[Firebase Crashlytics](https://firebase.google.com/docs/crashlytics/ios/get-started) is a lightweight, realtime crash reporter that makes it easy for you to manage stability issues in your app. Crashlytics saves you troubleshooting time by intelligently grouping crashes and highlighting the circumstances that lead up to them. This guide describes how to integrate Crashlytics into your Xcode project so that you can log ad response IDs. Later, when you troubleshoot crashes in your app, you can look up the ad response ID and use the Ad Review Center in [Ad Manager](https://support.google.com/admanager/answer/173120) to find and block the ads. ## **Step 1:** Add Firebase to an iOS application 1. If you would like to try logging with Firebase from a clean app, you can download or clone Google Mobile Ads SDK examples for iOS [repository](https://github.com/googleads/googleads-mobile-ios-examples) on GitHub. This guide specifically uses the [Banner Example](https://github.com/googleads/googleads-mobile-ios-examples/tree/main/Swift/admanager/AdManagerBannerExample). If you already have an app, you should be able to proceed to other steps with your app's bundle ID. The same steps can also be applied to other examples in the repository with minor adaptations. 2. In order to use Firebase Crashlytics, you must create a Firebase project and add your app to it. If you haven't already, create a Firebase project. Make sure to [register your app](https://firebase.google.com/docs/ios/setup#register-app) to it. 1. In the Crashlytics page of the Firebase console, click **Set up Crashlytics**. 2. In the screen that appears, click **No \> Set up a new Firebase app**.  3. In the Podfile, add the Pods for Google Analytics and Firebase Crashlytics. ``` source 'https://github.com/CocoaPods/Specs.git' platform :ios, '8.0' target 'AdManagerBannerExample' do use_frameworks! pod 'Google-Mobile-Ads-SDK' pod 'Firebase/Crashlytics' pod 'Firebase/Analytics' end ``` 4. In Terminal or a command prompt, install and update your Pods: ``` pod install --repo-update ``` 5. Open the `AdManagerBannerExample.xcworkspace` file for Xcode to load the project. ## **Step 2:** Configure Firebase for your app ### Swift In your `AppDelegate.swift`, add the following lines: ```swift import UIKit // Import the Firebase library import FirebaseCore @UIApplicationMain class AppDelegate: UIResponder, UIApplicationDelegate { var window: UIWindow? func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool { // Configure an instance of Firebase FirebaseApp.configure() return true } } ``` ### Objective-C In your `AppDelegate.m`, add the following lines: ```objective-c @import AppDelegate.h; // Import the Firebase library @import FirebaseCore; @interface AppDelegate () @end @implementation AppDelegate ‐ (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { // Override point for customization after application launch. // Initialize Firebase [FIRApp configure]; return YES; } ``` In Xcode, open **Build Settings** , click the **Build Phases** tab. Add the Fabric run script:  Clean your build folder; then, build and run your app. Now you can login to Firebase [web console](https://Googleconsole.firebase.google.com) and access the Crashlytics dashboard. ### **(Optional): Test your Setup** By [Adding a crash button](https://firebase.google.com/docs/crashlytics/ios/test-implementation) you can force a crash for causing an app crash with each button press. This test setup will trigger the code in Step 3 to send custom logs to Firebase Crashlytic dashboards. ### Swift In your `ViewController.swift` add the following lines to the `viewDidLoad()` function: ```swift override func viewDidLoad() { super.viewDidLoad() bannerView.delegate = self bannerView.adUnitID = "ca-app-pub-3940256099942544/2934735716" bannerView.rootViewController = self bannerView.load(AdManagerRequest()) let button = UIButton(type: .roundedRect) button.frame = CGRect(x: 20, y: 50, width: 100, height: 30) button.setTitle("Crash", for: []) button.addTarget(self, action: #selector(self.crashButtonTapped(_:)), for: .touchUpInside) view.addSubview(button) } ``` Then, add this `@IBAction` to the bottom of your class declaration: ```swift @IBAction func crashButtonTapped(_ sender: AnyObject) { fatalError("Test Crash Happened") } ``` ### Objective-C In your `ViewController.m` add the following lines to the `viewDidLoad` method: ```objective-c ‐ (void)viewDidLoad { [super viewDidLoad]; /// ... UIButton* button = [UIButton buttonWithType:UIButtonTypeRoundedRect]; button.frame = CGRectMake(20, 50, 100, 30); [button setTitle:@"Crash" forState:UIControlStateNormal]; [button addTarget:self action:@selector(crashButtonTapped:) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:button]; } ``` Then, add