Implementing API Documentation

@Operation(summary = "Place an order", description = "Creates an order from a cart")
@ApiResponses({
  @ApiResponse(responseCode = "201", description = "Created"),
  @ApiResponse(responseCode = "400", description = "Validation failed")
})
@PostMapping("/orders")
public OrderResponse place(@Valid @RequestBody CreateOrderRequest req) { ... }

@RequestBody(content = @Content(examples = {
  @ExampleObject(name = "minimal", value = "{\"customerId\":\"c_1\",\"lines\":[]}")
}))

@OpenAPIDefinition(security = @SecurityRequirement(name = "bearer"))
@SecurityScheme(name = "bearer", type = SecuritySchemeType.HTTP, scheme = "bearer", bearerFormat = "JWT")
public class OpenApiConfig {}

@ApiResponse(responseCode = "401", description = "Unauthenticated",
  content = @Content(schema = @Schema(implementation = ProblemDetail.class)))
@ApiResponse(responseCode = "429", description = "Rate limited",
  headers = @Header(name = "Retry-After", schema = @Schema(type = "integer")))

Limit: 1000 requests / minute / API key
Headers returned:
  X-RateLimit-Limit:     1000
  X-RateLimit-Remaining: 998
  X-RateLimit-Reset:     1717000000
On exceed: 429 Too Many Requests with Retry-After (seconds)