IronBee DevTools for VS Code & Cursor

IronBee DevTools — the Verification and Intelligence Layer for AI Coding Agents — brought to VS Code and Cursor via the Model Context Protocol (MCP).

This extension bundles the @ironbee-ai/devtools MCP server and registers it with your IDE, so AI assistants like GitHub Copilot and Cursor AI can drive, observe, and verify your application as they build it. Enable any of three platforms — each runs as its own MCP server:

Browser — Playwright-powered browser automation, DevTools inspection, and visual debugging.
Node — non-blocking debugging of Node.js processes (tracepoints, logpoints, exceptionpoints, watches).
Backend — runtime-agnostic backend verification (HTTP/gRPC/GraphQL/WebSocket) plus log capture (file/docker/kubernetes) and database verification (Postgres/MySQL/SQLite).

No npm setup at runtime — the server ships inside the extension.

Features

🌐 Browser Automation - Navigate, click, fill forms, and interact with web pages
📸 Screenshots - Capture full-page or element screenshots
♿ Accessibility - Run accessibility audits and get ARIA/AX tree snapshots
📊 Web Vitals - Measure Core Web Vitals (LCP, INP, CLS, TTFB, FCP)
🔍 Network Inspection - Monitor HTTP requests and responses
🎭 Request Mocking - Stub and mock API responses
⚛️ React DevTools - Inspect React components and elements
🔭 OpenTelemetry - Distributed tracing integration with trace context propagation
🎨 Figma Comparison - Compare pages with Figma designs
🐛 Non-Blocking Debugging - Tracepoints, logpoints, exceptionpoints, watch expressions, probe snapshots
⚡ Execute - Batch multiple tool calls in one request via JavaScript and callTool(); on browser platform page (Playwright Page) is available for page.evaluate(), page.locator(), etc.
🌐 Playwright Browsers - On first install/upgrade, the extension downloads the browsers selected in settings (default: Chromium + headless shell + ffmpeg) into Playwright’s normal cache using playwright-core’s installer—no npx required. VSIX builds set PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1 so binaries are not bundled. If that step fails for the Chromium stack, you may be prompted to use installed Google Chrome instead (Use system-installed browser). Run IronBee DevTools: Install Playwright Browsers... anytime to pick Chromium (default), Firefox, and/or WebKit: it updates install.chromium / install.firefox / install.webkit to match and downloads those engines.
📦 MCP Server - Shipped inside one universal VSIX (same artifact for all platforms). The package includes sharp + @img/sharp-wasm32; native sharp/libvips prebuild variants are excluded from VSIX contents. No npm required at runtime; the extension runs the bundled @ironbee-ai/devtools with node.

Installation

From Open VSX Registry

Open VS Code or Cursor
Go to Extensions (Ctrl+Shift+X / Cmd+Shift+X)
Search for "IronBee DevTools"
Click Install

Or install via command line:

# VS Code
code --install-extension ironbee-ai.ironbee-devtools-vscode

# Cursor
cursor --install-extension ironbee-ai.ironbee-devtools-vscode

From VSIX

# VS Code
code --install-extension ironbee-devtools-vscode-x.x.x.vsix

# Cursor
cursor --install-extension ironbee-devtools-vscode-x.x.x.vsix

Registration: In Cursor the extension registers the MCP server via Cursor’s native MCP API (no mcp.json needed). In VS Code 1.101+ it uses vscode.lm.registerMcpServerDefinitionProvider. The server is started automatically when the extension is enabled.

Telemetry

The extension can send anonymous usage events (install/uninstall, browser install step, etc.) to help improve the product. The same opt-in/opt-out rules apply as for the bundled @ironbee-ai/devtools server. No PII is collected; only an anonymous ID in ~/.ironbee-devtools/config.json, plus event name and environment properties (e.g. extension version, OS, Node version).

