Annotation Interface TemporalOperation

@Experimental
@Documented
@Retention(RUNTIME)
@Target(METHOD)
public @interface TemporalOperation

Marks a method on a ServiceImpl-annotated class as a Temporal-backed Nexus operation. The method body is the start handler — the framework wraps it in a TemporalOperationHandler at registration time, with default cancel behavior matching TemporalOperationHandler.cancel(OperationContext, OperationCancelDetails).

The declaring ServiceImpl-annotated class must be public so the annotated method can be accessed at registration time. The method must:

• be public,
• accept exactly three parameters: TemporalOperationStartContext, TemporalNexusClient, and the operation input type,
• return TemporalOperationResult.

Workflow-run example:

 @ServiceImpl(service = TransferService.class)
 public class TransferServiceImpl {
   @TemporalOperation
   public TemporalOperationResult<TransferResult> transfer(
       TemporalOperationStartContext ctx, TemporalNexusClient client, TransferInput input) {
     return client.startWorkflow(
         TransferWorkflow.class,
         TransferWorkflow::transfer,
         input,
         WorkflowOptions.newBuilder()
             .setWorkflowId("transfer-" + input.getTransferId())
             .build());
   }
 }
 

For custom cancel, or any other handler composition, use OperationImpl with a TemporalOperationHandler subclass that overrides TemporalOperationHandler.cancelWorkflowRun(io.temporal.nexus.TemporalOperationCancelContext, io.temporal.nexus.CancelWorkflowRunInput). Both annotations can coexist on the same ServiceImpl class, but never on the same method.