How do I block an operation in a Claude hook?

To block an operation in a PreToolUse hook, your script must exit with a status code of 2. This signals the CLI to stop the tool execution and show an error.

When should I use the PreToolUse event?

Use the PreToolUse event when you need to validate, modify input, or block an operation entirely before a tool actually executes.

Does this skill help with publishing hooks?

Yes, it includes a dedicated publishing guide for the PRPM registry, covering manifest configuration, versioning, and documentation best practices.

What is a Claude Code hook?

A hook is a specialized script that executes during specific lifecycle events of the Claude Code CLI, such as before or after a tool is used, allowing for automated validation or modification of behavior.

How can I make my Claude hooks faster?

Keep hooks deterministic and run heavy operations, such as full test suites or builds, in the background using shell subshells so they don't block the main CLI process.

Claude Hook Writer

Name: Claude Hook Writer
Author: secondsky

bysecondsky

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開発者ツール

Guides developers in building secure, high-performance Claude Code hooks with expert patterns and automated validation.

概要

Claude Hook Writer provides comprehensive guidance for creating, debugging, and optimizing Claude Code CLI hooks, ensuring they are both secure and efficient. It helps developers navigate the complexities of hook design—from selecting the correct trigger events like PreToolUse and PostToolUse to enforcing critical security patterns such as input sanitization and path validation. By providing ready-to-use code templates and identifying common pitfalls like unquoted variables or blocking operations, this skill accelerates the development of production-ready extensions for the Claude environment while minimizing runtime errors and performance bottlenecks.

主な機能

21 GitHub stars
Provides production-ready templates for formatting, logging, and sensitive file blocking
Enforces security best practices including input sanitization and path traversal prevention
Optimizes hook performance by identifying synchronous operations that should run in the background
Validates hook design decisions for lifecycle events like PreToolUse and PostToolUse
Guides the end-to-end publishing process for PRPM packages and manifest configuration

ユースケース

Debugging and profiling existing hooks to reduce latency and improve reliability during CLI sessions
Building a format-on-save hook that triggers linting before file modifications are finalized
Implementing security guardrails to block Claude from accessing sensitive files like .env or private keys

概要

主な機能

21 GitHub stars
Provides production-ready templates for formatting, logging, and sensitive file blocking
Enforces security best practices including input sanitization and path traversal prevention
Optimizes hook performance by identifying synchronous operations that should run in the background
Validates hook design decisions for lifecycle events like PreToolUse and PostToolUse
Guides the end-to-end publishing process for PRPM packages and manifest configuration

ユースケース

Debugging and profiling existing hooks to reduce latency and improve reliability during CLI sessions
Building a format-on-save hook that triggers linting before file modifications are finalized
Implementing security guardrails to block Claude from accessing sensitive files like .env or private keys