MCP Server Browser

Browser Use MCP Server

A fast, lightweight Model Context Protocol (MCP) server that empowers LLMs with browser automation via Puppeteer’s structured accessibility data, featuring optional vision mode for complex visual understanding and flexible, cross-platform configuration.

Key Features

• ⚡ Fast & lightweight. Utilizes Puppeteer's label index, not pixel-based input and accessibility DOM tree.
• 👁️ Vision Mode Support. Optional visual understanding capabilities for complex layouts and visual elements when structured data isn't sufficient.
• 🤖 LLM-optimized. No vision models needed, operates purely on structured data, less context reducing context token usage.
• 🧩 Flexible Runtime Configuration. Customize viewport size, coordinate system factors, and User-Agent at runtime via HTTP headers.
• 🌐 Cross-Platform & Extensible. Support for remote and local browsers, the use of a custom browser engine.

Requirements

• Node.js 18 or newer
• VS Code, Cursor, Windsurf, Claude Desktop or any other MCP client

Getting started

Local (Stdio)

First, install the Browser MCP server with your client. A typical configuration looks like this:

{
  "mcpServers": {
    "browser": {
      "command": "npx",
      "args": [
        "@agent-infra/mcp-server-browser@latest"
      ]
    }
  }
}

# For VS Code
code --add-mcp '{"name":"browser","command":"npx","args":["@agent-infra/mcp-server-browser@latest"]}'

{
  "mcpServers": {
    "browser": {
      "command": "npx",
      "args": [
        "@agent-infra/mcp-server-browser@latest"
      ]
    }
  }
}

{
  "mcpServers": {
    "browser": {
      "command": "npx",
      "args": [
        "@agent-infra/mcp-server-browser@latest"
      ]
    }
  }
}

{
  "mcpServers": {
    "browser": {
      "command": "npx",
      "args": [
        "@agent-infra/mcp-server-browser@latest"
      ]
    }
  }
}

Remote (SSE / Streamable HTTP)

At the same time, use --port $your_port arg to start the browser mcp can be converted into SSE and Streamable HTTP Server.

# normal run remote mcp server
npx @agent-infra/mcp-server-browser --port 8089

# run with DISPLAY environment for VNC or other virtual display
DISPLAY=:0 npx @agent-infra/mcp-server-browser --port 8089

You can use one of the two MCP Server remote endpoint:

• Streamable HTTP(Recommended): http://127.0.0.1::8089/mcp
• SSE: http://127.0.0.1::8089/sse

And then in MCP client config, set the url to the SSE endpoint:

{
  "mcpServers": {
    "browser": {
      "url": "http://127.0.0.1::8089/sse"
    }
  }
}

url to the Streamable HTTP:

{
  "mcpServers": {
    "browser": {
      "type": "streamable-http", // If there is MCP Client support
      "url": "http://127.0.0.1::8089/mcp"
    }
  }
}

In-memory call

If your MCP Client is developed based on JavaScript / TypeScript, you can directly use in-process calls to avoid requiring your users to install the command-line interface to use Browser MCP.

import { Client } from '@modelcontextprotocol/sdk/client/index.js';
import { InMemoryTransport } from '@modelcontextprotocol/sdk/inMemory.js';

// type: module project usage
import { createServer } from '@agent-infra/mcp-server-browser';
// commonjs project usage
// const { createServer } = await import('@agent-infra/mcp-server-browser')

const client = new Client(
  {
    name: 'test browser client',
    version: '1.0',
  },
  {
    capabilities: {},
  },
);

const server = createServer();
const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();

await Promise.all([
  client.connect(clientTransport),
  server.connect(serverTransport),
]);

// list tools
const result = await client.listTools();
console.log(result);

// call tool
const toolResult = await client.callTool({
  name: 'browser_navigate',
  arguments: {
    url: 'https://www.google.com',
  },
});
console.log(toolResult);

Configuration

Browser MCP server supports following arguments. They can be provided in the JSON configuration above, as a part of the "args" list:

> npx @agent-infra/mcp-server-browser@latest -h
  -V, --version              output the version number
  --browser <browser>        browser or chrome channel to use, possible values: chrome, edge, firefox.
  --cdp-endpoint <endpoint>  CDP endpoint to connect to, for example "http://127.0.0.1:9222/json/version"
  --ws-endpoint <endpoint>   WebSocket endpoint to connect to, for example "ws://127.0.0.1:9222/devtools/browser/{id}"
  --executable-path <path>   path to the browser executable.
  --headless                 run browser in headless mode, headed by default
  --host <host>              host to bind server to. Default is localhost. Use 0.0.0.0 to bind to all interfaces.
  --port <port>              port to listen on for SSE and HTTP transport.
  --proxy-bypass <bypass>    comma-separated domains to bypass proxy, for example ".com,chromium.org,.domain.com"
  --proxy-server <proxy>     specify proxy server, for example "http://myproxy:3128" or "socks5://myproxy:8080"
  --user-agent <ua string="">   specify user agent string
  --user-data-dir <path>     path to the user data directory.
  --viewport-size <size>     specify browser viewport size in pixels, for example "1280, 720"
  --output-dir <path>        path to the directory for output files
  --vision                   Run server that uses screenshots (Aria snapshots are used by default)
  -h, --help                 display help for command

Runtime Configuration

The browser runtime requires configuration for Viewport Size, Vision Model Coordinate Factors, and User Agent. These can be passed through corresponding HTTP headers:

Example:

x-viewport-size: 1920,1080
x-vision-factors: 1.0,1.0
x-user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36

Docker

We have unified the deployment of VNC and MCP under a single URL endpoint, The Dockerfile and DockerHub image will be published together! video

API

Tools

Resources

Developement

Access http://127.0.0.1:6274/:

npm run dev

Extended CLI Entry

#!/usr/bin/env node

const {
  BaseLogger,
  setConfig,
  addMiddleware,
} = require('@agent-infra/mcp-server-browser/dist/request-context.cjs');

class CustomLogger extends BaseLogger {
  info(...args) {
    console.log('custom');
    console.log(...args);
  }
}

addMiddleware((req, res, next) => {
  console.log('req', req.headers);
  next();
});

setConfig({
  logger: new CustomLogger(),
});

// start server
require('@agent-infra/mcp-server-browser/dist/index.cjs');