Integration Guide
Table Of Contents
- Express Checkout Integration Guide
- Contents
- Preface
- Introducing Express Checkout
- Express Checkout Button and Logo Image Integration
- PayPal Name-Value Pair API Basics
- Implementing the Simplest Express Checkout Integration
- Testing an Express Checkout Integration
- Customizing Express Checkout
- Implementing the Instant Update API
- Immediate Payment
- Handling Payment Settlements
- Handling Recurring Payments
- How Recurring Payments Work
- Recurring Payments Terms
- Recurring Payments With Express Checkout
- Options for Creating a Recurring Payments Profile
- Recurring Payments Profile Status
- Getting Recurring Payments Profile Information
- Modifying a Recurring Payments Profile
- Billing the Outstanding Amount of a Profile
- Recurring Payments Notifications
- Using Other PayPal API Operations
- Integrating giropay with Express Checkout
Implementing the Instant Update API
Setting Up the Callback
7
74 October 2009 Express Checkout Integration Guide
Setting Up the Callback
To set up the callback, you establish a connection with PayPal by providing the location where
PayPal can call your web service, along with your shipping options.
To start, you must build and operate a secure, reliable, and fast web service that computes the
shipping options based on the business rules. To verify that the callback request is indeed
originating from PayPal, you can check to see if the request originates from *.paypal.com as
described in the go-live checklist
at this location.
In the sandbox environment, you can use both HTTP and HTTPS. PayPal will validate the
following information about the callback:
z The callback URL must start with HTTPS for production integration.
z The callback URL must start with HTTP or HTTPS for sandbox integration.
In the call to SetExpressCheckout, you must complete the steps 1 through 3 below. Steps 4
and 5 are optional:
1. Provide line-item details for the merchandise the buyer selected. For details on how to
integrate line-item details, see Chapter 7, “Customizing Express Checkout,” in the
Express
Checkout Integration Guide.
2. Provide the URL to your web service for the callback. PayPal validates the URL as
described above.
3. Provide values for the flat rate shipping options. For each option, specify
– Option name (L_SHIPPINGOPTIONNAMEn)
– Option label (L_SHIPPINGOPTIONLABELn)
– Option amount (L_SHIPPINGOPTIONAMOUNTn)
– The shipping option to appear in the drop-down menu as the default (true)
(L_SHIPPINGOPTIONISDEFAULTn).
NOTE: Set L_SHIPPINGOPTIONISDEFAULTn to true (default) for one and only one
shipping option. Set L_SHIPPINGOPTIONISDEFAULTn to false for each of the
remaining options.
– If required, an adjusted value for TAXAMT
– If required, an adjusted value INSURANCEAMT
4. If necessary to adjust the callback timeout (default: 3 seconds), provide a value from 1 to 6
for the CALLBACKTIMEOUT parameter.
5. Optionally, provide values for any of the shipping option description details fields listed
below:
– Option weight (L_ITEMWEIGHTVALUEn, L_ITEMWEITHTUNITn)
– Option height (L_ITEMHEIGHTVALUEn, L_ITEMHEIGHTUNITn)