Browser Bridge MCP
An open-source MCP server + Chrome extension that gives AI coding assistants direct access to the browser. Navigate pages, click elements, fill forms, run JavaScript, take screenshots, and read page content — all from the terminal.
The Problem
AI coding assistants are powerful but blind — they can’t see what’s in the browser. Developers end up copy-pasting error messages, describing UI state in words, and manually relaying what they see on screen. It’s slow and lossy.
The Solution
Browser Bridge MCP connects any MCP-compatible AI assistant directly to the browser. One npx command starts the server, a Chrome extension handles the browser side. The assistant can then navigate, interact, inspect, and screenshot — no more alt-tabbing.
How It Works
MCP Client (Claude Code, Cursor, etc.)
↕ stdio
MCP Server (Node.js, runs locally)
↕ WebSocket (localhost:7483)
Chrome Extension (Manifest V3)
↕ Chrome APIs
Browser (any Chromium browser)
All communication stays on your machine. No data is sent to any remote server or third party.
What It Can Do
| Feature | Description |
|---|---|
| Navigate & Screenshot | Point the assistant at any URL and get a visual capture of the current state |
| Click & Fill Forms | Interact with UI elements by CSS selector — works with React’s synthetic event system |
| Run JavaScript | Execute arbitrary JS in the page context and get results back |
| Automated QA | Run structured QA checklists that drive the browser through test scenarios and report pass/fail |
Quick Start
# Add to Claude Code
claude mcp add browser-bridge -- npx -y mcp-browser-bridge
# Install the Chrome extension from the Web Store
# That's it. Start using browser_* tools.
Technical Highlights
- JSON-RPC 2.0 protocol — UUID-tracked requests with timeout auto-rejection
- React-compatible form filling — Uses native property setters to trigger React/Vue state updates
- WebSocket reconnection — Exponential backoff (1s to 30s) with stale-connection guards
- MCP Prompts as skills — QA and browsing workflows ship as MCP prompts
- Zero config — No API keys, no cloud services, no accounts
Links
License
MIT