What limitations and restrictions should be considered when designing a REST API?

When designing REST APIs, the following constraints are important to consider:

• Standardization of HTTP methods: use GET, POST, PUT, DELETE, and others according to their purpose.
• Resource identification: URIs should be understandable and reflect the data structure.
• Response statuses: correctly use HTTP codes to inform the client about the request result.
• Security: provide authentication and authorization, for example, through OAuth or JWT.
• API versioning: to avoid breaking compatibility when making changes.
• Size and time limitations: consider limits on request size and processing time.
• Idempotency: PUT and DELETE methods should be idempotent.

An example of a simple REST controller in Java using Spring Boot:

@RestController
@RequestMapping("/api/items")
public class ItemController {

    @GetMapping("/{id}")
    public ResponseEntity<Item> getItem(@PathVariable Long id) {
        // logic to retrieve the object
        return ResponseEntity.ok(item);
    }

    @PostMapping
    public ResponseEntity<Item> createItem(@RequestBody Item item) {
        // logic to create the object
        return ResponseEntity.status(HttpStatus.CREATED).body(createdItem);
    }
}