Get started using App Check with App Attest on Apple platforms

This page shows you how to enable App Check in an Apple app, using the built-in App Attest provider. When you enable App Check, you help ensure that only your app can access your project's Firebase resources. See an Overview of this feature.

App Check uses App Attest to verify that requests to Firebase services are coming from your authentic app. App Check currently does not use App Attest to analyze fraud risk.

If you want to use App Check with your own custom provider, see Implement a custom App Check provider.

1. Set up your Firebase project

1. You will need Xcode 12.5+ to use App Attest.

2. Add Firebase to your Apple project if you haven’t already done so.

3. Register your apps to use App Check with the App Attest provider in the App Check section of the Firebase console.

   You usually need to register all of your project's apps, because once you enable enforcement for a Firebase product, only registered apps will be able to access the product's backend resources.

4. Optional: In the app registration settings, set a custom time-to-live (TTL) for App Check tokens issued by the provider. You can set the TTL to any value between 30 minutes and 7 days. When changing this value, be aware of the following tradeoffs:

   • Security: Shorter TTLs provide stronger security, because it reduces the window in which a leaked or intercepted token can be abused by an attacker.
   • Performance: Shorter TTLs mean your app will perform attestation more frequently. Because the app attestation process adds latency to network requests every time it's performed, a short TTL can impact the performance of your app.
   • Quota and cost: Shorter TTLs and frequent re-attestation deplete your quota faster, and for paid services, potentially cost more. See Quotas & limits.

   The default TTL of 1 hour is reasonable for most apps. Note that the App Check library refreshes tokens at approximately half the TTL duration.

2. Add the App Check library to your app

1. Add the dependency for App Check to your project's Podfile:

   pod 'FirebaseAppCheck'

   Or, alternatively, you can use Swift Package Manager instead.

   Make sure you're also using the latest version of any other Firebase SDKs you depend on.

2. Run pod install and open the created .xcworkspace file.

3. In Xcode, add the App Attest capability to your app.

4. In your project's .entitlements file, set the App Attest environment to production.

3. Initialize App Check

You will need to initialize App Check before you use any other Firebase SDKs.

First, write an implementation of AppCheckProviderFactory. The specifics of your implementation will depend on your use case.

For example, If you only have users on iOS 14 and later, you can simply always create AppAttestProvider objects:

class YourSimpleAppCheckProviderFactory: NSObject, AppCheckProviderFactory {
  func createProvider(with app: FirebaseApp) -> AppCheckProvider? {
    return AppAttestProvider(app: app)
  }
}

@interface YourSimpleAppCheckProviderFactory : NSObject <FIRAppCheckProviderFactory>
@end

@implementation YourSimpleAppCheckProviderFactory

- (nullable id<FIRAppCheckProvider>)createProviderWithApp:(nonnull FIRApp *)app {
  return [[FIRAppAttestProvider alloc] initWithApp:app];
}

@end

Or, you can create AppAttestProvider objects on iOS 14 and later, and fall back to DeviceCheckProvider on earlier versions:

class YourAppCheckProviderFactory: NSObject, AppCheckProviderFactory {
  func createProvider(with app: FirebaseApp) -> AppCheckProvider? {
    if #available(iOS 14.0, *) {
      return AppAttestProvider(app: app)
    } else {
      return DeviceCheckProvider(app: app)
    }
  }
}

@interface YourAppCheckProviderFactory : NSObject <FIRAppCheckProviderFactory>
@end

@implementation YourAppCheckProviderFactory

- (nullable id<FIRAppCheckProvider>)createProviderWithApp:(nonnull FIRApp *)app {
  if (@available(iOS 14.0, *)) {
    return [[FIRAppAttestProvider alloc] initWithApp:app];
  } else {
    return [[FIRDeviceCheckProvider alloc] initWithApp:app];
  }
}

@end

After you have implemented a AppCheckProviderFactory class, configure App Check to use it:

let providerFactory = YourAppCheckProviderFactory()
AppCheck.setAppCheckProviderFactory(providerFactory)

FirebaseApp.configure()

YourAppCheckProviderFactory *providerFactory =
        [[YourAppCheckProviderFactory alloc] init];
[FIRAppCheck setAppCheckProviderFactory:providerFactory];

[FIRApp configure];

Next steps

Once the App Check library is installed in your app, start distributing the updated app to your users.

The updated client app will begin sending App Check tokens along with every request it makes to Firebase, but Firebase products will not require the tokens to be valid until you enable enforcement in the App Check section of the Firebase console.

Monitor metrics and enable enforcement

Before you enable enforcement, however, you should make sure that doing so won't disrupt your existing legitimate users. On the other hand, if you're seeing suspicious use of your app resources, you might want to enable enforcement sooner.

To help make this decision, you can look at App Check metrics for the services you use:

• Monitor App Check request metrics for Realtime Database, Cloud Firestore, Cloud Storage, Authentication (beta), and Vertex AI in Firebase.
• Monitor App Check request metrics for Cloud Functions.

Enable App Check enforcement

When you understand how App Check will affect your users and you're ready to proceed, you can enable App Check enforcement:

• Enable App Check enforcement for Realtime Database, Cloud Firestore, Cloud Storage, Authentication (beta), and Vertex AI in Firebase.
• Enable App Check enforcement for Cloud Functions.

Use App Check in debug environments

If, after you have registered your app for App Check, you want to run your app in an environment that App Check would normally not classify as valid, such as a simulator during development, or from a continuous integration (CI) environment, you can create a debug build of your app that uses the App Check debug provider instead of a real attestation provider.

See Use App Check with the debug provider on Apple platforms.