# DebugMCP
**Repository Path**: mirrors_microsoft/DebugMCP
## Basic Information
- **Project Name**: DebugMCP
- **Description**: Gift your VS Code agent a real debugger: breakpoints, stepping, inspection.
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No
## Statistics
- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-11-16
- **Last Updated**: 2026-05-09
## Categories & Tags
**Categories**: Uncategorized
**Tags**: None
## README
# DebugMCP (MCP Server) - Empowering AI Agents with Operational Debugging Capabilities
Let AI agents debug your code inside VS Code - set breakpoints, step through execution, inspect variables, and evaluate expressions. Works with **Codex**, **GitHub Copilot**, **GitHub Copilot CLI**, **Cline**, **Cursor**, **Windsurf**, **Roo Code**, and any MCP-compatible assistant. Supports **Python**, **JavaScript/TypeScript**, **Java**, **C#**, **C++**, **Go**, **Rust**, **PHP**, and **Ruby**.
[](https://opensource.org/licenses/MIT)
[](https://code.visualstudio.com/)
[](https://github.com/microsoft/DebugMCP)
[](https://marketplace.visualstudio.com/items?itemName=ozzafar.debugmcpextension)
> ⭐ **If you find DebugMCP useful, please [star the repo on GitHub](https://github.com/microsoft/DebugMCP)!** It helps others discover the project and motivates continued development.
> 🎬 Watch DebugMCP in action — your AI assistant autonomously sets breakpoints, steps through code, and inspects variables directly in VS Code.
> **📢 Developers Notice**: This extension is maintained by [ozzafar@microsoft.com](mailto:ozzafar@microsoft.com) and [orbarila@microsoft.com](mailto:orbarila@microsoft.com). We welcome feedback and contributions to help improve this extension.
## 🚀 Quick Install
**[Install from VS Code Marketplace](https://marketplace.visualstudio.com/items?itemName=ozzafar.debugmcpextension)** or use the direct link: `vscode:extension/ozzafar.debugmcpextension`
## Table of Contents
- [Overview](#overview)
- [Features](#features)
- [Installation](#installation)
- [Quick Start](#quick-start)
- [Supported AI Assistants](#supported-ai-assistants)
- [Supported Languages](#supported-languages)
- [Configuration](#configuration)
- [FAQ](#faq)
- [Troubleshooting](#troubleshooting)
- [How It Works](#how-it-works)
- [Contributing](#contributing)
- [License](#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
| Tool | Description | Parameters |
|------|-------------|------------|
| **get_debug_instructions** | Get the debugging guide with best practices and workflow instructions | None |
| **start_debugging** | Start a debug session for a source code file | `fileFullPath` (required) `workingDirectory` (required) `testName` (optional) `configurationName` (optional) |
| **stop_debugging** | Stop the current debug session | None |
| **step_over** | Execute the next line (step over function calls) | None |
| **step_into** | Step into function calls | None |
| **step_out** | Step out of the current function | None |
| **continue_execution** | Continue until next breakpoint | None |
| **restart_debugging** | Restart the current debug session | None |
| **add_breakpoint** | Add a breakpoint at a specific line | `fileFullPath` (required) `lineContent` (required) |
| **remove_breakpoint** | Remove a breakpoint from a specific line | `fileFullPath` (required) `line` (required) |
| **clear_all_breakpoints** | Remove all breakpoints at once | None |
| **list_breakpoints** | List all active breakpoints | None |
| **get_variables_values** | Get variables and their values at current execution point | `scope` (optional: 'local', 'global', 'all') |
| **evaluate_expression** | Evaluate an expression in debug context | `expression` (required) |
> **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](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](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](#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 AI Assistants
DebugMCP works with any MCP-compatible AI assistant. It auto-detects and offers to register itself with:
| Assistant | Auto-Registration | Manual Config |
|-----------|:-----------------:|:-------------:|
| **GitHub Copilot** | ✅ | [See config](#github-copilot) |
| **GitHub Copilot CLI** | ✅ | [See config](#github-copilot-cli) |
| **Cline** | ✅ | [See config](#cline) |
| **Cursor** | ✅ | [See config](#cursor) |
