MakiDevelop

Hook Gym — Testing skill for Claude Code

Testing community

Test harness for Claude Code hooks — batch-run violation cases against your guardrails.

How to install Hook Gym

This entry records only its repository, not the path inside it, so there is no exact command to give. Open MakiDevelop/hook-gym and copy the folder into ~/.claude/skills/, or the file into ~/.claude/agents/.

What Hook Gym does

Test harness for Claude Code hooks — batch-run violation cases against your guardrails.

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README

Hook Gym

Test harness for [Claude Code hooks](https://docs.anthropic.com/en/docs/claude-code/hooks). Batch-run violation cases against your guardrails and find out what slips through.

Why

You wrote hooks to protect against dangerous commands, secret leaks, and accidental file destruction. But have you actually tested them?

Hook Gym ships with **64 built-in test cases** across 8 security dimensions. Run them against your hooks and get a coverage report in seconds.

  PASS  pre-bash-danger-guard:     9/9
  PASS  pre-edit-sensitive-guard:  4/4
  PARTIAL  pre-bash-secrets-guard: 3/5
  FAIL  (no hook for chmod 777):   0/2

  Overall: 41/64 passed (64%)

Install

git clone https://github.com/MakiDevelop/hook-gym.git
cd hook-gym
pip install -e .

Quick Start

# Run all daily cases against your hooks
hook-gym run --exclude-tag extreme

# Run everything (including edge cases like reverse shells)
hook-gym run

# See what hooks and cases are loaded
hook-gym list

# Filter by category
hook-gym run --tag destructive
hook-gym run --tag credentials
hook-gym run --tag git

# Export markdown report
hook-gym run --report report.md

Built-in Test Cases

Category	Cases	What it tests
Destructive Ops	10	`git push --force`, `git reset --hard`, `DROP DATABASE`, `DELETE` without `WHERE`
File Destruction	7	`rm -rf /`, `rm -rf ~`, `rm -rf .git`, `rm -rf ~/.claude`
Credential Leaks	7	Hardcoded API keys, `cat .env`, `cat credentials.json`, `echo $TOKEN`
Sensitive Files	5	Editing `~/.ssh/`, `~/.gnupg/`, `.secrets/`, `.env`
Git Hygiene	5	`git add .`, commit without diff, English commit messages
Network Risks	7	`curl \| bash`, reverse shells, `ngrok`, `/dev/tcp`
Production Safety	8	`docker prune -af`, `--set-env-vars`, `kubectl delete namespace`, `TRUNCATE`
Permission Escalation	5	`chmod 777`, `sudo rm`, `chown root`
Scope Boundary	5	E