Paste an OpenAPI spec, a list of endpoints or a few example requests and responses, and get a design review of your API. It checks resource naming, use of HTTP methods and status codes, pagination, filtering, error format, idempotency, versioning, authentication and rate limits, and finds the places where your API is inconsistent with itself. Every issue comes with a severity, a before and after example, and a note on whether fixing it would break existing clients. It ends with a short style guide drawn from your own best endpoints and five contract tests to write.