Can GET and POST methods be idempotent, and what is their difference in this regard?

HTTP methods' idempotency means that executing the same request multiple times will not change the server's state after the first call.

• GET is always idempotent, as it is intended to retrieve data without changing the state. Repeated GET requests do not affect the server.

• POST is not idempotent by default, as it is used to create resources or perform operations that change the state. Repeating a POST may lead to duplicate creations or other changes.

However, in some cases, POST can be implemented as idempotent if the server handles repeated requests in the same way (for example, updating a resource with the same data).

Thus, the main difference in idempotency:

• GET — always idempotent.
• POST — usually not idempotent, but can be implemented as idempotent depending on the server's logic.