writing-hookify-rules

Create a markdown file named .claude/hookify.{rule-name}.local.md with YAML frontmatter containing name, enabled, event, and pattern fields. The markdown body after the frontmatter is the message shown when the rule triggers.

Hookify rules support bash, file, stop, prompt, and all event types. Bash matches commands, file matches Edit/Write/MultiEdit operations, stop matches completion attempts, and prompt matches user input.

Use the conditions array in frontmatter instead of a single pattern field. Each condition specifies a field, an operator like regex_match or contains, and a pattern; all conditions must match for the rule to trigger.

Yes, set action: block in the frontmatter to prevent the operation on PreToolUse events or stop the session on Stop events. If omitted, the action defaults to warn, which shows the message but allows the operation.

Common causes are unescaped special characters like dots and parentheses, overly broad patterns, or YAML quoting issues. Use unquoted patterns in YAML and test with python3 -c "import re; print(re.search(r'pattern', 'text'))" before saving.

Set enabled: false in the rule's frontmatter to deactivate it while keeping the file. Changes take effect immediately on the next tool use since rules are read dynamically.