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Standalone Activities are Activities that run independently, without being orchestrated by a Workflow. Instead of starting an Activity from within a Workflow Definition, you start a Standalone Activity directly from a Temporal Client.

The way you write the Activity and register it with a Worker is identical to Workflow Activities. The only difference is that you execute a Standalone Activity directly from your Temporal Client.

info

This documentation uses source code from the standalone-activity sample.

Get started with Standalone Activities​

Prerequisites:

  • Temporal TypeScript SDK (v1.17.0 or higher). See the TypeScript Quickstart for install instructions.

  • Temporal CLI v1.7.0 or higher. Install with Homebrew, or see the Temporal CLI install guide for other platforms. Verify the installation with temporal --version.

Start the Temporal development server with temporal server start-dev.

This command automatically starts the Temporal development server with the Web UI, and creates the default Namespace. It uses an in-memory database, so do not use it for real use cases.

The Temporal Server will now be available for client connections on localhost:7233, and the Temporal Web UI will now be accessible at http://localhost:8233.

brew install temporal
temporal --version
temporal server start-dev

Clone the sample​

Clone the samples-typescript repository to follow along:

git clone https://github.com/temporalio/samples-typescript.git
cd samples-typescript

The sample project is structured as follows:

standalone-activity/src/
├── activities.ts
├── execute.ts
├── list.ts
└── worker.ts

Write an Activity function​

The way you write a Standalone Activity is identical to how you write an Activity to be orchestrated by a Workflow. In fact, an Activity can be executed both as a Standalone Activity and as a Workflow Activity.

standalone-activity/src/activities.ts

activities.ts
import { ApplicationFailure } from '@temporalio/activity';

export async function greet(name: string): Promise<string> {
if (typeof name !== 'string') {
  throw ApplicationFailure.create({ message: 'name must be a string', nonRetryable: true });
}
return `Hello, ${name}!`;
}

Run a Worker with the Activity registered​

Running a Worker for Standalone Activities is the same as running a Worker for Workflow Activities — you create a Worker, register the Activity, and run the Worker. The Worker doesn't need to know whether the Activity will be invoked from a Workflow or as a Standalone Activity. See How to run a Worker for more details on Worker setup and configuration options.

standalone-activity/src/worker.ts

Open a new terminal, navigate to the samples-typescript/standalone-activity directory, and run the Worker. Leave this terminal running - the Worker needs to stay up to process activities.

worker.ts
import { NativeConnection, Worker } from '@temporalio/worker';
import * as activities from './activities';
import { loadClientConnectConfig } from '@temporalio/envconfig';

async function run() {
const config = loadClientConnectConfig();
const connection = await NativeConnection.connect(config.connectionOptions);
try {
  const worker = await Worker.create({
    connection,
    namespace: 'default',
    taskQueue: 'hello-standalone-activities',
    activities,
  });
  await worker.run();
} finally {
  await connection.close();
}
}

run().catch((err) => {
console.error(err);
process.exit(1);
});
npm run start

Run the sample client​

The sample file standalone-activity/src/execute.ts contains a program demonstrating various ways to execute Standalone Activities and fetch results. The code in the following sections is copied from this file.

To run it:

  1. Make sure the Temporal Server is running (from the Get Started step above).
  2. Make sure the Worker is running (from the Run a Worker step above).
  3. Open a new terminal, navigate to the samples-typescript/standalone-activity directory, and run the execute command.
npm run execute

Execute a Standalone Activity with type checking​

Start by creating a Temporal Client. Then call client.activity.typed() to get a typed Activity Client interface. Any TypeScript type can be used as type argument as long as it has Activity functions as its methods. An easy way to provide such a type is to use the typeof operator on imported activities. Note that calling typed does not create a new Client object - it only adjusts the type annotation of the existing Client. typed can be called multiple times with different type arguments to use the same Client for multiple Activity interfaces.

Afterwards, call the execute method of the typed client to execute a Standalone Activity. Call this from your application code, not from inside a Workflow Definition. This durably enqueues your Standalone Activity in the Temporal Server, waits for it to be executed on your Worker, and then fetches the result. An unknown or mistyped Activity name, or wrong argument types will cause compilation to fail.

import { Connection, Client, ActivityExecutionFailedError } from '@temporalio/client';
import { loadClientConnectConfig } from '@temporalio/envconfig';
import * as activities from './activities';
import { nanoid } from 'nanoid';

const config = loadClientConnectConfig();
const connection = await Connection.connect(config.connectionOptions);
const client = new Client({ connection });

const activitiesClient = client.activity.typed<typeof activities>();
const taskQueue = 'hello-standalone-activities';
const activityOptions = {
taskQueue,
startToCloseTimeout: '10s',
};

// In practice, use a meaningful business identifier, like customer or transaction identifier
const activityId = nanoid();

const result = await activitiesClient.execute('greet', {
...activityOptions,
id: activityId,
args: ['World'],
});

Execute a Standalone Activity without type checking​

Since Activity types are not always available, the start and execute methods can be called on ActivityClient directly without using the typed interface. When called that way, neither the Activity name nor argument types are checked client-side.

Or use the Temporal CLI.

await client.activity.execute('greet', {
...activityOptions,
id: activityId,
args: [1],
});
temporal activity execute \
--type greet \
--activity-id my-standalone-activity-id \
--task-queue hello-standalone-activities \
--start-to-close-timeout 10s \
--input '"World"'

Run with Temporal Cloud​

All code samples on this page use loadClientConnectConfig() to configure the Temporal Client connection. It responds to environment variables and TOML configuration files, so the same code works against a local dev server and Temporal Cloud without changes. See Run Standalone Activities with Temporal Cloud in the Feature Guide for mTLS and API key setup.

Next steps​