Appwrite has a role called Any, and it means anyone

Your Appwrite project id ships in your browser bundle, by design. It is not a secret and cannot be hidden.

Access is decided by permissions on each collection, and optionally on each document. The available roles include Any — which is every visitor, signed in or not.

In the console, open each collection → Settings → Permissions. Remove Read for the Any role anywhere the data is not genuinely public.

For per-user data, enable Document Security on the collection and set permissions per document when you create it, so each user can read only their own.

From a signed-out browser console, call listDocuments with your public project id against the collection. A closed collection returns a 401. Rows coming back means Any still has read.

Granting collection-level Read to Users and thinking that is enough. It means every signed-in person can read every row — including other customers. Per-user data needs document-level permissions, not just an authenticated role.