Browser REPL WebSocket

A WebSocket-based browser REPL tool that provides programmatic access to browser sessions via CLI and MCP server.

Features

• WebSocket server for browser REPL connections
• CLI tool for interactive JavaScript execution
• MCP server integration for seamless automation
• Playwright testing support
• Modular architecture for reusability

Installation

npm install

Usage

1. Start the WebSocket Server

npm start
# or
browser-repl-server

The server will output connection codes for both browser and CLI.

2. Connect Browser

Paste the provided JavaScript code into your browser's developer console.

3. Connect CLI

Use the provided CLI command:

browser-repl --session YOUR_SESSION_ID --host localhost --port 8080

4. MCP Server Configuration

Add to your Claude MCP configuration:

{
  "mcpServers": {
    "browser-repl": {
      "command": "node",
      "args": ["src/mcp/mcp-server.js"],
      "env": {
        "REPL_HOST": "localhost",
        "REPL_PORT": "8080",
        "REPL_SESSION": "YOUR_SESSION_ID"
      }
    }
  }
}

Architecture

• src/core/websocket.js - Core WebSocket server implementation
• src/core/client.js - WebSocket client for CLI connections
• src/server/index.js - Standalone WebSocket server
• src/cli/index.js - Interactive CLI client
• src/mcp/server.js - MCP server wrapper
• src/mcp/mcp-server.js - MCP protocol implementation

Testing

npm test

API

WebSocketREPLServer

import { WebSocketREPLServer } from './src/core/websocket.js';

const server = new WebSocketREPLServer({
  port: 8080,
  host: '0.0.0.0'
});

server.start();

WebSocketREPLClient

import { WebSocketREPLClient } from './src/core/client.js';

const client = new WebSocketREPLClient({
  host: 'localhost',
  port: 8080,
  sessionId: 'your-session-id'
});

await client.connect();
client.execute('document.title');

MCPBrowserREPLServer

import { MCPBrowserREPLServer } from './src/mcp/server.js';

const mcpServer = new MCPBrowserREPLServer({
  host: 'localhost',
  port: 8080,
  sessionId: 'your-session-id'
});

await mcpServer.initialize();
const result = await mcpServer.executeJavaScript('1 + 1');

License

MIT