Easily add sign-in to your iOS app with FirebaseUI

FirebaseUI is a library built on top of the Firebase Authentication SDK that provides drop-in UI flows for use in your app. FirebaseUI provides the following benefits:

Multiple providers: sign-in flows for email/password, email link, phone authentication, Google Sign-In, Facebook Login, and Twitter Login.
Account management: flows to handle account management tasks, such as account creation and password resets.
Anonymous account linking: flows to automatically link anonymous accounts to identity providers.
Customizable: customize the look of FirebaseUI to match your app. Also, because FirebaseUI is open source, you can fork the project and customize it exactly to your needs.

Before you begin

Add Firebase to your iOS project.

Add FirebaseUI to your Podfile:

pod 'FirebaseUI'

If you prefer, you can add only the Auth component and the providers you want to use:

pod 'FirebaseUI/Auth'

pod 'FirebaseUI/Google'
pod 'FirebaseUI/Facebook'
pod 'FirebaseUI/Twitter'
pod 'FirebaseUI/Phone'

If you haven't yet connected your app to your Firebase project, do so from the Firebase console.

Set up sign-in methods

Before you can use Firebase to sign in users, you must enable and configure the sign-in methods you want to support.

Email address and password

In the Firebase console, open the Authentication section and enable email and password authentication.

Email link authentication

In the Firebase console, open the Authentication section. On the Sign in method tab, enable the Email/Password provider. Note that email/password sign-in must be enabled to use email link sign-in.
In the same section, enable Email link (passwordless sign-in) sign-in method and click Save.
You can enable email link sign in by initializing an FUIEmailAuth instance with FIREmailLinkAuthSignInMethod. You will also need to provide a valid FIRActionCodeSettings object with handleCodeInApp set to true.

Swift

var actionCodeSettings = ActionCodeSettings()
actionCodeSettings.url = URL(string: "https://example.appspot.com")
actionCodeSettings.handleCodeInApp = true
actionCodeSettings.setAndroidPackageName("com.firebase.example", installIfNotAvailable: false, minimumVersion: "12")

let provider = FUIEmailAuth.initAuthAuthUI(FUIAuth.defaultAuthUI(), signInMethod: FIREmailLinkAuthSignInMethod, forceSameDevice: false, allowNewEmailAccounts: true, actionCodeSetting: actionCodeSettings)

Objective-C

FIRActionCodeSettings *actionCodeSettings = [[FIRActionCodeSettings alloc] init];
actionCodeSettings.URL = [NSURL URLWithString:@"https://example.appspot.com"];
actionCodeSettings.handleCodeInApp = YES;
[actionCodeSettings setAndroidPackageName:@"com.firebase.example"
                    installIfNotAvailable:NO
                           minimumVersion:@"12"];

id<FUIAuthProvider> provider = [[FUIEmailAuth alloc] initAuthAuthUI:[FUIAuth defaultAuthUI]
                                                       signInMethod:FIREmailLinkAuthSignInMethod
                                                    forceSameDevice:NO
                                              allowNewEmailAccounts:YES
                                                  actionCodeSetting:actionCodeSettings];

Additionally, you need to whitelist the URL you pass to the iniatializer. You can do so in the Firebase console, open the Authentication section. On the Sign in method tab, add the URL under Authorized domains.
Once you catch the deep link, you will need to pass it to the auth UI so it can be handled.

Swift

Auth.defaultAuthUI.handleOpenURL(url, sourceApplication: sourceApplication)

Objective-C

[FUIAuth.defaultAuthUI handleOpenURL:url sourceApplication:sourceApplication];

Email link sign-in in FirebaseUI-iOS is compatible with FirebaseUI-Android and FirebaseUI-web where one user starting the flow from FirebaseUI-Android can open the link and complete sign-in with FirebaseUI-web. The same is true for the opposite flow.

Google

In the Firebase console, open the Authentication section and enable Google Sign-in.
Add your reversed client ID as a URL scheme in your Xcode project. You can find this value in theGoogleService-Info.plist file.

