| AuthResult | Result object obtained from operations that can affect the authentication state. |
| FirebaseAuth.AuthStateListener | Listener called when there is a change in the authentication state. |
| FirebaseAuthProvider | Represents the Firebase Authentication provider type. |
| ProviderQueryResult | Result object that contains a list of strings that represent authentication provider IDs. |
| UserInfo | Represents a collection of standard profile information for a user. |
| AuthCredential | Represents a credential that the Firebase Authentication server can use to authenticate a user. |
| EmailAuthCredential | Wraps an email and password tuple for authentication purposes. |
| EmailAuthProvider | Represents the email and password authentication mechanism. |
| FacebookAuthCredential | Wraps a Facebook Login access token for authentication purposes. |
| FacebookAuthProvider | Represents the Facebook Login authentication provider. |
| FirebaseAuth | The entry point of the Firebase Authentication SDK. |
| FirebaseUser | Represents a user's profile information in your Firebase project's user database. |
| GetTokenResult | Result object that contains a Firebase Auth ID Token. |
| GithubAuthCredential | Wraps a Github OAuth access token for authentication purposes. |
| GithubAuthProvider | Represents the Github authentication provider. |
| GoogleAuthCredential | Wraps a Google Sign-In ID token and/or access token, for authentication purposes. |
| GoogleAuthProvider | Represents the Google Sign-In authentication provider. |
| TwitterAuthCredential | Wraps a Log in with Twitter token and secret tuple for authentication purposes. |
| TwitterAuthProvider | Represents the Twitter authentication provider. |
| UserProfileChangeRequest | Request used to update user profile information. |
| UserProfileChangeRequest.Builder | The request builder. |
| FirebaseAuthException | Generic exception related to Firebase Authentication. |
| FirebaseAuthInvalidCredentialsException | Thrown when one or more of the credentials passed to a method fail to identify and/or authenticate the user subject of that operation. |
| FirebaseAuthInvalidUserException | Thrown when performing an operation on a FirebaseUser instance that is no longer valid. |
| FirebaseAuthRecentLoginRequiredException | Thrown on security sensitive operations on a FirebaseUser instance that require the user
to have signed in recently, when the requirement isn't met. |
| FirebaseAuthUserCollisionException | Thrown when an operation on a FirebaseUser instance couldn't be completed due to a
conflict with another existing user. |
| FirebaseAuthWeakPasswordException | Thrown when using a weak password (less than 6 chars) to create a new account or to update an existing account's password. |