Hookify Plugin Help

Explain how the hookify plugin works and how to use it.

Overview

The hookify plugin makes it easy to create custom hooks that prevent unwanted behaviors. Instead of editing hooks.json files, users create simple markdown configuration files that define patterns to watch for.

How It Works

1. Hook System

Hookify installs generic hooks that run on these events:

• PreToolUse: Before any tool executes (Bash, Edit, Write, etc.)
• PostToolUse: After a tool executes
• Stop: When Claude wants to stop working
• UserPromptSubmit: When user submits a prompt

These hooks read configuration files from .claude/hookify.*.local.md and check if any rules match the current operation.

2. Configuration Files

Rules can be placed in two locations:

• ~/.claude/hookify.*.local.md - Global rules (apply to all projects)
• .claude/hookify.*.local.md - Project rules (apply to current project only)

Example rule file:

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

⚠️ **Dangerous rm command detected!**

This command could delete important files. Please verify the path.

Key fields:

• name: Unique identifier for the rule
• enabled: true/false to activate/deactivate
• event: bash, file, stop, prompt, or all
• pattern: Regex pattern to match

The message body is what Claude sees when the rule triggers.

3. Creating Rules

Option A: Use /hookify command

/hookify Don't use console.log in production files

This analyzes your request and creates the appropriate rule file.

Option B: Create manually Create .claude/hookify.my-rule.local.md with the format above.

Option C: Analyze conversation

/hookify

Without arguments, hookify analyzes recent conversation to find behaviors you want to prevent.

Available Commands

• /hookify - Create hooks from conversation analysis or explicit instructions
• /hookify:help - Show this help (what you're reading now)
• /hookify:list - List all configured hooks
• /hookify:configure - Enable/disable existing hooks interactively

Example Use Cases

Prevent dangerous commands:

---
name: block-chmod-777
enabled: true
event: bash
pattern: chmod\s+777
---

Don't use chmod 777 - it's a security risk. Use specific permissions instead.

Warn about debugging code:

---
name: warn-console-log
enabled: true
event: file
pattern: console\.log\(
---

Console.log detected. Remember to remove debug logging before committing.

Require tests before stopping:

---
name: require-tests
enabled: true
event: stop
pattern: .*
---

Did you run tests before finishing? Make sure `npm test` or equivalent was executed.

Pattern Syntax

Use Python regex syntax:

• \s - whitespace
• \. - literal dot
• | - OR
• + - one or more
• * - zero or more
• \d - digit
• [abc] - character class

Examples:

• rm\s+-rf - matches "rm -rf"
• console\.log\( - matches "console.log("
• (eval|exec)\( - matches "eval(" or "exec("
• \.env$ - matches files ending in .env

Dynamic Command Interpolation

Messages can include shell commands that get executed and replaced with their output. Use the syntax !​command`` (exclamation mark followed by backticks).

Example - Show Linear issues when linear is mentioned:

---
name: linear-issues
enabled: true
event: prompt
pattern: \blinear\b
---

**Your Linear Issues:**
!​`linear issue list --limit 10`

When this rule triggers, the !​linear issue list --limit 10`` will be replaced with the actual output of that command.

Notes:

• Commands timeout after 5 seconds
• Errors are shown as (error: ...)
• Empty output shows as (no output)
• Great for showing context like git status, issue lists, etc.

Important Notes

No Restart Needed: Hookify rules (.local.md files) take effect immediately on the next tool use. The hookify hooks are already loaded and read your rules dynamically.

Block or Warn: Rules can either block operations (prevent execution) or warn (show message but allow). Set action: block or action: warn in the rule's frontmatter.

Rule Files: Rules can be global (~/.claude/) or project-local (.claude/). Project rules should be git-ignored (add .claude/*.local.md to .gitignore).

Disable Rules: Set enabled: false in frontmatter or delete the file.

Troubleshooting

Hook not triggering:

• Check rule file is in .claude/ directory
• Verify enabled: true in frontmatter
• Confirm pattern is valid regex
• Test pattern: python3 -c "import re; print(re.search('your_pattern', 'test_text'))"
• Rules take effect immediately - no restart needed

Import errors:

• Check Python 3 is available: python3 --version
• Verify hookify plugin is installed correctly

Pattern not matching:

• Test regex separately
• Check for escaping issues (use unquoted patterns in YAML)
• Try simpler pattern first, then refine

Getting Started

1. Create your first rule:

   /hookify Warn me when I try to use rm -rf
   

2. Try to trigger it:

   • Ask Claude to run rm -rf /tmp/test
   • You should see the warning

3. Refine the rule by editing .claude/hookify.warn-rm.local.md

4. Create more rules as you encounter unwanted behaviors

For more examples, check the ${CLAUDE_PLUGIN_ROOT}/examples/ directory.