Before demonstrating an Adaptive Payments integration with the Tweet Relevance sample code from Appendix A, let’s take a closer look at the Adaptive Payments Pay^[2] and PaymentDetails^[3] APIs, which are integral to our implementation details. A complete and more comprehensive list of all of the Adaptive Payments API operations can be found at Adaptive Payments API documentation on X.com. This section focuses on two of the most essential APIs and relevant options for Tweet Relevance payment integration along with some sample code to quickly get you up and running.

If you come from an Express Checkout background or have been following along in the book chapter by chapter, an important distinction to make up front between Adaptive Payments and Express Checkout is the nature of the request parameters. Whereas Express Checkout involves sending in 3-Token credentials along with Name-Value pairs through the request body, Adaptive Payments require 3-Token credentials along with a mandatory application identifier and additional configuration information to be passed in as headers; the POST request payload identifies the API operation and its parameters. Let’s now turn to the Pay API and execute some sample API calls to see how it all works.