Custom domains

Knock supports setting up custom domains for your account to use for link tracking (including short links in SMS and WhatsApp) and email open tracking.

Setting a custom domain is important for deliverability and branding. You run the risk of having your messages marked as spam if the sending domain and the domain you're routing to for links are different.

By default, Knock uses a variety of domains for link tracking, short links in SMS and WhatsApp, and email open tracking. These domains are shared across all accounts and are not configurable. Custom domains enable you to override these defaults and use your own domains.

To set up a custom domain, you can navigate to the Custom domains page under the Account section of your account settings in your Knock dashboard and click the "Add domain" button.

You'll be prompted to enter the domain you want to use, for example link.yourcompany.com. From here, you will need to set DNS records for the domain to verify it.

Please note, we do not currently support apex domains (e.g., yourcompany.com) as custom domains. You must use a subdomain.

You'll need to add a CNAME record to your DNS configuration for the domain to verify it. The CNAME record should point to cname.knock.app. Here are some examples for common providers:

• Cloudflare

• Google Cloud DNS

• Route 53

• Vercel

• GoDaddy

Once set, you can click the "Verify domain" button to verify the domain and that the DNS records are pointing to the correct value. Please note that it can take up to 48 hours for the DNS changes to propagate.

Once a domain is verified, you can set how the domain will be used and the environments to which it is applied.

To select where a custom domain is used, choose the relevant option from the list of use cases and click "Apply and activate."

• Link tracking. These are links used for tracking link clicks within your notifications. Link tracking is used across many different channels, including email, in-app feed, SMS, and WhatsApp.
• Short links. These are links used for generating short links in SMS and WhatsApp messages.
• Open tracking. These are links used for generating a 1x1 transparent tracking pixel, currently used only within email notifications.

Custom domains are assigned to one or more environments. This means that you can easily assign the same custom domain to multiple environments, or you can use different custom domains for different environments for testing purposes.

To assign a custom domain to an environment, you can simply select the environment from the list of environments and click the "Apply and activate" button.

When you're ready to roll out your custom domains to production, you can simply assign the custom domain to your production environment and you're good to go. The changes will take effect immediately, and any future messages sent will use the custom domain for generated links and open tracking.