Build apps
Custom domains
Serve a published app at a domain you own, like example.com or app.example.com, with HTTPS.
Serve a published app at a domain you own, like example.com or app.example.com, with HTTPS.
A published app gets its own address, such as https://bake-sale-4.onedrop.example.com or https://onedrop-bake-sale.fly.dev. You can also point a domain you already own at it. OneDrop gets the HTTPS certificate for you.
Custom domains work when the project is published to Your domain or to Hosting. Tailscale addresses can’t have one. You can’t buy a domain in OneDrop; use one from any registrar.
In the workspace, open the Tools tab, then Domains.
Type the domain, such as example.com or app.example.com, and click Add. The first domain you add is the primary one.
The panel shows the records to add where your domain’s DNS is managed (your registrar, Cloudflare, Route 53…). Each value has a copy button.
OneDrop checks the domain by itself: every 30 seconds for the first 10 minutes, then every 5 minutes for two days. Click Check now to check right away. Once the DNS is right and the certificate is issued, the domain shows Active.
The records depend on where the project is published:
| Published to | Subdomain (app.example.com) | Root domain (example.com) |
|---|---|---|
| Your domain, on a server | CNAME to the server’s domain | A (and AAAA) records with the server’s addresses |
| Your domain, on OneDrop’s cloud | CNAME to the address the panel shows | CNAME flattening, ALIAS or ANAME to the same address |
| Hosting, an app with a server | CNAME to the app’s fly.dev address | A and AAAA records with the app’s addresses |
| Hosting, a front end | None | None |
A front end on Hosting is served by Cloudflare, which adds the DNS record itself. For that, the domain’s DNS has to be in the same Cloudflare account the app is hosted in. If your organization connected its own Cloudflare account, add the domain to that account first.
DNS changes can take a while to show up, from a minute to a few hours. While a domain is waiting, the panel says what’s wrong, for example which address it points at now.
Once the primary domain is active, it’s the app’s URL everywhere in OneDrop: the Publish menu, Tools → Publishing, the share page and “Sign in with OneDrop” callbacks.
example.com and www.example.com and either one works.fly.dev or workers.dev address keeps working.To change it, open a domain’s ⋮ menu and choose Make primary. Removing the primary domain makes the next active one primary, or goes back to the app’s own address.
A project published privately to Your domain stays private on its custom domains: visitors sign in to OneDrop first, then come back to the page they asked for, the same as on the app’s own address. Hosted apps are public on every domain.
A domain can only be added to one project on the install.