How Claude Code Hooks Work: A Practical Guide to PreToolUse Gates

Claude Code can run shell commands, edit files, and push to git on your behalf. That power is the point — and the risk. Hooks are the mechanism for putting deterministic guardrails around it: small scripts the harness runs at defined points in the agent's loop, able to inspect — and block — what the agent is about to do. This guide covers the PreToolUse hook specifically, because it's the one that can stop a dangerous action before it executes. The hook lifecycle Claude Code fires h...