title: What is the PayPal IPN reply url?
body: <p>In its guide, PayPal specifies the following:</p>
  
  <ol>
  <li>The API operation initiates a payment on PayPal.</li>
  <li>PayPal sends your IPN listener a message that notifies you of the event</li>
  <li><em><strong>Your listener sends the complete unaltered message back to PayPal</em></strong>; the message must contain the same fields in the same order and be encoded in the same way as the original message</li>
  <li>PayPal sends a single word back, which is either VERIFIED if the message originated with PayPal or INVALID if there is any discrepancy with what was originally sent </li>
  </ol>
  
  <p>What is the URL where we need to send the reply specified by step 3? Is this something we need to obtain from the HTTP request?</p>
  
  <p>Guide: <a href="https://www.x.com/developers/paypal/documentation-tools/ipn/integration-guide/IPNIntro" rel="nofollow">https://www.x.com/developers/paypal/documentation-tools/ipn/integration-guide/IPNIntro</a></p>