# Proxying the JavaScript client You can proxy the client-side JavaScript (Analytics.js) and all tracking event requests through your domain. You might want to do this to deal with ad blockers or to keep your analytics requests from being blocked by firewalls. ## How it works[](#how-it-works) When you load Analytics.js on your site, the script makes requests to Customer.io to load the library and to send calls. You can proxy these requests through your own domain, making all Customer.io requests look like first-party requests to your own domain. This can help you avoid problems with ad blockers or firewalls that don’t play nicely with third-party domains or requests. This page shows how to set up a custom domain that proxies to `cdp.customer.io` in Amazon CloudFront, but you can apply these principles to most modern content delivery networks (CDN). You’ll also need to add a CNAME record to your DNS settings and update your code to point to your new domain. ## Prerequisites[](#prerequisites) To set up a custom domain, you need: * Access to your site DNS settings * A content delivery network (CDN) you can serve assets from * Access to your CDN’s settings * A security certificate for the proxy domain If you have trouble setting up your proxy, you’ll need to contact your IT department for help. We don’t have access to your domain resources to help you configure a custom proxy. ## Set up a custom proxy with Amazon CloudFront[](#set-up-proxy) As a part of this process, you’ll set up two CloudFront distributions: one for the JavaScript host and one for our Data Pipelines API. You’ll also need to add a CNAME record to your DNS settings for each. ### Proxy the JavaScript host[](#proxy-the-javascript-host) 1. Log in to the AWS console and go to CloudFront. 2. Click **Create Distribution** and configure the distribution settings. 1. In the *Origin* section set: * **Origin Domain Name**: `cdp.customer.io` * **Protocol**: `HTTPS only` 2. In the *Default cache behavior* section, set: * **Viewer protocol policy**: `Redirect HTTP to HTTPS` * **Allowed HTTP Methods**: `GET, HEAD, OPTIONS, PUT, POST, PATCH, DELETE` 3. In the *Settings* section, set: * **Alternate domain name (CNAME)**: `cioanalytics..com` * **Custom SSL certificate**: Select an existing or new certificate and validate your authorization to use the **Alternate domain name (CNAME)** value. For more information, see Amazon’s documentation [Requirements for using alternate domain names](https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/CNAMEs.html). 3. Click **Create Distribution**. Take note of the Domain Name for use in the next step. 4. Go to your domain registrar and add a new “CNAME” record. 5. Set values for these fields: * **Name**: As a part of this process, you should use a name that makes it clear what you use the subdomain for, like `analytics.mysite.com`. * **Value**: The Domain Name value from CloudFront. 6. Save your record. This might take some time to take effect, depending on your TTL (Time To Live) settings. You should verify that you’ve set up the record correctly. You may want to make a `curl` request to your domain to verify that the proxy works. ### Add the proxy to your code[](#add-the-proxy-to-your-code) After you [set up a proxy](#set-up-proxy), you’ll need to add your new proxy address to your code. These instructions depend on whether you use our [Client-side JavaScript snippet](#snippet-instructions) or the [Node.js library](#npm-instructions). #### Client-side JavaScript snippet[](#client-side-javascript-snippet) If you use our [JavaScript client](/integrations/data-in/connections/javascript/), you need to modify the `cioanalytics.js` snippet inside your website’s ``. You’ll need to make two changes inside the declaration of the `analytics.load` function. We’ve highlighted the changes in an example below that’s formatted for readability. 1. Change the `t.src` parameter in the snippet to point to your proxy host. 2. Add an `analytics._cdn` property to the snippet containing your proxy host. ```html ``` To proxy API calls that typically go to `cdp.customer.io/v1`, you’ll set `integrations['Customer.io Data Pipelines'].apiHost` to your proxy address. ```javascript window.cioanalytics.load("", { integrations: { "Customer.io Data Pipelines": { apiHost: "YOUR-PROXY-HOST/v1", }, }, }); ``` #### npm instructions[](#npm-instructions) If you use our [Node.js library](/integrations/data-in/connections/node) and want to proxy requests through your domain, you need to: 1. Update the `cdnURL` setting. 2. Proxy tracking calls that typically go to `cdp.customer.io/v1` to your API host by configuring `integrations['Customer.io Data Pipelines'].apiHost`. ```ts const analytics = AnalyticsBrowser.load( { writeKey, // GET https://YOUR-PROXY-HOST/v1/projects//settings --> proxies to // https://cdp.customer.io/v1/projects//settings // GET https://YOUR-PROXY-HOST/next-integrations/actions/...js --> proxies to // https://cdp.customer.io/next-integrations/actions/...js cdnURL: 'https://YOUR-PROXY-HOST' }, { integrations: { 'Customer.io Data Pipelines': { // POST https://MY-CUSTOM-API-PROXY.com/v1/t --> proxies to // https://cdp.customer.io/v1/t apiHost: 'YOUR-PROXY-HOST/v1', protocol: 'https' // optional } } } ) ```