Hook Templates

Production-tested templates for Claude Code hooks (1.0.40+ schema).

Quick Start

1. Create hook script (bash/python)
2. Register in settings.json under hooks.{EventName}
3. Script receives JSON on stdin, outputs to stdout

Hook Types

Basic Registration

{
  "hooks": {
    "PreToolUse": [{
      "matcher": "Edit|Write",
      "hooks": [{
        "type": "command",
        "command": "script.sh",
        "timeout": 5
      }]
    }]
  }
}

Exit Codes

Best Practices

1. Read stdin - Input is JSON
2. Use jq - Reliable parsing
3. Exit 0 - Non-zero may block
4. Keep fast - Slow hooks degrade UX
5. Use $CLAUDE_PROJECT_DIR - Project path

Common Mistakes

• Missing nested hooks array
• Missing "type": "command"
• Using non-existent pattern or behavior fields

Advanced Patterns

• Subagent filtering: Parse tool_input.subagent_type for Task hooks
• Workflow gates: Combine with workflow-state-patterns for state files
• Skill auto-activation: Use skill-activation-patterns with UserPromptSubmit

References

• Full Examples - All templates with detailed code