# MCP Debug Server
MCP server for debugging Windows processes via WinDbg/CDB.
## Prerequisites
- Python 3.10+
- [Windows Debugging Tools](https://developer.microsoft.com/en-us/windows/downloads/windows-sdk/) (cdb.exe, dbgsrv.exe)
Debugger paths are auto-detected from Windows SDK installations.
## Installation
```bash
pip install -e .
```
### Quickstart
```bash
# 1. Start the debug server
.\dbgsrv.exe -t tcp:port=5005
# 2. Add to your MCP client config and connect
# 3. Ask the LLM: "Attach to notepad.exe and show me loaded modules"
```
## MCP Configuration
```json
{
"mcpServers": {
"mcp-debugserver": {
"type": "stdio",
"command": "python",
"args": ["<path-to>/mcp-debugserver/src/mcp_debugserver/server.py"],
"env": {
"arch": "x64"
}
}
}
}
```
Set `arch` to `x86` or `x64` to match your target process architecture.
## Usage
The LLM has access to all debugging tools. Simply describe what you want to debug:
- "Attach to notepad.exe and set a breakpoint on CreateFileW"
- "Show me the call stack and registers"
- "Read 64 bytes of memory at the current instruction pointer"
- "Find all calls to malloc in the process"
### Basic Workflow
1. `start_debug_server` - Launch debug server on a port
2. `connect_debugger` - Connect to the server
3. `attach_process` - Attach to target by PID or name
4. Use inspection/control tools as needed
5. `detach_process` / `disconnect_debugger` when done
## Available Tools
| Category | Tools |
|----------|-------|
| **Lifecycle** | `start_debug_server`, `stop_debug_server`, `connect_debugger`, `disconnect_debugger` |
| **Process** | `attach_process`, `detach_process`, `get_process_info` |
| **Execution** | `break_execution`, `resume_execution`, `step_into`, `step_over`, `step_out` |
| **Breakpoints** | `set_breakpoint`, `remove_breakpoint`, `list_breakpoints`, `enable_breakpoint`, `disable_breakpoint` |
| **Memory** | `read_memory`, `write_memory`, `search_memory` |
| **Registers** | `read_registers`, `write_register` |
| **Inspection** | `get_callstack`, `list_threads`, `switch_thread`, `list_modules`, `module_info`, `disassemble` |
| **Symbols** | `evaluate_expression`, `display_symbol`, `reload_symbols`, `set_symbol_path` |
| **Exceptions** | `get_exception_info`, `enable_exception_monitoring`, `get_last_exception_captured`, `set_exception_break`, `resume_with_monitoring`, `create_minidump` |
| **Hardware BP** | `set_hardware_breakpoint`, `remove_hardware_breakpoint`, `list_hardware_breakpoints`, `toggle_hardware_breakpoint` |
| **Raw** | `execute_command` - Run any WinDbg command directly |
## Troubleshooting
| Issue | Solution |
|-------|----------|
| RPC Error 0x80010007 | Architecture mismatch - set `arch` env var to match target |
| Can't find cdb.exe | Install Windows Debugging Tools from Windows SDK |
| Can't attach | Run with admin privileges; check no other debugger attached |
## License
MIT License - Copyright (c) 2025 MCP Debug Server
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