| **Codex** | ✅ | [See config](#codex) |
| **Windsurf** | ✅ | [See config](#windsurf) |
| **Roo Code** | ✅ | [See config](#roo-code) |
| **Antigravity** | ✅ | [See config](#antigravity) |
| Any MCP-compatible assistant | — | [See manual setup](#manual-mcp-server-registration-optional) |
## Supported Languages
DebugMCP supports debugging for the following languages with their respective VSCode extensions:
| Language | Extension Required | File Extensions | Status |
|----------|-------------------|-----------------|---------|
| **Python** | [Python](https://marketplace.visualstudio.com/items?itemName=ms-python.python) | `.py` | ✅ Fully Supported |
| **JavaScript/TypeScript** | Built-in / [JS Debugger](https://marketplace.visualstudio.com/items?itemName=ms-vscode.js-debug) | `.js`, `.ts`, `.jsx`, `.tsx` | ✅ Fully Supported |
| **Java** | [Extension Pack for Java](https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-pack) | `.java` | ✅ Fully Supported |
| **C/C++** | [C/C++](https://marketplace.visualstudio.com/items?itemName=ms-vscode.cpptools) | `.c`, `.cpp`, `.cc` | ✅ Fully Supported |
| **Go** | [Go](https://marketplace.visualstudio.com/items?itemName=golang.Go) | `.go` | ✅ Fully Supported |
| **Rust** | [rust-analyzer](https://marketplace.visualstudio.com/items?itemName=rust-lang.rust-analyzer) | `.rs` | ✅ Fully Supported |
| **PHP** | [PHP Debug](https://marketplace.visualstudio.com/items?itemName=xdebug.php-debug) | `.php` | ✅ Fully Supported |
| **Ruby** | [Ruby](https://marketplace.visualstudio.com/items?itemName=rebornix.ruby) | `.rb` | ✅ Fully Supported |
| **C#/.NET** | [C#](https://marketplace.visualstudio.com/items?itemName=ms-dotnettools.csharp) | `.cs`, `.csproj` | ✅ Fully Supported |
## 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.
You can also trigger the registration manually via the Command Palette:
- **`DebugMCP: Show Agent Selection Popup`**
### 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`:
```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`):
```json
{
"mcp": {
"servers": {
"debugmcp": {
"type": "http",
"url": "http://localhost:3001/mcp",
"description": "DebugMCP - Multi-language debugging support"
}
}
}
}
```
#### GitHub Copilot CLI
Add to `~/.copilot/mcp-config.json` (`${COPILOT_HOME}/mcp-config.json` if `COPILOT_HOME` is set):
```json
{
"mcpServers": {
"debugmcp": {
"type": "http",
"url": "http://localhost:3001/mcp",
"tools": ["*"]
}
}
}
```
#### Cursor
Add to Cursor's MCP settings:
```json
{
"mcpServers": {
"debugmcp": {
"type": "streamableHttp",
"url": "http://localhost:3001/mcp",
"description": "DebugMCP - Debugging tools for AI assistants"
}
}
}
```
#### Codex
Register DebugMCP with Codex:
```bash
codex mcp add debugmcp --url http://localhost:3001/mcp
```
Or add the equivalent configuration to `~/.codex/config.toml` (`${CODEX_HOME}/config.toml` if `CODEX_HOME` is set):
```toml
[mcp_servers.debugmcp]
url = "http://localhost:3001/mcp"
```
#### Windsurf
Add to Windsurf's MCP settings (`~/.windsurf/mcp_settings.json` or workspace `.windsurf/mcp_settings.json`):
```json
{
"mcpServers": {
"debugmcp": {
"type": "streamableHttp",
"url": "http://localhost:3001/mcp",
"description": "DebugMCP - Debugging tools for AI assistants"
}
}
}
```
#### Roo Code
Add to Roo Code's MCP settings:
```json
{
"mcpServers": {
"debugmcp": {
"type": "streamableHttp",
"url": "http://localhost:3001/mcp",
"description": "DebugMCP - Debugging tools for AI assistants"
}
}
}
```
#### Antigravity
Add to Antigravity's MCP settings:
```json
{
"mcpServers": {
"debugmcp": {
"type": "streamableHttp",
"url": "http://localhost:3001/mcp",
"description": "DebugMCP - Debugging tools for AI assistants"
}
}
}
```
### Extension Settings
Configure DebugMCP behavior in VSCode settings:
```json
{
"debugmcp.serverPort": 3001,
"debugmcp.timeoutInSeconds": 180
}
```
| Setting | Default | Description |
|---------|---------|-------------|
| `debugmcp.serverPort` | `3001` | Port number for the MCP server |
| `debugmcp.timeoutInSeconds` | `180` | Timeout for debugging operations |
## FAQ
Which AI assistants are supported?
DebugMCP works with any MCP-compatible AI assistant, including **GitHub Copilot**, **GitHub Copilot CLI**, **Cline**, **Cursor**, **Codex**, **Windsurf**, **Roo Code**, **Antigravity**, and others. If your assistant supports the Model Context Protocol, it can use DebugMCP.
