title: Workflow with PayKey using Paypal Adaptive Payment
body: <p>I'm trying to implement a payment system using the new Paypal API (Adaptive Payment).</p>
  
  <p>So far, I have this workflow :</p>
  
  <ul>
  <li>Send a request to Paypal for : <code>AdaptivePayments/Pay</code></li>
  <li>This create a Pay request, and return a payKey that is valid 3 hours (<a href="https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&amp;content_ID=developer/e_howto_api_APPaymentDetails" rel="noreferrer">source</a>)</li>
  <li>Now, I wait that paypal sends me request throught the IPN. When it will, I will get the pay_key with it</li>
  <li>Using this pay_key, I will call the <code>AdaptivePayments/PaymentDetails</code> to know the state of the payment.</li>
  </ul>
  
  <p>But I was wondering, how can I do if it's been more than 3 hours? (like in a refund?)</p>
  
  <p>What is the sure way to do then?</p>
  
  <p>Thanks for your help!</p>