hookify-rules

hookify-rules is a skill for Claude Code, Codex from JunMystery/Agent-Guidance-Python. It costs 47 tokens per session (931 once invoked), scanned C, a copy of hookify-rules, MIT.

This skill should be used when the user asks to create a hookify rule, write a hook rule, configure hookify, add a hookify rule, or needs guidance on hookify rule syntax and patterns.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/junmystery/agent-guidance-python/hookify-rules
Any agent
npx skills add JunMystery/Agent-Guidance-Python --skill hookify-rules
Clone the repo
git clone --depth 1 https://github.com/JunMystery/Agent-Guidance-Python

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for hookify-rules

README.md
[![agentmods](https://agentmods.dev/badge/skills/junmystery/agent-guidance-python/hookify-rules.svg)](https://agentmods.dev/skills/junmystery/agent-guidance-python/hookify-rules)
Your own site
<a href="https://agentmods.dev/skills/junmystery/agent-guidance-python/hookify-rules"><img src="https://agentmods.dev/badge/skills/junmystery/agent-guidance-python/hookify-rules.svg" alt="Measured on agentmods" height="20"></a>
Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 931 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. Scan, not verified.
Origin 88% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00047 $0.00931
Opus 5 $0.00023 $0.00465
Sonnet 5 $0.00009 $0.00186
Haiku 4.5 $0.00005 $0.00093

Measured today against content hash b604608e30ac, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

hookify-rules scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

- **Too specific**: `rm -rf /tmp` — use `rm\s+-rf`
Origin

This is a copy

88% identical to hookify-rules — 18 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/hookify-rules/SKILL.md · 129 lines

How it starts

The opening of the file, as written. The whole thing — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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

Field Required Values Description
name Yes kebab-case string Unique identifier (verb-first: warn-, block-, require-*)
enabled Yes true/false Toggle without deleting
event Yes bash/file/stop/prompt/all Which hook event triggers this
action No warn/block warn (default) shows message; block prevents operation
pattern Yes* regex string Pattern to match (*or use conditions for complex rules)

Advanced Format (Multiple Conditions)

---
name: warn-env-api-keys
enabled: true
event: file
conditions:
  - field: file_path
    operator: regex_match
    pattern: \.env$
  - field: new_text
    operator: contains
    pattern: API_KEY
---

You're adding an API key to a .env file. Ensure this file is in .gitignore!

Condition fields by event:

  • bash: command
  • file: file_path, new_text, old_text, content
  • prompt: user_prompt

Operators: regex_match, contains, equals, not_contains, starts_with, ends_with

All conditions must match for rule to trigger.

Event Type Guide

bash Events

Match Bash command patterns:

  • Dangerous commands: rm\s+-rf, dd\s+if=, mkfs
  • Privilege escalation: sudo\s+, su\s+
  • Permission issues: chmod\s+777

file Events

Match Edit/Write/MultiEdit operations:

  • Debug code: console\.log\(, debugger
  • Security risks: eval\(, innerHTML\s*=
  • Sensitive files: \.env$, credentials, \.pem$

Read the full file on GitHub · 129 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. today First seen · 129 lines · 47 tokens per session scan C b604608e30ac

Subscribe to this mod's changes

hookify-rules is a skill published in the GitHub repository JunMystery/Agent-Guidance-Python (2 stars, last pushed 1mo ago), licensed MIT. It adds 47 tokens to every session and 931 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). It is 88% identical to hookify-rules, differing in 18 lines, and is treated as a copy.

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