Writing Hookify Rules

You can create custom rules for Claude by defining YAML frontmatter with name, enabled, event, and pattern fields in a .claude/hookify.{rule-name}.local.md file, followed by a message body for Claude to display when the rule triggers.

Hook rules for Claude responses can target bash, file, stop, and prompt events, allowing you to define single-condition or multi-condition patterns that watch for specific triggers and emit contextual messages.

To set up a local hookify rule file, create a markdown file at your project root named .claude/hookify.{rule-name}.local.md, add the required YAML frontmatter schema, write your message body, then trigger the corresponding event to test it.

Yes, hookify rules support both single-condition and multi-condition pattern definitions, allowing you to map multiple pattern triggers to a single response or warning message within your local rule file.

Using frontmatter-based hook rules provides a structured, reusable way to shape Claude's behavior without hard-coding it in prompts, enabling local project-specific customization that does not affect the core model.

Local hookify rule definition files are limited to project-specific customization stored under .claude/hookify.{rule-name}.local.md, enforcing a strict frontmatter schema and relying on pattern matching across bash, file, stop, and prompt events to trigger messages.