How to Check user subscription status, cancelation, upgradation, on our Backend server.

Hey @Pradeep 

Sorry for the delay here. 

1- As we are managing the number of likes and super likes for the user on our server. So my question is how can we Check if user purchase, upgrade downgrade or cancel the Subscription.  (is there any way revenue cat provide to do this)? 

I would recommend setting up webhooks here and keeping track of their subscription status in the backend. RevenueCat will ping your servers whenever customers purchase a subscription, change products, cancel the subscription, encounter a billing issue, etc. To reduce webhook delivery delays, I also recommend setting up Platform Server Notifications. 

2- If user  have purchased the subscription in iOS using apple account (auto renewable subscription). and then he again try to purchase the subscription in android device how this will get managed. 

Neither RevenueCat nor Android will prevent the purchase from going through. In this scenario, the customer will have 2 subscriptions active at the same time -- one from iOS and one from Android. To help mitigate this from happening, you should have a subscription management page. I assume your customers will have an account for your app, so you can share the same app user ID across both platforms. From there, you can display information about a customer’s subscriptions by fetching the PurchaserInfo object. Docs for reference: https://docs.revenuecat.com/docs/purchaserinfo#get-user-information The PurchaserInfo object has a field for management URL, which you can use to determine which store the subscription is currently active at. For example, if the management URL is https://apps.apple.com/account/subscriptions you know that the customer currently has an active subscription in the app store and you can let the customer know they have an active subscription on their iOS device. 

https://apps.apple.com/account/subscriptions