This client can be utilized as an adapter for using the Shopify API with the ZendFramework version 2. The client requires PHP 5.3 for use. This is a community maintained library authored by Matthew Peterson and open sourced on GitHub. The client is endorsed for use on the Shopify API developer documentation's list of 3rd party libraries.
The third largest retailer in the world, Tesco, a grocery-and-more chain largely in the UK, will soon unveil a REST API for its online store (Tesco API profile). Developers will be able to search products, as well as get nutritional information, such as how many calories are in a serving of crisps or biscuits.
RetailNext, in-store analytics market leader, announced a set of enterprise APIs that retailers, shopping centers, business partners, and others can integrate with existing hardware systems to utilize RetailNext's analytics capabilities. RetailNext delivers analytics usually limited to ecommerce outfits to brick and mortar stores for better insights. The API is hardware agnostic; so, users can leverage existing infrastructure.