Design and Build Great Web APIs

The Goals of API Testing

First and foremost, the goal of API testing is to do just that—test the interface. That means you need to test each URL (or “endpoint”) in the API, including any possible input parameters. You also need to confirm the responses to those endpoint requests. For starters, you need to make sure each promised endpoint exists and accepts the inputs and produces the outputs expected. But that’s just a start.

Test the API’s Behavior

In addition to testing the interface, you also need to make sure the API behaves the way you’d expect from reading the Application-Level Profile Semantics (ALPS) description and the OpenAPI Specification (OAS) documents. For example, an API might have a rule that each request for a credit rating ...