Borrowing it
Nothing to install: this file belongs to msadigo/mcp-hayabusa. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/msadigo/mcp-hayabusa/master/CLAUDE.mdgit clone --depth 1 https://github.com/msadigo/mcp-hayabusaWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/msadigo/mcp-hayabusa/claude-md)<a href="https://agentmods.dev/instructions/msadigo/mcp-hayabusa/claude-md"><img src="https://agentmods.dev/badge/instructions/msadigo/mcp-hayabusa/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/msadigo/mcp-hayabusa/claude-md"><img src="https://agentmods.dev/badge/instructions/msadigo/mcp-hayabusa/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.02304 | $0.02304 |
| Opus 5.5 | $0.00922 | $0.00922 |
| Sonnet 5.5 | $0.00461 | $0.00461 |
| Haiku 4.5 | $0.00230 | $0.00230 |
Grade A, and why
mcp-hayabusa CLAUDE.md scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Runs shell commandslowCapability
Expected in a hook, worth knowing in a rule or an instructions file.
`sample_evtx/`. `scan()` tests monkeypatch `subprocess.run` with a fake that writes synthetic How it starts
The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
What this is
An MCP server that wraps the Hayabusa Windows event log
forensics/timeline CLI tool, exposing it as an MCP tool (scan_evtx) so an MCP client can run
Hayabusa detection scans over .evtx files.
Commands
pip install -e . # install the package (and mcp[cli] dependency) in editable mode
mcp-hayabusa # run the server over stdio (registered as a console script)
python -m mcp_hayabusa.server # equivalent, without the console script
python scripts/download_hayabusa.py # fetch the latest hayabusa binary for this platform into ./hayabusa/
pip install -e ".[test]" # install with pytest
pytest # run the test suite
The test suite (tests/) is hermetic — it never invokes the real hayabusa binary or needs
sample_evtx/. scan() tests monkeypatch subprocess.run with a fake that writes synthetic
CSV/JSON to whatever -o path was requested; list_rules() tests run against a small synthetic
rules directory (tests/conftest.py's rules_dir fixture); server.py tests monkeypatch
hayabusa.scan/hayabusa.list_rules directly to test response-shaping in isolation. There is no
linter or build step configured yet.
Manual testing
mcp dev (from the mcp[cli] package) launches the MCP Inspector against the server for interactive
tool calls:
mcp dev src/mcp_hayabusa/server.py
Actually exercising scan_evtx requires the hayabusa binary to be installed (see Configuration below
— scripts/download_hayabusa.py handles this) and at least one real or sample .evtx file. Yamato
Security ships a repo of sample .evtx files that's useful for this — clone it into ./sample_evtx/
(gitignored, not a submodule):
git clone https://github.com/Yamato-Security/hayabusa-sample-evtx.git sample_evtx
Architecture
Two files carry all the logic:
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 149 lines · 2,304 tokens per session scan A b57390690838
mcp-hayabusa CLAUDE.md is an instructions file published in the GitHub repository msadigo/mcp-hayabusa (0 stars, last pushed 3mo ago), licensed MIT. It adds 2,304 tokens to every session, about $0.0092 per session on Opus 5.5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.