real-browser-mcp

You ship a fix. Your agent says "done, please verify." You alt-tab to Chrome, navigate to the page, log in, click around, find the bug.

Your agent just wrote the code. It could also verify it. It already has your browser open right there. It just can't see it.

Now it can.

Quick Start

Two parts:

• MCP server - runs on your machine, talks to your AI agent

• Chrome extension - sits in your browser, executes the commands

1. Add the MCP server

Cursor (one click):

Or add manually in Cursor Settings > MCP > "Add new MCP server":

{
  "mcpServers": {
    "real-browser": {
      "command": "npx",
      "args": ["-y", "real-browser-mcp"]
    }
  }
}

Claude Desktop: Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows). Add the same JSON block.

Windsurf: Settings > MCP. Same config.

Any MCP-compatible client works.

2. Install the Chrome extension

Or load from source:

git clone https://github.com/ofershap/real-browser-mcp.git

1. Open chrome://extensions and enable Developer mode (toggle in the top right)

2. Click Load unpacked and select the extension/ folder from the cloned repo

Click the Real Browser MCP icon in your toolbar.

Green dot = connected. Gray = waiting for server.

Done. Your agent can see your browser.

Related MCP server: Chrome MCP Server

How Others Compare

🧠 Teach Your Agent

The agent can use all 18 tools out of the box, but it works better when it knows when and how to chain them. A config file teaches the right workflow - snapshot first, then act, then verify.

Run one command:

npx real-browser-mcp --setup cursor

This installs:

• ~/.cursor/rules/real-browser-mcp.mdc - teaches the snapshot-first workflow, how to handle dropdowns, when to use screenshots vs snapshots

• ~/.cursor/commands/check-browser.md - adds /check-browser to your Cursor chat

After that, type /check-browser in any chat. Or just say "check the result in my browser" and the agent knows what to do.

npx real-browser-mcp --setup claude

Adds an AGENTS.md to your project root. Claude Code auto-discovers it.

See agent-config/ for manual installation or to customize the rules.

What It Can Do

18 tools. Grouped by purpose.

See

Interact

Navigate

Debug

Configuration

Connection drops are handled automatically with exponential backoff (1s to 30s), ping/pong health checks every 10s, and per-tool timeouts (5s for clicks, 60s for navigation).

Run two server instances on different ports:

{
  "mcpServers": {
    "browser-work": {
      "command": "npx", "args": ["-y", "real-browser-mcp"]
    },
    "browser-personal": {
      "command": "npx", "args": ["-y", "real-browser-mcp"],
      "env": { "WS_PORT": "9333" }
    }
  }
}

Update the port in each extension popup to match.

Everything stays on your machine. The extension connects to the MCP server via WebSocket on localhost. No cloud, no proxy, nothing leaves your browser.

real-browser-mcp/
├── mcp-server/          MCP server (npm package, TypeScript)
│   └── src/tools/       One file per tool, registry pattern
├── extension/           Chrome extension (Manifest V3, plain JS)
│   ├── background.js    Service worker, WebSocket client, tool handlers
│   ├── content.js       Console capture
│   └── popup/           Connection status UI
├── agent-config/        Pre-built configs for Cursor + Claude Code
│   ├── cursor/          Rules and commands
│   ├── skills/          Browser automation skill
│   └── setup.mjs        One-command installer
└── tests/               Bridge + registry tests

Stack: TypeScript (strict) · MCP SDK · WebSocket · Chrome Extension Manifest V3 · Vitest

git clone https://github.com/ofershap/real-browser-mcp.git
cd real-browser-mcp
npm install
npm run build
npm test

FAQ

That's the whole point. The extension runs inside your actual Chrome - same cookies, same sessions, same local storage. No re-authentication needed.

No. The MCP server and extension talk over WebSocket on localhost. Nothing leaves your machine. There's no analytics, no telemetry, no cloud component. Privacy policy.

Any MCP-compatible client. Cursor, Claude Desktop, Claude Code, Windsurf, Cline, and anything else that speaks the MCP protocol.

Yes. Run two MCP server instances on different ports. See Configuration for the setup.

They launch a new browser instance from scratch - no state, no cookies, no sessions. You have to replay the full login flow every time. This connects to the browser you already have open with everything already loaded.

Contributing

Bug reports, feature requests, and PRs welcome. Open an issue first for larger changes.

Author

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License

MIT © Ofer Shapira