nexus

nexus

Temporal Nexus is a new feature of the Temporal platform designed to connect durable executions across team, namespace, region, and cloud boundaries. It promotes a more modular architecture for sharing a subset of your team’s capabilities via well-defined service API contracts for other teams to use, that abstract underlying Temporal primitives, like Workflows, or execute arbitrary code.

Learn more at temporal.io/nexus.

This sample shows how to use Temporal for authoring a Nexus service and call it from a workflow.

Sample directory structure

• service - shared service definition
• caller - caller workflows, worker, and starter, which execute Nexus operations
• handler - handler workflow, operations, and worker, which defines Nexus operations and creates a Nexus service
• options - command line argument parsing utility

Getting started locally

Get temporal CLI to enable local development

1. Follow the instructions on the docs site to install Temporal CLI.

NOTE: The recommended version is at least v1.3.0.

Spin up environment

Start temporal server

temporal server start-dev

Initialize environment

In a separate terminal window

Create caller and target namespaces

temporal operator namespace create --namespace my-target-namespace
temporal operator namespace create --namespace my-caller-namespace

Create Nexus endpoint

NOTE: this must be run in the nexus sample directory.

temporal operator nexus endpoint create \
  --name my-nexus-endpoint-name \
  --target-namespace my-target-namespace \
  --target-task-queue my-handler-task-queue \
  --description-file ./service/description.md

Getting started with a self-hosted service or Temporal Cloud

Self hosted users can try Nexus out in single cluster deployments with server version 1.25.0.

Make Nexus calls across namespace boundaries

Instructions apply for local development, for Temporal Cloud or a self hosted setups, supply the relevant CLI flags to properly set up the connection.

In separate terminal windows:

Nexus handler worker

cd handler
go run ./worker \
    -target-host localhost:7233 \
    -namespace my-target-namespace

Nexus caller worker

cd caller
go run ./worker \
    -target-host localhost:7233 \
    -namespace my-caller-namespace

Start caller workflow

cd caller
go run ./starter \
    -target-host localhost:7233 \
    -namespace my-caller-namespace

Output

which should result in:

2024/07/23 19:57:40 Workflow result: Nexus Echo 👋
2024/07/23 19:57:40 Started workflow WorkflowID nexus_hello_caller_workflow_20240723195740 RunID c9789128-2fcd-4083-829d-95e43279f6d7
2024/07/23 19:57:40 Workflow result: ¡Hola! Nexus 👋