Does it work with VS Code Remote SSH / Codespaces / WSL?
Yes. DebugMCP runs as a VS Code extension with `extensionKind: workspace`, so it activates in the remote environment where your code lives. The MCP server runs on `localhost` within that remote context.
Do I need to configure launch.json?
No. DebugMCP automatically generates appropriate debug configurations based on the file's language/extension. If you have a `launch.json`, it will automatically pick the most relevant configuration.
Is my code sent to any external service?
No. DebugMCP runs 100% locally. The MCP server runs on `localhost`, and no code, variables, or debug data is sent to any external service. The AI assistant communicates with the MCP server entirely within your local machine.
What if port 3001 is already in use?
Change the port in VS Code settings: `"debugmcp.serverPort": 3002` (or any available port). Then update your AI assistant's MCP configuration to use the new port.
Can I debug unit tests?
Yes. Pass the `testName` parameter to `start_debugging` to debug a specific test method. DebugMCP will configure the debug session to run and pause at breakpoints within that test.
Why is my AI assistant not using the debug tools?
Make sure DebugMCP is registered in your AI assistant's MCP settings. The extension should auto-detect and offer to register itself. If not, see the [Manual MCP Server Registration](#manual-mcp-server-registration-optional) section. Also enable auto-approval for DebugMCP tools for a smoother workflow.
Does it support ASP.NET / .csproj projects?
Yes. DebugMCP supports `.cs` files and `.csproj` project files for C#/.NET debugging, including ASP.NET applications.
## 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
#### Debug Session Not Stopping at Breakpoints
- **Symptom**: Breakpoints are set but execution doesn't pause
- **Solution**:
- Ensure the correct file is being debugged
- Check that the breakpoint line content matches exactly
- Verify the relevant language debugger extension is installed
#### Configuration Not Auto-Detected
- **Symptom**: Extension doesn't prompt to register with your AI assistant
- **Solution**:
- Run **`DebugMCP: Show Agent Selection Popup`** from the Command Palette (Ctrl+Shift+P / Cmd+Shift+P)
- Manually add the configuration (see [Manual MCP Server Registration](#manual-mcp-server-registration-optional))
## How It Works
### Architecture
```
AI Agent (Copilot/Cline/Cursor/Codex) → MCP/Streamable HTTP → DebugMCPServer → DebuggingHandler → VS Code Debug API
```
### 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
- Honor `configurationName` when explicitly provided by the agent
- Support JSONC (JSON with comments and trailing commas)
- **Default Configuration**: If `configurationName` is omitted, or if no matching named configuration is found, it creates an appropriate default configuration for each language based on file extension detection
## Requirements
- VSCode with appropriate language extensions installed:
- **Python**: [Python extension](vscode:extension/ms-python.debugpy) for `.py` files
- **JavaScript/TypeScript**: Built-in Node.js debugger or [JavaScript Debugger extension](vscode:extension/ms-vscode.js-debug)
- **Java**: [Extension Pack for Java](vscode:extension/vscjava.vscode-java-pack)
- **C#/.NET**: [C# extension](vscode:extension/ms-dotnettools.csharp)
- **C/C++**: [C/C++ extension](vscode:extension/ms-vscode.cpptools)
- **Go**: [Go extension](vscode:extension/golang.go)
- **Rust**: [rust-analyzer extension](vscode:extension/rust-lang.rust-analyzer)
- **PHP**: [PHP Debug extension](vscode:extension/xdebug.php-debug)
- **Ruby**: [Ruby extension](vscode:extension/rebornix.ruby) with debug support
- MCP-compatible AI assistant (Copilot, Cline, Cursor, Codex, Windsurf, Roo Code, etc.)
## Development
To build the extension:
```bash
npm install
npm run compile
```
To run linting:
```bash
npm run lint
```
To run tests:
```bash
npm test
```
## 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](https://opensource.microsoft.com/codeofconduct/).
For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or
contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.
## Security
Security vulnerabilities should be reported following the guidance at [https://aka.ms/SECURITY.md](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](https://www.microsoft.com/en-us/legal/intellectualproperty/trademarks/usage/general).
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.
## ⭐ Support DebugMCP
If DebugMCP has helped you debug faster, please consider giving it a star on GitHub! Stars help the project gain visibility and attract contributors.
**[⭐ Star DebugMCP on GitHub](https://github.com/microsoft/DebugMCP)**
### Star History
## License
MIT License - See [LICENSE](LICENSE.txt) for details
This extension was created by **Oz Zafar**, **Ori Bar-Ilan** and **Karin Brisker**.
