Microservices architecture helps in building an application as a suite of multiple fine-grained smaller services. Each of these services run in its own process and are independently deployable. They may have been developed in different programming languages and may use different data storage techniques and communicate with each other via lightweight mechanisms like RESTful APIs, message queues etc. Now that services(API clients) need to know how to interact with each other, there is a need of API documentation that should be clear, informative, and easy to go through.
OpenAPI makes documenting these RESTful services very easy and can be done by adding few annotations to a Spring-based project. Besides rendering documentation, it allows the API consumers to interact with the APIs without having their own implementation logic in place. Also, it can be used to generate the API client libraries for over 50+ languages. In this post, I’ll cover how to use OpenAPI to generate REST API documentation and Java clients for a Spring Boot project.