Reference

Versioning & deprecation

What we promise not to break.

The API is versioned in the path: /api/v1/…. Inside v1 we only make additive changes:

New endpoints, new optional request fields, new response fields and new error codes may appear at any time. Clients should ignore fields they don't recognise.
Existing fields, types, status codes, error codes and headers are never removed or renamed within v1.
Accuracy fixes that change an output to match a published standard (for example E.164 phone format) are announced in the changelog first.

Breaking changes

Breaking changes only ship in a new path version (/api/v2). When that happens v1 keeps working for at least 6 months, deprecated endpoints return a Deprecation and Sunset header, and every change is listed in the changelog and its RSS / JSON feed.

SDKs

The JavaScript and Python SDKs follow semantic versioning. Old import names (Zapinner, zapinner) remain as aliases.

Uptime

Our target is 99.9% monthly availability for the API, measured on the status page. This is a target, not a contractual SLA.