> ## Documentation Index
> Fetch the complete documentation index at: https://docs.metricanic.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Tracking domains

> Connect a dedicated subdomain and verify DNS, certificate, and tracking readiness.

A tracking domain is the hostname visitors and conversion senders use to reach Metricanic. It appears in campaign links, script URLs, click links, and incoming event URLs.

Use a dedicated subdomain such as `trk.example.com`. Your landing or offer can stay on a different hostname. Connecting a tracking domain does not move or host those pages.

A campaign can be saved without an attached domain, which is useful while preparing its settings. Attach an active domain before sending traffic. Both redirect tracking and direct scripts need a working tracking hostname.

## What activation checks

Activation has three parts:

| Check                    | DNS record              | Purpose                                     |
| ------------------------ | ----------------------- | ------------------------------------------- |
| Confirm domain ownership | TXT                     | Proves control of the hostname              |
| Validate certificate     | One or more TXT records | Validates the HTTPS certificate             |
| Connect domain           | CNAME                   | Routes the hostname to the tracking service |

Metricanic displays the exact names and values for your domain. The CNAME target and verification values are supplied by the service, so copy them from the interface. Do not substitute an example hostname or an IP address.

## Add the subdomain

1. Open **Tools** → **Domains**.
2. Enter the hostname, such as `trk.example.com`, and click **Add**. Enter only the hostname, without `https://`, a path, or a query string. Use a subdomain rather than an apex such as `example.com`.
3. Open its **How to activate** instructions. Wait for the record values to appear if the interface says **Preparing DNS records...**.
4. At your DNS provider, add every displayed record. Match **Type**, **Name**, and **Value** or **Target** exactly.
5. After DNS propagation, return to Metricanic and click **Verify now**.

Some DNS providers append your zone name automatically. For a displayed name such as `trk.example.com`, that provider may expect `trk` in its Name field. Check the complete resulting hostname to avoid accidentally creating `trk.example.com.example.com`.

Certificate validation may require multiple TXT values. Add all the records shown, including multiple values at the same name when requested.

## Know when it is ready

The domain becomes ready only when ownership, the certificate, and a request to the tracking service all pass. A visible CNAME alone does not establish that HTTPS tracking works. DNS and certificate processing can finish at different times.

When the domain is active, select it in the campaign's **Domain** field and save. Copy the generated link or script from **4. Finish** and test an actual campaign. Opening only the hostname's root path does not test the campaign route.

For example, a redirect campaign on `trk.example.com` sends the visitor to a landing on `pages.example.com`. The tracking hostname handles attribution. The landing hostname serves the page.

## If verification does not finish

* **Record name differs from the instructions.** Check whether the DNS provider appended the zone name twice.
* **Certificate validation remains pending.** Check every displayed certificate TXT record, including additional values.
* **Connection remains pending.** Check the exact CNAME target and whether another service forwards or redirects requests for this hostname.
* **Record values are missing.** Wait for provisioning and reload the domain instructions before entering DNS values.
* **Adding a domain reaches a plan limit.** Review existing domains and your plan's domain allowance.

Use the status of each check to locate the unfinished part. Repeatedly changing correct records makes the result harder to diagnose.

## Replace or archive a domain

Before retiring a domain, attach the replacement to its campaigns and update the links, scripts, and callbacks that still use the old hostname. Already distributed URLs do not rewrite themselves when you change a campaign setting.

Metricanic blocks **Archive domain** while any campaign references it. Archived campaigns also count, so archiving a campaign alone does not release its domain. Remove or change those domain references first.

Archiving also deprovisions the hostname from the tracking service. Keep an old hostname active for as long as you still need its published links or delayed callbacks to work.