MCP Py Sse Browser Control

🚀 Browser JavaScript Executor

This project offers a method to execute JavaScript code from a browser in Python using the MCP (Model Control Protocol).

⚠️ Important Note

This MCP server can execute arbitrary JavaScript in your browser. This can be dangerous. Please understand its potential impacts before using this plugin. Use at your own risk.

✨ Features

The project consists of two main components:

1. Web Server (web_server.py):

   • Handles browser connections via Server-Sent Events (SSE).
   • Provides a REST API endpoint to execute JavaScript.
   • Returns results synchronously.

2. MCP Server (mcp_server.py):

   • Manages the lifecycle of the Web Server.
   • Offers MCP tools to execute JavaScript in the browser.
   • Communicates with the Web Server through REST API calls.

🔧 Technical Details

How It Works

1. The MCP Server starts the Web Server during its initialization lifecycle.
2. The browser connects to the Web Server via SSE.
3. When an MCP tool is invoked, it makes a REST API call to the Web Server.
4. The Web Server sends JavaScript code to the browser via SSE.
5. The browser executes the code and returns the results to the Web Server via SSE.
6. The Web Server returns the results to the MCP Server.
7. The MCP Server returns the results to the caller.

🚀 Quick Start

Add the MCP Server to Your Claude Configuration

...
"browser-js-evaluator": {
    "command": "uv",
    "args": [
      "--directory",
      "/path/to/this/repo/mcp_py_sse_browser_control",
      "run",
      "browser_server.py"
    ]
  }
...

After starting Claude Desktop, this configuration will launch the MCP Server and the Web Server. Then, open your browser and visit http://127.0.0.1:8000 to connect to the Web Server.

Use MCP Tools

The MCP Server provides the following two tools:

1. execute_javascript: Execute arbitrary JavaScript code in the browser.
2. add_numbers: Add two numbers using JavaScript in the browser.

These tools can be called from any MCP client.

💻 Usage Examples

Run the Web Server Independently (for Testing)

python web_server.py

This will start a service with only the Web Server, without MCP integration.