Facebook

Set up the Facebook Login SDK by following Facebook's getting started page.
In the Firebase console, open the Authentication section and enable Facebook. To enable Facebook sign-in, you must provide your Facebook App ID and App Secret, which you can get in the Facebook Developers console.
Enable keychain sharing in your Xcode project from the Project Settings > Capabilities screen.
Add fbFACEBOOK_APP_ID as a URL scheme in your Xcode project.
Add your Facebook App ID and display name to the Info.plist file:

Key Value

FacebookAppID FACEBOOK_APP_ID (for example, 1234567890)

FacebookDisplayName The name of your app

Key	Value
FacebookAppID	`FACEBOOK_APP_ID` (for example, `1234567890`)
FacebookDisplayName	The name of your app

Twitter

In the Firebase console, open the Authentication section and enable Twitter. To enable Twitter sign-in, you must provide your Twitter API consumer key and secret, which you can get in the Twitter Application Management console.

Initialize an OAuth provider instance configured for Twitter login:

Swift

provider = FUIOAuth(authUI: self.authUI!,
                providerID: "twitter.com",
                buttonLabelText: "Sign in with Twitter",
                shortName: "Twitter",
                buttonColor: buttonColor,
                iconImage: UIImage(contentsOfFile: iconPath)!,
                scopes: ["user.readwrite"],
                customParameters: ["prompt" : "consent"],
                loginHintKey: nil)

Objective-C

FUIOAuth *provider = [[FUIOAuth alloc] initWithAuthUI:[FUIAuth defaultAuthUI]
                                       providerID:@"twitter.com"
                                  buttonLabelText:@"Sign in with Twitter"
                                        shortName:@"Twitter"
                                      buttonColor:buttonColor
                                        iconImage:[UIImage imageWithContentsOfFile:iconPath]
                                           scopes:@[@"user.readwrite"]
                                 customParameters:@{@"prompt" : @"consent"}
                                     loginHintKey:nil];

Phone number

In the Firebase console, open the Authentication section and enable phone number sign-in.
Firebase must be able to verify that phone number sign-in requests are coming from your app. One of the ways this is accomplished is through APNs notifications. See Enable app verification for details.

To enable APNs notifications for use with Firebase Authentication:
1. In Xcode, enable push notifications for your project.
2. Upload your APNs authentication key to Firebase. If you don't already have an APNs authentication key, see Configuring APNs with FCM.
  1. Inside your project in the Firebase console, select the gear icon, select Project Settings, and then select the Cloud Messaging tab.
  2. In APNs authentication key under iOS app configuration, click the Upload button.
  3. Browse to the location where you saved your key, select it, and click Open. Add the key ID for the key (available in Certificates, Identifiers & Profiles in the Apple Developer Member Center) and click Upload.
  If you already have an APNs certificate, you can upload the certificate instead.
When APNs notifications can't be received on a device, Firebase uses reCAPTCHA to verify requests.

To enable reCAPTCHA verification, if you haven't already added your reversed client ID as a URL scheme (for example, to enable Google Sign-in), do so in your Xcode project. You can find this value in theGoogleService-Info.plist file.
Optional: Firebase uses method swizzling to automatically obtain your app's APNs token, to handle the silent push notifications that Firebase sends to your app, and to automatically intercept the custom scheme redirect from the reCAPTCHA verification page during verification.

If you prefer not to use swizzling, see Appendix: Using phone sign-in without swizzling in Firebase SDK authentication docs.

Sign in

To kick off the FirebaseUI sign in flow, first initialize FirebaseUI:

Swift

import FirebaseUI

/* ... */

FirebaseApp.configure()
let authUI = FUIAuth.defaultAuthUI()
// You need to adopt a FUIAuthDelegate protocol to receive callback
authUI.delegate = self

Objective-C

@import FirebaseUI;

...

[FIRApp configure];
FUIAuth *authUI = [FUIAuth defaultAuthUI];
// You need to adopt a FUIAuthDelegate protocol to receive callback
authUI.delegate = self;

Then, configure FirebaseUI to use the sign-in methods you want to support:

Swift

import FirebaseUI

let providers: [FUIAuthProvider] = [
  FUIGoogleAuth(),
  FUIFacebookAuth(),
  FUITwitterAuth(),
  FUIPhoneAuth(authUI:FUIAuth.defaultAuthUI()),
]
self.authUI.providers = providers

Objective-C

@import FirebaseUI;

...

