A Claude Code hookis an event-driven automation script that runs at specific points during Claude's tool execution lifecycle. Hooks intercept actions like file writes, shell commands, and code generation to inject custom logic without requiring manual input from the developer. They are the primary mechanism for building guardrails, enforcing standards, and extending Claude Code's capabilities beyond its default behavior.
The hook system in Claude Code operates on a simple but powerful model: trigger, match, execute. Each hook defines a trigger event (such as PreToolUse or PostToolUse), an optional tool name matcher to narrow scope, and a command that runs when conditions are met. The command receives structured JSON input through stdin containing the tool name, parameters, and context. It returns a JSON response that can approve the operation, block it with a reason, or modify the inputs before they reach the tool.
Pre-tool hooks fire before Claude executes a tool. They are ideal for security enforcement, input validation, and policy compliance. A common pre-tool hook pattern is the secret scanner, which inspects file content for API keys, passwords, and tokens before Claude writes them to disk. Another popular pattern is the command guard, which blocks dangerous shell commands like rm -rf /, git push --force, or database drop statements from ever executing.
Post-tool hooks fire after a tool completes and are used for notifications, logging, follow-up actions, and result validation. For example, a post-tool hook can send a Slack message every time Claude modifies a critical configuration file, log all shell command outputs to an audit trail, or automatically run a linter on any code file Claude has changed. Post-tool hooks are also valuable for chaining workflows: after Claude writes a test file, a hook can automatically run the test suite and feed results back into the conversation.
Security-focused teams find hooks indispensable. By layering multiple hooks, you create a defense-in-depth architecture around Claude's tool usage. A pre-commit review hook can analyze all staged changes for code quality before Claude commits them. A dependency audit hook can check newly added packages against vulnerability databases. These automated checks run consistently on every operation, eliminating the human inconsistency that comes with manual code review.
Notification hooks bridge Claude Code with your team's communication tools. When Claude completes a significant operation, such as finishing a refactoring task, deploying to staging, or encountering an error it cannot resolve, notification hooks can post updates to Slack channels, create Jira tickets, send email alerts, or update project management dashboards. This keeps the entire team informed about what the AI agent is doing without anyone needing to monitor the terminal.
Building custom hooks requires minimal boilerplate. A hook script can be as simple as a ten-line bash script that checks a condition and returns a JSON verdict, or as sophisticated as a Python service that calls external APIs for validation. The hook protocol is language-agnostic: anything that reads JSON from stdin and writes JSON to stdout works. This flexibility means you can integrate hooks with existing tooling, corporate compliance systems, or custom business logic without rearchitecting your workflow.
This directory contains 14 curated hooks covering the most common automation patterns. Each hook has been tested for reliability, documented for ease of installation, and categorized by use case. Whether you need to enforce security policies, automate notifications, ensure code quality, or build custom workflow triggers, you will find production-ready solutions below.