Introduction

Let Claude use the Chrome you are already logged into. Not a fresh automated browser that greets every site as a stranger — your Chrome, with your sessions, your cookies, your 2FA already done. If you can see a page in your browser, your agent can read it, without logging in again and without pasting credentials anywhere.

Most browser MCP servers launch their own Chromium and hand your agent a signed-out window. chrome-mcp does the opposite: an MV3 extension dials into a localhost WebSocket server and drives the browser you already have open, through chrome.scripting/chrome.tabs. Works with Claude Code, Claude Desktop, and any other MCP host.

Distributed as an npx CLI (the MCP server) plus a load-unpacked extension.

This build is extension-only. It never launches or attaches a Chromium of its own, so the extension is required, not optional — without it, no tool can run. The CDP flags (--cdp-fallback, --no-cdp-fallback, --cdp-endpoint, --prefer) are still accepted for back-compat but are ignored.

Full design: docs/BLUEPRINT.md — architecture, wire protocol, the complete tool surface, the extension manifest, the security model, and the phased build plan.

Where to go next

• Quickstart: register the server and load the extension in three steps.
• Agent setup: hand one URL to your agent and let it do the install.
• Tools reference: all the tools, with arguments.
• Security: the deny-all default and what you can opt into.
• Architecture: the blueprint, wire protocol and build plan.