The API access account making the Express Checkout service calls may be the sender, one of the receivers, or a third party. The process involves 1) PayPal as a payment method, 2) redirection to PayPal for login and payment, and 3) transaction review and confirmation.

3. A person or business
A person or business
whose PayPal account
whose PayPal account is
is being credited
being debited
The API access account making the Express
Checkout service calls: may be the sender, one
of the receivers, or a third party

4. 1. PayPal as a Payment Method
2. Redirection to PayPal and Login
3. Transaction Review and Confirmation

6. protected void DoSetEC(object sender, EventArgs e)
{
try
{ Caller API Details
caller = new NVPCallerServices();
setProfile(MyProfile, “APIUsername”,”APIPassword”,”APISignature”);
MyCodec["METHOD"] = "SetExpressCheckout";
MyCodec["VERSION"] = “82“;
MyCodec["CANCELURL"] = ”MyCancelURL"; General API Settings
MyCodec["RETURNURL"] = ”MyReturnURL”;
MyCodec["PAYMENTREQUEST_0_CURRENCYCODE"] = "GBP";
MyCodec["PAYMENTREQUEST_0_PAYMENTACTION"] = "Sale";
MyCodec["L_PAYMENTREQUEST_0_NAME0"] = ”Item in my Shopping cart";
MyCodec["L_PAYMENTREQUEST_0_AMT0"] = "24.48"; Payment Request Information
MyCodec["L_PAYMENTREQUEST_0_QTY0"] = "2”;
MyCodec["PAYMENTREQUEST_0_ITEMAMT"] = "43.96";
MyCodec["PAYMENTREQUEST_0_SHIPPINGAMT"] = "1.50";
MyCodec["PAYMENTREQUEST_0_AMT"] = ”45.46”
caller.Initialize();
caller.APIProfile = MyProfile;
MyNVPRequest = MyCodec.Encode();
MyNVPResponse = caller.Call(MyNVPRequest);
MyRespoCodec.Decode(MyNVPResponse);
if (MyRespoCodec["ACK"] != "Success" && MyRespoCodec["ACK"] != "SUCCESSWITHWARNING")
{ /*display error message*/}
else Transaction Specific Token
{
MyToken = MyRespoCodec["TOKEN"].ToString();
Response.Redirect(@"https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token=" + MyToken);
}
}
catch (Exception exp) Redirection to PayPal
{/*sort out exceptions*/}
}

9. 1. Waiter prints the bill
5. Table is closed
3. Customer pays with PayPal
2. Customer types in the 12 digit
code from the bill into the Pizza
Express app, generating the token for
the transaction
4. Transaction completed

12. https://www.x.com/developers/paypal/products/adaptive-payments

13. $10 $100 $10
$100 $40
$40
$50
$50

15. How curl -s --insecure
-H "X-PAYPAL-SECURITY-USERID: api_username"
-H "X-PAYPAL-SECURITY-PASSWORD: api_password"
-H "X-PAYPAL-SECURITY-SIGNATURE: api_signature" HTTP Headers
-H "X-PAYPAL-REQUEST-DATA-FORMAT: NV"
-H "X-PAYPAL-RESPONSE-DATA-FORMAT: NV"
-H "X-PAYPAL-APPLICATION-ID: app_id"
https://svcs.sandbox.paypal.com/AdaptivePayments/Pay -d
"requestEnvelope.errorLanguage=en_US
&actionType=PAY
&senderEmail=sender@domain
&receiverList.receiver(0).email=receiver@domain
&receiverList.receiver(0).amount=100.00
Payment
&currencyCode=USD
instructions
&feesPayer=EACHRECEIVER
&memo=Simple payment example.
&cancelUrl=http://your_cancel_url
&returnUrl=http://your_return_url
&ipnNotificationUrl=http://your_ipn_notification_url”

16. responseEnvelope.timestamp=2009-07-13T12%3A34%3A29.316-07%3A00
&responseEnvelope.ack=Success
&responseEnvelope.correlationId=d615a365bed61 Response envelope
&responseEnvelope.build=DEV
&payKey=AP-3TY011106S4428730 Pay key and
&paymentExecStatus=CREATED payment status

19. responseEnvelope.timestamp=2009-08-14T09%3A00%3A37.748-07%3A00
&responseEnvelope.ack=Success
&responseEnvelope.correlationId=7967b2d03745a
&responseEnvelope.build=DEV
&cancelUrl=your_cancel_url
&currencyCode=USD
&logDefaultShippingAddress=false
&memo=Simple payment example.
&paymentInfoList.paymentInfo(0).receiver.amount=100.00
&paymentInfoList.paymentInfo(0).receiver.email=receiver@domain Payment details
&paymentInfoList.paymentInfo(0).receiver.primary=false
&returnUrl=your_return_url
&senderEmail=sender@domain
&status=CREATED
&payKey=AP-3TY011106S4428730
&actionType=PAY
&feesPayer=EACHRECEIVER

22. • Designed to be integrated in less than 10 minutes
• No need to code payment UI
• Don’t need to worry about sensitive financial info
• More convenient than always typing credit card
• Can use existing account information
• Physical goods and services
• In-app purchase

24. - Simple, Chained, Parallel, and Pre-approved payments
- Supports Android 1.5 and above, iOS 3.0 and above
More information you can find here:
https://www.x.com/developers/paypal/products/mobile-payment-libraries

25. Your Application Your Server
Your Activity (Optional)
onCreate(){
… Item delivery
getCheckoutButton(…);
} Purchase data
onClickListener() {
… PayPal Checkout Activity
startActivityForResult(…);
} Instant Payment
onPaymentSucceeded() { Notifications
… (Optional)
}
onPaymentFailed(){
…
} PayPal Server
onPaymentCanceled() {
…
User Wallet
}
onActivityResult(){
… Fraud/Risk
}
Transaction data