Custom domains and DNS (why your site takes hours to go live)

What it actually is

DNS (Domain Name System) is the lookup that turns a name humans can read, like yoursite.com, into the address a computer actually needs to find your server. It works like the contacts app on your phone: you tap a person’s name, and behind the scenes your phone looks up their actual number, you never dial it yourself. A domain name is the contact name. A DNS record is the entry that says what number it maps to.

Buying a domain from a registrar (Namecheap, GoDaddy, Cloudflare, Infomaniak) only gets you the name. It doesn’t put a website behind it. Your host, wherever your app actually runs (Vercel, Netlify, a VPS), gives you specific values to add at the registrar: usually an A record (a domain pointed straight at a numeric IP address) for the bare domain, and a CNAME record (a domain pointed at another domain name) for a subdomain like www. You add those in the registrar’s DNS panel, and that’s the wire that actually connects your name to your app.

Why your AI just did this

Your agent can build and deploy your app, but it can’t log into your domain registrar for you, that account and its DNS settings live outside any codebase, in a dashboard only you can access. So once you say “connect my domain,” the agent’s real job is to walk you through the handoff: add the domain inside your hosting platform’s project settings, which generates the exact records that platform needs, then go add those same records at the registrar. The agent is also usually reminding you that the SSL certificate (the padlock in the address bar) only gets issued automatically once the platform confirms your DNS is actually pointing at it, which is another reason things aren’t instant.

When you’ll run into it

• Vercel or Netlify shows “Invalid Configuration” or “Domain not verified” right after you add the records. That’s expected for a while, it’s not necessarily broken.
• The site loads the new version on one wifi network and an old placeholder page, or nothing at all, on another. That’s caching, not your DNS “still moving.”
• A browser warning like “Your connection is not private” right after switching domains, because the certificate hasn’t been issued yet since DNS wasn’t confirmed.
• Your registrar’s panel asking you to pick a record “Type” (A, CNAME, TXT) and a “Host” field, and you’re not sure whether @ means the bare domain or something else.
• Adding www.yoursite.com but not yoursite.com (or the reverse) and finding one of them 404s, because most platforms need both added as separate domains.

What to check

• Whether you need an A record (bare domain, e.g. yoursite.com) or a CNAME (subdomain, e.g. www.yoursite.com); most hosts state this explicitly on the domain settings page
• The value you pasted matches exactly what the host gave you, no extra spaces, no trailing dot typed in by hand
• Both the bare domain and the www version are added inside your hosting project, not just one
• The TTL (time to live) on the record; a lower number like 300 seconds means future changes take effect faster, worth setting before you expect to edit records again
• A DNS checker site (search “DNS checker”) to see what value the internet is currently returning, since reloading your own browser only shows you your own cache

Say it like a dev

Instead of: “my domain isn’t working, I just bought it” Say: “I added the domain in my hosting dashboard, but the DNS records aren’t verified yet”

Instead of: “it works for me but not my friend, is it broken” Say: “could this just be DNS caching on their network, or did the record actually fail to verify”

Instead of: “I don’t know what box to put the domain in” Say: “does this need an A record for the root domain or a CNAME for www”