Integration Guide

Table Of Contents
Implementing the Instant Update API
Using the Callback
7
88 May 2010 Express Checkout Integration Guide
Callback Request
The PayPal sends the parameters in the callback request to the location you specified for
CALLBACK. The callback request parameters include:
z Line-item details you sent in the call to SetExpressCheckout. PayPal also sends back
any line-item description details you may have specified such as the
L_ITEMWEIGHTUNIT1 and L_ITEMWEIGHTVALUE1 values shown in the example below.
By passing this data back to you, PayPal expedites your callback response by eliminating
the need for you to perform a database query to get this information.
z Shipping address of the buyer.
Using the information in the callback request, calculate the rates and options yourself or send
the information in an API call to your carrier to perform the calculations for you. Then send
the shipping options, insurance amounts, and taxes to PayPal in the callback response.
This is an example callback request.
METHOD=CallbackRequest
&CALLBACKVERSION=57.0
&TOKEN=EC-0EE85728D547104V
&CURRENCYCODE=USD
&LOCALECODE=en_US
&L_NAME0=10% Decaf Kona Blend Coffee
&L_NUMBER0=623083
&L_DESC0=Size: 8-oz
&L_AMT0=9.95
&L_QTY0=2
&L_NAME1=Coffee Filter bags
&L_NUMBER1=6230
&L_DESC1=Size: Two 24-piece boxes
&L_AMT1=39.70
&L_QTY1=2
&L_ITEMWEIGHTUNIT1=lbs
&L_ITEMWEIGHTVALUE1=0.5
&SHIPTOSTREET=1 Main St
&SHIPTOCITY=San Jose
&SHIPTOSTATE=CA
&SHIPTOCOUNTRY=US
&SHIPTOZIP=95131
&SHIPTOSTREET2
Callback Response
Each time your callback server receives a request from PayPal, it must process the request and
respond with the appropriate details.
This is an example callback response.