# Standalone Nexus Operation

> Learn about Standalone Nexus Operations in Temporal, their benefits, execution model, and when to use them.

> **Pre-release** — Go, Java, Python, TypeScript, .NET
> APIs are experimental and may be subject to backwards-incompatible changes.

## What is a Standalone Nexus Operation? 

A Standalone Nexus Operation is a top-level [Nexus Operation Execution](/nexus/operations) started
directly by a [Client](/encyclopedia/architecture/temporal-sdks#temporal-client), without using a caller
Workflow. Instead of calling a Nexus Operation from within a Workflow Definition, you execute it
directly from a Nexus Client created from the Temporal SDK Client and bound to a
[Nexus Endpoint](/nexus/endpoints) and Service.

Standalone Nexus Operations use the same Service contract, Operation handlers, and Worker setup as
Workflow-driven Operations — only the caller side differs. The same Operation can be executed as a
Standalone Nexus Operation and as a Workflow-driven Nexus Operation with no handler code changes.

If you need to orchestrate multiple Nexus Operations, call them from a [Workflow](/workflows). But if
you just need to execute a single Nexus Operation across Namespace boundaries, use a Standalone
Nexus Operation.

### Get started with your SDK

To make your first standalone Nexus call:

1. Create a caller Namespace where durable Nexus Operations will be started.
2. Import the Temporal SDK in your language of choice.
3. Execute a Nexus Operation through your caller Namepace using the Temporal SDK Client.

See the SDK guides below for details:

- [Standalone Nexus Operations - Go](/develop/go/nexus/standalone-operations)
- [Standalone Nexus Operations - Java](/develop/java/nexus/standalone-operations)
- [Standalone Nexus Operations - Python](/develop/python/nexus/standalone-operations)
- [Standalone Nexus Operations - TypeScript](/develop/typescript/nexus/standalone-operations)
- [Standalone Nexus Operations - .NET](/develop/dotnet/nexus/standalone-operations)

## Use cases

### Make Nexus calls from anywhere

Standalone Nexus Operations let you make Nexus calls from anywhere using the Temporal SDK Client.
Any code that can construct a Temporal Client can durably hand off a Nexus Operation to Temporal, such as a UI backend or BFF, a non-Temporal microservice, an HTTP handler, or a script.
You still get automatic retries, built-in rate limiting and circuit breaking, and full execution visibility: the reliability of Nexus without the overhead of a caller (proxy) Workflow.

## Key features

- Execute any Nexus Operation as a top-level primitive without the overhead of a caller Workflow
- Same Service contract, Operation handlers, and Worker setup as Workflow-driven Operations
- Supports both synchronous and asynchronous (Workflow-backed) Nexus Operations
- At-least-once execution with automatic retries by the Nexus Machinery
- Get a handle to retrieve results, with the Operation token for asynchronous Operations
- List and count Standalone Nexus Operation Executions using [List Filter](/list-filter) queries
- Execute the same Operation from a Workflow or standalone with no handler code changes

## Migrate a single-Operation caller Workflow to a Standalone Nexus Operation 

A common pattern is a caller Workflow whose only purpose is to invoke a single Nexus Operation.
When that's all the Workflow does, you can drop the caller Workflow entirely and call the
Operation as a Standalone Nexus Operation. The handler Namespace's Service contract, Operation
handlers, and Workers do not change — only the caller side does.

Considerations when migrating:

- If the caller Workflow does more than one Operation call, or has business logic between calls,
  keep the Workflow. Standalone Nexus Operations are only a fit when a single top-level Operation
  is all the Workflow did.
- Pick a stable Operation ID if you previously relied on Workflow ID reuse semantics for
  deduplication.
- Update Visibility queries that filtered by caller Workflow attributes.

For SDK-specific syntax, see the per-SDK guide — for example
[Go: Standalone Nexus Operations](/develop/go/nexus/standalone-operations).

## Observability 

You can use [List Filters](/list-filter) to query Standalone Nexus Operation Executions by Endpoint,
Service, Operation, status, and other attributes using the SDK.

`CountNexusOperations` returns the total number of Standalone Nexus Operation Executions matching a
filter. This is the total count of executions (running, completed, failed, etc.) — not the number of
queued tasks.

## Pre-release limitations

Standalone Nexus Operations are at Pre-release. APIs are experimental and may be subject to
backwards-incompatible changes.

The following features are not supported yet:
  - Delete and reset
  - Batch `--query` support for cancel, terminate, and delete
  - UI list-page operator actions
  - HA / multi-region (global) namespaces using selective API forwarding

## Temporal CLI support

Standalone Nexus Operations require a Pre-release build of the [Temporal CLI](/cli) that includes
the `temporal nexus operation` command family. All commands are Experimental.

Download for your platform:

```bash title="macOS (Apple Silicon)"
curl -L https://github.com/temporalio/cli/releases/download/v1.7.4-standalone-nexus-operations/temporal_cli_1.7.4-standalone-nexus-operations_darwin_arm64.tar.gz | tar xz
```

```bash title="macOS (Intel)"
curl -L https://github.com/temporalio/cli/releases/download/v1.7.4-standalone-nexus-operations/temporal_cli_1.7.4-standalone-nexus-operations_darwin_amd64.tar.gz | tar xz
```

```bash title="Linux (arm64)"
curl -L https://github.com/temporalio/cli/releases/download/v1.7.4-standalone-nexus-operations/temporal_cli_1.7.4-standalone-nexus-operations_linux_arm64.tar.gz | tar xz
```

```bash title="Linux (amd64)"
curl -L https://github.com/temporalio/cli/releases/download/v1.7.4-standalone-nexus-operations/temporal_cli_1.7.4-standalone-nexus-operations_linux_amd64.tar.gz | tar xz
```

Verify the installation:

```bash
./temporal --version
# temporal version 1.7.4-standalone-nexus-operations
```

Move the binary to your PATH or run it from the current directory as `./temporal`.

> **⚠️ Warning:**
>
> - The standard `brew install temporal` or `brew upgrade temporal` does not include Standalone Nexus Operation support during Pre-release.
> - If you see `unknown command "nexus operation"` then you are using the standard Temporal CLI instead of the Pre-release version above.
> - If you see `Standalone Nexus Operations are disabled` when running commands against a local dev server, then your server does not support the feature. Start it with the Pre-release dev server build above, which enables Standalone Nexus Operations by default.
> - If you don't see the Standalone Nexus Operations button in the Temporal UI, make sure the UI is running the latest release and has the `EnableStandaloneNexusOperations` feature flag enabled.
>

The `temporal nexus operation` subcommand supports Standalone Nexus Operations with commands
including: `start`, `execute`, `result`, `list`, `count`, `describe`, `cancel`, and `terminate`.
The Nexus Endpoint must already exist on the server — create it with
[`temporal operator nexus endpoint create`](/cli/command-reference/operator#create-1).

## Temporal Cloud support

Standalone Nexus Operations in Temporal Cloud is available as a Pre-release feature.