Sven Scharmentke
96bc35b657
The 1.2.0 release PR collected several red CI runs that nobody could act on: ``` CI #193: Pull request #98 synchronize by github-actions (Bot) ✗ 6m 2s CI #192: Pull request #98 opened by github-actions (Bot) ✗ 6m 20s CI #191: Pull request #91 synchronize by github-actions (Bot) ✗ 16s CI #190: Pull request #91 synchronize by github-actions (Bot) ✗ 31s ``` ## Why they fail release-please pushes the version bump, and `sync-lockfile` updates `uv.lock` a moment later. CI triggered in between sees a lockfile that does not match `pyproject.toml`, fails `uv lock --check`, and reports red on a state that will never be merged. The check is right; the timing means it fires on an intermediate commit. ## Why the run is not needed at all The release PR carries version bumps and the CHANGELOG entry. Nothing else. `publish-mcp.yml` runs the full five-version matrix again before anything reaches PyPI, and the `preflight` gate asserts every version and the CHANGELOG before a tag exists. A run on the PR proves nothing that is not proved later, with teeth. ## Correcting an earlier claim I previously recorded that a job-level condition could not help here, because these runs are blocked at `action_required` before job conditions are evaluated. That holds for the run the bot opens on a fresh PR - but the **synchronize** runs execute normally, and those are the ones going red. A job-level `if` does work for them: ```yaml if: ${{ !startsWith(github.head_ref, release-please--) }} ``` `head_ref` is empty on push events, so pushes to `develop` and `main` are unaffected.
MCP Server for WinDbg Crash Analysis
A Model Context Protocol server that bridges AI models with WinDbg for crash dump analysis, user-mode remote debugging, and kernel debugging.
Overview
This server drives the Windows debuggers - CDB for user mode (dumps and -remote) and KD for kernel targets (-k) - so you can debug in natural language: "Show me the call stack and explain this access violation" or "Open a kernel session and tell me which driver bugchecked."
It is not a magical auto-fix. It is a Python wrapper around cdb.exe / kd.exe that lets an LLM run real debugger commands and reason about the output.
Features
- Crash dump analysis - open a
.dmp/.mdmp/.hdmpand get automated triage (!analyze -v, stacks, modules, threads) in a single call. - User-mode remote debugging - attach to a live
cdb/WinDbg debug server (-remote) over TCP, a named pipe, or COM, and break in on demand. - Kernel debugging - attach to a kernel target (
-k, driven bykd.exe) over KDNET, a named pipe, or serial; the server waits for the target and breaks in for you. - Run any WinDbg/KD command - drive an open session with arbitrary commands (
kb,!process 0 0,!heap,lm, ...) described in natural language. - Session ids - every open returns a session id; several sessions (dumps, remote, kernel) can be open at once and are addressed independently.
- Resilient live sessions - per-call timeouts, and a slow live command that outruns its timeout is broken into with CTRL+BREAK and the session resynchronized instead of wedging.
- Multi-dump triage - discover and compare many dumps across a directory.
- Text filter hooks - a
--filter-scriptcan redact PII/secrets from tool arguments and output before they leave the machine. - stdio or HTTP - run locally over stdio, or as a streamable-HTTP service you drive from another machine.
Use cases
| You have | You want to | Guide |
|---|---|---|
A .dmp from a crash |
Root-cause it: exception, faulting frame, why it happened | Analyze a crash dump |
A live user-mode process (via cdb -server) |
Break in and inspect a hang or live state | Debug a remote target |
| A KD-enabled machine or VM | Debug drivers, bugchecks, and boot-time issues | Debug a kernel target |
| A folder full of dumps | Triage the batch and find the common signature | Triage multiple dumps |
| A debugging host, but you work elsewhere | Drive it over HTTP from another machine | Debug from another machine |
| Dumps with secrets or PII | Scrub tool output before it leaves the box | Redact sensitive data |
Tools
Every open_* tool returns an opaque session_id (e.g. cdb-1a2b3c4d); pass it to the matching run_*, close_*, send_ctrl_break, and wait_for_break calls. User-mode targets (dumps and -remote) run under cdb.exe; kernel targets run under kd.exe.
