Pages - custom domain inheritance

[ChadCleveland]

🏷️ Discussion Type

Question

💬 Feature/Topic Area

Pages

Body

Hello,
I have a couple repos that I want to serve to the public from a custom domain, but am unable to get it working. From what I have been able to determine via docs, if I want to use a shared custom domain for multiple repos, I need to add an "umbrella" repo that is the same name as the organization account name. The project repos then don't have a custom domain setting enabled, but are intended to inherit the custom domain configuration from the account-name-matched repo.

My configuration:

• Custom domain: cdn.thehotline.us

  • Visibility: public
  • Umbrella repo: the-hotline (which is the org name)
    • README in the root
    • CNAME in the root - cdn.thehotline.us
  • When I visit cdn.thehotline.us, it loads the repo successfully.

• Project repo: thl-site-feedback

  • README in the root
  • thl-site-feedback.js in the root
  • Visibility: public
  • When I visit cdn.thehotline.us/thl-site-feedback/thl-site-feedback.js, I get a GitHub branded 404 error

---

"404
File not found

The site configured at this address does not contain the requested file.

If this is your site, make sure that the filename case matches the URL as well as any file permissions.
For root URLs (like http://example.com/) you must provide an index.html file.

Read the full documentation for more information about using GitHub Pages."

---

• When I was first setting this up, I added the custom domain setting to a project repo and the .js file loaded as expected.
• DNS is correct. Confirmed by the umbrella repo loading the README and the project repo working before I wanted to share the custom domain.
• I have cycled unpublishing and republishing the umbrella repo and project repos (in both directions to see if the project repos or the umbrella repose need to be published first), purge CloudFlare cache, cleared local cache, waited.

What am I missing?

Thank you in advance for any help!

[shourya011]

The key thing that trips people up: for a project repo to inherit the org's custom domain, Pages still needs to be enabled and actively publishing on that repo — you just don't set a custom domain value there. If Pages got turned off on thl-site-feedback when you removed its custom domain, there's nothing for GitHub to serve at that path — hence the branded 404 (it's hitting Pages infra, just finding no site).

Check: thl-site-feedback → Settings → Pages → make sure a publishing source is set and Pages shows as active/built. Don't re-add a CNAME or custom domain there — that's the umbrella repo's job only.

Also confirm the umbrella repo's Pages build is actually succeeding, since it's the one carrying the domain config others inherit.

If Pages is already on and building there and it still 404s, that's unusual — worth a support ticket, since it'd suggest a propagation bug rather than a config issue.

[ChadCleveland]

Thank you. I did confirm both of these are both published and succeeding. When I follow the link to the thl-site-feedback "Page" (https://the-hotline.github.io/thl-site-feedback/), it loads the readme for that repo, and when I follow the link to the umbrella repo (https://cdn.thehotline.us), it loads the readme for that repo.

Thanks again!

[clackes]

Hey! The problem is the name of your umbrella repo.

For the custom-domain inheritance to kick in, the umbrella repo has to be named the-hotline.github.io — not just the-hotline. Only the repo matching .github.io is treated as the organization Pages site, and that's the one whose custom domain gets shared with sibling project repos.

Right now the-hotline is just a regular project repo that happens to have a CNAME, so nothing propagates — which is why your .js file 404s.

Try this:

Rename the-hotline → the-hotline.github.io (keep the CNAME with cdn.thehotline.us inside).
In thl-site-feedback: enable Pages, but leave the custom domain blank and don't add a CNAME file.
Give it a minute, then hit cdn.thehotline.us/thl-site-feedback/thl-site-feedback.js.
One gotcha if you're on Cloudflare: keep the DNS record grey-cloud (DNS only) until HTTPS shows as verified in the Pages settings — the orange-cloud proxy can block domain verification and cert issuance.

Hope that unblocks you!

[ChadCleveland]

This fixed it!!!
Thank you

[amkabin]

I think there may be a misunderstanding about how GitHub Pages handles custom domains.

The repository named after your organization (e.g. the-hotline) becomes the organization site. Assigning cdn.thehotline.us to that repository only serves the content from that repository—it doesn't automatically make other repositories available under that domain.

Project Pages (thl-site-feedback) are separate sites. By default, they're published at:

https://<org>.github.io/thl-site-feedback/

or, if they have their own custom domain configured, at that custom domain.

A custom domain configured on the organization site isn't inherited by project sites. That's why cdn.thehotline.us/thl-site-feedback/thl-site-feedback.js returns a GitHub Pages 404—the organization site's published content doesn't contain that path.

A few things to check:

• Make sure thl-site-feedback is actually published from the correct branch/folder in Settings → Pages.
• Visit https://the-hotline.github.io/thl-site-feedback/ to confirm the project site is being served correctly.
• If your goal is to host multiple projects under a single custom domain (e.g. cdn.thehotline.us/project1, cdn.thehotline.us/project2), GitHub Pages doesn't support that automatically through an organization site. You'd typically need to use a reverse proxy (such as Cloudflare or another web server) or place all the content within a single Pages site.

If you can share the URLs for both the organization Pages site and the project Pages site, it would be easier to determine whether this is a Pages configuration issue or a DNS/proxy issue.