Events: cursor_ext_activated / cursor_ext_deactivated (extension lifecycle), cursor_ext_installed (only when first-install/upgrade path ran and bundled MCP path resolved), cursor_ext_install_failed, cursor_ext_browser_installed / cursor_ext_browser_install_failed, and cursor_ext_uninstalled (when the extension is uninstalled and deactivate runs with the extension listed in .obsolete). MCP registration state is included where relevant (mcp_server_registered / mcp_server_unregistered). If telemetry is disabled (setting, env, or config), no events are sent.
Timing: Clients may batch or delay sending—events might not appear in analytics immediately. TELEMETRY_ENABLE=false and ~/.ironbee-devtools/config.json apply to both the extension and the bundled MCP process (the extension forwards the parent environment to the server).

How to disable telemetry

Setting (recommended): Set ironbeeDevTools.telemetry.enable to false in VS Code/Cursor settings. The extension syncs this to ~/.ironbee-devtools/config.json on activate and when the setting changes, so no telemetry events (including uninstall) are sent.
Environment variable: Set TELEMETRY_ENABLE=false before starting VS Code/Cursor.
Config file: Edit ~/.ironbee-devtools/config.json and set "telemetryEnabled": false.

MCP Server (bundled)

The @ironbee-ai/devtools package is a dependency of this extension and is included in the published VSIX with production node_modules. We publish a single universal VSIX where native sharp/libvips prebuild variants are excluded from the bundle and @img/sharp-wasm32 is included. @img/sharp-wasm32 is a direct extension dependency (aligned with the bundled sharp), and .npmrc sets force=true so npm installs it on normal hosts.

Activate: The extension resolves node_modules/@ironbee-ai/devtools/dist/index.js inside the extension folder. No npm and no network required for the server binary itself.
New server versions: Publish/build workflows are lockfile-driven (npm ci --omit=optional). Bump @ironbee-ai/devtools in package.json and refresh lockfile when you want to roll forward.
Dependencies: @ironbee-ai/devtools and @img/sharp-wasm32 are regular dependencies in package.json for maintainers; end users do not run npm for MCP.

Maintainer: universal VSIX

PR / CI: .github/workflows/build.yml — workflow_dispatch, pull_request (master), and push (main) triggers; on ubuntu-latest it runs npm ci --omit=optional, lint, build, and npx vsce package.
Release / Open VSX: .github/workflows/publish-vscode-extension.yml — single release job runs npm ci --omit=optional, lint, build, version bump/tag/release, then publishes to Open VSX via HaaLeo/publish-vscode-extension@v2 (skipDuplicate: true) and uploads the produced VSIX as artifact.
Packaging filter: .vscodeignore excludes @img/sharp-darwin-*, @img/sharp-win32-*, @img/sharp-linux-*, @img/sharp-libvips-* and keeps sharp + @img/sharp-wasm32. vsce collects production dependencies via npm list --production, so devDependencies are not bundled.

Local packaging check:

npm ci --omit=optional
npx vsce package

Playwright Browsers

The extension uses Playwright’s browser binaries (Chromium, Firefox, WebKit), stored in the default cache (e.g. ~/.cache/ms-playwright on Linux, ~/Library/Caches/ms-playwright on macOS).

Which browsers to install: In Settings, use ironbeeDevTools.install.chromium, install.firefox, and install.webkit (default: Chromium group). On first install/upgrade, the extension calls Playwright’s installBrowsersForNpmInstall with that selection (unless Use system-installed browser is on or platform is Node). Playwright skips work when the chosen builds are already present in the cache (INSTALLATION_COMPLETE). Changing these settings triggers another install pass; restart the MCP session if it was already running. Install Playwright Browsers... in the Command Palette does the same selection UI and writes those three settings to match your choice, then runs the installer (so the sidebar/settings panel stay in sync).
VSIX / CI: PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1 is set when packaging so browser ZIPs are not part of the extension.
Download failures (Chromium stack): If Playwright’s install step fails while the Chromium group is requested (network, proxy, firewall, Winldd on Windows, etc.), the extension shows one notification (error text in details) and may offer Use Google Chrome to enable Use system-installed browser (ironbeeDevTools.browser.useSystemBrowser). Google Chrome must be installed on the machine. Firefox/WebKit-only installs get a generic failure message instead. Restart the MCP session (or Restart Server) after accepting. You can also turn on Use system-installed browser manually in settings anytime.

