Users can purchase gold coins through IAP in my app. How can I synchronize the gold coin balance across the user's devices (logged in with the same Google ID or Apple ID)? I don’t want to force users log in. In-app subscriptions are bound to the Google or Apple account and don’t require login. How can I achieve a similar functionality for gold coins? Can I obtain a unique ID representing the Google ID or Apple ID when the user makes a purchase? Then, when the user recharges or spends gold coins, the unique ID can be sent to my server to update the gold coin balance? (Essentially, using this unique ID as a credential for an invisible user system.)
Best answer by jeffrey_bunn
Hi @Chang! We strongly recommend using custom (not anonymous) app user IDs in this case. While anonymous IDs can work fine for users with subscriptions on different devices (on the same underlying platform), as subscriptions can be restored, consumables won’t work in this case because they can’t be restored (they’re not present on the receipt). Apple and Google also don’t provide easy ways to identify users/devices in a stable way (for privacy reasons). Perhaps you could introduce a login system only if users indicate that they want to use your app on multiple devices? I know this is a big change, but it’s the best way to ensure their purchases can be accessed on different devices/platforms.
Hi @Chang! We strongly recommend using custom (not anonymous) app user IDs in this case. While anonymous IDs can work fine for users with subscriptions on different devices (on the same underlying platform), as subscriptions can be restored, consumables won’t work in this case because they can’t be restored (they’re not present on the receipt). Apple and Google also don’t provide easy ways to identify users/devices in a stable way (for privacy reasons). Perhaps you could introduce a login system only if users indicate that they want to use your app on multiple devices? I know this is a big change, but it’s the best way to ensure their purchases can be accessed on different devices/platforms.
+6