API Contract Design
API Contract Design is the practice of formally defining the interface specifications for an API before implementation, typically using standards like OpenAPI, GraphQL schemas, or gRPC protobufs. It establishes clear agreements between API providers and consumers regarding endpoints, data formats, request/response structures, and behaviors. This approach ensures consistency, reduces integration errors, and facilitates automated documentation and testing.
Developers should learn API Contract Design when building or consuming APIs in distributed systems, microservices architectures, or public-facing services to prevent breaking changes and improve collaboration. It is crucial for scenarios like API-first development, where teams design contracts upfront to parallelize work, and for maintaining backward compatibility in long-lived APIs. Using it helps enforce standards, streamline client SDK generation, and support contract testing tools.