Writing Hookify Rules

The Hookify Rules skill is a specialized utility for defining guardrails and custom automated responses within Claude Code. It allows developers to create markdown files with YAML frontmatter that monitor real-time activity, including bash command executions, file modifications (edit/write), and agent lifecycle events like 'stop' or 'prompt' submission. This is essential for enforcing repository-specific standards, preventing the introduction of dangerous code patterns, or providing contextual guidance during development workflows.

• Define rule patterns using Python regex syntax for granular matching against commands, file paths, or content snippets.

• Supports multiple event types: bash, file, stop, prompt, and all for flexible trigger conditions.

• Advanced configuration via multiple condition fields including regex_match, contains, equals, not_contains, starts_with, and ends_with.

• Enables reactive automation by defining clear action modes: 'warn' for suggestions or 'block' to prevent unsafe operations (PreToolUse).

• Integrated with Claude Code's file system, storing configurations in .claude/hookify.{rule-name}.local.md files for easy version control and toggle-ability via the 'enabled' boolean flag.

• Rules are highly effective for catching common pitfalls such as hardcoded API keys in .env files, dangerous bash commands like rm -rf, or improper console.log statements in production code.

• Provide helpful, actionable feedback by defining custom message bodies in markdown, allowing you to explain the problem and suggest specific alternatives or best practices to the agent.

• Use the provided python-based testing tips to validate your regex patterns before deploying them as active rules.

• Ideal for team leads and infrastructure engineers who need to enforce security policies and coding standards across a project codebase without building custom plugins from scratch.

• Remember that all conditions in an advanced configuration must match for a rule to trigger, allowing for very specific, high-precision safety enforcement.