Call another team's namespace or service from a Temporal workflow using Nexus endpoints, services, and operations

Documented steps

1. Understand the routing model: a Nexus Endpoint acts as a reverse proxy that decouples callers from handlers, so callers reference an Endpoint by name and never need to know the target namespace or task queue.
2. On the handler side, define a Nexus Service — a named collection of Nexus Operations that forms your team's public contract for other teams to call.
3. Implement each operation as either Asynchronous (backed by a Workflow, documented as able to run up to 60 days, returning an operation token the caller can reattach to) or Synchronous (must complete within the 10-second handler deadline, suited to quick signals, queries, updates, and SDK client calls).
4. Register a Worker that polls the Endpoint's target task queue and hosts your Services. A single Worker can host multiple Nexus Services, either colocated with the workflows they abstract or on a dedicated router queue.
5. As the platform owner, create the routing Endpoint: `temporal operator nexus endpoint create --name <endpoint-name> --target-namespace <handler-namespace> --target-task-queue <handler-task-queue>`, or `--target-url` for an external URL. Manage it with `temporal operator nexus endpoint get|list|update|delete --name <endpoint-name>`.
6. On the caller side, schedule the Nexus Operation by name against the Endpoint and Service from within a Workflow using your SDK's Nexus client integration. This issues a ScheduleNexusOperation command and records a NexusOperationScheduled history event; for async operations the caller's Nexus machinery starts the target workflow and receives an operation token, retrying until a timeout threshold.
7. Check SDK support before building: Nexus is supported in the Go, Java, Python, TypeScript, and .NET SDKs, and the per-language feature guides are separate pages that can lag one another.
8. On Temporal Cloud, use `tcld nexus` commands for endpoint and policy management. Cloud adds multi-region support, endpoint access-control policies, and audit logging on top of the open-source feature set.
9. Reference docs: https://docs.temporal.io/nexus | https://temporal.io/blog/temporal-nexus-now-available | https://docs.temporal.io/production-deployment/self-hosted-guide/nexus | https://docs.temporal.io/cli/operator