What problem does it solve? Adding or changing an API endpoint risks breaking existing callers, drifting from the OpenAPI contract, or leaking sensitive error details. This Skill enforces consistent resource naming, status codes, validation, authorization, and keeps the OpenAPI spec, generated clients, and runtime implementation in lockstep. ## Core Features & Use Cases - Contract-first design: Guides resource naming, HTTP method semantics, status code selection, pagination, rate limits, and error envelope conventions aligned with the repository's existing Express API. - OpenAPI lockstep workflow: Ensures every contract change updates lib/api-spec/openapi.yaml, regenerates clients and validators, and passes pnpm run check:api-generated. - Review checklist: Verifies backward compatibility, authentication and capability scope, input validation, bounded payloads, and idempotency before shipping. - Use Case: When adding a new endpoint to the Express 5 API server, use this Skill to design the route, update the OpenAPI spec, regenerate the Zod schemas and React hooks, and confirm runtime behavior matches the documented contract. ## Quick Start Ask the AI to design a new API endpoint for the project following the api-design skill, including the OpenAPI update and generated client regeneration.
