We are launching the SAAS web application and are going to launch our application in the Apple app store (so far we had a mobile web application).
We want to offer the opportunity to purchase an in-app subscription because of the ease of use for our customers. No problem, we know how to do it.
The question is whether there is an easy way to keep our db web application updated with the current subscription status of users, so if they access our web application, we know if their subscription is valid.
Ideally, it would be great if Apple offered a web-hook option where they posted an update for the URL on our server. From what I read, this is not an option.
We can always send data to our server from the iPhone application when the user logs in, but if the user does not log on to the iPhone for a while, the subscription status recorded on our server will be outdated.
How do other people deal with this? Are we missing something?
Update:
The closest I found this thread: https://forums.developer.apple.com/message/70707#70707
The application receives a receipt on the first purchase of a subscription or restores a subscription. The application can send this original receipt to any server. Any server can then use this original receipt to check the current sub-crisis at any time. You cannot do this with a non-renewable subscription, but with a non-renewing subscription, the user must purchase an extension from the iOS device every time period.
Following this: https://hetzel.net/2011-04-01/server-side-auto-renewable-subscription-receipt-verification/
And from Apple, it sounds like they definitely don't make any positions at their end for synchronization:
Cross platform considerations
Product identifiers are associated with one application. Applications that both iOS and OS X have separate products with separate product identifiers on each platform. You can allow users who have a subscription in the iOS application to access content from the OS X application (or vice versa), but the implementation of this functionality is a responsibility. You will need a system to identify users and keep track of what content they have signed up, similar to how you must implement an application that uses non-renewable subscriptions.