The eWAY Rapid PHP SDK by eWAY allows developer to integrate the eWAY Rapid API's payment methods into their PHP applications. This library requires PHP 5.4.0+ with the cURL, JSON, and OpenSSL extensions.
The W3C Web Payments Working Group has published working drafts of Web Payments HTTP Specifications that include the Web Payments HTTP API 1.0 and Web Payments HTTP Messages 1.0. The two specifications are designed to work together to enable payment requests outside of a browser context.
SparrowOne has opened access to its managed payments services through its new Services API. The API allows for simple, HTTP POST access to SparrowOne's payment gateway. The API is expected to greatly reduce the time and effort needed for partner and client integration solutions.