title: How to do server verification for PayPal Adaptive (MPL) Payment
body: <p>We got PayPal Adaptive payments working on our iOS app using MPL due to the requirement to support Parallel payments to PayPal accounts other than our own.</p>
  
  <p><strong>My question is where do I find documentation that teaches server side verification of the Adaptive payments?</strong></p>
  
  <p>My understanding of the flows is:</p>
  
  <ol>
  <li>Our Mobile App calls MPL, which handles payment.</li>
  <li>MPL returns a success payKey to Mobile App</li>
  <li>Mobile App forward payKey to our Server</li>
  <li>Our server checks the payKey with PayPal to verify payment with PayPal</li>
  <li>Our server returns a status back to Mobile App with a success / failure code from PayPal check in (4)</li>
  <li>Our Mobile app is happy, does some funky dance moves and proceeds to start on the order fulfilment side of things</li>
  </ol>
  
  <p><strong>I'm wondering where documentation is for Step (4)?</strong></p>
  
  <p><strong>Alternately, how have you done server side payment validation?</strong></p>
  
  <p>I sense fraud issues if we skipped steps (4) onwards...</p>
  
  <p>Following links don't seem to apply to MPL libraries directly:</p>
  
  <ul>
  <li><p>Verify PayPal payment when using mobile SDK (RESTful API, not MPL)
  <a href="https://developer.paypal.com/docs/integration/mobile/verify-mobile-payment/" rel="nofollow">https://developer.paypal.com/docs/integration/mobile/verify-mobile-payment/</a></p></li>
  <li><p>Getting started with mobile MPL page doesn't talk about a server verification step
  <a href="https://developer.paypal.com/webapps/developer/docs/classic/mobile/gs_MPL/" rel="nofollow">https://developer.paypal.com/webapps/developer/docs/classic/mobile/gs_MPL/</a></p></li>
  <li><p>PayPal MPL Developer guide &amp; ref manual doesn't talk about a server verification step
  <a href="https://www.paypalobjects.com/webstatic/en_US/developer/docs/pdf/pp_mpl_developer_guide_and_reference_iphone.pdf" rel="nofollow">https://www.paypalobjects.com/webstatic/en_US/developer/docs/pdf/pp_mpl_developer_guide_and_reference_iphone.pdf</a></p></li>
  </ul>
  
  <p>Any help would be appreciated!</p>
  
  <p><em>EDIT:</em> formatting</p>