Write, generate, or review an OpenAPI 3.1 specification for an HTTP API so that it is accurate to the implementation, complete for consumers (schemas, examples, errors, auth, pagination), and usable by tooling (validation, client generation, mock servers). Covers design-first and code-first workflows, linting with Spectral, and keeping the spec in sync in CI. Use when documenting an API, when a client generator or contract test needs a spec, or when the existing spec no longer matches the routes.
