I know that they are possible since I implemented consumable purchases and they work but:

If I upload a new version of the app or re install it the consumable purchases are gone. Does not matter if for iOS or android. I used the device ID but that is not reliable and does indeed change in some scenarios

I would like to offer inapp purchases (consumable) and keep track how many a user has. Ideally over multiple devices but for sure for multiple installations (meaning they keep them after updates or reinstalls)

Is this even possible without some kind of login? Is it possible to implement subscriptions without this problem? I use revenuecat if that matters but asking more generally

CodePudding user response：

In case of consumable in app purchase it is definitely lost and cannot be recovered across devices without saving them for the relevant user. You may have to create your own saving and recovery system if you wish to make it available across devices.. maybe you can take a look at non consumable products or subscription

CodePudding user response：

Good afternoon

Theoreticaly Possibly, but there are several ways that you need to use all together in order for everything to work correctly. For example - It is necessary to store the user_id in the keyChain, then the saved id will not change when reinstalling (this only applies to iOS). It is also necessary to get information from the Receipt for different users (with different devices) but having one check and merge them. Therefore, it is desirable to have 2 ids for the user user_id and device_id. You need to receive and process webhooks from Apple/Google to understand the current status of a particular product. Doing this on the client is not the most pleasant experience. Some of this is generally impossible to do only on the client side. Better use the ready-made solution Apphud, RC ... If you have a free time and a team of backend developers, then you can implement all this yourself.

Look at the internal implementation of the services above (the code is open) how they work with Receipts and ids. You will understand that without the usage of unique identifiers you will encounter a lot of problem cases.