/braintrust-codex-plugin ;;
-            cursor) dist_repo=braintrustdata/braintrust-cursor-plugin ;;
+            cursor) dist_repo=braintrustdata/braintrust-cursor-extension ;;
             grok) dist_repo=braintrustdata/braintrust-grok-plugin ;;
           esac
           {

.github/workflows/smoke-cursor.yml

@@ -93,8 +93,9 @@ jobs:
           import json, pathlib, sys
           root = pathlib.Path(sys.argv[1])
           manifest = json.loads((root / '.cursor-plugin/plugin.json').read_text())
-          assert manifest['name'] == 'trace-cursor', manifest
+          assert manifest['name'] == 'braintrust', manifest
           assert (root / 'hooks/hooks.json').is_file()
+          assert (root / 'mcp.json').is_file()
           PY
           mkdir -p "${RUNNER_TEMP}/cursor-smoke/.cursor"
           cat > "${RUNNER_TEMP}/cursor-smoke/.cursor/hooks.json" <<'JSON'

AGENTS.md

@@ -65,7 +65,7 @@ is unversioned.
 | antigravity | `braintrustdata/braintrust-antigravity-plugin` |
 | claude | `braintrustdata/braintrust-claude-plugin` |
 | codex | `braintrustdata/braintrust-codex-plugin` |
-| cursor | `braintrustdata/braintrust-cursor-plugin` |
+| cursor | `braintrustdata/braintrust-cursor-extension` |
 | grok | `braintrustdata/braintrust-grok-plugin` |
 
 A distribution repository is a generated artifact. Each deploy clones it,

README.md

@@ -28,7 +28,7 @@ All six support `bt trace enable`, `update`, `disable`, and `doctor`.
 | [Google Antigravity](src/plugins/antigravity/content/README.md) | `antigravity` | — | Yes | [GitHub](https://github.com/braintrustdata/braintrust-antigravity-plugin) |
 | [Claude Code](src/plugins/claude/content/README.md) | `claude` | Yes | Yes | [GitHub](https://github.com/braintrustdata/braintrust-claude-plugin) |
 | [Codex](src/plugins/codex/content/README.md) | `codex` | Yes | Yes | [GitHub](https://github.com/braintrustdata/braintrust-codex-plugin) |
-| [Cursor](src/plugins/cursor/content/README.md) | `cursor` | Yes | Yes, transcript-limited | [GitHub](https://github.com/braintrustdata/braintrust-cursor-plugin) |
+| [Cursor](src/plugins/cursor/content/README.md) | `cursor` | Yes | Yes, transcript-limited | [GitHub](https://github.com/braintrustdata/braintrust-cursor-extension) |
 | [Grok](src/plugins/grok/content/README.md) | `grok` | — | — | [GitHub](https://github.com/braintrustdata/braintrust-grok-plugin) |
 | [OpenCode](src/plugins/opencode/content/README.md) | `opencode` | Yes | — | [npm](https://www.npmjs.com/package/@braintrust/trace-opencode) |
 | [Pi](src/plugins/pi/content/README.md) | `pi` | Yes | — | [npm](https://www.npmjs.com/package/@braintrust/pi-extension) |

bt-daemon/src/setup/cursor/mod.rs

@@ -16,7 +16,8 @@ use serde_json::Value;
 use std::path::Path;
 
 const PLUGIN_NAME: &str = "trace-cursor";
-const PLUGIN_SOURCE: &str = "braintrustdata/braintrust-cursor-plugin";
+const PLUGIN_SOURCE: &str = "braintrustdata/braintrust-cursor-extension";
+const LEGACY_PLUGIN_SOURCE: &str = "braintrustdata/braintrust-cursor-plugin";
 const MONOREPO_SOURCE: &str = "braintrustdata/braintrust-coding-agent-plugins";
 const PLUGIN_MANIFEST: &str = plugin_source!("cursor/content/.cursor-plugin/plugin.json");
 const HOOKS_MANIFEST: &str = plugin_source!("cursor/content/hooks/hooks.json");
@@ -33,21 +34,26 @@ exit 0
 "#;
 const README: &str = plugin_source!("cursor/content/README.md");
 const LICENSE: &str = plugin_source!("cursor/content/LICENSE");
+const MCP_MANIFEST: &str = plugin_source!("cursor/content/mcp.json");
+const LOGO: &str = plugin_source!("cursor/content/logo.svg");
 