NSArray<id<FUIAuthProvider>> *providers = @[
  [[FUIGoogleAuth alloc] init],
  [[FUIFacebookAuth alloc] init],
  [[FUITwitterAuth alloc] init],
  [[FUIPhoneAuth alloc] initWithAuthUI:[FUIAuth defaultAuthUI]]
];
_authUI.providers = providers;

If you enabled Google or Facebook sign-in, implement a handler for the result of the Google and Facebook sign-up flows:

Swift

func application(_ app: UIApplication, open url: URL,
    options: [UIApplicationOpenURLOptionsKey : Any]) -> Bool {
  let sourceApplication = options[UIApplicationOpenURLOptionsKey.sourceApplication] as! String?
  if FUIAuth.defaultAuthUI()?.handleOpen(url, sourceApplication: sourceApplication) ?? false {
    return true
  }
  // other URL handling goes here.
  return false
}

Objective-C

- (BOOL)application:(UIApplication *)app
            openURL:(NSURL *)url
            options:(NSDictionary *)options {
  NSString *sourceApplication = options[UIApplicationOpenURLOptionsSourceApplicationKey];
  return [[FUIAuth defaultAuthUI] handleOpenURL:url sourceApplication:sourceApplication];
}

Finally, get an instance of AuthViewController from FUIAuth. You can then either present it as the first view controller of your app or present it from another view controller in your app.

Swift

To get the sign-in method selector:

let authViewController = authUI.authViewController()

If you only use phone number sign-in, you can display the phone number sign-in view directly instead:

let phoneProvider = FUIAuth.defaultAuthUI().providers.first as! FUIPhoneAuth
phoneProvider.signIn(withPresenting: currentlyVisibleController, phoneNumber: nil)

Objective-C

To get the sign-in method selector:

UINavigationController *authViewController = [authUI authViewController];

If you only use phone number sign-in, you can display the phone number sign-in view directly instead:

FUIPhoneAuth *phoneProvider = [FUIAuth defaultAuthUI].providers.firstObject;
[phoneProvider signInWithPresentingViewController:currentlyVisibleController phoneNumber:nil];

After you present the authentication view and the user signs in, the result is returned to the FirebaseUI Auth delegate in the didSignInWithUser:error: method:

Swift

func authUI(_ authUI: FUIAuth, didSignInWith user: FIRUser?, error: Error?) {
  // handle user and error as necessary
}

Objective-C

   - (void)authUI:(FUIAuth *)authUI
didSignInWithUser:(nullable FIRUser *)user
            error:(nullable NSError *)error {
  // Implement this method to handle signed in user or error if any.
}

Sign Out

FirebaseUI provides convenience methods to sign out of Firebase Authentication as well as all social identity providers:

Swift

authUI.signOut()

Objective-C

[authUI signOut];

Customization

You can customize the sign-in screens by subclassing FirebaseUI's view controllers and specifying them in FUIAuth's delegate methods:

Swift

func authPickerViewController(forAuthUI authUI: FUIAuth) -> FUIAuthPickerViewController {
  return FUICustomAuthPickerViewController(nibName: "FUICustomAuthPickerViewController",
                                           bundle: Bundle.main,
                                           authUI: authUI)
}

func emailEntryViewController(forAuthUI authUI: FUIAuth) -> FUIEmailEntryViewController {
  return FUICustomEmailEntryViewController(nibName: "FUICustomEmailEntryViewController",
                                           bundle: Bundle.main,
                                           authUI: authUI)
}

func passwordRecoveryViewController(forAuthUI authUI: FUIAuth, email: String) -> FUIPasswordRecoveryViewController {
  return FUICustomPasswordRecoveryViewController(nibName: "FUICustomPasswordRecoveryViewController",
                                                 bundle: Bundle.main,
                                                 authUI: authUI,
                                                 email: email)
}

