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

# Terraform Cloud Webhooks

> Develop and test Terraform webhooks from localhost.

This guide shows you how to use ngrok to receive Terraform Cloud webhooks on your localhost app.

By integrating ngrok with Terraform Cloud, you can:

* Develop and test Terraform Cloud webhooks locally without deploying to a public environment or setting up HTTPS.
* Inspect and troubleshoot requests from Terraform Cloud in real time via the inspection UI and API.
* Modify and replay Terraform Cloud webhook requests with a single click instead of reproducing events manually in your Terraform Cloud account.
* Secure your app with Terraform Cloud webhook validation provided by ngrok.
  Invalid requests are blocked by ngrok before reaching your app.

## What you'll need

* An [ngrok account](https://ngrok.com/signup) and your [authtoken](https://dashboard.ngrok.com/get-started/your-authtoken).
* The [ngrok agent](https://ngrok.com/download) installed.
* [Node.js](https://nodejs.org/) installed (for the sample app, or use your own app).
* A Terraform Cloud account.

## 1. Start your app

For this tutorial, you can use the [sample Node.js app on GitHub](https://github.com/ngrok/ngrok-webhook-nodejs-sample).

To install the sample, run the following in a terminal:

```bash theme={null}
git clone https://github.com/ngrok/ngrok-webhook-nodejs-sample.git
cd ngrok-webhook-nodejs-sample
npm install
```

Then start the app:

```bash theme={null}
npm start
```

The app runs on port 3000 by default.

You can confirm it's running by visiting `http://localhost:3000`.
The app logs request headers and body in the terminal and shows a message in the browser.

## 2. Expose your app with ngrok

Once your app is running locally, you're ready to put it online securely using ngrok.

* Copy [your ngrok authtoken](https://dashboard.ngrok.com/get-started/your-authtoken) from the dashboard.

<Tip>
  The ngrok agent uses your authtoken to authenticate when you start a tunnel.
</Tip>

* Start ngrok:

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

* Copy the URL ngrok displays.
  Your app is now exposed at that URL for use with Terraform Cloud.

## 3. Configure Terraform Cloud to send webhooks

Terraform Cloud can send webhook requests to your app when workspace events occur.
To register for those events:

* Sign in to [Terraform Cloud](https://app.terraform.io/) and open your workspace.
* Click **Settings** and **Notifications** in the left menu.
* On **Notifications**, click **Create Notification**.
* On **Create a Notification**, click the **Webhook** tile, enter a **Name** (for example, `ngrok`), and enter your ngrok URL in **Webhook URL** (for example, `https://1a2b-3c4d-5e6f-7g8h-9i0j.ngrok.app`).
* Under **Triggers**, click **All events**.

Confirm your localhost app receives the verification request and logs both headers and body in the terminal.
You can also click **Send a test** on the notification details page to trigger a test notification.

### Run webhooks with Terraform Cloud and ngrok

Terraform Cloud sends different request body contents depending on the event.
To trigger a run:

* At the top of the workspace, click **Actions** and **Start new run**.
* Enter a reason (for example, `My New Run`), select **Plan and apply** for **Choose run type**, and click **Start run**.

Confirm your localhost app receives event notifications and logs both headers and body in the terminal.

### Inspecting requests

ngrok's [Traffic Inspector](https://dashboard.ngrok.com/traffic-inspector) captures all requests made through your ngrok endpoint to your localhost app.
Select any request to view detailed information about both the request and response.

<Info>
  To avoid exposing secrets, accounts only collect traffic metadata by default.
  You must enable full capture in the **Traffic Inspector** section of [your account settings](https://dashboard.ngrok.com/settings) to capture complete request and response data.
</Info>

Use the traffic inspector to:

* Validate webhook payloads and response data
* Debug request headers, methods, and status codes
* Troubleshoot integration issues without adding logging to your app

### Replaying requests

Test your webhook handling code without triggering new events from your service using the Traffic Inspector's replay feature:

1. Send a test webhook from your service to generate traffic in your Traffic Inspector.

2. Select the request you want to replay in the traffic inspector.

3. Choose your replay option:
   * Click **Replay** to send the exact same request again
   * Select **Replay with modifications** to edit the request before sending

4. (Optional) Modify the request: Edit any part of the original request, such as changing field values in the request body.

5. Send the request by clicking **Replay**.

Your local application will receive the replayed request and log the data to the terminal.

## Secure webhook requests

ngrok can verify that incoming requests are from your Terraform Cloud webhook so only that traffic reaches your app.

<Note>
  Webhook verification is limited to 500 validations per month on free accounts.
  If you need more, you can upgrade to Hobbyist or Pay-as-you-go.
  See [TPU Pricing](/pricing-limits/traffic-policy-unit-pricing/) for details.
</Note>

To add verification:

* In [Terraform Cloud](https://app.terraform.io/), open your workspace, then **Settings**, **Notifications**, and the notification you created (for example, **ngrok**).

* Click **Edit Notification**, enter a value in the **Token** field (for example, `12345`), and click **Update notification**.

* Create a Traffic Policy file named `terraform_policy.yml`.
  Replace `{your webhook token}` with that token value:

  ```yaml theme={null}
  on_http_request:
    - actions:
        - type: verify-webhook
          config:
            provider: terraform
            secret: "{your webhook token}"
  ```

* Restart ngrok with the policy file:

  ```bash theme={null}
  ngrok http 3000 --traffic-policy-file terraform_policy.yml
  ```

* Start a new run (e.g. **Actions** > **Start new run** with **Plan and apply**) to trigger the webhook.

Your app should receive the request and log it in the terminal.