api-design

API contract design involves defining resources, methods, request/response envelopes, and error semantics upfront. This approach establishes stable HTTP boundaries and ownership decisions, ensuring consistent behavior across client implementations before any backend coding begins.

Contract-first API design is the process of outlining HTTP resources and error models before building backend services. You need it when aligning multiple teams on API behavior to prevent miscommunications that derail product timelines during development.

Modeling errors and pagination in an HTTP API requires explicit failure design within the API contract. You define standardized error semantics, pagination rules, and response envelopes to support consistent data retrieval and safe API evolution across versions.

Best practices for API versioning involve establishing explicit compatibility rules and versioning plans within the contract. This ensures safe API evolution by documenting migration notes and maintaining consistent behavior across different client versions.

Contract-first API design applies to both public and internal HTTP surfaces. It enforces consistent behavior across all client implementations by defining explicit idempotency requirements, pagination, and error semantics regardless of the API's exposure level.