cxgd3urn.api.sanity.io is a subdomain of Sanity.io, a popular content platform used by developers and publishers to manage digital content. If you've landed on this URL, it's almost certainly because an app or website you're using is fetching data from Sanity's backend — not because you're supposed to browse it like a normal site.
For an API endpoint, the security signals are clean: a valid SSL certificate, enforced HTTPS, and no blacklisting on Google's Web Risk or DNS blocklists. The hosting runs on Google Cloud, which is a reputable infrastructure provider. There's no contact form or privacy policy on this subdomain, but that's completely standard for an API — Sanity.io provides all that on its main website.
So is cxgd3urn.api.sanity.io a scam? No. It's a technical endpoint from a known platform. If you see this domain in an app you trust, it's nothing suspicious. If you're building something with Sanity, this is just a typical API address. No consumer risk here.