The first step is to implement a sign-in experience to allow users to provide
their email addresses or phone number.
The authentication system that you use must provide an email address or
phone number associated with the user.The following steps outline the process
for securely collecting sign-in information usingFirebase Authentication, but you
can skip this step if you already have an authentication system that collects
user emails or phone numbers and continue toStep 2: Integrate Google Analytics.
Make sure you have the prerequisites for this tutorial
Your own app that can run on iOS 12 or higher
Your app registered as a Firebase App that's linked to Google Analytics
and Ads
Your preferred IDE
Set up an authentication system
Use aFirebase Authenticationsign-in method
You can useFirebase Authenticationto allow users to sign in to your app using one or
more sign-in methods, including email address, phone number, password sign-in,
and federated identity providers (like Google, Facebook or Twitter).
Please reviewGet started withFirebase Authentication.
IntegrateFirebase Authenticationwith a custom authentication system
Alternatively, you can integrateFirebase Authenticationwith a custom
authentication system by modifying your authentication server to produce custom
signed tokens when a user successfully signs in. Your app receives this token
and uses it to authenticate with Firebase. Please reviewGet started with a custom
authentication system.
Get the authenticated user's email address or phone number
After you've set up an authentication system withFirebase Authentication, you can
get the currently signed-in user.
The recommended way to get the current user is by setting a listener on theAuthobject:
Swift
handle=Auth.auth().addStateDidChangeListener{auth,userin// Get the user's email addressletemail=user.email// or get their phone numberletphoneNumber=user.phoneNumber// ...}
Objective-C
self.handle=[[FIRAuthauth]addAuthStateDidChangeListener:^(FIRAuth*_Nonnullauth,FIRUser*_Nullableuser){// Get the user's email addressNSString*email=user.email;// or get their phone numberNSString*phoneNumber=user.phoneNumber;// ...}];
Unity
Firebase.Auth.FirebaseAuthauth;Firebase.Auth.FirebaseUseruser;// Handle initialization of the necessary firebase modules:voidInitializeFirebase(){auth=Firebase.Auth.FirebaseAuth.DefaultInstance;auth.StateChanged+=AuthStateChanged;AuthStateChanged(this,null);}// Track state changes of the auth object.voidAuthStateChanged(objectsender,System.EventArgseventArgs){if(auth.CurrentUser!=user){boolsignedIn=user!=auth.CurrentUser&&auth.CurrentUser!=null;user=auth.CurrentUser;if(signedIn){// Get the user's email addressstringemail=user.Email;// or get their phone numberstringphoneNumber=user.PhoneNumber;// ...}}}// Handle removing subscription and reference to the Auth instance.// Automatically called by a Monobehaviour after Destroy is called on it.voidOnDestroy(){auth.StateChanged-=AuthStateChanged;auth=null;}
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-05 UTC."],[],[],null,["Step 1: Implement a sign-in experience\n\n\u003cbr /\u003e\n\n|----------------------------------------------------------------------------------------------------------------------------------|\n| Introduction: [Measure iOS Ads conversions](/docs/tutorials/ads-ios-on-device-measurement/index-first-party) |\n| **Step 1: Implement a sign-in experience** \u003cbr /\u003e |\n| Step 2: [Integrate Google Analytics](/docs/tutorials/ads-ios-on-device-measurement/step-2) |\n| Step 3: [Initiate on-device conversion measurement using Google Analytics](/docs/tutorials/ads-ios-on-device-measurement/step-3) |\n| Step 4: [Troubleshoot and handle common issues](/docs/tutorials/ads-ios-on-device-measurement/step-4) |\n\n\u003cbr /\u003e\n\nThe first step is to implement a sign-in experience to allow users to provide\ntheir email addresses or phone number.