Contract-First Designer Protocol

This skill enforces API design before implementation. It breaks the habit of writing controller code and auto-generating the spec from it. By designing the OpenAPI/AsyncAPI contract first, backend and frontend teams can work in parallel.

Core assumption: Code is cheap, contracts are expensive to change. A well-designed API contract prevents endless integration meetings.

1. Specification Generation (Static)

Analyze the business requirements to output a standard API documentation format.

REST APIs (OpenAPI 3.x)

• Define all endpoints, methods (GET, POST, etc.).
• Explicitly define standard HTTP status codes (200 OK, 201 Created, 400 Bad Request, 401 Unauthorized, 404 Not Found, 500 Internal Server Error).
• Define strict Request/Response JSON schemas using $ref components.
• Include pagination parameters (limit, cursor/offset) for all collection endpoints.