Versioning
The version is in the path (/v1). Within a version we only make additive changes: new endpoints, optional parameters, response fields and enum values. Your code must ignore fields and values it doesn't recognize.
Breaking changes ship as a new version. The old version keeps working for at least 12 months after the new one launches. Anything deprecated is announced in the changelog (with an RSS feed) and by email, and its responses carry a Deprecation header (RFC 9745) and, once the date is set, a Sunset header (RFC 8594). Watch for those headers in your logs.