Sign Customiser’s previous-generation public API is now deprecated. Existing integrations continue to work, but developers should move to API v3 before the scheduled 22 January 2027 Sunset.
The new v2 to v3 migration guide maps every previous-generation operation to its v3 replacement. It also covers scoped Store-bound keys, pricing field changes, webhook subscriptions, order and product writes, error handling, pagination, and a safe cutover sequence that avoids duplicate writes.
Deprecated responses now include standard Deprecation, Sunset, and Link headers. These make the timeline and migration guide visible to API clients without changing existing response bodies, status codes, validation, or authentication behaviour.
