title: Server side verification of Google Play in-app billing version 3 purchase (part 2)
body: <p>So I thought I understood how in-app billing and server-side verification works thanks to an answer to a <a href="https://stackoverflow.com/questions/16067180/server-side-verification-of-google-play-in-app-billing-version-3-purchase">previous question of mine</a> but now that I think of it I'm still lost...</p>
  
  <p>This is what I have and what I want to do:</p>
  
  <p>I have an app where the users can purchase several "items". Each item is stored on a server and and item should be made available for downloaded within the app upon purchase. The items are managed items that can be purchased only once (ie non-consumable). I have no problem defining items in the Google Play Developer console and I can perform a successful purchase.</p>
  
  <p>What I don't understand is how I can get my server to not only validate the purchase (using the purchaseToken and signature) but also know that it is item X and not item Y that is purchased? Is there some Google API where the server can talk to Google and ask what item id a certain purchaseToken belongs to? Is there some other way to do this?</p>