To skip browser download (e.g. you use a system browser or custom path), set the environment variable PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1 before starting VS Code/Cursor.

Configuration

Quick Settings

Open the IronBee DevTools panel in the Explorer sidebar to configure common settings.

Full Settings

Open VS Code Settings (Ctrl+, / Cmd+,) and search for "IronBee DevTools" or use the command:

IronBee DevTools: Open Settings

To (re)download Playwright binaries immediately:

IronBee DevTools: Install Playwright Browsers...

Available Settings

Settings below are passed to the MCP server as environment variables. Change them in Settings or in the IronBee DevTools sidebar panel (subset); restart the MCP session to apply.

General

Setting	Default	Description
`ironbeeDevTools.enable`	`true`	Enable or disable the extension (and all MCP servers)
`ironbeeDevTools.telemetry.enable`	`true`	Allow anonymous install/uninstall telemetry (see Telemetry)
`ironbeeDevTools.platform.browser.enable`	`true`	Enable the Browser platform (registered as the `ironbee-dt-browser` MCP server)
`ironbeeDevTools.platform.node.enable`	`false`	Enable the Node platform (registered as the `ironbee-dt-node` MCP server)
`ironbeeDevTools.platform.backend.enable`	`false`	Enable the Backend platform — HTTP/gRPC/GraphQL/WS + log capture + DB verification (registered as the `ironbee-dt-backend` MCP server)

Install (Playwright browsers to download on activate)

Setting	Default	Description
`ironbeeDevTools.install.chromium`	`true`	Browser group selection used on first install/upgrade; changing it triggers Playwright install pass.
`ironbeeDevTools.install.firefox`	`false`	Browser group selection used on first install/upgrade; changing it triggers Playwright install pass.
`ironbeeDevTools.install.webkit`	`false`	Browser group selection used on first install/upgrade; changing it triggers Playwright install pass.

Browser

Setting	Default	Description
`ironbeeDevTools.browser.headless`	`true`	Run browser in headless mode
`ironbeeDevTools.browser.persistent`	`false`	Enable persistent browser context
`ironbeeDevTools.browser.userDataDir`	`""`	Directory for persistent user data
`ironbeeDevTools.browser.useSystemBrowser`	`false`	Use system browser instead of bundled
`ironbeeDevTools.browser.executablePath`	`""`	Custom browser executable path
`ironbeeDevTools.browser.locale`	`""`	Browser locale (e.g., en-US, tr-TR)
`ironbeeDevTools.browser.cdp.enable`	`false`	Enable CDP attach mode (Chromium only).
`ironbeeDevTools.browser.cdp.endpointUrl`	`""`	Optional CDP endpoint (`http://host:port` or `ws://...`).
`ironbeeDevTools.browser.cdp.openInspect`	`true`	On loopback CDP failure, open `chrome://inspect/#remote-debugging` when Chrome is running.
`ironbeeDevTools.browser.consoleMessagesBufferSize`	`1000`	Max console messages to buffer
`ironbeeDevTools.browser.httpRequestsBufferSize`	`1000`	Max HTTP requests to buffer

Node (when platform is `node`)

Setting	Default	Description
`ironbeeDevTools.node.inspectorHost`	`""`	Inspector host for Docker (e.g., host.docker.internal)
`ironbeeDevTools.node.consoleMessagesBufferSize`	`1000`	Max console messages to buffer in Node process

