Explain Repo

This skill turns a repository into an atlas — a navigable set of HTML chapters a developer opens to understand a codebase well enough to keep building it, plus a distilled SUMMARY.md that bootstraps a future agent session.

Everything in the atlas is grounded: every claim cites the file, commit, or issue it came from, or it is cut. This is the skill's root discipline — cite or cut. Never describe the repo from a parametric guess of what code like this "usually" does. Read it, then cite it. The two chapters most prone to invention — History and Strengths/Weaknesses — get an adversarial refute pass (step 5) for exactly this reason.

The atlas lives in .repo-atlas/ inside the target repo, gitignored so it never dirties the tree, and stamped with the as-of commit it was built against so it can be refreshed when the code drifts.

Work the steps in order. Each ends on a completion criterion — do not advance until it is met.

The atlas workspace

Two layers, mirroring the territory and your map of it.

Presentation layer — what the developer opens (HTML), under .repo-atlas/.