nexus_standalone_operations

This sample demonstrates how to execute Nexus operations directly from client code, without wrapping them in a workflow. It shows both synchronous and asynchronous (workflow-backed) operations, plus listing and counting operations.

Temporal Python SDK support for Standalone Nexus Operations is at Pre-release.

All APIs are experimental and may be subject to backwards-incompatible changes.

Standalone Nexus operations require a server version that supports this feature. Use the dev server build at https://github.com/temporalio/cli/releases/tag/v1.7.2-standalone-nexus-operations.

Sample directory structure

• service.py - Nexus service definition with echo (sync) and hello (async) operations
• handler.py - Nexus operation handlers and the backing workflow for the async operation
• worker.py - Temporal worker that hosts the Nexus service
• starter.py - Client that executes standalone Nexus operations

Instructions

Run the Temporal dev server build that supports standalone Nexus operations. (If you are going to run locally, you will want to start it in another terminal; this command is blocking and runs until it receives a SIGINT (Ctrl + C) command.)

Start a Temporal dev server with the dynamic config flags required for standalone Nexus operations:

temporal server start-dev \
  --dynamic-config-value "nexusoperation.enableStandalone=true" \
  --dynamic-config-value "history.enableChasmCallbacks=true"

Create the Nexus endpoint:

temporal operator nexus endpoint create \
  --name nexus-standalone-operations-endpoint \
  --target-namespace default \
  --target-task-queue nexus-standalone-operations

In one terminal, start the worker:

uv run nexus_standalone_operations/worker.py

In another terminal, run the starter:

uv run nexus_standalone_operations/starter.py

Expected output

Echo result: hello
Echo result from existing operation handle: hello

Started `MyNexusService.Hello`. OperationID: hello-...
`MyNexusService.Hello` result: Hello, World!

Listing Nexus operations:
  OperationId: echo-..., Operation: echo, Status: COMPLETED
  OperationId: hello-..., Operation: hello, Status: COMPLETED

Total Nexus operations: 2

If you run the starter code multiple times, you should see additional operations in the listing results, as more operations are run. The same goes for the total number of operations.