\n\n**The authentication system that you use must provide an email address or\nphone number associated with the user.** The following steps outline the process\nfor securely collecting sign-in information using Firebase Authentication, but you\ncan skip this step if you already have an authentication system that collects\nuser emails or phone numbers and continue to [Step 2: Integrate Google Analytics](/docs/tutorials/ads-ios-on-device-measurement/step-2).\n\n\u003cbr /\u003e\n\n**Make sure you have the prerequisites for this tutorial**\n\n\u003cbr /\u003e\n\n- Your own app that can run on iOS 12 or higher\n\n- Your app registered as a Firebase App that's linked to Google Analytics\n and Ads\n\n- Your preferred IDE\n\n \u003cbr /\u003e\n\n\u003cbr /\u003e\n\nSet up an authentication system\n\nUse a Firebase Authentication sign-in method\n\nYou can use Firebase Authentication to allow users to sign in to your app using one or\nmore sign-in methods, including email address, phone number, password sign-in,\nand federated identity providers (like Google, Facebook or Twitter).\nPlease review [Get started with Firebase Authentication](/docs/auth/ios/start).\n\nIntegrate Firebase Authentication with a custom authentication system\n\nAlternatively, you can integrate Firebase Authentication with a custom\nauthentication system by modifying your authentication server to produce custom\nsigned tokens when a user successfully signs in. Your app receives this token\nand uses it to authenticate with Firebase. Please review [Get started with a custom\nauthentication system](/docs/auth/ios/custom-auth).\n\nGet the authenticated user's email address or phone number\n\nAfter you've set up an authentication system with Firebase Authentication, you can\nget the currently signed-in user.\n\nThe recommended way to get the current user is by setting a listener on the\n`Auth` object: \n\nSwift \n\n```swift\nhandle = Auth.auth().addStateDidChangeListener { auth, user in\n // Get the user's email address\n let email = user.email\n // or get their phone number\n let phoneNumber = user.phoneNumber\n // ...\n}\n```\n\nObjective-C \n\n```objective-c\nself.handle = [[FIRAuth auth]\n addAuthStateDidChangeListener:^(FIRAuth *_Nonnull auth, FIRUser *_Nullable user) {\n // Get the user's email address\n NSString *email = user.email;\n // or get their phone number\n NSString *phoneNumber = user.phoneNumber;\n // ...\n }];\n```\n\nUnity \n\n```c#\nFirebase.Auth.FirebaseAuth auth;\nFirebase.Auth.FirebaseUser user;\n\n// Handle initialization of the necessary firebase modules:\nvoid InitializeFirebase() {\n auth = Firebase.Auth.FirebaseAuth.DefaultInstance;\n auth.StateChanged += AuthStateChanged;\n AuthStateChanged(this, null);\n}\n\n// Track state changes of the auth object.\nvoid AuthStateChanged(object sender, System.EventArgs eventArgs) {\n if (auth.CurrentUser != user) {\n bool signedIn = user != auth.CurrentUser && auth.CurrentUser != null;\n user = auth.CurrentUser;\n if (signedIn) {\n // Get the user's email address\n string email = user.Email;\n // or get their phone number\n string phoneNumber = user.PhoneNumber;\n // ...\n }\n }\n}\n\n// Handle removing subscription and reference to the Auth instance.\n// Automatically called by a Monobehaviour after Destroy is called on it.\nvoid OnDestroy() {\n auth.StateChanged -= AuthStateChanged;\n auth = null;\n}\n```\n| **Note:** Find more code examples demonstrating Firebase Authentication in the [Firebase quickstarts](https://github.com/firebase/quickstart-ios).\n\n\u003cbr /\u003e\n\n*** ** * ** ***\n\n\u003cbr /\u003e\n\n[arrow_back_ios**Introduction**](/docs/tutorials/ads-ios-on-device-measurement/index-first-party)\n[**Step 2** : Integrate Google Analyticsarrow_forward_ios](/docs/tutorials/ads-ios-on-device-measurement/step-2)\n\n\u003cbr /\u003e\n\n*** ** * ** ***"]]
