Claude Hooks

Claude Hooks Skill

Creates and configures hooks for Claude Code to automate workflows and extend functionality.

What This Skill Does

• Creates PreToolUse validation hooks
• Sets up PostToolUse logging/cleanup
• Configures notification hooks
• Implements custom automation
• Documents hook patterns

When to Use

• Tool execution validation
• Audit logging
• Custom notifications
• Workflow automation
• Security controls

Reference Files

• references/CLAUDE_HOOK.template.md - Hook configuration examples and patterns

Hook Events

Configuration Location

Hooks are configured in ~/.claude/settings.json under the hooks key.

Best Practices

• Keep hooks fast (< 1 second)
• Handle errors gracefully
• Use specific matchers
• Test hooks independently
• Avoid verbose output

Hook Configuration Template

Hooks are shell commands that execute in response to Claude Code events.

Hook Configuration Location

Hooks are configured in ~/.claude/settings.json under the hooks key.

Hook Events

Configuration Structure

{
  "hooks": {
    "{{EVENT_NAME}}": [
      {
        "matcher": "{{TOOL_OR_PATTERN}}",
        "hooks": [
          {
            "type": "command",
            "command": "{{SHELL_COMMAND}}"
          }
        ]
      }
    ]
  }
}

Examples

Pre-Tool Validation Hook

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "echo 'Executing bash command...'"
          }
        ]
      }
    ]
  }
}

Post-Tool Logging Hook

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Write",
        "hooks": [
          {
            "type": "command",
            "command": "echo 'File written: $CLAUDE_FILE_PATH' >> ~/.claude/file_log.txt"
          }
        ]
      }
    ]
  }
}

Notification Hook

{
  "hooks": {
    "Notification": [
      {
        "matcher": "*",
        "hooks": [
          {
            "type": "command",
            "command": "osascript -e 'display notification \"$CLAUDE_MESSAGE\" with title \"Claude Code\"'"
          }
        ]
      }
    ]
  }
}

Environment Variables Available

Matcher Patterns

Best Practices

1. Keep hooks fast - Long-running hooks block Claude 2. Use async for slow operations - Background with & if needed 3. Handle errors gracefully - Don't let hook failures break workflow 4. Log sparingly - Avoid verbose output that clutters context 5. Test hooks independently - Verify shell commands work before adding

Quality Checklist

• [ ] Event type matches intended trigger
• [ ] Matcher pattern is specific enough
• [ ] Command executes quickly (<1s)
• [ ] Error handling prevents cascade failures
• [ ] Environment variables used correctly
• [ ] Hook tested in isolation before deployment