DebugMCP (MCP Server) - Empowering AI Agents with Multi-Language Debugging Capabilities

Let AI agents debug your code inside VS Code — set breakpoints, step through execution, inspect variables, and evaluate expressions. Works with GitHub Copilot, Cline, Cursor, and any MCP-compatible assistant. Supports Python, JavaScript/TypeScript, Java, C#, C++, Go, Rust, PHP, and Ruby.

📢 Beta Version Notice: This is a beta version of DebugMCP maintained by ozzafar@microsoft.com and orbarila@microsoft.com. We welcome feedback and contributions to help improve this extension.

Watch DebugMCP in action — your AI assistant autonomously sets breakpoints, steps through code, and inspects variables directly in VS Code.

🚀 Quick Install

Install from VS Code Marketplace or use the direct link: vscode:extension/ozzafar.debugmcpextension

Table of Contents

• Overview
• Features
• Installation
• Quick Start
• Supported Languages
• Configuration
• Troubleshooting
• Contributing
• License

Overview

DebugMCP is an MCP server that gives AI coding agents full control over the VS Code debugger. Instead of reading logs or guessing, your AI assistant can autonomously set breakpoints, launch debug sessions, step through code line by line, inspect variable values, and evaluate expressions — just like a human developer would. It runs 100% locally, requires zero configuration, and works out of the box with any MCP-compatible AI assistant.

Features

🔧 Tools

Note: The get_debug_instructions tool is particularly useful for AI clients like GitHub Copilot that don't support MCP resources. It provides the same debugging guide content that is also available as an MCP resource.

🎯 Debugging Best Practices

DebugMCP follows systematic debugging practices for effective issue resolution:

• Start with Entry Points: Begin debugging at function entry points or main execution paths
• Follow the Execution Flow: Use step-by-step execution to understand code flow
• Root Cause Analysis: Don't stop at symptoms - find the underlying cause

🛡️ Security & Reliability

• Secure Communication: All MCP communications use secure protocols
• Local Operation: The MCP server runs 100% locally with no external communications and requires no credentials
• State Validation: Robust validation of debugging states and operations

Installation

Quick Install Options

Option 1: Direct Link (Fastest)

• Click this link: vscode:extension/ozzafar.debugmcpextension
• Or copy and paste in your browser: vscode:extension/ozzafar.debugmcpextension

Option 2: VS Code Marketplace

• Visit: https://marketplace.visualstudio.com/items?itemName=ozzafar.debugmcpextension
• Click "Install"

Option 3: Within VS Code

1. Open VSCode
2. Go to Extensions (Ctrl+Shift+X / Cmd+Shift+X)
3. Search for "DebugMCP"
4. Click Install
5. The extension automatically activates and registers as an MCP server

Verification

After installation, you should see:

• DebugMCP extension in your installed extensions
• MCP server automatically running on port 3001 (configurable)
• Debug tools available to connected AI assistants

📝 Note: No additional debugging rule instructions are needed - the extension works out of the box.

💡 Tip: Enable auto-approval for all debugmcp tools in your AI assistant to create seamless debugging workflows without constant approval interruptions.

Quick Start

1. Install the extension (see Installation)
2. Open your project in VSCode
3. Ask your AI to debug - it can now set breakpoints, start debugging, and analyze your code!

Supported Languages

DebugMCP supports debugging for the following languages with their respective VSCode extensions:

Configuration

MCP Server Configuration (Recommended)

The extension runs an MCP server automatically. It will pop up a message to auto-register the MCP server in your AI assistant.

Manual MCP Server Registration (Optional)

🔄 Auto-Migration: If you previously configured DebugMCP with SSE transport, the extension will automatically migrate your configuration to the new Streamable HTTP transport on activation.

Cline

Add to your Cline settings or cline_mcp_settings.json:

{
  "mcpServers": {
    "debugmcp": {
      "type": "streamableHttp",
      "url": "http://localhost:3001/mcp",
      "description": "DebugMCP - AI-powered debugging assistant"
    }
  }
}

GitHub Copilot

Add to your VS Code settings (settings.json):

{
  "mcp": {
    "servers": {
      "debugmcp": {
        "type": "http",
        "url": "http://localhost:3001/mcp",
        "description": "DebugMCP - Multi-language debugging support"
      }
    }
  }
}

Cursor

Add to Cursor's MCP settings:

{
  "mcpServers": {
    "debugmcp": {
      "type": "streamableHttp",
      "url": "http://localhost:3001/mcp",
      "description": "DebugMCP - Debugging tools for AI assistants"
    }
  }
}

Extension Settings

Configure DebugMCP behavior in VSCode settings:

{
  "debugmcp.serverPort": 3001,
  "debugmcp.timeoutInSeconds": 180
}

FAQ

Troubleshooting

Common Issues

MCP Server Not Starting

• Symptom: AI assistant can't connect to DebugMCP
• Solution:
  • Check if port 3001 is available
  • Restart VSCode
  • Verify extension is installed and activated

How It Works

Architecture

Launch Configuration Integration

The extension handles debug configurations intelligently:

• Existing launch.json: If a .vscode/launch.json file exists, it will:

  • Search for a relevant configuration
  • Use a specific configuration if found

• Default Configuration: If no launch.json exists or no relevant config, it creates an appropriate default configurations for each language based on file extension detection

Requirements

• VSCode with appropriate language extensions installed:
  • Python: Python extension for .py files
  • JavaScript/TypeScript: Built-in Node.js debugger or JavaScript Debugger extension
  • Java: Extension Pack for Java
  • C#/.NET: C# extension
  • C/C++: C/C++ extension
  • Go: Go extension
  • Rust: rust-analyzer extension
  • PHP: PHP Debug extension
  • Ruby: Ruby extension with debug support
• MCP-compatible AI assistant (Copilot, Cline, Roo..)

Development

To build the extension:

npm install
npm run compile

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

Security

Security vulnerabilities should be reported following the guidance at https://aka.ms/SECURITY.md. Please do not report security vulnerabilities through public GitHub issues.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party's policies.

⭐ Star History

License

MIT License - See LICENSE for details

This extension was created by Oz Zafar, Ori Bar-Ilan and Karin Brisker.