The PromisePay Ruby SDK by PromisePay communicates with the API to access payment features. Main industries that benefit from PromisePay include real estate, auto, and trade. Resources show how to access HTTP and REST formats.
Square now has an E-commerce API that brings Square services to third party websites. Square is usually associated with its mobile credit card reader and complementary software. With the E-commerce API, merchants can use their own systems with all the benefit of Square's modern payment services.