Integration Guide

Website Payments Standard Integration Guide September 2008 249
Third-Party Shopping Carts – The Cart Upload Command
Integrating PayPal with Third Party Shopping Carts
5
Integrating PayPal with Third Party Shopping Carts
Instead of relying on the PayPal Shopping Cart, many merchants use third party shopping carts
that are already integrated with PayPal. The section describes how developers of third party
carts integrate with PayPal using Website Payments Standard.
Required Third Party Shopping Cart Variables
Your HTML code requires at least the following hidden HTML variables. For a complete list
of variables, see Appendix A, “HTML Variables for Website Payments Standard.”
There are two ways to integrate your third party shopping cart with PayPal and Website
Payments Standard:
z Pass the details of the individual items.
z Pass the aggregate amount of the total cart payment, rather than the individual item details.
Passing Individual Item Details to PayPal
If you code your third party shopping cart to pass individual items to PayPal, information
about the items is included in buyers’ and the merchants’ transaction histories and
notifications.
1. Set the cmd variable to _cart.
2. Include the upload variable:
<input type="hidden" name="upload" value="1">
3. Define item details for each item in the cart.
Specify the required variables and any optional variables listed inTable A.1, “Allowable
Values for the cmd HTML Variable.” Append _
x to the variable name, where x is the item
number, starting with 1 and increasing by one for each item added to the cart. The first item in
the cart must be defined with variables ending in _1, like item_name_1, amount_1, and
quantity_1; the second item with variables like item_name_2, amount_2, and
TABLE 5.1 Required Third Party Shopping Cart Variables
Name Description
amount_1 Price of a single item or the total price of all items in the
shopping cart
business Email address of your PayPal account
item_name_1 Name of the item or a name for the entire shopping cart
upload Indicates the use of third party shopping cart