OpenTelemetry

Setting	Default	Description
`ironbeeDevTools.opentelemetry.enable`	`false`	Enable OpenTelemetry instrumentation
`ironbeeDevTools.opentelemetry.serviceName`	`"frontend"`	Service name for traces
`ironbeeDevTools.opentelemetry.serviceVersion`	`""`	Service version for traces
`ironbeeDevTools.opentelemetry.assetsDir`	`""`	OpenTelemetry assets directory
`ironbeeDevTools.opentelemetry.instrumentationUserInteractionEvents`	`""`	Comma-separated events to instrument (default: click)
`ironbeeDevTools.opentelemetry.exporterType`	`"none"`	Exporter: `none`, `console`, `otlp/http`
`ironbeeDevTools.opentelemetry.exporterUrl`	`""`	OTLP collector URL
`ironbeeDevTools.opentelemetry.exporterHeaders`	`""`	HTTP headers for collector

AWS / Amazon Bedrock

Setting	Default	Description
`ironbeeDevTools.aws.region`	`""`	AWS region for Bedrock
`ironbeeDevTools.aws.profile`	`""`	AWS profile name
`ironbeeDevTools.bedrock.enable`	`false`	Enable Bedrock for AI features
`ironbeeDevTools.bedrock.imageModelId`	`""`	Image embedding model ID
`ironbeeDevTools.bedrock.textModelId`	`""`	Text embedding model ID
`ironbeeDevTools.bedrock.visionModelId`	`""`	Vision model ID

Figma

Setting	Default	Description
`ironbeeDevTools.figma.accessToken`	`""`	Figma API access token
`ironbeeDevTools.figma.apiBaseUrl`	`""`	Figma API base URL (default: https://api.figma.com/v1)

Advanced (MCP)

Setting	Default	Description
`ironbeeDevTools.toolOutputSchemaDisable`	`false`	Omit tool output schema from MCP registration (can reduce token usage)
`ironbeeDevTools.platform.browser.availableToolDomains`	`""`	Browser tool domains to enable. Empty = all. Domains: a11y, content, debug, figma, interaction, navigation, o11y, react, run, scenario, stub, sync.
`ironbeeDevTools.platform.node.availableToolDomains`	`""`	Node tool domains to enable. Empty = all. Domains: debug, run.
`ironbeeDevTools.platform.backend.availableToolDomains`	`""`	Backend tool domains to enable. Empty = all. Domains: db, log, o11y, request, run.

Usage

Once installed, the MCP server is automatically available to AI assistants. Try prompts like:

Navigation & Screenshots:

Navigate to https://example.com and take a screenshot
Take a full-page screenshot of the current page
Wait for network to be idle and then take a screenshot

Accessibility Testing:

Check the accessibility of the current page
Get the ARIA snapshot for the navigation menu
Get the AX tree snapshot with occlusion checking enabled

Performance:

Get the Web Vitals for https://google.com
What is the LCP score of this page?
Measure Core Web Vitals and give me recommendations

Interaction:

Fill the login form with test@example.com and click submit
Click the "Sign Up" button and wait for the page to load
Scroll to the bottom of the page

Debugging:

Show me the console errors on this page
What network requests failed on this page?
Set a tracepoint at line 50 in main.js and capture the call stack
Get probe snapshots after triggering the code path

API Mocking:

Mock the /api/users endpoint to return an empty array
Intercept all API requests and add an auth header
List all active stubs and clear them

Execute (batch tool calls + optional page script):

Use execute to fill the login form and click submit in one call
Run a script that calls callTool('navigation_go-to', { url: '...' }) then callTool('a11y_take-aria-snapshot', {}, true)

Visualizer UI

Visualizer UI screenshot:

Visualizer UI renders MCP tool events as an animated scene. The UI connects to the Visualizer WebSocket stream at ws://localhost:<wsPort>.

How to open

Open the IronBee DevTools panel in VS Code/Cursor.
Set Show Visualizer to true.
Run IronBee DevTools: Restart Server.
Run any MCP tool (for example navigation_go-to, then content_take-screenshot).

