Machine-readable API contracts — Swagger UI, code generation, validation, and design-first workflows.
Five passes over the same idea, each from a different angle. Do them in order, or jump to whichever you need.
OpenAPI Specification (formerly Swagger) describes REST APIs in YAML/JSON. Enables: interactive docs (Swagger UI, Redoc), client/server code generation, request validation, and contract testing. Design-first approach: write the spec before code. Tools: Swagger Editor, Spectral (linting), openapi-generator.
