API design best practices center on clarity, consistency, and long‑term maintainability, not just “making it work” for the first client.

Core principles

  • Treat the API as a product for developers: stable contracts, clear onboarding, and minimal surprises.
  • Prefer resource‑oriented design (nouns like /users, /orders) with HTTP methods for actions (GET, POST, PUT/PATCH, DELETE).
  • Keep communication stateless: every request includes all necessary context (auth, tenant, locale), so servers can scale horizontally.

URLs, methods, and payloads

  • Use predictable URIs with plural nouns and logical nesting, e.g. /articles/{id}/comments, but avoid mirroring internal database schemas.
  • Use HTTP methods semantically: GET=read, POST=create, PUT/PATCH=update, DELETE=remove.
  • Standardize payloads and field naming; avoid changing naming style between endpoints and keep response envelopes consistent if you use them.

Errors, pagination, and performance

  • Return meaningful HTTP status codes and structured error bodies with codes, messages, and validation details to aid debugging.
  • Never return unbounded lists: implement pagination (cursor or offset), plus filtering and sorting for large collections.
  • Optimize responses: support caching, compression, and optional/expandable fields so expensive data is only fetched when requested.

Security and stability

  • Enforce HTTPS everywhere, validate and sanitize all inputs, and use proper auth like OAuth 2.0 or JWT rather than custom schemes.
  • Apply rate limiting and provide rate‑limit headers so clients can back off before hitting hard limits.
  • Version your API explicitly (e.g. /v1/) and evolve via additive changes; avoid breaking changes without a new version.

Documentation, testing, and DX

  • Publish up‑to‑date OpenAPI/Swagger or similar docs, including examples for common and edge cases.
  • Add automated tests, monitoring, and logging around key endpoints to catch regressions and incidents early.
  • Make developer experience a first‑class concern: consistent conventions, helpful error messages, and “quick start” examples lead to APIs people actually want to use.

Quick Scoop

In 2024–2025, discussions about “API design best practices” on blogs and forums heavily emphasize developer experience, consistency in responses, and resilience features like pagination, rate limiting, and proper error handling as the baseline expectations for any serious public or internal API.