API design best practices

Design APIs that are easier to integrate, safer to evolve, and simpler to operate—without over-engineering.

Jan 08, 2026api-developmentintegrations

Most API problems are not “code” problems—they’re contract problems. A few upfront decisions make integrations faster, support easier, and future changes less painful.

If you want help implementing: API Development and Integrations.

1) Design around resources and outcomes

Prefer clear nouns for resources:

  • GET /customers/{id}
  • POST /subscriptions

Avoid leaking internal architecture through endpoints. Model what clients need to do, not how you do it internally.

2) Make errors predictable

Return consistent error shapes with:

  • A stable error code (machine readable)
  • A human message
  • Optional metadata (field name, limits, etc.)

3) Version with intent

The easiest way to “version” is to avoid breaking changes. When you must:

  • Use a clear strategy (path versioning, header versioning, etc.)
  • Document timelines and deprecation

4) Treat auth and rate limits as part of the product

Good APIs protect customers and your infrastructure:

  • Explicit scopes/permissions
  • Rate limiting per key/customer
  • Audit logging for sensitive actions

5) Document the contract (and keep it current)

OpenAPI specs help you:

  • Generate SDKs
  • Validate requests
  • Keep docs and code aligned

If integrations are a core channel, invest in docs early—it pays back quickly.

Next read: Integrations that scale.

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