> ## 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.

<Note title="Need a different webhook provider?">
  If you don't see your preferred webhook provider, you can [request support for it](https://dashboard.ngrok.com/early-access#webhook-providers).
</Note>

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

Follow [Buildkite's documentation for adding a webhook notification](https://buildkite.com/docs/apis/webhooks/pipelines), and set the following:

* **Webhook URL**: your ngrok URL (for example, `https://1a2b-3c4d-5e6f-7g8h-9i0j.ngrok.app`).
* **Events**: choose which events trigger the webhook (for this example, subscribe to all events across all pipelines).

### Run webhooks with Buildkite and ngrok

Buildkite sends a different request body for each event type.
Create a new build on one of your pipelines to trigger new calls to your app.

Confirm your app receives the event and logs its headers and body in the terminal.
You can also review the delivery in your webhook's request log.

### 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](/docs/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.


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