 fn installed_manifest_at(plugin: &Path) -> Option<Value> {
     let raw = std::fs::read(plugin.join(".cursor-plugin/plugin.json")).ok()?;
     serde_json::from_slice(&raw).ok()
 }
 
 fn is_ours(manifest: &Value) -> bool {
-    manifest.get("name").and_then(Value::as_str) == Some(PLUGIN_NAME)
-        && manifest
-            .get("repository")
-            .and_then(Value::as_str)
-            .is_some_and(|repo| {
-                github_repo_matches(repo, MONOREPO_SOURCE)
-                    || github_repo_matches(repo, PLUGIN_SOURCE)
-            })
+    matches!(
+        manifest.get("name").and_then(Value::as_str),
+        Some("braintrust" | PLUGIN_NAME)
+    ) && manifest
+        .get("repository")
+        .and_then(Value::as_str)
+        .is_some_and(|repo| {
+            github_repo_matches(repo, MONOREPO_SOURCE)
+                || github_repo_matches(repo, PLUGIN_SOURCE)
+                || github_repo_matches(repo, LEGACY_PLUGIN_SOURCE)
+        })
 }
 
 /// Fail unless the plugin at `plugin_dir` is the Braintrust plugin, so setup
@@ -100,6 +106,20 @@ fn plugin_is_installed_for_platform_at(plugin: &Path, windows: bool) -> bool {
     if contents != expected_contents {
         return false;
     }
+    if std::fs::read_to_string(plugin.join("mcp.json"))
+        .ok()
+        .as_deref()
+        != Some(MCP_MANIFEST)
+    {
+        return false;
+    }
+    if std::fs::read_to_string(plugin.join("logo.svg"))
+        .ok()
+        .as_deref()
+        != Some(LOGO)
+    {
+        return false;
+    }
     #[cfg(unix)]
     if !windows {
         use std::os::unix::fs::PermissionsExt;
@@ -213,6 +233,8 @@ fn install_plugin_at_for_platform(plugin_dir: &Path, windows: bool) -> anyhow::R
         (".cursor-plugin/plugin.json", PLUGIN_MANIFEST.to_owned()),
         ("hooks/hooks.json", hooks_manifest),
         ("hooks/trace.sh", HOOK_LAUNCHER.to_owned()),
+        ("mcp.json", MCP_MANIFEST.to_owned()),
+        ("logo.svg", LOGO.to_owned()),
         ("README.md", README.to_owned()),
         ("LICENSE", LICENSE.to_owned()),
     ];
@@ -366,6 +388,7 @@ mod tests {
         .unwrap();
         assert!(plugin_is_installed_at(&plugin));
         assert!(is_ours(&manifest));
+        assert!(plugin.join("mcp.json").is_file());
     }
 
     #[test]

scripts/set-plugin-version.py

@@ -36,17 +36,25 @@ def main() -> None:
         sys.exit(f"no plugin manifests found for '{agent}' ({pattern})")
 
     surfaces = [(path, VERSION_RE, "version") for path in manifests]
+    if agent == "cursor":
+        content = "src/plugins/cursor/content"
+        surfaces.extend([
+            (f"{content}/package.json", VERSION_RE, "extension version"),
+            (f"{content}/package-lock.json", VERSION_RE, "lockfile versions"),
+        ])
 
