writing-rules

name	writing-rules
description	Creates behavioral rules in markdown to block dangerous commands or restrict AI behavior. Use when adding safety guardrails or preventing specific commands.
alwaysApply	false
category	hook-development
tags	["hookify","rules","patterns","validation","safety"]
dependencies	[]
estimated_tokens	2500
complexity	beginner
model_hint	fast
provides	{"patterns":["rule-writing","pattern-matching","condition-building"],"infrastructure":["rule-validation"]}
usage_patterns	["creating-rules","pattern-matching","behavioral-enforcement"]

Table of Contents

• Overview
• Quick Start
• Rule File Format
• Frontmatter Fields
• Event Types
• Advanced Conditions
• Operators
• Field Reference
• Pattern Writing
• Regex Basics
• Examples
• Test Patterns
• Example Rules
• Block Destructive Commands
• Warn About Debug Code
• Require Tests
• Protect Production Files
• Management
• Related Skills
• Best Practices

Hookify Rule Writing Guide

When To Use

• Creating behavioral rules to prevent unwanted actions
• Defining persistent guardrails for Claude Code sessions

When NOT To Use

• Complex multi-step workflows - use agents instead
• One-time operations that do not need persistent behavioral 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.

Quick Start

Create .claude/hookify.dangerous-rm.local.md:

---
name: dangerous-rm
enabled: true
event: bash
pattern: rm\s+-rf
action: block
---

🛑 **Dangerous