claude-hook-builder

Hooks automate Claude Code by triggering custom scripts at specific events like PreToolUse, PostToolUse, UserPromptSubmit, SessionStart, and SessionEnd. You define event-driven actions in settings.json that validate, block, or enhance tool operations without manual intervention.

Yes. Create a PreToolUse hook that inspects bash commands before execution and returns a JSON decision to allow, deny, or modify them. This prevents risky operations like `rm -rf /` while auto-approving safe commands.

Claude Code supports six hook events: PreToolUse (before any tool runs), PostToolUse (after execution), UserPromptSubmit (when you submit a prompt), SessionStart (at session init), SessionEnd (on exit), and Stop (when execution halts). Each event enables different automation patterns.

Define a PostToolUse hook targeting Write and Edit tools that runs formatting scripts—like Python linters—on modified files. The hook executes automatically after each operation, eliminating manual formatting steps.

Hooks support Read, Write, Edit, Bash, Grep, and Glob tools. You can validate, transform, or conditionally execute any of these via hook scripts that receive tool metadata and return JSON control decisions.

The hook builder skill streamlines hook creation and validation by generating properly formatted hook definitions for settings.json. It handles event configuration, command structure, and JSON output validation so you don't manually construct complex hook logic.