Gdbmi

An MCP server for interacting with GDB/MI (GDB Machine Interface).

Output from GDB/MI is "compressed" using json5 to reduce the token count for data structures. Hex values are also "compressed" by stripping out long 0x00000000000 prefixes ie 0x0000004 becomes 0x4

[!CAUTION] GDB/MI can be very verbose, and this tool will destroy your quota VERY quickly if you are not careful with what you ask for! You have been warned.

Installation

Clone the repo and install the deps:

pip install .

Setup

Claude CLI

# run the mcp server
fastmcp run gdb_mcp.py:mcp --transport http --port 3333

# add it to claude
claude mcp add --transport http gdb http://localhost:3333/mcp

Gemini CLI (FastMCP and uv)

Gemini CLI 🤝 FastMCP

This command simplifies the process and makes the server capabilities instantly available and configured within Gemini CLI.

fastmcp install gemini-cli gdb_mcp.py

Gemini CLI (Manual)

.gemini/settings.json

{
  "mcpServers": {
    "GDB MCP Server": {
      "command": "fastmcp",
      "args": ["run", "/absolute/path/to/mcp-gdbmi/gdb_mcp.py:mcp"]
    }
  }
}

Usage

Start your program with gdbserver:

gdbserver localhost:1234 ./program

Then use the tools through your MCP client:

Ask Claude/Gemini to:

• Set breakpoints
• Run the program
• Step through code
• Analyse registers
• Anything that is possible via the GDB machine interface

Tools

connect(target: str)

Connect to GDB, which connects to the target (e.g., "localhost:1234" for a gdbserver instance).

disconnect()

Disconnect and terminate the GDB session.

command(command: str, wait_for_done: bool = True)

Execute a GDB/MI command (e.g., "-break-insert main", "-exec-run").

Common GDB/MI Commands

• -break-insert LOCATION - Set breakpoint
• -break-delete NUM - Delete breakpoint
• -exec-run - Start program
• -exec-continue - Continue execution
• -exec-step / -exec-next - Step through code
• -stack-list-frames - Show stack frames
• -data-evaluate-expression EXPR - Evaluate expression

See GDB/MI docs for more.

License

MIT