# Set up your local with the Typescript SDK

> Configure your local development environment to get started developing with Temporal

# Quickstart

Configure your local development environment to get started developing with Temporal.

## Install Node.js

The TypeScript SDK requires Node.js 20 or later. Install Node.js via your package manager by following the official
Node.js instructions.

## Install the Temporal TypeScript SDK

You can create a new project with the Temporal SDK:

If you're creating a new project using `npx @temporalio/create`, the required SDK packages will be installed
automatically.

To add Temporal to an existing project, install the required packages manually with
`npm install @temporalio/client @temporalio/worker @temporalio/workflow`.

Next, you'll configure a local Temporal Service for development.

```bash
npx @temporalio/create@latest ./my-app
```

## Install Temporal CLI

The fastest way to get a development version of the Temporal Service running on your local machine is to use
[Temporal CLI](https://docs.temporal.io/cli).

Choose your operating system to install Temporal CLI.

```bash
brew install temporal
```

```bash
sudo mv temporal /usr/local/bin
```

## Start the development server

Once you've installed Temporal CLI and added it to your PATH, open a new Terminal window and run the following command.

This command starts a local Temporal Service. It starts the Web UI, creates the default Namespace, and uses an in-memory
database.

The Temporal Service will be available on localhost:7233. The Temporal Web UI will be available at
http://localhost:8233.

Leave the local Temporal Service running as you work through tutorials and other projects. You can stop the Temporal
Service at any time by pressing CTRL+C.

Once you have everything installed, you're ready to build apps with Temporal on your local machine.

```bash
temporal server start-dev
```

```bash
temporal server start-dev --ui-port 8080
```

## Run Hello World: Test Your Installation

Now let's verify your setup is working by creating and running a complete Temporal application with both a Workflow and
Activity.

This test will confirm that:

- The Temporal TypeScript SDK is properly installed
- Your local Temporal Service is running
- You can successfully create and execute Workflows and Activities
- The communication between components is functioning correctly

### 1. Create the Activity

Create an Activity file (activities.ts):

```ts
export async function greet(name: string): Promise<string> {
  return `Hello, ${name}!`;
}
```

An Activity is a normal function or method that executes a single, well-defined action (either short or long running),
which often involve interacting with the outside world, such as sending emails, making network requests, writing to a
database, or calling an API, which are prone to failure. If an Activity fails, Temporal automatically retries it based
on your configuration.

### 2. Create the Workflow

Create a Workflow file (workflows.ts):

```ts
import { proxyActivities } from '@temporalio/workflow';
// Only import the activity types
import type * as activities from './activities';

const { greet } = proxyActivities<typeof activities>({
  startToCloseTimeout: '1 minute',
});

/** A workflow that simply calls an activity */
export async function example(name: string): Promise<string> {
  return await greet(name);
}
```

Workflows orchestrate Activities and contain the application logic. Temporal Workflows are resilient. They can run and
keep running for years, even if the underlying infrastructure fails. If the application itself crashes, Temporal will
automatically recreate its pre-failure state so it can continue right where it left off.

### 3. Create and Run the Worker

Create a Worker file (worker.ts):

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

async function run() {
  // Step 1: Establish a connection with Temporal server.
  //
  // Worker code uses `@temporalio/worker.NativeConnection`.
  // (But in your application code it's `@temporalio/client.Connection`.)
  const connection = await NativeConnection.connect({
    address: 'localhost:7233',
    // TLS and gRPC metadata configuration goes here.
  });
  try {
    // Step 2: Register Workflows and Activities with the Worker.
    const worker = await Worker.create({
      connection,
      namespace: 'default',
      taskQueue: 'hello-world',
      // Workflows are registered using a path as they run in a separate JS context.
      workflowsPath: require.resolve('./workflows'),
      activities,
    });

    // Step 3: Start accepting tasks on the `hello-world` queue
    //
    // The worker runs until it encounters an unexpected error or the process receives a shutdown signal registered on
    // the SDK Runtime object.
    //
    // By default, worker logs are written via the Runtime logger to STDERR at INFO level.
    //
    // See https://typescript.temporal.io/api/classes/worker.Runtime#install to customize these defaults.
    await worker.run();
  } finally {
    // Close the connection once the worker has stopped
    await connection.close();
  }
}

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

Run the Worker and keep this terminal running:

```bash
npm run start
```

With your Activity and Workflow defined, you need a Worker to execute them. A Worker polls a Task Queue, that you
configure it to poll, looking for work to do. Once the Worker dequeues a Workflow or Activity task from the Task Queue,
it then executes that task.

Workers are a crucial part of your Temporal application as they're what actually execute the tasks defined in your
Workflows and Activities. For more information on Workers, see
[Understanding Temporal](/evaluate/understanding-temporal#workers) and a [deep dive into Workers](/workers).

### 4. Execute the Workflow

Now that your Worker is running, it's time to start a Workflow Execution.

This final step will validate that everything is working correctly with your file labeled `client.ts`.

Create a separate file called `client.ts`.

```ts
import { Client, Connection } from '@temporalio/client';
import { nanoid } from 'nanoid';
import { example } from './workflows';

async function run() {
  // Connect to the default Server location
  const connection = await Connection.connect({ address: 'localhost:7233' });
  // In production, pass options to configure TLS and other settings:
  // {
  //   address: 'foo.bar.tmprl.cloud',
  //   tls: {}
  // }

  const client = new Client({
    connection,
    // namespace: 'foo.bar', // connects to 'default' namespace if not specified
  });

  const handle = await client.workflow.start(example, {
    taskQueue: 'hello-world',
    // type inference works! args: [name: string]
    args: ['Temporal'],
    // in practice, use a meaningful business ID, like customerId or transactionId
    workflowId: 'workflow-' + nanoid(),
  });
  console.log(`Started workflow ${handle.workflowId}`);

  // optional: wait for client result
  console.log(await handle.result()); // Hello, Temporal!
}

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

Then run:

```bash
npm run workflow
```

### Verify Success

If everything is working correctly, you should see:

- Worker processing the workflow and activity
- Output: `Workflow result: Hello, Temporal!`
- Workflow Execution details in the [Temporal Web UI](http://localhost:8233)

#### <strong>Additional details about Workflow Execution</strong>

- Temporal clients are not explicitly closed.
- To enable TLS, set the `tls` option to `true` for default settings or pass a [`TLSConfig`](https://typescript.temporal.io/api/interfaces/worker.TLSConfig) for custom configuration.
- Calling `client.workflow.start()` and `client.workflow.execute()` send a command to Temporal Server to schedule a new
  Workflow Execution on the specified Task Queue.
- If you started a Workflow with `client.workflow.start()`, you can choose to wait for the result anytime with
  handle.result().
- Using a Workflow Handle isn't necessary with `client.workflow.execute()`.

- [Run your first Temporal Application](https://learn.temporal.io/getting_started/typescript/first_program_in_typescript/): Create a basic Workflow and run it with the Temporal TypeScript SDK

- [Take a Temporal 101 course](https://learn.temporal.io/courses/): Learn Temporal concepts and build your first application with a guided course