this `IBAction` to the bottom of your class declaration: ```objective-c ‐ (IBAction)crashButtonTapped:(id)sender { assert(NO); } ``` In the Xcode toolbar, press the **Stop** button, and then relaunch the app through a simulator. After the app is loaded, you can click the **Crash** button. Come back to Xcode and click the **Play** button for the crash log to be uploaded to Crashlytics. > [!IMPORTANT] > **Key Point:** While the crash and session data might be visible instantly in the Firebase console, custom keys may take an hour or more to propagate. ## **Step 3:** Log the ad response ID If you load multiple ads and show them at different times, it is a good idea to log each ad response ID with a separate key. For instance, this guide uses an example that has only one banner ad. Hence, we log the ad response ID as the `banner_ad_response_id` key in the following snippet. You can also create multiple custom key / value pairs in Firebase Crashlytics for different ad types and ad events. Refer to the ad request lifecycle notifications for - [Banners](https://developers.google.com/ad-manager/mobile-ads-sdk/ios/api/reference/Protocols/GADBannerViewDelegate.md.txt#ad-request-lifecycle-notifications) - [Interstitials](https://developers.google.com/ad-manager/mobile-ads-sdk/ios/api/reference/Protocols/GADInterstitialDelegate#ad-request-lifecycle-notifications) - [Unified native](https://developers.google.com/ad-manager/mobile-ads-sdk/ios/api/reference/Protocols/GADUnifiedNativeAdDelegate#ad-lifecycle-events) - [Rewarded](https://developers.google.com/ad-manager/mobile-ads-sdk/ios/api/reference/Protocols/GADRewardedAdDelegate) - [Rewarded video](https://developers.google.com/ad-manager/mobile-ads-sdk/ios/api/reference/Protocols/GADRewardBasedVideoAdDelegate) Visit [Customize your Firebase Crashlytics crash reports](https://firebase.google.com/docs/crashlytics/ios/customize-crash-reports) for more information on custom logging. ### Swift Add the following code to your `ViewController.swift`. Essentially, it uses the [`Crashlytics.setCustomValue()`](https://firebase.google.com/docs/reference/swift/firebasecrashlytics/api/reference/Classes/Crashlytics#setcustomvalue_:forkey:) function in the `adViewDidReceiveAd` callback function. ```swift import GoogleMobileAds import UIKit class ViewController: UIViewController, BannerViewDelegate { /// The banner view. @IBOutlet weak var bannerView: AdManagerBannerView! override func viewDidLoad() { super.viewDidLoad() ... bannerView.delegate = self ... } /// Tells the delegate an ad request loaded an ad. func adViewDidReceiveAd(_ bannerView: AdManagerBannerView) { if let responseInfo = bannerView.responseInfo, responseId = responseInfo.responseId { print("adViewDidReceiveAd from network: \(responseInfo.adNetworkClassName), response Id='\(responseId)'") Crashlytics.sharedInstance().setCustomValue(responseId, forKey: "banner_ad_response_id") } } } ``` ### Objective-C Add the following code to your `ViewController.m`. Essentially, it uses the `[FIRCrashlytics crashlytics]` [`setCustomValue`](https://firebase.google.com/docs/reference/ios/firebasecrashlytics/api/reference/Classes/FIRCrashlytics#-setcustomvalueforkey) function in the `adViewDidReceiveAd` function. ```objective-c @import GoogleMobileAds; @interface ViewController () @property(nonatomic, strong) GADBannerView *bannerView; @end @implementation ViewController ‐ (void)viewDidLoad { [super viewDidLoad]; // In this case, we instantiate the banner with desired ad size. self.bannerView = [[GADBannerView alloc] initWithAdSize:GADAdSizeBanner]; [self addBannerViewToView:self.bannerView]; } ‐ (void)addBannerViewToView:(UIView *)bannerView { bannerView.translatesAutoresizingMaskIntoConstraints = NO; [self.view addSubview:bannerView]; [self.view addConstraints:@[ [NSLayoutConstraint constraintWithItem:bannerView attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self.bottomLayoutGuide attribute:NSLayoutAttributeTop multiplier:1 constant:0], [NSLayoutConstraint constraintWithItem:bannerView attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view kattribute:NSLayoutAttributeCenterX multiplier:1 constant:0] ]]; } - (void)adViewDidReceiveAd:(GADBannerView *)bannerView { NSString *adResponseId = bannerView.responseInfo.responseId; if (adResponseId) { NSLog(@"adViewDidReceiveAd from network: %@ with response Id: %@", bannerView.responseInfo.adNetworkClassName, adResponseId); [[FIRCrashlytics crashlytics] setCustomValue:adResponseId forKey:@"banner_ad_response_id"]; } } @end ``` Congratulations! You will now see the most recent `adResponseId` in the key section of crash sessions on your Crashlytics dashboard. Note that some keys may take up to an hour to become visible in your dashboard.