Integration Guide

Table Of Contents
Express Checkout Integration Guide May 2010 85
Implementing the Instant Update API
Using the Callback
7
The sample code below illustrates the callback response when you do not ship to the buyers
address.
METHOD=CallbackResponse
NO_SHIPPING_OPTION_DETAILS=1
The figure below illustrates the PayPal Review page when your callback servers sends the
above response. The page has these features:
z A message at the top of the page describes the error.
z The shipping and handling section and the insurance section are dimmed.
z The buyer can change the shipping address.
z A new callback request is sent if the buyer changes the shipping address.
Example PayPal Review Page When You Do Not Ship to the Buyer’s Address
Using the Callback
To use the callback, you add parameter fields to SetExpressCheckout, provide PayPal a
URL for sending a callback request, and send PayPal the callback response in Name-Value
pair (NVP) format.
SetExpressCheckout
In the call to SetExpressCheckout, set the following parameters:
z Set the CALLBACK field to the URL where PayPal can call your callback server. PayPal
makes the HTTPS callback request each time either of the following events occur:
The buyer changes their shipping address