API fundamentals

Start with the contract between the application making a request and the service answering it. Identify the resource, the operation, the required inputs, and the meaning of a successful response. Reading those pieces together helps you distinguish documented behavior from assumptions carried over from another API.

The guides in this category develop a repeatable approach to exploration. Use the REST resource guide to understand interface structure, then inspect how a method affects the intended operation. Pay attention to empty results, repeated requests, optional fields, and changes made by another client while your own request is in progress.

For a practical next step, read GET versus PUT with repeatable requests. Record the result of a small, authorized experiment alongside the reference that defines it. That note becomes a useful starting point for implementation and later debugging.