Add support for the new FCM registration ID.

FirebaseMessaging/Apps/Shared/AppDelegate.swift

@@ -39,12 +39,21 @@
     return true
   }
 
+  func application(_ application: UIApplication,
+                   didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
+    let tokenString = deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
+    print("APNs Device Token: \(tokenString)")
+    if Messaging.messaging().isInstallationIdEnabled {
+      Messaging.messaging().register()
+    }
+  }
+
   // Implement this to display notification when app is in foreground.
   func userNotificationCenter(_ center: UNUserNotificationCenter,
                               willPresent notification: UNNotification,
                               withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions)
                                 -> Void) {
     completionHandler([.alert, .sound])
   }
 
   func userNotificationCenter(_ center: UNUserNotificationCenter,

FirebaseMessaging/Apps/Shared/ContentView.swift

@@ -148,24 +148,34 @@ struct ContentView: View {
   }
 
   func getFCMToken() {
-    Messaging.messaging().token { token, error in
-      guard let token = token, error == nil else {
-        self.log = "Failed getting iid and token: \(String(describing: error))"
-        return
+    if Messaging.messaging().isInstallationIdEnabled {
+      Messaging.messaging().register()
+      log = "Called register()"
+    } else {
+      Messaging.messaging().token { token, error in
+        guard let token = token, error == nil else {
+          self.log = "Failed getting iid and token: \(String(describing: error))"
+          return
+        }
+        self.identity.token = token
+        self.log = "Successfully got token."
+        print("Token: ", self.identity.token ?? "")
       }
-      self.identity.token = token
-      self.log = "Successfully got token."
-      print("Token: ", self.identity.token ?? "")
     }
   }
 
   func deleteFCMToken() {
-    Messaging.messaging().deleteToken { error in
-      if let error = error as NSError? {
-        self.log = "Failed deleting token: \(error)"
-        return
+    if Messaging.messaging().isInstallationIdEnabled {
+      Messaging.messaging().unregister()
+      log = "Called unregister()"
+    } else {
+      Messaging.messaging().deleteToken { error in
+        if let error = error as NSError? {
+          self.log = "Failed deleting token: \(error)"
+          return
+        }
+        self.log = "Successfully deleted token."
       }
-      self.log = "Successfully deleted token."
     }
   }
 
@@ -210,6 +220,7 @@ struct ActivityViewController: UIViewControllerRepresentable {
 }
 
 struct SettingsView: View {
+  @EnvironmentObject var identity: Identity
   @EnvironmentObject var settings: UserSettings
   @State var shouldUseDelegate = true
   @State private var isSharePresented: Bool = false
@@ -235,7 +246,7 @@ struct SettingsView: View {
         .sheet(isPresented: $isSharePresented, onDismiss: {
           print("Dismiss")
         }, content: {
-          let items = [Messaging.messaging().fcmToken]
+          let items = [identity.token ?? "None"]
           ActivityViewController(activityItems: items as [Any])
         })
       }

FirebaseMessaging/Apps/Shared/SceneDelegate.swift

@@ -76,4 +76,11 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate, MessagingDelegate {
     print("Did refresh token:\n", identity.token ?? "")
     print("\n=============================\n")
   }
+
+  func messaging(_ messaging: Messaging, didReceiveRegistration installationId: String?) {
+    identity.token = installationId
+    print("=============================")
+    print("Did refresh FCM installation ID: \(String(describing: installationId))")
+    print("=============================")
+  }
 }

FirebaseMessaging/CHANGELOG.md

@@ -1,3 +1,6 @@
+# Unreleased
+- [added] Add support for the new FCM registration ID.
+
 # 12.8.0
 - [fixed] Fix missing database crash on launch. (#14880)
 

FirebaseMessaging/Sources/FIRMessaging.m

@@ -57,6 +57,9 @@
 NSString *const kFIRMessagingPlistAutoInitEnabled =
     @"FirebaseMessagingAutoInitEnabled";  // Auto Init Enabled key stored in Info.plist
 
