Top 10 of 2010: What You Can Do with the PayPal APIs

[This was my most popular X.com item last year.]

PayPal has been around for more than a decade now (see the article “A Brief History of Micropayments” for more details on the evolution of finance and electronic transactions including the early history of PayPal), but its PayPal X APIs were launched to the developer community as recently as November 2009. The PayPal X APIs are proving to be a very big deal, however, in that they open up the power of PayPal’s payment processing system to developers everywhere the PayPal network operates. As of this writing that’s 190 countries, in 24 currencies, enabling truly global reach for your applications.

The X APIs and tools provide developers with the ability to directly integrate PayPal-based financial transactions into their own applications. Whereas the previously available PayPal API required that a developer’s application take the user directly to PayPal’s own Web site at a given point in the transaction process, the new X APIs enable developers to build most PayPal functionality directly into their own Web, desktop, or mobile applications. This provides much greater flexibility in the appearance and behavior of PayPal-enabled applications while still providing the standard PayPal transaction processing security and features.

PayPal X uses Web form operations and supports both REST and SOAP API calls. PayPal X’s REST implementation in turn accepts JSON, name-value pair (NVP), and XML requests and/or responses (you can mix and match your formats even within one request-response pairing if you like, i.e. JSON request with an XML response). From here on I will assume you are familiar with all of the terminology in this paragraph; please click through the links and learn more about any areas with which you aren’t already comfortable.

Please note that you will need a PayPal X developer login to access many of the resources listed in this article. You will also need to use your login to setup and access API credentials (I’ll provide more details on this in a future article on getting started developing with PayPal X). If you don’t already have a developer login, you will need to create one via the Register button on the PayPal X Developer Network homepage. You are also required to have a PayPal user account in order to create your developer account; you may opt to link your developer account to a pre-existing PayPal user account, or to create a new user account. You will also need to review and agree to the PayPal X Developer Agreement as part of the developer account creation process.

Once you have a developer login, you are ready to proceed with learning about each of the areas of the X APIs and related technologies. This article will provide an overview of the PayPal X platform including:

• PayPal merchant operations
• Creating and manipulating PayPal accounts
• Web-based payments
• Processing credit card transactions
• Express checkout
• Moving money
• Fraud management and filtering
• Mobile checkout and payments

Click here to read the complete article on the PayPal X Developer Network.