pwndbg-mcp

Overview

pwndbg-mcp runs a local GDB session with pwndbg loaded and exposes it to an MCP client. The client reads live debugger state and runs approved commands against it. Built for pentesting, CTF pwn, exploit development, and crash analysis.

Run the server on the analysis machine, next to GDB and the target. It starts GDB in MI mode and expects your own GDB setup to load pwndbg. The inferior gets a PTY, so clients can read it, write to it, and interrupt interactive programs. The server tracks inferior state, and any tool that needs it stopped checks first.

Related MCP server: mcp-gdbserver

Background

This started from RocketMaDev/pwndbg-mcp, which drives pwndbg over MCP for ELF and CTF pwn work in 19 tools, and whose PTY and controller scaffold this project's bridge.py is derived from. That project in turn credits pwno-mcp as its bootstrap framework.

What this adds: 169 tools against their 19, attach by PID or process name, remote gdbserver over target remote and target extended-remote, decompiler context through pwndbg's di commands rather than decomp2dbg directly, and an installer that writes a per-tool approval inventory into the client's config.

Features

169 registered tools, split 84 read-only and 85 mutating. Serve them over stdio, HTTP, or SSE.

For the full list, read src/pwndbg_mcp/tools/_registry.py or ask a client for tools/list.

Large results are capped, and anything truncated says so in its response. src/pwndbg_mcp/util.py holds the limits. A GDB command that fails comes back as an MCP error, not as partial output that looks like success.

Installation

Prerequisites: Linux, Python 3.11+, uv, GDB, pwndbg.

From a clone, with client configuration:

git clone https://github.com/h0w1tzxr/pwndbg-mcp.git
cd pwndbg-mcp
python install.py
pwndbg-mcp doctor

Tool only:

uv tool install git+https://github.com/h0w1tzxr/pwndbg-mcp.git
pwndbg-mcp doctor

Configure clients

Two entry points:

• python install.py is interactive. It installs the tool and configures Claude Code, Codex, or both. Only it accepts --clients and --codex-config.

• pwndbg-mcp install does Claude Code only. It has no Codex flags.

The server uses FastMCP, whose CLI exposes stdio (the default), HTTP, and SSE. Any client that can launch a stdio server works; configure those yourself.

Claude Code

pwndbg-mcp install --scope user
pwndbg-mcp status

That registers the server over stdio and writes one exact rule per tool: read-only tools into permissions.allow, mutating tools into permissions.ask. Use --unsafe only in an isolated test environment. It moves both inventories to allow.

User, project, and local policies live in ~/.claude/settings.json, .claude/settings.json, and .claude/settings.local.json. --scope selects only the Claude Code scope. Without the Claude CLI, the JSON fallback supports user and project scopes, and local scope requires the CLI.

Codex

Configure Codex through python install.py --codex-config (default ~/.codex/config.toml). Any Claude scope other than user leaves the Codex path unset, so pass --codex-config yourself when you configure both. Codex manages approvals itself, and the installer's per-tool inventory is not written there.

Manual configuration:

[mcp_servers.pwndbg]
command = "pwndbg-mcp"
args = [
  "--transport", "stdio",
  "--pwndbg", "gdb",
]

If the client cannot find the binary, use the absolute path from command -v pwndbg-mcp.

tools/list publishes standard MCP readOnlyHint and destructiveHint annotations from the same inventories. They are advisory; the client's approval policy decides.

Decompiler integration

Requires pwndbg 2026.02.18 or newer, which exposes one decompiler-integration command (aliased di) for IDA, Binary Ninja, Ghidra, and angr-management. A local provider also needs decomp2dbg in pwndbg's own Python environment. That is not a pwndbg-mcp dependency.

Stop the inferior first, then:

1. Call decompiler_status. It reports the command, pwndbg version, host, port, live provider, and the installed and required dependency versions.

2. Install a matching plugin with pwndbg's di install <provider>. This writes files and may download a plugin, so run it through the approval-gated execute_command tool only after review.

3. Open the same binary in the decompiler and start its server with Ctrl+Shift+D.

4. Call decompiler_connect, then decompiler_sync once the inferior starts.

5. Call decomp with an optional address and line count. Call decompiler_disconnect when done.

A dependency or provider mismatch raises MissingDependency. A closed listener raises RemoteConnectionError naming its endpoint. For a local provider, pass literal localhost to decompiler_connect so pwndbg runs its local dependency and version checks.

IDA and Ghidra expose unauthenticated, unencrypted XML-RPC. Bind their listeners only to 127.0.0.1:3662 and confirm the socket with ss. Linux may show the same IPv4-mapped loopback as [::ffff:127.0.0.1]:3662. Reject wildcard and non-loopback listeners.

Remote debugging

Load local symbols before connecting:

file /path/to/local/binary
set sysroot /path/to/target-root

Then call gdb_target_remote for a regular gdbserver target, or gdb_target_extended_remote for extended mode. A failed connection names the endpoint. To recover, restart gdbserver, run disconnect through the approval-gated execute_command tool before reconnecting, or call mcp_hard_reset when GDB stops responding.

remote_pwncat_* needs pwncat (uv tool install pwncat). ROP helpers report a missing ROPgadget, ropper, one_gadget, or pwntools and name the install. leakfind ships with pwndbg and needs no external binary.

To find your way around, call version_info, then list_pwndbg_commands, then pwndbg_help on whatever looks useful. Clients can also use tools/list.

Development

Clone it, then work with uv directly:

uv tool install --editable . --reinstall   # link for development
uv run --extra dev ruff check src/         # lint
uv run --extra dev mypy src/               # typecheck
uv run --extra dev ruff format src/        # format
uv build                                   # wheel + sdist
pwndbg-mcp doctor                          # check gdb, pwndbg, and PATH

List the tool surface over stdio:

echo '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' | pwndbg-mcp --transport stdio --pwndbg gdb

Before publishing or handing off:

uv run --extra dev ruff check src/
uv run --extra dev mypy src/
uv build
uv lock --check
git diff HEAD --check

Check the registry split:

uv run --extra dev python - <<'PY'
from pwndbg_mcp.tools._registry import SAFE_TOOLS, MUTATING_TOOLS
print(len(SAFE_TOOLS), len(MUTATING_TOOLS), len(SAFE_TOOLS) + len(MUTATING_TOOLS))
PY

Expected output:

84 85 169

Layout:

• src/pwndbg_mcp/bridge.py: GDB/MI controller, PTY handling, state tracking, response parsing.

• src/pwndbg_mcp/tools/: tool modules grouped by debugging domain.

• src/pwndbg_mcp/tools/_registry.py: FastMCP singleton and the read-only and mutating inventories.

• src/pwndbg_mcp/installer/: client registration and config helpers.

• install.py: interactive installer.

Credits

Built on pwndbg, whose command surface this server exposes, and GDB underneath it.

RocketMaDev/pwndbg-mcp (MIT, Copyright (C) 2025-present RocketDev) is where the PTY and controller scaffold in bridge.py comes from, along with much of the tool naming. It credits pwno-mcp as its own bootstrap framework. pwntools does the payload-oriented process I/O.

Also ida-pro-mcp, FastMCP, and pygdbmi.

License

MIT. See LICENSE.