Nexus samples and dev guide docs for sync Nexus ops that use signal, signal-with-start, update, query, ...

Is your feature request related to a problem? Please describe.

community Slack feedback

Hey! It would be helpful to include Python examples of how to define Nexus operations for sending signals, updates, etc. I don't see it on GitHub or official doc.

other user feedback

Quick nexus question does it support signaling workflow in Java? Couldn’t find example so guessing no

here's the related sample and docs

Ah I missed this buried inside service, yeah I think having a sample that does signal, query, start workflow would be good to make it more obvious

Describe the solution you'd like

1. Provide working temporalio/samples for each SDKs that supports Nexus at Public Preview or higher.
2. Add Nexus dev guide section for each SDKs, with examples for signal, update, and query.

1. Working Nexus samples in each SDK for signal, signal-with-start, update (short), query

For example in Python sending a signal is done using the client in a @sync_operation handler:

@nexusrpc.handler.sync_operation
async def notify_signal_operation(
    self, ctx: nexusrpc.handler.StartOperationContext, params: SomeSignal
) -> None:
    """
    Nexus operation handler that sends a notify signal to the SomeWorkflow.
    """
    workflow_handle = nexus.client().get_workflow_handle(f"Notify-{params.workflow_id}")
    await workflow_handle.signal(SomeWorkflow.notify, params)

In Go like this:

var nh NexusHandlers

func (nh *NexusHandlers) handleShippingUpdateNotification(ctx context.Context, input shipment.ShipmentStatusNotification, soo nexus.StartOperationOptions) (nexus.NoValue, error) {
	c := temporalnexus.GetClient(ctx)
	return nil, c.SignalWorkflow(ctx, input.CallerID, "", shipmentNotificationSignalName, input)
}

w := worker.New(client, TaskQueue, worker.Options{})

	s := nexus.NewService(OrderServiceName)
	s.Register(
		nexus.NewSyncOperation(ShipmentNotificationOperationName, nh.handleShippingUpdateNotification),
	)
	w.RegisterNexusService(s)

For Java we have a comment in one sample and the docs that briefly mention it

// Nexus.getOperationContext().getWorkflowClient(ctx) to make arbitrary calls such as
// signaling, querying, or listing workflows.

Working examples would make it more discoverable and easier for new users to get started.

2. Add Nexus dev guide section for each SDKs, with examples for signal, update, and query.

• similar to the section on writing Nexus async op handler to start a Workflow
• For Signaling a Workflow, Signal-With-Start, Update, Query
• Consider doing it as part of an entity pattern example as @Quinn-With-Two-Ns suggested.

Additional context

Per-SDK Tickets

• Go -
• Java -
• Core -
• TypeScript -
• Python -
• .NET -
• Ruby -
• PHP -
• Temporal CLI -