Git Hooks Skill

When to Activate

Activate this skill when:

• Setting up pre-commit hooks

• Configuring commit message validation

• Installing secrets scanners

• Enforcing code quality standards

• Automating pre-push tests

Quick Installation

Use interactive installer (recommended)

./AgentUsage/pre_commit_hooks/install_hooks.sh

Or manual installation for Python project

cp AgentUsage/pre_commit_hooks/commit-msg .git/hooks/ cp AgentUsage/pre_commit_hooks/pre-commit-python .git/hooks/pre-commit cp AgentUsage/pre_commit_hooks/pre-commit-secrets-scanner .git/hooks/pre-commit-secrets cp AgentUsage/pre_commit_hooks/pre-push .git/hooks/ chmod +x .git/hooks/*

Available Hooks

Core Hooks (All Projects)

Hook Purpose

commit-msg

Validates conventional commit format

pre-commit-secrets-scanner

Prevents leaked API keys/secrets

Language-Specific

Hook Language Checks

pre-commit-python

Python Black, Ruff

pre-commit-javascript

JS/TS Prettier, ESLint, TypeScript

pre-commit-go

Go gofmt, go vet

pre-commit-multi-language

Mixed Auto-detects and runs appropriate tools

Automation Hooks

Hook Purpose

pre-push

Runs tests before push

post-checkout

Auto-updates dependencies on branch switch

post-commit

Shows commit summary and TODOs

Hook Selection by Project

Python Project

commit-msg + pre-commit-python + pre-commit-secrets-scanner + pre-push

JavaScript Project

commit-msg + pre-commit-javascript + pre-commit-secrets-scanner + pre-push

Go Project

commit-msg + pre-commit-go + pre-commit-secrets-scanner + pre-push

Multi-language

commit-msg + pre-commit-multi-language + pre-commit-secrets-scanner + pre-push

What Each Hook Does

commit-msg

Validates commit message format:

Accepted formats

feat: Add user authentication fix: Correct validation error docs(readme): Update installation

Rejected

Update files # No type feat add feature # Missing colon

pre-commit-secrets-scanner

Scans for exposed secrets:

• Anthropic API keys (sk-ant-... )

• OpenAI API keys (sk-... )

• AWS credentials (AKIA... )

• GitHub tokens (ghp_... )

• Hardcoded passwords

pre-commit-python

Runs automatically on staged .py files

uv run black --check $file uv run ruff check $file

pre-push

Runs before push

uv run pytest tests/ # or pnpm test, go test, cargo test

Testing Hooks

Test pre-commit directly

.git/hooks/pre-commit

Test with sample commit

git add . git commit -m "test: verify hooks"

Run with debug output

bash -x .git/hooks/pre-commit

Bypassing Hooks (Emergency Only)

Skip all hooks

git commit --no-verify -m "Emergency fix"

Only use when:

- Emergency production fixes

- Hook malfunction

- Intentional override

Troubleshooting

Hook Not Running

Check existence

ls -l .git/hooks/

Fix permissions

chmod +x .git/hooks/*

Check syntax

bash -n .git/hooks/pre-commit

Permission Denied

chmod +x .git/hooks/*

Failed Quality Checks

Run tools manually

uv run black --check . uv run ruff check .

Fix issues

uv run black . uv run ruff check --fix .

Retry commit

git commit -m "Your message"

Missing Tools

Install code quality tools

uv add --dev black ruff

Verify installation

which black uv run black --version

Custom Hook Configuration

Modify pre-commit for Your Project

#!/bin/bash

.git/hooks/pre-commit

Get staged Python files

FILES=$(git diff --cached --name-only --diff-filter=ACM | grep '.py$')

if [ -n "$FILES" ]; then # Run your tools uv run black --check $FILES || exit 1 uv run ruff check $FILES || exit 1 fi

exit 0

Hook Execution Order

• pre-commit - Before commit (code quality)

• commit-msg - Validates message format

• post-commit - After commit (notifications)

• pre-push - Before push (tests)

Best Practices

DO ✅

• Install secrets scanner on ALL projects

• Use commit-msg for consistent history

• Run tests in pre-push

• Test hooks after installation

DON'T ❌

• Skip hooks regularly

• Disable secrets scanning

• Ignore hook failures

• Commit without testing hooks first

Related Resources

See AgentUsage/pre_commit_hooks/ for:

• setup_guide.md

• Complete installation guide

• examples.md

• Custom hook examples

• TROUBLESHOOTING.md

• Common issues

• Individual hook scripts for reference