Adopting the API First Principle

The API-first principle

The concept of API-first has a long and varied history. Although the phrase has been in use for almost ten years, it’s become particularly popular over the last couple of years.

A simple web search on the term “API-first” brings up lots of related articles from all corners of the IT world, which targets a wide audience, from developers to CEOs.

API-first was described by Kas Thomas in a blog post called “API-First Design.” He described the idea this way: “API-first design means identifying and/or defining key actors and personas, determining what those actors and personas expect to be able to do with APIs.” This definition is important because it points out that creating APIs is about understanding who is using the API and what they want to do with it. Frankly, it’s pretty hard to go wrong with this point of view in mind.

Another key element wrapped up in API-first is the notion of designing the API before we get excited about all the implementation details, such as programming languages, protocols, URLs, and message formats. Well-known API advocate Kin Lane puts it directly in his blog post “What Is an API-First Strategy? ​​Adding Some Dimensions To This New Question,” where he states, “Before you build your website, web, mobile or single page application you develop an API first…”

So, two key elements of the API-first principle are: focus on who’s using the API and what they want to accomplish, and design the API first before we start to think about technical details. A third important element in all this pertains to the business side of things—APIs exist to solve ...