The Stripe Java Library by Stripe is a REST resource. The library API is designed for predictable, resource-oriented URLs and HTTP response codes to indicate API errors. Further, it is aims to support the built-in HTTP features, like HTTP authentication and HTTP verbs with off-the-shelf HTTP clients, and the support cross-origin resource sharing to allow interaction with the API from a client-side web application. The returns are in JSON, including errors.
Shopify has replaced its legacy Discounts API with the New Price Rules API. The API keeps what worked from the Discounts API, and greatly enhances those features with more flexibility and capability. One and five Shopify sales includes a discount of some sort, and Shopify wants to capitalize.
Prosperent has released "the performance advertising industry's first and only celebrity product API." The celebrity product API will allow content creators and developers to include products associated with celebrities into advertising campaigns. According to Propserent's CEO, Brian Lovett, "hundreds of hours" are currently spent researching celebrity-product affiliations.