GDB MCP Server (FastMCP)

A lightweight MCP server that runs inside GDB. It exposes a single tool, gdb-command, which proxies input directly to GDB’s command interpreter and returns the textual output. The server runs over SSE and is started from within GDB via the mcp-server command.

Features

• gdb-command: pass any GDB command, get back its output.
• Minimal, self-contained script: gdb-mcp (loaded via source).

Requirements

• GDB with Python support enabled.
• Python 3.x and the fastmcp library available to GDB’s embedded Python.

Check Python support: gdb -q -ex "python print('ok')" -ex quit

Install FastMCP: python3 -m pip install fastmcp If import fails in GDB, ensure fastmcp is installed to the same Python environment GDB uses.

Quick Start

1. Start GDB with the MCP extension loaded

• gdb -q -ex 'source ./gdb-mcp'
• Alternatively, load from within gdb source ./gdb-mcp

2. Launch the SSE server from within GDB

• mcp-server 127.0.0.1 3333

3. Connect an MCP client to the server

• Configure your MCP client to connect to the SSE server at the host/port selected above and call tool gdb-command.

Tool: gdb-command

• Parameters:
  • command (string): the exact GDB command to run (e.g., info registers).
• Returns: string (captured GDB output or an error message).

Notes & Tips

• No timeout or stop control is provided by this script. To interrupt long-running target execution, issue the interrupt command.
• Do not bind publicly unless you trust clients; this endpoint can execute arbitrary GDB commands.
• To auto-load, add a line to your ~/.gdbinit: source /absolute/path/to/gdb-mcp.
• There is no builtin 'stop server' functionality. To teardown the server, exit GDB.

License

MIT — see LICENSE.

Acknowledgements

• Built on top of the excellent fastmcp library.