How do I prevent infinite loops in hooks?

To prevent infinite loops, always check for the 'stop_hook_active' flag and ensure your hooks are idempotent, meaning they won't trigger themselves repeatedly.

What handler types are supported in Claude Code?

Claude Code supports three handler types: command (shell scripts), prompt (single-turn LLM evaluation), and agent (multi-turn subagents with tool access).

What is the difference between a hook and a rule?

Hooks are deterministic system-level handlers that cannot be ignored and can block or modify actions, whereas rules (like CLAUDE.md) are advisory guidelines for Claude's behavior.

Can hooks block tool execution?

Yes, specific events like UserPromptSubmit and PreToolUse can block execution by returning an exit code 2 (for scripts) or a block decision (for agents).

Claude Code Hooks Guide

Name: Claude Code Hooks Guide
Author: CaptainCrouton89

byCaptainCrouton89

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Productivity & Workflow

Master the implementation of lifecycle events and system-level handlers to create deterministic guardrails and context-aware automations.

This skill provides a comprehensive reference for Claude Code hooks, enabling developers to build robust, non-ignorable system-level handlers. It covers the full spectrum of lifecycle events—from session starts to tool executions and task completions—allowing for the injection of context, enforcement of quality gates, and implementation of complex decision controls. Whether you are building automated security guardrails or streamlining Git workflows, this guide offers the patterns and best practices needed to ensure your hooks are performant, idempotent, and effective within the Claude Code environment.

Key Features

01Comprehensive guide to deterministic lifecycle events and triggers

02Detailed comparison of command, prompt, and agent handler types

0324 GitHub stars

04Advanced decision control for blocking or modifying tool inputs

05Configurable matchers for shell commands and MCP tools

06Best practices for performance, idempotency, and loop prevention

Use Cases

01Injecting dynamic project context during session starts or tool usage

02Implementing automated security guardrails and code quality enforcement

03Creating quality gates that require successful test runs before task completion

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add captaincrouton89/crouton-kit hooks

For use in Claude.ai and ChatGPT

Download Skill