Security rules

Before creating a database and collection in Cloud Firestore, it prompts you to apply the security rules for our database.

Take a look at the following screenshot:

Here are some code example of Firestore rules:

service cloud.firestore {
    match /databases/{database}/documents {
           match /{document=**} {
           allow read, write;
        }
    }
}

service cloud.firestore {
    match /databases/{database}/documents {
        match /users/{userId} {
           allow read, write: if request.auth.uid == userId;
        }
    }
}

service cloud.firestore {
    match /databases/{database}/documents {
       match /{document=**} {
          allow read, write: if false;
       }
    }
}