Master Claude Code for Production Shipping · 35 min · Claude Code

Hooks — Automating the Guardrails

A CLAUDE.md is an instruction Claude Code might follow. A hook is a shell command that runs -- guaranteed -- when a specific event fires.

Hiring signal: Knowing precisely when to reach for a hook instead of a CLAUDE.md instruction -- and debugging one that doesn't fire as expected -- is real, hands-on configuration skill most Claude Code users never go deep enough to need.

What you will learn

Explain the hook lifecycle and what events are available
Configure a real hook in .claude/settings.json
Debug a hook that doesn't fire as expected

What You're Building

One real, working hook in your own repo — something that runs automatically at a specific point in Claude Code's workflow, not something you have to remember to ask for.

A CLAUDE.md instruction is a suggestion. A hook is guaranteed.

This is the actual distinction that decides which tool to reach for
Writing "always run tests after editing a file" in CLAUDE.md is a strong hint Claude Code will usually follow — but it's still a judgment call it makes each time, and it can reasonably decide a specific edit doesn't warrant a full test run. A hook configured on the right event runs every single time that event fires, no judgment call involved. Use CLAUDE.md for things that benefit from judgment ("usually run the tests, use your discretion for trivial changes"); use a hook for things that must always happen ("never let an edit to a protected file through," "always run the linter after any file write").

Unlock the full lesson

You've read the first 2 sections. The rest of this lesson covers Configuring a real hook, What you're building today — plus a hands-on lab, quiz, and project artifact.

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Key terms in this lesson

Guardrails