If the panel does not open automatically, open Command Palette (Cmd+Shift+P) and run IronBee DevTools: Show Visualizer.

Alternative (run Visualizer UI locally for development):

From repo root:

cd visualizer npm install npm run dev

Open http://localhost:3000 in your browser.

How it works (summary)

The extension starts a Visualizer WebSocket server on ironbeeDevTools.visualizer.wsPort.
The UI reads VIS_WS_PORT in visualizer/src/main.ts and connects to ws://localhost:<wsPort>.
Tool events (run_started, tool_started, tool_finished, run_done, etc.) are represented in the scene.

Settings you should configure

Show Visualizer: set to true to enable both the webview UI and the Visualizer WebSocket server.
ironbeeDevTools.visualizer.wsPort (default 3020): change this if the port is busy, then run Restart Server.

Available MCP Tools

Navigation Tools

Tool	Description
`navigation_go-to`	Navigate to a URL
`navigation_reload`	Reload the page
`navigation_go-back-or-forward`	Go back or forward in history (direction: back \| forward)

Content Tools

Tool	Description
`content_take-screenshot`	Take a screenshot (full page or element)
`content_get-as-html`	Get page HTML with filtering options
`content_get-as-text`	Get visible text content
`content_save-as-pdf`	Save page as PDF

Interaction Tools

Tool	Description
`interaction_click`	Click an element
`interaction_fill`	Fill an input field
`interaction_hover`	Hover over an element
`interaction_scroll`	Scroll page or element
`interaction_press-key`	Press a keyboard key
`interaction_drag`	Drag and drop
`interaction_select`	Select dropdown option
`interaction_resize-viewport`	Resize viewport (Playwright emulation)
`interaction_resize-window`	Resize browser window (OS-level)

Accessibility Tools

Tool	Description
`a11y_take-aria-snapshot`	Get ARIA snapshot (YAML format)
`a11y_take-ax-tree-snapshot`	Get AX tree with visual diagnostics

Observability Tools

Tool	Description
`o11y_get-web-vitals`	Get Web Vitals (LCP, INP, CLS, TTFB, FCP)
`o11y_get-console-messages`	Get console logs with filtering
`o11y_get-http-requests`	Get network requests with filtering
`o11y_get-trace-id`	Get current OpenTelemetry trace ID
`o11y_new-trace-id`	Generate new trace ID
`o11y_set-trace-id`	Set trace ID for distributed tracing

Synchronization Tools

Tool	Description
`sync_wait-for-network-idle`	Wait for network to become idle

Stub Tools

Tool	Description
`stub_mock-http-response`	Mock HTTP response
`stub_intercept-http-request`	Intercept and modify requests
`stub_list`	List installed stubs
`stub_clear`	Clear stubs

React Tools

Tool	Description
`react_get-component-for-element`	Get React component for DOM element
`react_get-element-for-component`	Get DOM element for React component

Execute

Tool	Description
`execute`	Batch-execute multiple tool calls in one request via JavaScript; use `callTool(name, input, returnOutput?)` to invoke tools. On browser platform the script has `page` (Playwright Page) for `page.evaluate()`, `page.locator()`, etc. Reduces round-trips and token usage.

Figma Tools

Tool	Description
`figma_compare-page-with-design`	Compare page with Figma design

Debug Tools (Non-Blocking)

Tool	Description
`debug_put-tracepoint`	Set a tracepoint (captures call stack)
`debug_put-logpoint`	Set a logpoint (evaluates expression)
`debug_put-exceptionpoint`	Configure exception breakpoints (none, uncaught, all)
`debug_add-watch`	Add watch expression (evaluated at every tracepoint hit)
`debug_remove-probe`	Remove a tracepoint, logpoint, or watch by type and id
`debug_list-probes`	List tracepoints, logpoints, and/or watches
`debug_clear-probes`	Clear tracepoints, logpoints, and/or watch expressions
`debug_get-probe-snapshots`	Get tracepoint, logpoint, and/or exceptionpoint snapshots
`debug_clear-probe-snapshots`	Clear probe snapshots (optional types, probeId)
`debug_status`	Get debugging status (probe counts, exceptionpoint state)
`debug_resolve-source-location`	Resolve bundle location to original source via source maps

When the Node platform is enabled (ironbeeDevTools.platform.node.enable), additional tools: debug_connect, debug_disconnect, debug_get-logs.

