windbg-mcp-rs

windbg-mcp-rs is a pure WinDbg extension DLL that exposes the current debugging session as an MCP server.

• Read official WinDbg command documentation extracted from docs/debugger.chm
• Execute WinDbg commands through dbgeng
• Interrupt a running target from MCP
• Use the server from any MCP client over Streamable HTTP

Screenshots

Quick Start

1. Build the DLL

cargo build --release

2. Load it in WinDbg

.load path\to\windbg_mcp_rs.dll

3. Start the MCP server

!mcp serve 127.0.0.1:50051

The MCP endpoint will be:

http://127.0.0.1:50051/mcp

4. Connect your MCP client

Point your client to:

http://127.0.0.1:50051/mcp

WinDbg Commands

Use !mcp help to list all plugin commands.

Common ones:

!mcp help
!mcp serve 127.0.0.1:50051
!mcp status
!mcp stop

What MCP Exposes

• Resources: a low-context guide resource and compact/full WinDbg command documentation resources
• Tools: a compact toolset for catalog search, execution-state query, command execution, and target interrupt

Pure UI shortcut topics remain available as documentation, and command execution is exposed through a single windbg_execute_command tool.

Recommended agent flow: call windbg_search_catalog, read windbg://command/{id}, fall back to windbg://command-full/{id} only when needed, call windbg_get_execution_state, and then call windbg_execute_command.

If the debugger is running or busy, call windbg_interrupt_target explicitly and verify state again before executing the command.

Development

cargo check
cargo test

Notes

• This project was written entirely with a Vibe Coding workflow
• The server runs inside the WinDbg process
• The runtime does not parse docs/debugger.chm; it uses the prebuilt static catalog in src/catalog.json
• The transport is Streamable HTTP
• Set your MCP client timeout as high as possible, because some WinDbg operations can take a long time to finish