title: Can I validate Google Play in-app subscription renewals completely server-side?
body: <p>When a user first purchases a subscription from the Google Play Store, my app sends my server a receipt which contains the package name, the subscription/product ID, and the purchase token.  I can then call the <a href="https://developers.google.com/android-publisher/api-ref/purchases/subscriptions/get">Purchases.subscriptions.get API</a> to verify the subscription.</p>
  
  <p>What I am unclear about is whether I can verify the subscription entirely server side once a renewal happens?  The docs are pretty unclear about this.</p>
  
  <p>As I understand it, with the V3 purchases API the app needs to poll to see if a subscription has been renewed and then forward the new receipt onto the server.  I assume the purchase token would be different across renewals, which would suggest that it's not possible to implement renewal checks entirely server-side.</p>
  
  <p>Am I missing anything?</p>