| Tool | Purpose |
|---|---|
list_dumps |
List crash dump files in a directory |
open_cdb_dump |
Open and triage a crash dump |
open_cdb_remote |
Attach to a user-mode remote debug server (-remote) |
open_kd_session |
Attach to a kernel target (-k, KDNET / named pipe / serial) |
run_cdb_command |
Run a command on a user-mode session |
run_kd_command |
Run a command on a kernel session |
close_cdb_session |
Close a user-mode session |
close_kd_session |
Close a kernel session (resumes the target machine) |
send_ctrl_break |
Break into a running live session |
wait_for_break |
Wait for a target you resumed with g to stop again |
Parameters, timeouts, and the built-in triage prompts are in the tools reference.
Quick start
Prerequisites
- Windows with Debugging Tools for Windows or WinDbg from the Microsoft Store, which ship
cdb.exeandkd.exe(auto-detected). - Python 3.10 or higher.
- Any MCP-compatible client (Claude Code, GitHub Copilot, Claude Desktop, Cursor, Windsurf, Cline, ...).
Tip
In enterprise environments, MCP server usage might be restricted by organizational policies. Check with your IT team about AI tool usage and ensure you have the necessary permissions before proceeding.
Claude Code - install the plugin. This is the shortest path: no pip install, no MCP
config to edit. It brings the ten tools, four skills (analyze-dump, debug-remote,
kernel-debug, windbg-doctor) and a crash-analyst agent that investigates a dump on its own
and reports back.
/plugin marketplace add svnscha/mcp-windbg
/plugin install mcp-windbg-uvx@mcp-windbg
The plugin launches the server with uv's uvx, which fetches the
pinned version from PyPI on first use. See the plugin
README for symbols setup and how to run it without uv.
Any other client - install the package
pip install mcp-windbg
Configure your client. The two most common setups are below; see the client configuration guide for Claude Desktop, Copilot CLI, Autohand Code, HTTP, and from-source.
Claude Code - if you did not use the plugin above, register the server directly:
claude mcp add mcp-windbg -s user -e _NT_SYMBOL_PATH="SRV*C:\Symbols*https://msdl.microsoft.com/download/symbols" -- python -m mcp_windbg
VS Code (GitHub Copilot) - press F1 and select MCP: Open User Configuration to enable it in every workspace:
{
"servers": {
"mcp_windbg": {
"type": "stdio",
"command": "python",
"args": ["-m", "mcp_windbg"],
"env": {
"_NT_SYMBOL_PATH": "SRV*C:\\Symbols*https://msdl.microsoft.com/download/symbols"
}
}
}
}
Restart your client, then start debugging:
Analyze the crash dump at C:\dumps\app.dmp
Connect to tcp:Port=5005,Server=192.168.0.100 and show me the current thread state
Open a kernel session on net:port=50000,key=1.2.3.4, run !analyze -v, and tell me which driver bugchecked
Server options (--cdb-path, --kd-path, --symbols-path, --filter-script, --transport, ...) are documented in the command-line reference.
Documentation
| Topic | Description |
|---|---|
| Getting started | Setup and your first crash dump analysis |
| Analyze a crash dump | Root-cause an exception: faulting frame, why it happened |
| Debug a remote target | Break into a live user-mode process and inspect a hang |
| Debug a kernel target | Drivers, bugchecks, and boot-time issues over KDNET or a pipe |
| Triage multiple dumps | Scan a folder and find the common signature |
| Debug from another machine | Run the server over HTTP and drive it remotely |
| Redact sensitive data | Scrub secrets from tool output before it leaves the box |
| Reference | Tools, prompts, CLI options, and client configuration |
| Troubleshooting | Common issues and solutions |
| Development | Run from a local checkout and point a client at the dev build |
Blog
Read about the development journey: The Future of Crash Analysis: AI Meets WinDbg
License
MIT