api-design

Contract-first API design defines interface contracts before implementation to prevent scope drift and protect callers from breaking changes. It ensures consistent REST interfaces by exposing the smallest observable surface area you are willing to support forever.

To apply REST conventions and resilience patterns, model resources with plural endpoints and standard HTTP status codes, then attach circuit breakers and exponential backoff retries to external calls. This enforces clear REST guidelines and documented resilience designs.

You need circuit breakers and health checks in API architecture when external calls may fail unpredictably. Circuit breakers prevent cascading failures, while explicit health endpoints signal service readiness to ensure robust API operations.

Contract-first API design helps with REST versioning and Hyrum's Law by enforcing early versioning of exposed surfaces and documenting guarantees. Heeding Hyrum's Law prevents implicit behaviors from becoming accidental contracts that break users.

The best way to design REST APIs that avoid inconsistent interfaces is drafting a contract-first interface before implementation. This approach enforces clear REST guidelines, consistent request and response shapes, and documented resilience designs.

The limitation of implementation-first API development is scope drift, which creates inconsistent interfaces and exposes unintended contracts. Without a contract-first approach, implementation changes risk breaking callers and expanding the supported surface area.