The Art of CTO API Contract Designer is a visual endpoint builder that generates OpenAPI specifications, detects breaking changes, and documents REST APIs with versioning support.
Frequently Asked Questions
What is API contract-first design?
Contract-first (or API-first) design means defining your API specification before writing implementation code. You create the OpenAPI/Swagger document specifying endpoints, request/response schemas, and error codes, then generate server stubs and client SDKs from that contract. This approach ensures frontend and backend teams can work in parallel, catches design issues early, and produces consistent, well-documented APIs. It is particularly effective for public APIs and microservices architectures.
How do you prevent breaking API changes?
Prevent breaking changes by versioning your API from day one (URL path or header-based), using automated contract testing in CI/CD that compares new schemas against the previous version, and following additive-only change policies (new fields are optional, existing fields never removed or type-changed). When breaking changes are unavoidable, use a deprecation cycle: announce the deprecation, support both versions for a migration period (typically 6-12 months), provide migration guides, and monitor usage of deprecated endpoints before removal.