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Custom Domains on Mythex: Buy One or Connect Your Own

Pro apps on Mythex can run on your own domain. Buy one inside Mythex or point a domain you own at your app with a CNAME. Steps, renewal, and limits.

Mythex Team · 2026-09-29 · 4 min read

A published Mythex app can live on your own domain — app.example.com instead of a *.mythex.ai link. On Pro you can either buy a domain inside Mythex and have it connected for you, or connect one you already own with a single DNS record. HTTPS is set up automatically either way.

What it does

Every published app gets a Mythex subdomain. That's fine for testing and sharing with friends, but a business, a portfolio or a product launch usually wants its own name.

Custom domains are included with Pro. On the pricing page you may see a "Free custom domain" badge: that means custom domains come with the plan, not that the domain itself is free. If you buy a name through Mythex, the registration is billed separately.

Everything lives in one place: the Domains page in settings. From there you can buy or connect a domain, attach it to a project, verify DNS, and open each domain's menu for configuration, auto-renew, setting a primary, disconnecting or transferring out. On a live project, Publish → Custom domain is a shortcut that does the same things for that project.

Why it's built this way

People arrive at custom domains from two directions. Some already own a name at a registrar and just want it pointing at their app. Others don't have one yet and would rather not learn a second website to get it. So Mythex supports both routes, and in both cases takes care of HTTPS, which is the part that most often goes wrong. If DNS is new to you, how domains and DNS work explains the pieces.

Option 1: Buy a domain in Mythex

  1. Open Domains and choose Buy.
  2. Search for a name and pick an available result.
  3. Optionally choose a project to connect it to, or pick Buy only — connect later.
  4. Check out. Mythex registers the domain.

You can also buy from Publish → Custom domain → Buy domain on a live project, which connects the new domain to that project automatically.

What you can configure

From Domains → ⋯ → Configure on a bought domain:

  • DNS records — add or delete A, AAAA, CNAME, MX, TXT and SRV records, for example for email or a Google verification. The records Mythex uses for your site are locked.
  • WHOIS privacy — available for domains registered through Mythex.
  • Primary — when several domains point at one project, choose which hostname is the main one.

Nameservers for bought domains are read-only. To use different nameservers, transfer the domain out first: Mythex unlocks it and gives you an auth code to paste at your new registrar.

Renewal

A bought domain is registered for a year with auto-renew on by default. About 45 days before it expires, the card you bought it with is charged the renewal price shown on the Domains page, and you get an email receipt. If the card is declined, the domain shows a warning and a Renew now button. You can turn auto-renew off from the ⋯ menu; if this year's renewal was already paid but hasn't gone through yet, it's refunded.

Option 2: Connect a domain you already own

  1. Publish the project.
  2. On Domains, choose Connect (or Publish → Custom domain → Connect existing on the project).
  3. Enter your hostname, such as app.example.com, and pick the project.
  4. At your DNS provider, create a CNAME record from that hostname to the target Mythex shows you ({slug}.mythex.ai).
  5. Click Verify.

When DNS is ready the status turns active, and Mythex issues HTTPS for the domain. For a longer walkthrough, see how to connect a custom domain.

Common snags

  • Still pending. DNS changes can take a few minutes to spread, sometimes longer depending on your provider. Check the record is a CNAME (not an A record) to the exact target shown, then click Verify again.
  • Wrong target. The CNAME must match this app's slug. A typo or an old slug fails verification.
  • Proxied DNS. If your DNS provider offers to proxy traffic, set the record to DNS only so Mythex can issue HTTPS.
  • Site won't load right after verifying. DNS can verify before HTTPS setup has finished. Wait a few minutes and verify again; if it still fails, contact support.
  • Root domains. Prefer a subdomain like www or app. A bare example.com depends on your DNS provider supporting ALIAS/ANAME or flattening; if unsure, use www and redirect the root at your provider.

Limits

  • Pro only. Free plans publish to a Mythex subdomain.
  • The project must be published and live for the domain to serve traffic.
  • Registration and renewal are billed separately from Pro when you buy through Mythex.
  • Disconnecting a domain stops serving the app on that hostname; it doesn't cancel or transfer the domain.

Read more

  • Custom domains — full reference and troubleshooting
  • Plans — what Pro includes

Keep reading

  • A Landing Page for Every Kind of Business — Search for a booking system for a dental clinic or a website for a bakery and land on a Mythex page written for that business, with a prompt ready to build it.
  • A Private Workspace and a Live Preview for Every Project — Every Mythex project runs in its own private cloud workspace with a live preview beside the chat. How it works, how to use it, and what to expect.
  • Auto-Reload: Keep Your Published App Running When Credits Run Low — Auto-reload buys Mythex credits when your balance runs low, so a long build or a busy published app does not stop at zero. How to set it up, and its limits.
  • Build Mythex Apps from Claude, Cursor or Codex — Mythex runs a remote MCP server: connect Claude, Cursor or Codex, and they code in your Mythex cloud sandbox with a live preview, database and publishing.
  • Checkpoints: Undo Any Change the Agent Makes — After every successful turn, Mythex saves a checkpoint of your project. Revert to any of them in two clicks, or edit an earlier message and try again.
  • Connect Gmail, Google Sheets and Slack to Your App Builder — Mythex Connectors link Gmail, Google Sheets, Slack, Notion and more to the chat agent, with no API keys in your code. How it works, setup, and limits.

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