🚀 New Release: mcp-windbg 1.4.0

Only two days after 1.3.1, here's mcp-windbg 1.4.0 with two new features: you can now open kernel crash dumps, and you can have your favorite debugger extensions loaded automatically in every session.

Both ideas came from the community. Thanks to @robster7674 for suggesting kernel dump support, and to @RamanaIntel for the init commands and for giving the kernel dump tool a good workout before release.

Open Kernel Crash Dumps

When Windows shows a blue screen, it writes a dump to C:\Windows\MEMORY.DMP and a small one to C:\Windows\Minidump. You can now hand those straight to mcp-windbg:

Analyze the kernel dump at C:\dumps\MEMORY.DMP and tell me which driver bugchecked

The new open_kd_dump tool opens the dump with kd.exe, runs vertarget and !analyze -v, and keeps the session open for follow-up questions like !process 0 0 or !thread. It works with complete, kernel, and bitmap memory dumps as well as minidumps (#111).

If you've used mcp-windbg for a while, this may feel familiar. Before 1.0, open_windbg_dump took any crash dump, kernel ones included. When 1.0 split the tools into user mode (cdb.exe) and kernel (kd.exe), the dump tool became open_cdb_dump and was described as user mode only. Kernel dumps still opened with it, but nothing told you so. With open_kd_dump, kernel dumps are officially back, with their own tool, the kernel commands, and a longer default timeout for them.

I tried it on real blue screens from a test VM, and CI now checks it against a real kernel minidump. A fresh Claude session also picked the new tool all by itself when I gave it a minidump without mentioning the word "kernel". @RamanaIntel went a step further and tested it on a 66 GB memory dump, which opened in 12 seconds. On dumps that big, some commands can take a minute or two, so pass timeout_seconds or raise --timeout if you need more time.

Load Your Extensions Automatically

If you use your own debugger extensions, maybe an in-house .dll or .loadby sos clr for .NET, you no longer have to load them in every session. @RamanaIntel's #121 adds --init-command:

"args": [
  "--init-command", ".load C:\\Extensions\\myext.dll"
]

The commands run as soon as a session opens, before the first analysis, so !analyze -v can already use your extension. You can also set them with MCP_WINDBG_INIT_COMMANDS, one command per line. Commands that only make sense on a kernel go into --kernel-init-command or MCP_WINDBG_KERNEL_INIT_COMMANDS, and they run only on kernel sessions and kernel dumps.

Upgrading

pip install -U mcp-windbg

If you use the Claude Code plugin:

/plugin marketplace update mcp-windbg
/plugin update mcp-windbg-uvx@mcp-windbg

The MCP registry now gets every new release automatically too.

The full details are in the v1.4.0 release notes and the kernel dump guide. Have fun with it, and if something doesn't work the way you'd expect, open an issue.