sakamoto-family-smile 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$,credentials,\.pem$
stop Events
Completion checks and reminders. Pattern .* matches always.
prompt Events
Match user prompt content for workflow enforcement.
Pattern Writing Tips
Regex Basics
- Escape special chars:
.to\.,(to\( \swhitespace,\ddigit,\wword char+one or more,*zero or more,?optional|OR operator
Common Pitfalls
- Too broad:
logmatches "login", "dialog" — useconsole\.log\( - Too specific:
rm -rf /tmp— userm\s+-rf - YAML escaping: Use unquoted patterns; quoted strings need
\\s
Testing
python3 -c "import re; print(re.search(r'your_pattern', 'test text'))"
File Organization
- Location:
.claude/directory in project root - Naming:
.claude/hookify.{descriptive-name}.local.md - Gitignore: Add
.claude/*.local.mdto.gitignore
Commands
/hookify [description]- Create new rules (auto-analyzes conversation if no args)/hookify-list- View all rules in table format/hookify-configure- Toggle rules on/off interactively/hookify-help- Full documentation
Quick Reference
Minimum viable rule:
---
name: my-rule
enabled: true
event: bash
pattern: dangerous_command
---
Warning message here