# Cloudflare Configuration Guide

This Documentation is based on the following official Cloudflare Docs: [URL forwarding](https://developers.cloudflare.com/rules/page-rules/how-to/url-forwarding/)

***

### 1. Create the Cloudflare Worker <a href="#id-1.-create-the-cloudflare-worker" id="id-1.-create-the-cloudflare-worker"></a>

You will write a simple JavaScript function to intercept the request, modify the URL, and fetch the content from the new location.

#### Worker Code (JavaScript) <a href="#worker-code-javascript" id="worker-code-javascript"></a>

1. **Log in to your Cloudflare Dashboard** and navigate to **Workers & Pages**.
2. Click **Create Application** and then **Create Worker**. Give your worker a meaningful name (e.g., `reverse-proxy-hash`).
3. Replace the default code with the following script:

{% code overflow="wrap" lineNumbers="true" %}

```javascript
export default {
  async fetch(request, env, ctx) {
    const url = new URL(request.url);
    const hash = "{{your-subdomain-hash}}";
    const domain = "{{your-domain}}";
    const trackingDomain = `${hash}.${domain}`;

    if (url.pathname.startsWith(`/${hash}`)) {
      // 1. Define the destination
      const targetUrl = new URL(request.url);
      targetUrl.hostname = trackingDomain;
      // 2. Strip the '/{{hash}}' prefix so the second server sees the request as root '/'
      targetUrl.pathname = url.pathname.replace(`/${hash}`, "");
      if (targetUrl.pathname === "") targetUrl.pathname = "/";
      // 3. Create a new request to modify headers
      const modifiedRequest = new Request(targetUrl, request);
      // 4. CRITICAL: Tell the second server it's receiving a request for the subdomain
      modifiedRequest.headers.set("Host", trackingDomain);
      return fetch(modifiedRequest);
    }
    return fetch(request);
  },
};
```

{% endcode %}

### 2. Deploy the Worker and Set the Route <a href="#id-2.-deploy-the-worker-and-set-the-route" id="id-2.-deploy-the-worker-and-set-the-route"></a>

Once you have saved and deployed the worker code, you need to tell Cloudflare **when** to execute it. This is done by setting a **Route**.

#### Route Configuration <a href="#route-configuration" id="route-configuration"></a>

1. Navigate back to your **Workers & Pages** dashboard and select your new Worker.
2. Go to the **Triggers** tab.
3. In the **Routes** section, click **Add route**.
4. Configure the route:
   * **Route:** `url.com/hash` (Replace `url.com` with your actual domain).
   * **Worker:** Select the Worker you just created (e.g., `reverse-proxy-hash`).
5. Click **Add route**.

{% hint style="danger" %}
After enabling Cookie lifetime extender, the DCP will give a proxy code that is expected to be setup on `https://domain.*/hash` however, if it is set up on `https://www.domain.*/hash` it will cause a CORS Error on the Cookie Lifetime Extender Requests.

For more details on WWW configuration follow this [guide](https://docs.jentis.com/key-features/cookie-lifetime-extender/configure-your-tracking#www-configuration-guide-optional).
{% endhint %}