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

bash

# 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

bash

# 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:

bash

# 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

bash

# Runs automatically on staged .py files
uv run black --check $file
uv run ruff check $file

pre-push

bash

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

Testing Hooks

bash

# 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)

bash

# Skip all hooks
git commit --no-verify -m "Emergency fix"

# Only use when:
# - Emergency production fixes
# - Hook malfunction
# - Intentional override

Troubleshooting

Hook Not Running

bash

# Check existence
ls -l .git/hooks/

# Fix permissions
chmod +x .git/hooks/*

# Check syntax
bash -n .git/hooks/pre-commit

Permission Denied

bash

chmod +x .git/hooks/*

Failed Quality Checks

bash

# 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

bash

# 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

bash

#!/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