Versioning APIs is inevitable as your product evolves. A well-designed versioning strategy allows adding functionality without breaking existing consumers.
Versioning strategies
URL Path Versioning (/api/v1/users, /api/v2/users): the most common and explicit. Easy to implement and debug, but clutters URLs and makes maintaining multiple versions harder.
Header Versioning (Accept: application/vnd.api.v1+json): cleaner than URL, but less visible for developers testing with curl or Postman. Requires clients to configure headers correctly.
Query Parameter Versioning (/api/users?version=1): simple but easy to forget on the client side. Not recommended for public APIs.
Best practices
Keep old versions long enough for clients to migrate (6-12 months). Clearly document each version's changes and deprecated endpoints. Implement Deprecation and Sunset headers per RFC 8594.
Forward-compatible evolution is the ideal: adding optional fields to responses never breaks existing clients. Removing fields or changing types requires a new version.
Alternative: versioning-free
Some successful APIs (Stripe, GitHub) minimize versioning by using extensible design: optional fields, tolerance to unknown fields, and backward-compatible changes.
Versioning is a strategic API design decision. At Vynta, we design APIs with clear versioning strategies that let your product evolve painlessly.