> ## 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.

# Buildkite Webhooks

> Develop and test Buildkite webhooks from localhost.

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

By integrating ngrok with Buildkite, you can:

* Develop and test Buildkite webhooks locally without deploying to a public environment or setting up HTTPS.
* Inspect and troubleshoot requests from Buildkite in real time via the inspection UI and API.
* Modify and replay Buildkite webhook requests with a single click instead of reproducing events manually in your Buildkite account.
* Secure your app with Buildkite 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 Buildkite 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 Buildkite.

## 3. Configure Buildkite to send webhooks

Buildkite can send webhook requests to your app when events occur in your account.
To register for those events:

* Sign in to [Buildkite](https://buildkite.com/).
* On the welcome page, click **Settings** in the top menu and **Notification Services** in the left menu.
* On **Notification Services**, click **Add** for the **Webhook** row.
* On **Add Webhook Notification**, enter a description in **Description** (for example, `My LocalHost App`) and paste the ngrok URL in **Webhook URL** (for example, `https://1a2b-3c4d-5e6f-7g8h-9i0j.ngrok.app`).
* In **Events**, select all events.
* In **Pipelines**, select **All Pipelines** and click **Add Webhook Notification**.

### Run webhooks with Buildkite and ngrok

Buildkite sends different request body contents depending on the event.
To trigger new calls from Buildkite to your app:

* Click **Pipelines** in the top menu and open one of your pipelines.

<Note>
  If you don't have a pipeline, click **Create your first pipeline** and follow the instructions.
</Note>

* On the pipeline page, click **New Build**, enter a message in **Message**, and click **Create Build**.

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

You can also check the webhook request in Buildkite: go to **Settings**, **Notification Services**, open your webhook, and look at the **Request Log** section.

### 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 Buildkite 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 [Buildkite](https://buildkite.com/), go to **Settings** and **Notification Services**.

* On **Notification Services**, click your webhook tile, copy the value of **Token**, select **Send an HMAC signature**, and click **Save Webhook Settings**.

* Create a Traffic Policy file named `buildkite_policy.yml`.
  Replace `{your token}` with the value you copied:

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

* Restart ngrok with the policy file:

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

* Create a new build on one of your pipelines to trigger the webhook.

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