devtools-mcp

What is devtools-mcp?

devtools-mcp is an MCP server that provides LLMs with access to Chrome DevTools Protocol (CDP) commands, enabling browser automation and inspection through a natural language interface. It is intended for developers integrating LLMs with browser debugging and control.

How to use devtools-mcp?

Start Chrome with remote debugging on port 9222, install dependencies with npm install, then add the server as a local MCP server (e.g., with Claude Code using claude mcp add). The server exposes a single cdp_command tool that accepts a CDP method and optional parameters, and automatically saves binary output (screenshots, PDFs) to the ./cdp-output/ directory.

Key features of devtools-mcp

• Execute any CDP command through the cdp_command tool
• Automatic binary data handling with file path references
• Seamless integration with LLM-based clients
• Supports all Chrome DevTools Protocol methods

Use cases of devtools-mcp

• Navigating pages and evaluating JavaScript via LLMs
• Taking screenshots and capturing PDFs during automated testing
• Debugging web applications through conversational AI assistants

FAQ from devtools-mcp

What is the cdp_command tool?

It is the single tool exposed by the server. It takes a method (required) and params (optional JSON string) to execute any Chrome DevTools Protocol command.

How is binary data handled?

Large binary responses (e.g., screenshots, PDFs) are automatically saved to the ./cdp-output/ directory. The tool returns a file path reference instead of raw binary data.

What runtime or dependencies are required?

Node.js and Chrome (or Chromium) running with remote debugging enabled on port 9222. Install npm dependencies via npm install.

How is the server started or configured?

You add it as a local MCP server in your client (e.g., Claude Code). The example command is claude mcp add devtools-server -- npx tsx ~/projects/devtools-mcp/src/index.ts.

What transport or authentication does it use?

The README does not specify authentication or transport details. It communicates with a locally running Chrome instance over HTTP (CDP via WebSocket).