Railway

"records": { "CNAME": "abcd12.up.railway.app" }

Railway generates a unique *.up.railway.app CNAME target for each custom domain in its dashboard, so abcd12.up.railway.app above is a stand-in. Copy the exact value Railway shows you, not this one.

1. In the Railway dashboard: your service → Settings → Networking → Custom Domain → enter you.runs-on.dev. Railway shows you the CNAME target to use.
2. Fork the registry and edit domains/you.json, setting CNAME to the exact value Railway gave you.
3. Open a pull request. Once merged, the CNAME is synced to DNS automatically.

Railway also asks for a TXT record to verify domain ownership, alongside the CNAME. Our schema will not accept both at once: CNAME cannot coexist with TXT at the same name, since a DNS name with a CNAME cannot carry any other record type. If Railway shows the TXT record at the same hostname as the CNAME (you.runs-on.dev itself), there is no way to add it here, so skip it and add only the CNAME above. If Railway's dashboard keeps the domain unverified without the TXT record, this is the limit of what this registry can express for Railway: contact Railway support about verifying without it, or host on a provider that only needs a CNAME.

If Railway instead shows the TXT record at a different hostname (a prefixed subdomain, for example), add it under subdomains at that label instead, since a subdomain entry and the root records object don't share the CNAME-exclusivity rule with each other.

Networking → Custom Domain shows the domain as active once Railway has confirmed it. Visiting https://you.runs-on.dev should then serve the service.