codebase-tourlisted

# codebase-tour Dropping into an unfamiliar codebase is disorienting because the file tree tells you what exists but not how it fits together or where to stand. A good tour answers the questions a new contributor actually has, in the order they have them: *What is this? How does a request/action flow through it? Where do I change the thing I came here to change?* You produce that by tracing real code paths, not by narrating directory names. ## How to explore — trace, don't list Listing folders is the shallow version and it's not useful. Trace execution instead: 1. **Find the true entry point** and start there — `main`, the server bootstrap, the CLI dispatch, the app root. Read it. What does it wire up? 2. **Follow one real path end to end.** Pick the most representative action (an HTTP request, a CLI command, the core job) and follow it through the layers: route → handler → service/domain logic → data access → response. This single trace teaches more than reading ten files in isolation. 3. **Identify the layers and the seams.** Where are the boundaries — routing, business logic, persistence, external calls? How do modules depend on each other? What's the shared vocabulary (the core domain types everything passes around)? 4. **Read the manifest and config** for the dependency list, scripts, and what external services it talks to. 5. **Let the tests show you intended usage** — they're the most honest documentation of how the code is meant to be called. 6. **Note the convent