Charles

Charles, or Charles Web Debugging Proxy, is a cross-platform HTTP debugging proxy server application written in Java. It enables users to view HTTP, HTTPS, HTTP/2 and enabled TCP port traffic accessed from, to, or via the local computer. This includes requests and responses including HTTP headers and metadata, such as cookies, caching, and encoding information with functionality targeted at assisting developers analyze connections and messaging.

Charles is available for download in the App Store for US$8.99, and is available to Apple employees free-of-charge via Apple's Self Service MDM.