Hook Authoring

Hooks live in claude/hooks/ and are triggered by Claude Code lifecycle events.

Shell Hooks

• Shebang: #!/usr/bin/env bash
• Always: set -euo pipefail
• Quote all variables: "$VAR", never bare $VAR
• Conditionals: [[ ... ]], not [ ... ]
• Validate after writing: shellcheck claude/hooks/<name>.sh

Python Hooks

• Shebang: #!/usr/bin/env python3
• Target Python 3.14; use uv run to execute
• Type-hint all public functions
• No subprocess.shell=True; use subprocess.run([...], check=True) with a list
• Validate after writing: uv run ruff check claude/hooks/<name>.py