| FirebaseApp | The entry point of Firebase SDKs. |
| FirebaseInitProvider | Initializes Firebase APIs at app startup time. |
| FirebaseNetworkException | Exception thrown when a request to a Firebase service has failed due to a network error. |
| FirebaseOptions | Configurable Firebase options. |
| FirebaseOptions.Builder | Builder for constructing FirebaseOptions. |
| FirebaseTooManyRequestsException | Exception thrown when a request to a Firebase service has been blocked due to having received too many consecutive requests from the same device. |
| Timestamp | A Timestamp represents a point in time independent of any time zone or calendar, represented as seconds and fractions of seconds at nanosecond resolution in UTC Epoch time. |