Chrome DevTools

browser_engine: chrome-devtools — drives a real Google Chrome through the chrome-devtools-mcp server (built on Puppeteer + the Chrome DevTools Protocol). Use it when you want DevTools-grade signal: performance traces, Lighthouse audits, and deep network/console inspection with source-mapped stack traces.

When to use it

• Your app targets Chrome and you want DevTools-level fidelity.
• You care about performance insights (performance_start_trace, performance_analyze_insight) or lighthouse_audit.
• You want richer network and source-mapped console data than the default.

Chrome-only

chrome-devtools-mcp officially supports Google Chrome and Chrome for Testing. Other Chromium browsers may work but are unsupported. For Firefox/WebKit coverage, use the Playwright engine.

Configuration

/qa-catalog:init writes this mcpServers block into each project-level browser agent:

mcpServers:
  - chrome-devtools:
      type: stdio
      command: npx
      args: ["-y", "chrome-devtools-mcp@latest", "--isolated", "--headless"]

• --isolated gives each spawn a temporary user-data dir that is cleaned up on exit. This is important for parallel safety: without it, chrome-devtools-mcp shares a single profile dir across all instances and parallel runners would collide on cookies/localStorage.
• --headless runs without a visible window. Drop it (or set browser_headless: false) to watch the browser.
• To pin a channel, add --channel=stable|beta|dev|canary.

Concurrency note

If your Claude Code build shares a single MCP server across subagents instead of spawning one per agent, add --experimentalPageIdRouting so each agent can route tool calls to its own tab. With the inline-per-agent model this plugin uses (one server process per spawn), --isolated alone is sufficient.

Tool-name differences

The agent prompts are engine-neutral; on this engine the underlying tools are navigate_page / new_page, click, fill / type_text, take_snapshot, take_screenshot, evaluate_script, list_console_messages, list_network_requests. See the capability map.

Relevant settings (/plugin)

| Setting | Effect | |---|---| | browser_channel | Map to --channel (stable/beta/dev/canary). chromium/webkit/firefox are not valid here — use Playwright for those. | | browser_headless | true keeps --headless; false drops it for a visible window. | | settle_ms, parallel_* | Same meaning as the default engine. |

Requirements

• Node.js (current LTS) + npx.
• Google Chrome (current stable) or Chrome for Testing installed.

Privacy

chrome-devtools-mcp collects anonymous usage statistics by default and may send performance trace URLs to the Chrome UX Report (CrUX) API. Disable with --no-usage-statistics and --no-performance-crux, or set the CI / CHROME_DEVTOOLS_MCP_NO_USAGE_STATISTICS env vars. See the upstream README.