hayabusa-mcp

An MCP (Model Context Protocol) server that wraps Hayabusa for EVTX (Windows Event Log) analysis, exposing scan_evtx and get_hayabusa_rules tools, plus read-only detection:// resources for browsing the bundled Sigma rule set (see Resources below).

Note: this README covers licensing and the Claude Desktop extension build step. Full setup/usage documentation is still in progress — see HANDOFF.md for detailed background in the meantime.

Setup

1. ./download_hayabusa.sh — downloads and checksum-verifies the Hayabusa binary into ./hayabusa/

2. pip install -r requirements.txt (or use a .venv)

3. Connect via .mcp.json (Claude Code) or as a Claude Desktop extension (see below)

Related MCP server: EventWhisper

Resources

Alongside the two tools, the server exposes four read-only detection:// MCP resources for browsing the bundled Sigma/Hayabusa rule set and looking up MITRE ATT&CK technique coverage:

• detection://rules — a compact JSON index of the bundled rules (resource_id, id_source, title, level only — not full rule bodies). Capped at 500 entries per read; truncated/total_rules in the response indicate when more exist.

• detection://rules/{rule_identifier} — the complete YAML text of one rule. rule_identifier is the rule's own YAML id: (a UUID); a small number of rules missing a valid id get a stable fallback-<hash> identifier instead — check id_source in the index to tell them apart.

• detection://rules/by-technique/{technique_id} — rules tagged with a given MITRE ATT&CK technique ID (case-insensitive). A bare parent ID like T1003 matches its own tag plus any sub-technique tagged beneath it (labeled inherited_subtechnique in the response); a specific sub-technique query like T1003.001 matches only that exact tag, never its parent or sibling sub-techniques.

• detection://attack/techniques/{technique_id} — local coverage facts for a technique ID (match count, covered/not_covered), computed solely from the bundled rule set. This server does not bundle an ATT&CK technique-name/tactic/description dataset, so no such fields are returned — the response only contains what can be derived from local rule data.

Claude Desktop extension

The extension's manifest.json points PYTHONPATH at a vendored ./lib/ directory rather than any external virtualenv. lib/ is not tracked in git (it contains compiled, platform-specific wheels) — build it locally with:

./package_extension.sh

This regenerates ./lib/ from requirements.txt and produces dist/hayabusa-mcp.zip. You'll still need ./hayabusa/ populated separately via download_hayabusa.sh before the extension can run.

License

This project is licensed under the MIT License.

Hayabusa itself is a separate project licensed under AGPL-3.0. It is downloaded at setup time by download_hayabusa.sh and invoked as an external subprocess — it is not vendored or linked into this repository.