My client app is accessing to Firestore through API created by Firebase Functions. However, the Firebase Functions imports firebase-admin which bypass all the d
I think it is possible to access Firestore via an admin-sdk but scope it to the logged-in user if you are use REST APIs to access Firestore.
For authentication, the Cloud Firestore REST API accepts either a Firebase Authentication ID token or a Google Identity OAuth 2.0 token. The token you provide affects your request's authorization:
Use Firebase ID tokens to authenticate requests from your application's users. For these requests, Cloud Firestore uses Cloud Firestore Security Rules to determine if a request is authorized.