Beetle

(Binary-Encoded Event Tracing Log for Exceptions)

dotnet tool update -g beetle

Beetle is a tool that records all .NET exceptions with callstacks system-wide into a binary log file that can be viewed on another machine. It works for both the desktop .NET Framework and modern .NET runtime. It is Windows-only.

Beetle starts a copy of itself under admin if it's not running as administrator. It needs admin permissions to create a kernel ETW session.

Usage:

beetle [<log-file>.beetle] Starts recording, press Ctrl+C to stop, optional log path defaults to %TEMP%\AllExceptions.beetle.

beetle.exe start [<log-file>.beetle] Starts recording and returns immediately, while another instance of beetle.exe continues recording.

beetle.exe stop Finds an existing instance of beetle.exe and stops recording, waits for it to finish writing the log, then returns.

BeetleMcp (MCP server for AI)

beetlemcp lets an AI assistant (Claude / Copilot / etc.) read and analyze .beetle files: list processes, query/count/bin exceptions, walk parent chains, fetch stack traces, diff two recordings, and more.

dotnet tool update -g beetlemcp

Configure your MCP-aware client to launch it. For VS Code, add to .vscode/mcp.json:

{
  "servers": {
    "beetlemcp": {
      "type": "stdio",
      "command": "beetlemcp"
    }
  }
}

Beetle.Core

Beetle.Core is a NuGet package that lets you read (or write!) .beetle files and provides an object model around them.

https://www.nuget.org/packages/Beetle.Core

What is a .beetle file?

A .beetle file is a binary recording of every managed (.NET) exception thrown system-wide during a recording window on a Windows machine, captured via kernel + CLR ETW providers. For each exception it stores:

• the process that threw it (full process tree, image file name, command line, parent),
• the timestamp (absolute UTC),
• the exception type and message,
• the managed stack trace (resolved against the JIT'd methods + module symbols recorded in the same file).

It also captures every process's loaded managed modules and native images.

The file is produced by the beetle global tool (dotnet tool update -g beetle, then beetle out.beetle, Ctrl+C to stop). It can be read programmatically via the Beetle.Core NuGet package, or analyzed by an AI assistant via the beetlemcp MCP server.

The on-disk envelope is a GZip stream; the file is not human-readable. Treat the .beetle extension as the canonical signal.