Why are APIs important

API stands for Application Programming Interface and refers to a set of procedures that allows one software application to communicate with another, and importantly exchange data. API’s first appeared in the 1970’s with the move to computer networks and are now quite literally the glue that holds today’s digital world together. API’s came into their own in 2005 with the rapid development of four major components of our modern digital world, namely e-commerce, social media sites, the cloud and mobile.

The ability to have disparate systems talk to one another is central to the digital transformation of existing businesses. For many businesses, digital transformation relies on the integration of cloud and on-premises IT infrastructure and API’s lie at the heart of such an integration. API’s are the layer through which organisations can adopt a bi-modal transformation strategy where legacy applications run alongside more innovative digital solutions.

The API interface is often referred to as one between a client and a server whereby the client makes a request in a specific format and receives a response from the server. This form on an API is also referred to as a Web API as the request typically occurs over the web. Web API’s allow communities on social media sites such as Facebook and Instagram to share content whereby content that is created in one place can be posted and be viewed by multiple locations on the web.

When Instagram first launched, the company refused to release an API thereby preventing outside developers from building applications that communicated with the platform. One of these external developers simply made their own API for Instagram by reverse-engineering the application. This forced Instagram’s hand and they launched their own Instagram API.

Web API’s enable the server to only expose objects and actions necessary for the client to perform its tasks. This is key to enabling businesses to connect the different silos within their organisation and making it accessible to external parties. This is how Amazon opened up its website to vendors all over the world so they could sell their goods on their platform. What made Amazon successful was Jeff Bezos’ insistence that “All service interfaces must be externalizable. The team must plan and design to be able to expose the interface to developers in the outside world”.

The success of ecommerce sites such as Amazon is due to the application of ‘public’ API’s and thereby giving external developers access to the companies. The internet browser such as Chrome, Internet Explorer and Safari have also used partner API’s to encourage external developers to make more effective use of their platforms. One such API is the Indexed Database API (or IndexedDB) which allows external developers to store and retrieve database objects in the browser. IndexedDB is used extensively by SC Spheres to provide offline availability of its content to users.

API’s can also be used for integrating IT systems that are internal to an organisation (private API’s) and for collaboration with business partners (partner API’s). The principle behind API’s is one of information hiding. Different developers can work on different parts of the IT system by gaining access to the data and information they need without being exposed to the complexities that exist elsewhere in the system. This also enables different parts of the system to be developed in different environments. On-premises systems operating in a Windows environment can in this way interface with an open-source cloud-based environment used for rapid development of a mobile client-facing system.