Codebase Onboarding systematically analyzes unfamiliar codebases to generate a structured onboarding guide containing an architecture map, key entry points, conventions, and a starter configuration file. It is designed for developers joining new projects or setting up AI assistance in an existing repository for the first time. The workflow uses a reconnaissance phase to gather raw signals from package manifests, framework configurations, and directory trees, followed by architecture mapping and convention identification. Reach for it when you need to quickly understand a new codebase or generate project documentation.