Art of API Design

APIs are a set of protocols that define how system components interact with each other. As architectural styles evolve, APIs have gained prominence in recent years. In-process calls in monolithic applications transition to inter-process calls in microservice and serverless applications. Additionally, each process might reside on a different physical server, and service calls can fail due to various network issues.

The code-first approach is a more traditional approach to building APIs, with the development of code happening after the business requirements are laid out, eventually generating the documentation from the code.

Like any product, the concept of the API starts with the business team identifying an opportunity. The opportunity is analyzed and a plan to capitalize on it is created in a text document by strategists, analysts and other business folks. This document is then passed along to the development teams like front-end developers, testers and other R&D team members, which is where the plan is being coded into the API.

API Design :

APIs don’t exist in isolation. Instead, APIs expose functionality of an application or service that exists independently of the API. In my view, the job of the RESTful API designer is two-fold.

Understanding enough of the important details of the application for which an API is to be created, so that an informed decision can be made as to what functionality needs to be exposed, how it needs to be exposed, and what functionality can instead be left out.

Modeling this functionality in an API that addresses all use cases that come up in the real world, following the RESTful principles as closely as possible.

There are three distinct components involved in RESTful API design: the application, the API code, and the client.

What is OpenAPI Specification?

OpenAPI is a description of HTTP-based APIs which are typically, RESTful APIs. It comes in the form of a YAML file or definition, that describes the inputs and outputs of an API. It can also include information such as where the API is hosted, what authorization is required to access it, and other details needed for consumers and producers (such as web-developers).

Definitions can be written by hand, by tools, or even generated from code. Once an API has been written down, we say it has been described. Once API has been described into a definition, it becomes a platform for tools and humans to make use of. A typical example of making use of API definitions is to generate human readable documentation from it.

Describing APIs into an OpenAPI definition allows you to leverage tools to help automate a lot of API related processes.

For better understanding and supporting your design-first approach, you can use SaaS products like RestCase, which allows you to build your API definitions using a visual designer, generate great documentation which can be easily changed to your feel & look, API quality and security insights for the design phase and more.

API First offers several advantages like Improved system integration , Enhanced collaboration and quality and Increased scalability.