Manage Users in Firebase

Create a user

You create a new user in your Firebase project by calling the createUserWithEmail:password:completion: method or by signing in a user for the first time using a federated identity provider, such as Google Sign-In or Facebook Login.

You can also create new password-authenticated users from the Authentication section of the Firebase console, on the Users page.

Get the currently signed-in user

The recommended way to get the current user is by setting a listener on the Auth object:

self.handle = [[FIRAuth auth]
    addAuthStateDidChangeListener:^(FIRAuth *_Nonnull auth, FIRUser *_Nullable user) {
      // ...
    }];

handle = FIRAuth.auth()?.addStateDidChangeListener() { (auth, user) in
  // ...
}

By using a listener, you ensure that the Auth object isn't in an intermediate state—such as initialization—when you get the current user.

You can also get the currently signed-in user by using the currentUser property. If a user isn't signed in, currentUser is nil:

if ([FIRAuth auth].currentUser) {
  // User is signed in.
  // ...
} else {
  // No user is signed in.
  // ...
}

if FIRAuth.auth()?.currentUser != nil {
  // User is signed in.
  // ...
} else {
  // No user is signed in.
  // ...
}

Get a user's profile

To get a user's profile information, use the properties of an instance of FIRUser. For example:

FIRUser *user = [FIRAuth auth].currentUser;
NSString *email = user.email;
// The user's ID, unique to the Firebase project.
// Do NOT use this value to authenticate with your backend server,
// if you have one. Use getTokenWithCompletion:completion: instead.
NSString *uid = user.uid;
NSURL *photoURL = user.photoURL;

let user = FIRAuth.auth()?.currentUser
// The user's ID, unique to the Firebase project.
// Do NOT use this value to authenticate with your backend server,
// if you have one. Use getTokenWithCompletion:completion: instead.
let email = user?.email
let uid = user?.uid
let photoURL = user?.photoURL

Get a user's provider-specific profile information

To get the profile information retrieved from the sign-in providers linked to a user, use the providerData property. For example:

id<FIRUserInfo> userInfo = [FIRAuth auth].currentUser.providerData[indexPath.row];
cell.textLabel.text = [userInfo providerID];
// Provider-specific UID
cell.detailTextLabel.text = [userInfo uid];

let userInfo = FIRAuth.auth()?.currentUser?.providerData[(indexPath as NSIndexPath).row]
cell?.textLabel?.text = userInfo?.providerID
// Provider-specific UID
cell?.detailTextLabel?.text = userInfo?.uid

Update a user's profile

You can update a user's basic profile information—the user's display name and profile photo URL—with the FIRUserProfileChangeRequest class. For example:

FIRUserProfileChangeRequest *changeRequest =
    [[FIRAuth auth].currentUser profileChangeRequest];
changeRequest.displayName = userInput;
[changeRequest commitChangesWithCompletion:^(NSError *_Nullable error) {
  // ...
}];

let changeRequest = FIRAuth.auth()?.currentUser?.profileChangeRequest()
changeRequest?.displayName = userInput
changeRequest?.commitChanges() { (error) in
  // ...
}

Set a user's email address

You can set a user's email address with the updateEmail:completion: method. For example:

[[FIRAuth auth]
        .currentUser
    updateEmail:userInput
     completion:^(NSError *_Nullable error) {
       // ...
     }];

FIRAuth.auth()?.currentUser?.updateEmail(userInput) { (error) in
  // ...
}

Send a user a verification email

You can send an address verification email to a user with the sendEmailVerificationWithCompletion: method. For example:

[[FIRAuth auth]
        .currentUser sendEmailVerificationWithCompletion:^(NSError *_Nullable error) {
  // ...
}];

FIRAuth.auth()?.currentUser?.sendEmailVerification(completion: { (error) in
  // ...
})

You can customize the email template that is used in Authentication section of the Firebase console, on the Email Templates page. See Email Templates in Firebase Help Center.

Set a user's password

You can set a user's password with the updatePassword:completion: method. For example:

[[FIRAuth auth]
        .currentUser
    updatePassword:userInput
        completion:^(NSError *_Nullable error) {
          // ...
        }];

FIRAuth.auth()?.currentUser?.updatePassword(userInput) { (error) in
  // ...
}

Send a password reset email

You can send a password reset email to a user with the sendPasswordResetWithEmail:completion: method. For example:

[[FIRAuth auth]
    sendPasswordResetWithEmail:userInput
                    completion:^(NSError *_Nullable error) {
                      // ...
                    }];

FIRAuth.auth()?.sendPasswordReset(withEmail: userInput) { (error) in
  // ...
}

You can customize the email template that is used in Authentication section of the Firebase console, on the Email Templates page. See Email Templates in Firebase Help Center.

You can also send password reset emails from the Firebase console.

Delete a user

You can delete a user account with the deleteWithCompletion method. For example:

FIRUser *user = [FIRAuth auth].currentUser;

[user deleteWithCompletion:^(NSError *_Nullable error) {
  if (error) {
    // An error happened.
  } else {
    // Account deleted.
  }
}];

let user = FIRAuth.auth()?.currentUser

user?.delete { error in
  if let error = error {
    // An error happened.
  } else {
    // Account deleted.
  }
}

You can also delete users from the Authentication section of the Firebase console, on the Users page.

Re-authenticate a user

Some security-sensitive actions—such as deleting an account, setting a primary email address, and changing a password—require that the user has recently signed in. If you perform one of these actions, and the user signed in too long ago, the action fails with the FIRAuthErrorCodeCredentialTooOld error. When this happens, re-authenticate the user by getting new sign-in credentials from the user and passing the credentials to reauthenticate. For example:

FIRUser *user = [FIRAuth auth].currentUser;
FIRAuthCredential *credential;

// Prompt the user to re-provide their sign-in credentials

[user reauthenticateWithCredential:credential completion:^(NSError *_Nullable error) {
  if (error) {
    // An error happened.
  } else {
    // User re-authenticated.
  }
}];

let user = FIRAuth.auth()?.currentUser
var credential: FIRAuthCredential

// Prompt the user to re-provide their sign-in credentials

user?.reauthenticate(with: credential) { error in
  if let error = error {
    // An error happened.
  } else {
    // User re-authenticated.
  }
}

Import user accounts

You can import user accounts from a file into your Firebase project by using the Firebase CLI's auth:import command. For example:

firebase auth:import users.json --hash-algo=scrypt --rounds=8 --mem-cost=14