The Backend platform (ironbeeDevTools.platform.backend.enable) adds runtime-agnostic verification tool domains: request_* (HTTP/gRPC/GraphQL/WebSocket), log_* (file/docker/kubernetes log capture), db_* (Postgres/MySQL/SQLite), and o11y_* (W3C trace context). See the @ironbee-ai/devtools docs for the full backend tool list.

Database drivers are not bundled. The db_* tools load their engine driver on demand — pg (Postgres), mysql2 (MySQL), better-sqlite3 (SQLite). These are native/optional and the published VSIX is built with npm ci --omit=optional, so they are not shipped. The request_* and log_* paths work out of the box; to use db_*, install the driver for your database where the bundled node can resolve it (or run the MCP server from a project that has it). HTTP/gRPC/GraphQL/WebSocket verification needs no extra install.

Development

Prerequisites

Node.js 22+
VS Code 1.101+ or Cursor

Build

# Install dependencies
npm install

# Compile TypeScript
npm run compile

# Watch for changes
npm run watch

# Package extension
npm run package

Testing

Press F5 in VS Code/Cursor to launch Extension Development Host
The extension will be loaded in the new window
Open AI Chat (Copilot or Cursor AI) and test MCP tools

Troubleshooting

Restart the MCP server

If you run into problems—for example the MCP server fails to start, the browser that was opened has closed, MCP processes have leaked, or you see other odd behavior—try restarting the MCP server first:

Open the Command Palette (Ctrl+Shift+P / Cmd+Shift+P)
Run IronBee DevTools: Restart Server

This unregisters the server, stops any running MCP processes (e.g. Cursor-started ones), and registers it again so a fresh process is started.

MCP Server Not Starting

Reinstall the extension or install a fresh VSIX—the MCP server is bundled; a missing dist/index.js usually means a broken or partial install.
Check that Node.js 22+ is available to the IDE (extension host) and the extension is enabled.
Check Output panel for "IronBee DevTools" logs.

Browser Not Launching

Run IronBee DevTools: Install Playwright Browsers... and ensure Chromium (or your engine) is selected, or rely on install.* settings on first install/upgrade. If the Playwright download fails, enable Use system-installed browser in settings or choose Use Google Chrome when the extension prompts (Chromium stack only; Chrome must be installed). Skip download if you use a system browser only.
Try disabling headless mode in settings
Check if a custom executable path is needed (e.g. system browser or custom build)

Settings Not Applying

After changing settings, restart the MCP session:

Run the command IronBee DevTools: Restart Server
Or reload the VS Code/Cursor window (Cmd+Shift+P → "Developer: Reload Window")

Contributing

Contributions are welcome! Please open an issue or submit a pull request on GitHub.

License

Elastic License 2.0 (ELv2) - see LICENSE for details.

Links

GitHub Repository - Extension source code
Open VSX Registry - Extension page
@ironbee-ai/devtools - Main MCP server (npm)
VS Code MCP Documentation
Model Context Protocol

Name		Name	Last commit message	Last commit date
.github/workflows		.github/workflows
images		images
rules		rules
scripts		scripts
src		src
visualizer		visualizer
.gitignore		.gitignore
.npmrc		.npmrc
.release-it.json		.release-it.json
.vscodeignore		.vscodeignore
AGENTS.md		AGENTS.md
CLAUDE.md		CLAUDE.md
LICENSE		LICENSE
README.md		README.md
eslint.config.js		eslint.config.js
package-lock.json		package-lock.json
package.json		package.json
tsconfig.json		tsconfig.json

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