There are two main ways by which microservice applications can interact with each other: REST services and messaging systems. The REST approach is the most common and will be treated in this article. We will see how Spring boot can make the development process of REST APIs fairly easy, with the use of a set of useful annotations and some implicit background behavior, like the serialization of model objects to JSON format.

Another important issue is related to the documentation and sharing of APIs, and we will see that these concerns are addressed effectively with a solution named Swagger. Integrating Swagger with Spring Boot allows us to generate the documentation from the source code, as a Swagger JSON file, and even browse and manage all the exposed REST services with a web user interface.