api-design
Stable consumer-facing API and interface design patterns. Use when designing REST endpoints, cross-team boundaries, or any externally consumed or versioned service contract. Covers contract-first development, error semantics (RFC 9457), REST conventions, pagination, idempotency, rate limiting, and backward compatibility. For an in-process feature or module's coherent responsibility and interface depth, use codebase-design. For TypeScript type patterns and trust-boundary validation, see typescript-strict.