> ## Documentation Index
> Fetch the complete documentation index at: https://www.agent37.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# ngrok

> Expose a localhost app with ngrok so you can access it from the internet

ngrok creates a secure public URL that forwards traffic to a port running inside your Agent 37 terminal. That means your app can stay bound to `localhost` in the instance while still being reachable from the internet.

For example, if your app runs inside the Agent 37 terminal on:

```text theme={null}
http://localhost:3000
```

ngrok can create a public URL that forwards requests to that app.

## Step 1: Open the Agent 37 terminal

1. Sign in to the [Agent 37 dashboard](https://www.agent37.com/dashboard)
2. Open the instance where your app is running
3. Click **Terminal**

ngrok is already available in the Agent 37 terminal, so you can start from authentication and tunnel setup.

## Step 2: Add your authentication token

Before you continue, confirm ngrok is available:

```bash theme={null}
ngrok version
```

Then sign in to the [ngrok dashboard](https://dashboard.ngrok.com/get-started/your-authtoken) and copy your authtoken.

<Frame>
  <img src="https://mintcdn.com/agent37/kPkzNYRAp7OPJ3sy/images/image-46.png?fit=max&auto=format&n=kPkzNYRAp7OPJ3sy&q=85&s=6b10b468556da5bf7e8c9edb63d140d3" alt="Image" width="3016" height="1572" data-path="images/image-46.png" />
</Frame>

Then run:

```bash theme={null}
ngrok config add-authtoken YOUR_AUTHTOKEN
```

This connects the ngrok client inside your Agent 37 instance to your ngrok account.

## Step 3: Start an ngrok tunnel from the Agent 37 terminal

If your app runs on port `3000`, run:

```bash theme={null}
ngrok http 3000
```

If your app uses another port, replace `3000` with that port number.

ngrok will start a tunnel and show output similar to:

```text theme={null}
Forwarding  https://abc123.ngrok-free.app -> http://localhost:3000
```

## Step 4: Open the public URL

Copy the `https://...ngrok...` forwarding URL and open it in your browser.

You should see the app running inside your Agent 37 instance through the ngrok URL.