The Authorize.net iOS SDK by Authorize.net offers API interaction with the aim to interact with the gateway. Includes installation and guides to implement with ApplePay. Developer Brian McManus mentions that the kit can be useful to build Mobile Point-of Sales applications.
Metal, a cryptocurrency-based payment solution provider, announced the early beta release of its Proton Open SDK. The company breaks the SDK into three categories: native wallet SDKs, Proton API, and Web SDKs. The native wallet SDKs and Proton API are now available for beta testing.