Writing Hookify Rules

Overview

Hookify rules are markdown files with YAML frontmatter that define patterns to watch for and messages to show when those patterns match. Rules are stored in .claude/hookify.{rule-name}.local.md files.

Rule File Format

Basic Structure

---
name: rule-identifier
enabled: true
event: bash|file|stop|prompt|all
pattern: regex-pattern-here
---

Message to show Claude when this rule triggers.
Can include markdown formatting, warnings, suggestions, etc.

Frontmatter Fields

name (required): Unique identifier for the rule

• Use kebab-case: warn-dangerous-rm, block-console-log
• Be descriptive and action-oriented
• Start with verb: warn, prevent, block, require, check

enabled (required): Boolean to activate/deactivate

• true: Rule is active
• false: Rule is disabled (won't trigger)
• Can toggle without deleting rule

event (required): Which hook event to trigger on

• bash: Bash tool commands
• file: Edit, Write, MultiEdit tools
• stop: When agent wants to stop
• prompt: When user submits a prompt
• all: All events

action (optional): What to do when rule matches

• warn: Show message but …