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

# Auth Key

> Telnyx uses a Tailscale Subnet Router's auth key to enroll it, then discards the key.

The key is sent in the create request, or in a `PATCH` after a failed enrollment. Telnyx stores it encrypted until enrollment succeeds, then discards it. No response returns it. A router that has enrolled stays on that tailnet. Joining another tailnet means creating a new router.

Counting `auth_key` in the list of routers checks this. `$API` holds the API base URL and `$AUTH` the bearer header:

```bash theme={null}
curl -s "$API/tailscale_subnet_routers" -H "$AUTH" | grep -c auth_key
```

The key appears nowhere in the response:

```text Output theme={null}
0
```