writing-hookify-rules

To write agent guardrails, create a markdown file with frontmatter containing fields like name, enabled, event, and pattern, plus a message body to enforce specific behaviors during tool use and prompts. Validation ensures correct syntax before deployment.

Hookify rules are frontmatter-based definitions that monitor and enforce guardrails on agent behavior by matching patterns and events, triggering markdown message bodies during tool use or prompt interactions. Optional conditions can further refine when rules apply.

Validate hookify rules by checking the frontmatter schema for required fields like name, enabled, event, pattern, and messages, ensuring optional conditions are properly formatted and the markdown body is present. This prevents syntax errors during agent execution.

Yes, hookify rules support optional conditions within the frontmatter schema, allowing you to specify contextual criteria that must be met before a pattern triggers a message during agent tool use. This enables fine-grained control over guardrail enforcement.

The best way to structure a guardrail markdown file is placing frontmatter with name, enabled, event, and pattern fields at the top, followed by a markdown message body that defines the rule's enforcement output. Save it in the .claude/hookify directory.