Exploring REST APIs

A REST API can be simple or complicated, have thousands of different resources with millions of entities, or expose only one resource with a few entities. Every developer can decide how to use query parameters, HTTP headers, and HTTP verbs. Nothing is written in stone here because REST provides the guiding principles, but the developer always makes the final decision.

For this reason, it’s essential to have the right tools and resources to understand an API properly before consuming it, as well as the right tools to explore and investigate how to use that API in real life.

This chapter will explore three tools I consider the bread and butter of any API user:

• OpenAPI: The OpenAPI documentation defines our REST API, declaring the resources, entities, and operations we can perform on each resource, as well as the authentication mechanism; everything is exposed in OpenAPI.
• Postman: Postman is one of the most popular applications for...