Advanced Features Guide

Table Of Contents
Express Checkout Advanced Features Guide April 2012 79
7
Implementing the Instant Update
API
The Instant Update API is a callback you can use to obtain the buyers shipping address.
About the Instant Update API
The Instant Update API is a server call to your callback server that instantly updates PayPal
pages and enhances the Express Checkout experience on the Review your information page.
The Instant Update API enables you to specify a URL with which PayPal can call your
callback server with the buyers shipping address, so you can provide the buyer with more
detailed shipping, insurance, and tax information.
Here is how the Instant Update API works:
1. When a buyer logs in to PayPal, the PayPal server calls your callback server with the
buyers default shipping address, which is stored in the PayPal system.
2. Your callback server responds with the shipping options available for that address, along
with any insurance options and tax adjustments on the order.
3. PayPal displays this information in the cart review area so buyers can choose from the
options.
4. The buyers final choices are returned in the GetExpressCheckoutDetails response.
Integration Steps
Integrating the Instant Update API requires some preparation and modification to the Express
Checkout API calls.
To integrate the server API, follow these steps:
1. Set up a secure, fast web service to accept HTTP requests from PayPal. On the live site, it
needs to be secured by means of SSL.
2. Enable the callback service to process PayPal requests and return responses.
3. Modify the existing Express Checkout API calls to accommodate new parameters.
Send the callback URL, shipping, insurance, and tax information to PayPal in the call to
SetExpressCheckout.
Call GetExpressCheckoutDetails to obtain the buyers final choices for shipping
and insurance, if applicable.
Call DoExpressCheckoutPayment with the buyer’s final selections.