How to connect a custom domain to a Google AI Studio app
Short answer. An app published from Google AI Studio can already open on an address such as name.ai.studio. A domain of your own is optional. If Add mapping is greyed out or mapping fails, waiting for DNS will not fix it. Reports up to 19 October 2026 point to three causes; the table below shows which one is yours.
- On a Starter Tier project the Add mapping button can be disabled (report, 21 September 2026). Firebase on that kind of project can say: “This product is not available as part of this Starter tier project” (report, 28 September 2026). On 5 October 2026 a forum reply said the team was looking into an upgrade path for Starter Tier projects. That reply did not say the path was finished (same thread).
- Some projects get the error “Domain mappings are not available in the region of the selected service” (report, 28 April 2026). Cloud Run domain mapping is limited to the regions listed on Google’s mapping page. Other regions need a different option. The feature is in preview, and Google does not recommend it for production (Cloud Run custom domains, read 19 October 2026).
- The Add domain mapping button stays disabled when the account lacks
run.domainmappings.create. In the report the account had Cloud Run Viewer and could not open billing (report, 8 October 2026).
Which case you are in
| What you see | What it points to | What you can do |
|---|---|---|
| Add mapping is greyed out on a Starter Tier project | The managed project does not offer mapping | Route A or Route B |
| “This product is not available as part of this Starter tier project” | Firebase products are closed on that project | Route A or Route B |
| “Domain mappings are not available in the region of the selected service” | The service region is outside the mapping list | Another option on the Cloud Run page, or Route B |
Add domain mapping is disabled, and the account lacks run.domainmappings.create | The account is a viewer on a managed project | Route A or Route B |
Google sign-in fails with auth/unauthorized-domain | The host is not on the Firebase Authentication allowlist | See the sign-in note under Route A |
Before you buy a name
A verified domain you own comes up only for Google’s OAuth checks, and not for every app. Brand verification applies when the app is in production for any Google Account user and you want a logo or display name on the consent screen (authentication verification, read 19 October 2026). Sensitive or restricted scopes need review unless an exception applies. Google’s examples of sensitive data include calendar entries and files in Drive (sensitive-scope verification, read 19 October 2026).
When that review applies, the homepage must be hosted on a verified domain you own. The privacy policy must be on that same domain and linked from the consent screen. Do not put them on a platform where you cannot verify your subdomain. Google’s examples are Google Sites, Facebook, Instagram and Twitter (App homepage, read 19 October 2026). A domain you already own and can verify is enough.
You do not need that review for personal use by you and a few people you know, for an app still in development or testing, or for an internal app of a Google Workspace or Cloud Identity organization (authentication verification).
Route A. Stay on Google
This needs a Google Cloud project with billing.
- In AI Studio, remix the app and publish the copy to a billing-enabled Google Cloud project. If you want to reuse the same
.ai.studioaddress, unpublish the original first. A new project does not automatically migrate database records or signed-in users (staff reply, 9 October 2026). - For the address, follow the option the Cloud Run page actually gives you. Google recommends a global external Application Load Balancer. Domain mapping is a separate preview option, not recommended for production, and only in the listed regions. Firebase Hosting is the third option on that page (Cloud Run custom domains, read 19 October 2026). On a Starter Tier project, Firebase can refuse with the sentence quoted above.
- Add exactly the records the console shows. For domain mapping, the record type is the one returned: A, AAAA or CNAME. The name
wwwmapswww.example.com. The name@maps the root (same page). - If people should sign in on a host that is not the project’s default hosting domain, whitelist that full domain name for Firebase Authentication. Localhost and the project’s hosting domain are included by default (Firebase help, read 19 October 2026). A July 2026 report of
auth/unauthorized-domainon an*.ai.studioaddress said the hostname was missing from Authorized domains and the managed project had no Add Domain control. A reply on that thread said a fix had been deployed and to republish, then test sign-in on the published URL (report, 27 July 2026).
Route B. Keep the Starter Tier app and deploy a copy
- Export a ZIP of the project from AI Studio and deploy that copy separately in Google Cloud (same staff reply, 9 October 2026).
- Point the domain with the records that deployment shows.
- Database records and signed-in users of the original app stay where they are unless you move them. The staff reply says a new project does not migrate them automatically.
If you do not have a name yet
Buy it where you like, then follow Route A or Route B. The console shows the exact records.
At Namecheap, open Advanced DNS, then Host Records, then Add New Record. For a CNAME, Host is the label, such as www, and Value is the target. Namecheap appends your domain to the Host field: enter mysubdomain, not mysubdomain.example.com. Keep the full CNAME target in Value exactly as the host provides it. If a validation record’s Host already includes domain.tld, remove that part before you add it (Namecheap: create a CNAME record, read 19 October 2026).
| Purpose | Type | Host | Value |
|---|---|---|---|
| Whatever the console asked for | The type it shows | The label it shows, such as www or @ | The exact target or verification value it shows |
If you are stuck
Copy the exact error line to the assistant that built the app and ask it to follow this page.
Checking a name
Any registrar works. To see whether a name is free, with the renewal price next to the first year, and open it at Namecheap, use Add Domain. You pay the registrar in your own account.