     changes = []
     for path, version_re, label in surfaces:
         with open(path) as f:
             text = f.read()
+        expected = 2 if label == "lockfile versions" else 1
         new_text, n = version_re.subn(
             lambda match: f"{match.group(1)}{version}{match.group(2)}",
             text,
+            count=expected,
         )
-        if n != 1:
-            sys.exit(f"expected one {label} field in {path}, found {n}")
+        if n != expected:
+            sys.exit(f"expected {expected} {label} field(s) in {path}, found {n}")
         changes.append((path, label, new_text))
 
     for path, label, new_text in changes:

src/plugins/cursor/content/.cursor-plugin/plugin.json

@@ -1,10 +1,25 @@
 {
-  "name": "trace-cursor",
+  "name": "braintrust",
+  "displayName": "Braintrust",
   "version": "0.2.0",
-  "description": "Trace Cursor agent sessions, model output, and tool operations to Braintrust through the shared bt daemon.",
-  "author": { "name": "Braintrust" },
-  "homepage": "https://www.braintrust.dev",
-  "repository": "https://github.com/braintrustdata/braintrust-coding-agent-plugins",
-  "license": "Apache-2.0",
-  "hooks": "hooks/hooks.json"
+  "description": "Connect Cursor to Braintrust MCP and trace agent sessions.",
+  "author": { "name": "Braintrust Data, Inc.", "email": "support@braintrust.dev" },
+  "homepage": "https://braintrust.dev",
+  "repository": "https://github.com/braintrustdata/braintrust-cursor-extension",
+  "license": "MIT",
+  "keywords": ["braintrust", "mcp", "ai", "evaluation", "experiments", "observability", "logs", "tracing"],
+  "logo": "logo.svg",
+  "hooks": "hooks/hooks.json",
+  "mcpServers": "mcp.json",
+  "variables": {
+    "type": "object",
+    "properties": {
+      "BRAINTRUST_API_KEY": {
+        "type": "string",
+        "title": "Braintrust API key",
+        "description": "API key for the Braintrust MCP server"
+      }
+    },
+    "required": ["BRAINTRUST_API_KEY"]
+  }
 }

src/plugins/cursor/content/.gitignore

@@ -0,0 +1,4 @@
+node_modules/
+out/
+*.vsix
+.vscode-test/

src/plugins/cursor/content/.vscode/launch.json

@@ -0,0 +1,13 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Run Extension",
+      "type": "extensionHost",
+      "request": "launch",
+      "args": ["--extensionDevelopmentPath=${workspaceFolder}"],
+      "outFiles": ["${workspaceFolder}/out/**/*.js"],
+      "preLaunchTask": "npm: build"
+    }
+  ]
+}

src/plugins/cursor/content/.vscode/tasks.json

@@ -0,0 +1,18 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "type": "npm",
+      "script": "build",
+      "group": "build",
+      "problemMatcher": ["$tsc"]
+    },
+    {
+      "type": "npm",
+      "script": "watch",
+      "group": "build",
+      "isBackground": true,
+      "problemMatcher": ["$tsc-watch"]
+    }
+  ]
+}

src/plugins/cursor/content/.vscodeignore

@@ -0,0 +1,12 @@
+src/**
+.vscode/**
+.cursor-plugin/**
+mcp.json
+logo.svg
+tsconfig.json
+CONTRIBUTING.md
+.gitignore
+**/*.ts
+**/*.map
+node_modules/**
+.vscode-test/**

