mcp-dap

mcp-dap

MCP-DAP bridge for enabling code agents to debug processes via the Debug Adapter Protocol (DAP).

Overview

This package provides an MCP (Model Context Protocol) server that exposes debugging capabilities through DAP. It allows AI coding agents to:

• Launch and attach to debug sessions
• Set breakpoints and step through code
• Inspect variables and evaluate expressions
• Control execution flow (continue, step over, step into, step out)

Installation

pip install mcp-dap

Run with uvx

Run directly from this repo:

uvx --from . mcp-dap

Run directly from GitHub:

uvx --from git+https://github.com/ztripez/mcp-dap mcp-dap

For MCP client config, point the server command at uvx:

{
  "mcpServers": {
    "dap": {
      "command": "uvx",
      "args": ["--from", "git+https://github.com/ztripez/mcp-dap", "mcp-dap"]
    }
  }
}

Debug adapters

mcp-dap is the MCP bridge; language DAP servers are separate runtime tools.

• Python (debugpy): included as a Python dependency.
• Rust/C/C++ (codelldb): install CodeLLDB (vadimcn.vscode-lldb) or codelldb on PATH.
• JavaScript/TypeScript (jsdebug): install Node.js and js-debug-dap (or have VS Code js-debug).
• Java (javadebug): install JDK + VS Code Java Debug extension (vscjava.vscode-java-debug).
• Go (godlv): install Delve (go install github.com/go-delve/delve/cmd/dlv@latest).

You can configure adapter paths with environment variables or mcp-dap.toml.

Rust evaluate tip (CodeLLDB)

When using the Rust adapter (rust/codelldb), expression evaluation in repl context is handled by LLDB's command console.

• Prefix expressions with ? to evaluate as Rust expressions.
• Example: ? cli.steps
• Example: ? cli

Without the ? prefix, LLDB may interpret input as a debugger command and return errors like 'cli' is not a valid command.

If local variables appear empty at a breakpoint, set the breakpoint one or two lines after variable initialization and try again.

Example:

[adapters.codelldb]
enabled = true
codelldb_path = "/path/to/codelldb"

[adapters.jsdebug]
enabled = true
node_path = "/usr/bin/node"
jsdebug_path = "/home/user/.local/share/mcp-dap/js-debug/src/dapDebugServer.js"

Development

# Install with dev dependencies
pip install -e ".[dev]"

# Run tests
pytest

# Run linting
ruff check .
ruff format --check .

# Run type checking
mypy src

Usage

Configure in your MCP client:

{
  "mcpServers": {
    "dap": {
      "command": "mcp-dap"
    }
  }
}

License

MIT