Clearent is an integration tool for eCommerce, combining sites, shopping carts, mobile interfaces, payment processing, and Point of Sale applications to create comprehensive payment-enabled eCommerce applications. The API is compatible with shopping carts such as ZenCart, OpenCart, OSCommerce, and custom user applications. Using the Clearent API, providers can process sales, authorizations, captures, refunds, and voids. The RESTful Clearent API is processed via HTTP. All requests require an API key for access. Clearent offers an API sandbox for testing purposes.