timestamp: 2026-06-20
tags: [glossary, firebase, auth, domain]
auth domain
auth.oriz.in: custom domain, one Firebase project serves all *.oriz.in sites
auth domain
Definition
The auth domain is auth.oriz.in — the Firebase custom auth domain
configured on the single oriz-app project, which lets every
*.oriz.in subdomain (and every Chrome extension) share one Firebase
user across the family.
Expanded
Without a custom auth domain, OAuth redirects bounce through the
default oriz-app.firebaseapp.com, which fragments cookies and
pop-ups across sites. With auth.oriz.in, every site sees the same
session, and Chrome extensions use
chrome.identity.launchWebAuthFlow() to bounce through this domain
and store the resulting ID token in chrome.storage.local.
This is the single piece of Firebase config that makes “one subscription unlocks everything” architecturally feasible.