EventWhisper — A Windows Event Log MCP

EventWhisper exposes fast, scriptable access to Windows .evtx logs via an MCP (Model Context Protocol) server. It’s pure Python (uses the evtx library), instead of a PowerShell wrapper and does not execute commands on the host — safer for incident response, digital forensics, and threat hunting.

The server exposes two primary tools:

• List EVTX files (optionally recursive) for any directory.
• Filter events to directly search for specific records.

Built specifically for IR/DFIR & hunting so you don’t need to look up Event IDs all day. Designed, developed, and tested on Windows with Claude — and usable from any MCP client.

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Features

• Targeted filtering: time window, EventID(s), and case-insensitive keywords (include/exclude)
• Field projection: return only the dotted paths you need (huge output reduction)
• Input normalization: accepts flexible input formats so it still works if types/format aren’t perfect.
• MCP-ready: plugs into Claude Desktop (and other MCP clients)

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Demo

https://github.com/user-attachments/assets/e1878c86-56f6-466b-bbc4-04d1edeeb36b

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Requirements (Windows)

EventWhisper can be set up with Poetry, whether you run it inside Claude or standalone. On Windows, make sure Poetry is on your PATH.

Install Poetry (PowerShell):

(Invoke-WebRequest -Uri https://install.python-poetry.org -UseBasicParsing).Content | py -

Add Poetry to PATH (user install):

C:\Users\<YourUser>\AppData\Roaming\Python\Scripts

Verify:

poetry --version

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Install & Run

Primarily developed for use with Claude, but you can run the MCP server standalone and plug it into other LLMs.

Clone and install:

git clone https://github.com/hexastrike/eventwhisper
cd eventwhisper
poetry install

Run the MCP server:

poetry run python -m eventwhisper.mcp.server
# (or) plain Python if deps are installed globally:
python -m eventwhisper.mcp.server

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Claude MCP configuration

Add this to Claude Desktop’s MCP config (e.g., %AppData%\Claude\claude_desktop_config.json):

{
  "mcpServers": {
    "EventWhisper": {
      "type": "stdio",
      "command": "poetry",
      "args": [
        "-C",
        "C:\\Path\\To\\eventwhisper",
        "run",
        "python",
        "-m",
        "eventwhisper.mcp.server"
      ],
      "env": { "PYTHONIOENCODING": "utf-8" }
    }
  }
}

Open Settings → Developer to confirm EventWhisper is registered and “running”.

When prompted, allow the tool:

Try a first prompt:

Use EventWhisper to list .evtx files in C:\Windows\System32\winevt\Logs.

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Development

EventWhisper was written to be simple and maintainable. We use pytest for tests and ruff for linting/formatting. Run everything locally (or via pre-commit):

poetry install
poetry run ruff format .
poetry run ruff check . --fix
poetry run pytest --cov=eventwhisper --cov-report=term-missing
# pre-commit on all files:
poetry run pre-commit run --all-files
# pre-push hooks (full tests + coverage):
poetry run pre-commit run --hook-stage push --all-files

When making pull requests, ensure all tests pass and coverage thresholds are met. Every new utility or feature should include clear tests and follow PEP 8. Tests live in the tests/ directory.

Core layout & API

Primary logic lives in eventwhisper/evtxio/evtxio.py — EVTX iteration/filtering/projection.

The core server function is get_events_from_evtx() (a wrapper around the iterator iter_events_from_evtx()):

def get_events_from_evtx(
    provider: str | Path,
    start: datetime | str | None = None,
    end: datetime | str | None = None,
    results_limit: int | str | None = RESULTS_LIMIT,
    event_ids: int | str | Sequence[int] | Sequence[str] | None = None,
    contains: str | Sequence[str] | None = None,
    not_contains: str | Sequence[str] | None = None,
    fields: str | Sequence[str] | None = None,
) -> list[str]:

Constants live in eventwhisper/utils/config.py and include both:

• RESULTS_LIMIT — max number of events returned (LLMs have token/char caps).
• SCAN_LIMIT — max events scanned to keep responses fast on huge logs.

Example Python usage

# example.py
from __future__ import annotations
from datetime import datetime, timezone
from eventwhisper.evtxio.evtxio import get_events_from_evtx

# 1) First matching event from Security log
print(get_events_from_evtx(r"C:\Windows\System32\winevt\Logs\Security.evtx", results_limit=1))

# 2) Filter by keywords and project fields
events = get_events_from_evtx(
    r"C:\Windows\System32\winevt\Logs\Security.evtx",
    contains=["powershell", "Invoke-"],
    fields=["Event.System.EventID", "Event.EventData.Image", "Event.EventData.CommandLine"],
    results_limit=5,
)
for e in events:
    print(e)

# 3) Time-bounded query (UTC)
start = datetime(2025, 1, 1, tzinfo=timezone.utc)
end = datetime(2025, 1, 31, 23, 59, 59, tzinfo=timezone.utc)
print(len(get_events_from_evtx(r"C:\Windows\System32\winevt\Logs\Security.evtx", start=start, end=end)))

Run it with poetry run python example.py.

Troubleshooting

• Big logs: results are capped by RESULTS_LIMIT and scanning is bounded to keep responses fast. If your MCP client doesn’t realize results are capped, run a second, narrower query.
• “Blocked” files: if you downloaded .evtx from the Internet, right-click → Properties → Unblock.
• Paths: in Python, prefer raw strings for Windows paths, e.g., r"C:\path\file.evtx".
• README video: GitHub doesn’t render <video>; use a thumbnail → MP4 link (see Demo section).

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Roadmap

• Faster scanning for very large .evtx files
• Better normalization for malformed/corrupted EVTX
• Convenience utilities (e.g., quick overview: counts, unique EventIDs, time range)
• Optional paging / multi-query strategies for huge datasets

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License

Distributed under the GPLv3. See LICENSE.