func passwordSignInViewController(forAuthUI authUI: FUIAuth, email: String) -> FUIPasswordSignInViewController {
  return FUICustomPasswordSignInViewController(nibName: "FUICustomPasswordSignInViewController",
                                               bundle: Bundle.main,
                                               authUI: authUI,
                                               email: email)
}

func passwordSignUpViewController(forAuthUI authUI: FUIAuth, email: String) -> FUIPasswordSignUpViewController {
  return FUICustomPasswordSignUpViewController(nibName: "FUICustomPasswordSignUpViewController",
                                               bundle: Bundle.main,
                                               authUI: authUI,
                                               email: email)
}

func passwordVerificationViewController(forAuthUI authUI: FUIAuth, email: String, newCredential: AuthCredential) -> FUIPasswordVerificationViewController {
  return FUICustomPasswordVerificationViewController(nibName: "FUICustomPasswordVerificationViewController",
                                                     bundle: Bundle.main,
                                                     authUI: authUI,
                                                     email: email,
                                                     newCredential: newCredential)
}

Objective-C

- (FUIAuthPickerViewController *)authPickerViewControllerForAuthUI:(FUIAuth *)authUI {
  return [[FUICustomAuthPickerViewController alloc] initWithNibName:@"FUICustomAuthPickerViewController"
                                                             bundle:[NSBundle mainBundle]
                                                             authUI:authUI];
}

- (FUIEmailEntryViewController *)emailEntryViewControllerForAuthUI:(FUIAuth *)authUI {
  return [[FUICustomEmailEntryViewController alloc] initWithNibName:@"FUICustomEmailEntryViewController"
                                                             bundle:[NSBundle mainBundle]
                                                             authUI:authUI];

}

- (FUIPasswordSignInViewController *)passwordSignInViewControllerForAuthUI:(FUIAuth *)authUI
                                                                     email:(NSString *)email {
  return [[FUICustomPasswordSignInViewController alloc] initWithNibName:@"FUICustomPasswordSignInViewController"
                                                                 bundle:[NSBundle mainBundle]
                                                                 authUI:authUI
                                                                  email:email];

}

- (FUIPasswordSignUpViewController *)passwordSignUpViewControllerForAuthUI:(FUIAuth *)authUI
                                                                     email:(NSString *)email {
  return [[FUICustomPasswordSignUpViewController alloc] initWithNibName:@"FUICustomPasswordSignUpViewController"
                                                                 bundle:[NSBundle mainBundle]
                                                                 authUI:authUI
                                                                  email:email];

}

- (FUIPasswordRecoveryViewController *)passwordRecoveryViewControllerForAuthUI:(FUIAuth *)authUI
                                                                         email:(NSString *)email {
  return [[FUICustomPasswordRecoveryViewController alloc] initWithNibName:@"FUICustomPasswordRecoveryViewController"
                                                                   bundle:[NSBundle mainBundle]
                                                                   authUI:authUI
                                                                    email:email];

}

- (FUIPasswordVerificationViewController *)passwordVerificationViewControllerForAuthUI:(FUIAuth *)authUI
                                                                                 email:(NSString *)email
                                                                         newCredential:(FIRAuthCredential *)newCredential {
  return [[FUICustomPasswordVerificationViewController alloc] initWithNibName:@"FUICustomPasswordVerificationViewController"
                                                                       bundle:[NSBundle mainBundle]
                                                                       authUI:authUI
                                                                        email:email
                                                                newCredential:newCredential];
}

You can customize the URL to your app's terms of service, which is linked on the account creation screen:

Swift

let kFirebaseTermsOfService = URL(string: "https://example.com/terms")!
authUI.tosurl = kFirebaseTermsOfService

Objective-C

authUI.TOSURL = [NSURL URLWithString:@"https://example.com/terms"];

Finally, you can customize the messages and prompts shown to your users by specifying a custom bundle:

Swift

authUI.customStringsBundle = NSBundle.mainBundle() // Or any custom bundle.

Objective-C

authUI.customStringsBundle = [NSBundle mainBundle]; // Or any custom bundle.

Next Steps

For more information on using and customizing FirebaseUI, see the README file on GitHub.
If you find and issue in FirebaseUI and would like to report it, use the GitHub issue tracker.