Push notification receipt IDs will change string formats

The Expo push notification service uses receipts to communicate whether the underlying push notification providers – APNs and FCM – received notifications correctly or if there was an error. Each receipt has an ID, which is an opaque string. Developers receive these IDs from the Expo push notification service and use them to fetch receipts.

Historically, receipt IDs were UUIDv4 strings. On Monday, April 8, the receipt IDs will experimentally switch to UUIDv7 strings. This change will not impact code that handles receipt IDs as opaque strings. However, given there may be code that relies on undocumented implementation details, we are communicating this change publicly. Moreover, we recommend code not assume receipt IDs will be UUIDv4 values, let alone a UUID at all, as the only guarantee is that receipt IDs will be strings.