DevTools Server

A specialized Model Context Protocol (MCP) server focused on process management, development server control, and browser console log collection. Solves common development challenges including npm run dev blocking and browser debugging visibility.

Features

Process Management

• kill_process - Kill process by name or PID with signal control
• detailed_process_list - Get detailed process info with CPU/memory usage and sorting
• find_process_url - Find URLs/ports for a process by name (development servers)

Development Server Management

• start_dev_server - Start development server in background (solves npm run dev blocking)
• stop_dev_server - Stop running development server
• check_dev_server - Check server status and port availability
• list_running_servers - List all running servers
• get_server_logs - Get server logs for debugging
• restart_dev_server - Restart a development server

Browser Log Collection

• get_browser_logs - Retrieve browser console logs with filtering
• get_browser_log_stats - Get statistics about collected logs
• clear_browser_logs - Clear stored browser logs

Installation

npm install

Development

npm run dev

Build

npm run build

MCP Server Configuration

Claude Code (claude.ai/code) Configuration

Add the following configuration to your ~/.claude/mcp_servers.json:

{
  "devtools": {
    "command": "node",
    "args": ["/path/to/devtools-mcp/dist/index.js"],
    "cwd": "/path/to/devtools-mcp"
  }
}

Claude Desktop Configuration

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "devtools": {
      "command": "node",
      "args": ["/path/to/devtools-mcp/dist/index.js"],
      "cwd": "/path/to/devtools-mcp"
    }
  }
}

General MCP Client Configuration

For other MCP-compatible clients, configure the server with:

• Command: node
• Args: ["/path/to/devtools-mcp/dist/index.js"]
• Working Directory: /path/to/devtools-mcp
• Transport: stdio

Make sure to build the project first:

npm run build

Usage

The server runs on stdio and can be integrated with MCP-compatible clients.

Development Server Management Examples

// Start a development server in background
{
  "tool": "start_dev_server",
  "arguments": {
    "command": "npm run dev",
    "name": "my-app",
    "port": 3000,
    "cwd": "/path/to/project"
  }
}

// Check server status
{
  "tool": "check_dev_server",
  "arguments": {
    "name": "my-app",
    "port": 3000
  }
}

// Get server logs for debugging
{
  "tool": "get_server_logs",
  "arguments": {
    "name": "my-app",
    "lines": 50
  }
}

// Stop server when done
{
  "tool": "stop_dev_server",
  "arguments": {
    "name": "my-app"
  }
}

This solves the common issue where npm run dev blocks Claude Code execution. The server starts in the background and returns immediately, allowing Claude Code to continue with other tasks while monitoring the development server status.

Process Management Examples

// Kill process by name
{
  "tool": "kill_process",
  "arguments": {
    "name": "node",
    "signal": "TERM",
    "force": false
  }
}

// Get detailed process list sorted by CPU usage
{
  "tool": "detailed_process_list",
  "arguments": {
    "filter": "node",
    "sortBy": "cpu",
    "limit": 10
  }
}

// Find development server URL by process name
{
  "tool": "find_process_url",
  "arguments": {
    "processName": "node"
  }
}
// Returns: "Development server likely running at: http://localhost:3000"

Browser Log Collection

The browser log collection feature requires installing a Chrome extension to capture console logs from localhost development servers.

Chrome Extension Installation

The browser log collection requires a Chrome extension to capture console logs from localhost development servers.

Prerequisites:

• Google Chrome or Chromium-based browser
• DevTools MCP Server running (the extension sends logs to http://localhost:3456)

Installation Steps:

1. Open Chrome Extensions Management

   • Navigate to chrome://extensions/
   • Or click Chrome menu → More Tools → Extensions

2. Enable Developer Mode

   • Toggle "Developer mode" switch in the top right corner

3. Load the Extension

   • Click "Load unpacked" button
   • Navigate to and select the extension directory from this project
   • The extension should appear in your extensions list

4. Verify Installation

   • You should see "DevTools Browser Log Collector" in your extensions
   • The extension icon may appear in your browser toolbar
   • Start your MCP server (npm run dev) to begin collecting logs

Automatic Log Collection:

• The extension automatically detects localhost URLs (ports 3000-9999)
• Captures all console.log, console.warn, console.error messages
• Sends logs to the MCP server running on port 3456
• No additional configuration required

Troubleshooting:

• If logs aren't appearing, check that your MCP server is running
• Verify your development server is running on a supported port (3000-9999)
• Check Chrome extension permissions in chrome://extensions/
• Refresh localhost tabs after installing the extension

Using Browser Log Tools

// Get recent browser logs
{
  "tool": "get_browser_logs",
  "arguments": {
    "filter": {
      "port": "3000",
      "level": ["error", "warn"],
      "limit": 50
    }
  }
}

// Get browser log statistics
{
  "tool": "get_browser_log_stats",
  "arguments": {}
}
// Returns: { totalLogs: 234, portStats: { "3000": 150, "8080": 84 }, activePorts: ["3000", "8080"] }

// Clear logs for specific port
{
  "tool": "clear_browser_logs",
  "arguments": {
    "port": "3000"
  }
}

The MCP server automatically starts an HTTP server on port 3456 to receive logs from the Chrome extension. Logs are stored in memory and can be filtered by:

• Port number (e.g., "3000", "8080")
• Log level (log, warn, error, info, debug)
• Time range
• Project ID (auto-detected from page)

License

MIT