How do I block an action using a hook?

In a command hook, exiting with code 2 will deny the action and display your error message; in a prompt hook, you instruct Claude to set the permissionDecision to 'deny' based on specific criteria.

What is a Claude Code hook?

A hook is an event-driven mechanism that allows you to execute scripts or prompts at specific points in Claude's execution lifecycle, such as before a tool is used or when a session starts.

Which event should I use to validate file edits?

You should use the PreToolUse event combined with a matcher for 'Write|Edit' to intercept and validate file changes before they are actually written to disk.

What is the difference between a command hook and a prompt hook?

Command hooks execute external scripts (like Node.js) and use exit codes for logic, while prompt hooks use Claude's own reasoning to evaluate conditions semantically.

What environment variables are available for pathing?

Plugin-level hooks should use ${CLAUDE_PLUGIN_ROOT} for absolute paths, whereas project-specific hooks utilize the "$CLAUDE_PROJECT_DIR" variable.

Claude Hook Developer

Name: Claude Hook Developer
Author: nthplusio

bynthplusio

Herramientas para Desarrolladores

Streamlines the creation of event-driven hooks to validate, log, and modify Claude's behavior during the development lifecycle.

Acerca de

This skill provides a comprehensive framework for implementing custom hooks within Claude Code, allowing developers to intercept tool usage and session events. It covers the configuration of hooks.json, the implementation of both script-based command hooks and AI-driven prompt hooks, and the management of critical event lifecycles like PreToolUse and SessionStart. By utilizing this skill, developers can enforce coding standards, automate cache refreshes, and capture session learnings, ensuring a more controlled and efficient AI interaction.

Características Principales

Comprehensive event lifecycle coverage from SessionStart to Stop
0 GitHub stars
Support for script-based Command hooks and semantic Prompt hooks
Standardized hooks.json configuration and schema guidance
Pre-built templates for validation scripts and exit code management
Advanced tool matching using regex patterns for specific tool interception

Casos de Uso

Automating environment setup or cache refreshing at the beginning of a Claude session
Capturing architectural decisions or session learnings automatically when a task concludes
Enforcing file modification standards by validating code before a Write or Edit tool executes

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add nthplusio/functional-claude hook-development

For use in Claude.ai and ChatGPT

Download Skill

GitHub