Android In-App Billing Subscription status change callbacks

Question

I'm writing an app that will support in-app subscriptions. The subscriptions will enable my users to use a number of services and benefits outside the Android world. I know that I can use Google Play Developer API to query the status of a subscription, but due to the nature of the offered services and benefits, it is not very convenient to do that. I was wondering if there is a way to get notified about the status of the subscription when it changes. Something like a web hook for example.

Answer 1

I wanted to post a comment in response to yours, but apparently this was too long. In addition to that, it is also kind of an answer to your question, so I thought this might be a good thing to just post it as an answer instead. Maybe it even solves your problem.

So, regarding your comment. You don't necessarily have to do it that way. Now, I don't know your system requirements, but I'll just share mine and hope it helps you out.

Save Users and Subscriptions on your server (database tables). Have a check_at column on the Subscriptions table, besides a renew_at one. Suppose the user has a monthly subscription created on the 1st of January. On that first day, you call your server from Android after the purchase is finished, save the subscription details, then set renew_at as February 1st and check_at as February 4th, considering you set 3 days as delay for transaction failure in Google Play Developer Console. This way, the user has time from 1st February to 3rd February to change credit card details if the payment fails on the 1st. Then on the 4th you will check the Google Play API for subscription details. But don't disable premium functionality during 1st-4th February. Disable it on the 4th if the subscription was canceled. This way, premium content is not delayed nor tampered with in any way. If the subscription end date returned by the API is in the future, then it was renewed, so you should keep premium activated. Now, how do you check it monthly on the 4th you may ask. Use some kind of scheduler to schedule tasks on the database.

This way you remove the need to rely on webhooks. Although I agree, webhooks would've been more efficient and probably even easier to implement.

Let me know if you have any questions or there are some flaws in the system I described.

Answer 2

Take a look at Real Time Notifications using Google Cloud's PubSub service. It sends notifications of payment/subscription events like: new buy, renewal, cancellation etc. It includes the token which can be used to retrieve additional info from the API like you do now.

You can also configure this PubSub Subscription to call a custom webhook (which still needs to query the PubSub) on each message that you receive.