| name | explain-codebase |
| description | Use when the user asks to explain the codebase, onboard a new developer, give an overview of the project, or describe the architecture and structure. |
Give a clear, layered explanation of this codebase suitable for a developer who is new to the project.
Steps:
- Read
README.md and any CLAUDE.md files at the root and in subdirectories.
- Identify the primary language(s) and framework(s) in use.
- Map out the top-level directory structure and explain the purpose of each major directory.
- Trace the main execution path or request lifecycle from entry point to output.
- Highlight the key abstractions, data models, and interfaces a new developer needs to understand first.
- Note any non-obvious conventions, environment requirements, or gotchas (e.g. monorepo tooling, code generation, required env vars).
- Suggest which files to read first for a developer wanting to make their first contribution.
Format the response as:
- Tech stack — one-line summary
- Directory map — annotated tree (max two levels deep)
- Request / execution lifecycle — numbered steps
- Key abstractions — bulleted list with brief descriptions
- Gotchas — anything a new developer would wish they'd known earlier
- Where to start — 3–5 recommended files in order