---

name: hook-creator description: Help me create a Claude Code hook. Interviews about what to catch, then generates PreToolUse or PostToolUse hook.

Hook Creator

Use the interview skill protocol to understand what guardrail they want, then create the hook.

Questions to Ask

1. "What do you want to catch or check?"

   • Get the core concern

2. "Describe a scenario where this should fire."

   • Helps determine Pre vs Post

3. "What should happen when it fires?"

   • Block, warn, remind, validate

Pre vs Post Heuristic

Based on their answers, determine:

PreToolUse (fires BEFORE action):

• Catch wrong approach before it happens
• "Don't do X directly, do Y instead"
• "Pause and consider before acting"
• Can BLOCK the action

PostToolUse (fires AFTER action):

• Validate output (lint-like)
• "Check the result follows pattern X"
• Deterministic checks on what was written
• Cannot block (already happened), but can warn

Tool Matching

Common patterns:

• Bash with db:migrate - catches migration runs
• Edit with app/models/ - catches model edits
• Write with db/migrate/ - catches migration file creation
• Bash with rm or delete - catches destructive commands

After the Interview

Create:

1. Hook Script

Create .claude/hooks/<hook-name>.sh (or .py):

Copy#!/bin/bash
# Hook: <name>
# Fires: <Pre|Post>ToolUse on <tool>

echo "Reminder: <message>"
exit 0

For blocking hooks, exit non-zero:

Copyecho "Blocked: <reason>"
exit 1

2. Settings Entry

Add to .claude/settings.json:

Copy{
  "hooks": {
    "<Pre|Post>ToolUse": [
      {
        "matcher": {
          "tool": "<Bash|Edit|Write>",
          "<command|file_path>": "<pattern>"
        },
        "hooks": [
          {
            "type": "command",
            "command": ".claude/hooks/<hook-name>.sh"
          }
        ]
      }
    ]
  }
}

Matcher Patterns

• command: regex match on Bash command (e.g., "db:migrate")
• file_path: glob match on file path (e.g., "app/models/**")

Example Hooks

Pre-migrate reminder:

Copy{
  "matcher": { "tool": "Bash", "command": "db:migrate" },
  "hooks": [{ "type": "command", "command": "echo 'Did you review the migration?'" }]
}

Post-model edit lint:

Copy{
  "matcher": { "tool": "Edit", "file_path": "app/models/**" },
  "hooks": [{ "type": "command", "command": ".claude/hooks/check-model.sh" }]
}