Creating Claude Hooks

It covers the four main events (session start, prompt submit, tool call, assistant response), shows you how to handle JSON input from stdin and use exit codes to block operations, and walks through the PRPM package structure if you want to publish. The format requirements are specific: you need shebangs, executable permissions, and proper quoting around variables. Most useful when you're actually writing a hook and need to remember whether blocking is exit 2 or when to use stderr vs stdout. The examples are practical, showing real validation and logging patterns in both bash and TypeScript.