creating-hooks

Hooks automate tasks at key workflow moments—PreToolUse, PostToolUse, UserPromptSubmit, SessionStart, SessionEnd, Stop—by running scripts you define in settings.json. Create a hook script, reference it in .claude/settings.json, and it executes automatically when that event fires, eliminating manual setup.

Claude Code supports six hook events: PreToolUse and PostToolUse (before/after tool execution), UserPromptSubmit (on user input), SessionStart and SessionEnd (workflow lifecycle), and Stop (interruption). Each fires at a specific workflow moment where you can inject logging, validation, or context.

Add hook configuration to .claude/settings.json with the hook event name and script path. Use templates from the templates/ directory as starting points, then test with sample JSON input: echo '{"hook_event_name":"PreToolUse","tool_name":"Write"}' | bash ".claude/hooks/my-hook.sh".

Hooks reduce repetitive configuration by automating logging (track tool calls), context injection (add data at key moments), and validation (check inputs before execution). Common use cases include auditing workflows, dynamically enriching prompts, and enforcing guardrails.

Yes—hooks require writing or customizing scripts that accept JSON input matching the hook event structure. Templates provide starting points, but you need to understand how to parse JSON and define logic for your automation scenario.

Yes. PreToolUse hooks execute before a tool runs, so you can inspect the tool name and parameters, log them, validate against rules, or inject context. PostToolUse hooks run after execution to process or transform tool output.