src/plugins/cursor/content/CONTRIBUTING.md

@@ -0,0 +1,136 @@
+# Contributing
+
+The source for this plugin and extension lives in
+[braintrust-coding-agent-plugins](https://github.com/braintrustdata/braintrust-coding-agent-plugins)
+under `src/plugins/cursor/content/`. The
+[braintrust-cursor-extension](https://github.com/braintrustdata/braintrust-cursor-extension)
+repository is generated from this directory during a release. Make changes and
+open pull requests in the monorepo.
+
+## Development Setup
+
+### Prerequisites
+
+- Node.js 20.18.1 or newer
+- npm
+
+### Build from Source
+
+```bash
+# Clone the source repository
+git clone https://github.com/braintrustdata/braintrust-coding-agent-plugins.git
+cd braintrust-coding-agent-plugins/src/plugins/cursor/content
+
+# Install dependencies
+npm ci
+
+# Build the extension
+npm run build
+```
+
+From the monorepo root, run `make validate-cursor` to build and validate the
+Cursor distribution tree, including its plugin manifest, MCP configuration,
+and tracing hooks.
+
+### Running in Development
+
+1. Open `src/plugins/cursor/content/` in Cursor
+2. Press `F5` to launch the Extension Development Host
+3. A new Cursor window will open with the extension loaded
+
+### Setting the Environment Variable for Development
+
+The extension reads `BRAINTRUST_API_KEY` from the process environment at runtime. You must set this variable **before** launching Cursor so the extension host process inherits it.
+
+#### macOS / Linux
+
+```bash
+# Set the environment variable and launch Cursor
+export BRAINTRUST_API_KEY="your-api-key-here"
+cursor .
+
+# Or in a single line
+BRAINTRUST_API_KEY="your-api-key-here" cursor .
+```
+
+For persistent configuration, add to your shell profile (`~/.bashrc`, `~/.zshrc`, etc.):
+
+```bash
+export BRAINTRUST_API_KEY="your-api-key-here"
+```
+
+Then restart your terminal and Cursor.
+
+#### Windows (PowerShell)
+
+```powershell
+# Set for current session
+$env:BRAINTRUST_API_KEY = "your-api-key-here"
+
+# Launch Cursor
+cursor .
+```
+
+For persistent configuration:
+
+```powershell
+# Set permanently for user
+[Environment]::SetEnvironmentVariable("BRAINTRUST_API_KEY", "your-api-key-here", "User")
+```
+
+Then restart PowerShell and Cursor.
+
+#### Windows (Command Prompt)
+
+```cmd
+# Set for current session
+set BRAINTRUST_API_KEY=your-api-key-here
+
+# Launch Cursor
+cursor .
+```
+
+For persistent configuration, use System Properties > Environment Variables.
+
+### Installing a Local Build
+
+1. From `src/plugins/cursor/content/`, build the extension: `npm run build`
+2. Package it: `npx vsce package` (produces a `.vsix` file)
+3. In Cursor, open Command Palette (`Cmd+Shift+P` / `Ctrl+Shift+P`)
+4. Run **Extensions: Install from VSIX...**
+5. Select the generated `.vsix` file
+
+## Project Structure
+
+```
+braintrust-coding-agent-plugins/src/plugins/cursor/content/
+├── .cursor-plugin/     # Cursor plugin manifest
+├── hooks/              # Tracing hooks
+├── mcp.json            # Braintrust MCP server
+├── package.json        # Extension manifest
+├── tsconfig.json       # TypeScript configuration
+├── src/
+│   └── extension.ts    # Main extension code
+├── out/                # Compiled output (git-ignored)
+└── README.md
+```
+
+## Scripts
+
+- `npm run build` — Compile TypeScript
+- `npm run watch` — Compile in watch mode
+- `npm run lint` — Run ESLint (requires eslint to be installed)
+- `npm run package` — Create a `.vsix` package
+- `npm run publish:openvsx` — Publish to OpenVSX (for Cursor)
+- `npm run publish:vscode` — Publish to VS Code Marketplace
+
+## Publishing
+
+The monorepo's **Release Plugin** workflow prepares a version pull request.
+After that pull request is approved and merged, the workflow publishes the
+generated Cursor plugin tree to `braintrustdata/braintrust-cursor-extension`.
+The version script updates the Cursor plugin manifest, `package.json`, and
+`package-lock.json` together. Do not edit the distribution repository directly.
+
+Publishing the VS Code extension to an extension marketplace is a separate
+release action. `npm run package` creates a `.vsix` file for local testing.