The WebKit Apple Pay Payment Request API enables you to integrate Apple Payments in your web application. Safari 11.1 on macOS and Safari on iOS 11.3 support the W3C Payment Request API for conducting Apple Pay transactions on the web. It follows the W3C Payment Request specification that allows merchants to utilize one or more payment methods with minimal integration. Browsers and user agents facilitate the payment flow between merchant and user. WebKit is an open source web browser engine that is used by Safari, Mail, App Store, and many other applications on macOS, iOS, and Linux.