+NSString *const kFIRMessagingPlistInstallationIdEnabled =
+    @"FirebaseMessagingInstallationIdEnabled";  // Installation ID Enabled key stored in Info.plist
+
 NSString *const FIRMessagingErrorDomain = @"com.google.fcm";
 
 BOOL FIRMessagingIsAPNSSyncMessage(NSDictionary *message) {
@@ -232,7 +235,7 @@
       // happens before developers able to set the delegate
       // Hence first token set must be happen here after listener is set
       // TODO(chliangGoogle) Need to investigate better solution.
-      [self updateDefaultFCMToken:self.FCMToken];
+      [self updateDefaultFCMToken:[self.tokenManager tokenAndRequestIfNotExist]];
     }];
   } else if (self.isAutoInitEnabled && self.APNSToken) {
     // When there is no cached token, must check auto init is enabled.
@@ -493,7 +496,19 @@
   }
 }
 
+- (BOOL)isInstallationIdEnabled {
+  id isInstallationIdEnabledObject =
+      [[NSBundle mainBundle] objectForInfoDictionaryKey:kFIRMessagingPlistInstallationIdEnabled];
+  return [isInstallationIdEnabledObject boolValue];
+}
+
 - (NSString *)FCMToken {
+  if (self.isInstallationIdEnabled) {
+    FIRMessagingLoggerDebug(
+        kFIRMessagingMessageCodeInstallationIdEnabled,
+        @"FirebaseMessagingInstallationIdEnabled is set to YES, token is not available.");
+    return nil;
+  }
   // Gets the current default token, and requests a new one if it doesn't exist.
   NSString *token = [self.tokenManager tokenAndRequestIfNotExist];
   return token;
@@ -617,14 +632,27 @@
 // NOTE: Once |didReceiveRegistrationToken:| can be made a required method, this
 // check can be removed.
 - (void)validateDelegateConformsToTokenAvailabilityMethods {
-  if (self.delegate &&
-      ![self.delegate respondsToSelector:@selector(messaging:didReceiveRegistrationToken:)]) {
-    FIRMessagingLoggerWarn(kFIRMessagingMessageCodeTokenDelegateMethodsNotImplemented,
-                           @"The object %@ does not respond to "
-                           @"-messaging:didReceiveRegistrationToken:. Please implement "
-                           @"-messaging:didReceiveRegistrationToken: to be provided with an FCM "
-                           @"token.",
-                           self.delegate.description);
+  if (self.delegate) {
+    if ([self isInstallationIdEnabled]) {
+      if (![self.delegate respondsToSelector:@selector(messaging:didReceiveRegistration:)]) {
+        FIRMessagingLoggerWarn(
+            kFIRMessagingMessageCodeTokenDelegateMethodsNotImplemented,
+            @"The object %@ does not respond to "
+            @"-messaging:didReceiveRegistration:. Please implement "
+            @"-messaging:didReceiveRegistration: to be provided with an installation ID.",
+            self.delegate.description);
+      }
+    } else {
+      if (![self.delegate respondsToSelector:@selector(messaging:didReceiveRegistrationToken:)]) {
+        FIRMessagingLoggerWarn(
+            kFIRMessagingMessageCodeTokenDelegateMethodsNotImplemented,
+            @"The object %@ does not respond to "
+            @"-messaging:didReceiveRegistrationToken:. Please implement "
+            @"-messaging:didReceiveRegistrationToken: to be provided with an FCM "
+            @"token.",
+            self.delegate.description);
+      }
+    }
   }
 }
 
@@ -636,8 +664,14 @@
     });
     return;
   }
-  if ([self.delegate respondsToSelector:@selector(messaging:didReceiveRegistrationToken:)]) {
-    [self.delegate messaging:self didReceiveRegistrationToken:self.tokenManager.defaultFCMToken];
+  if ([self isInstallationIdEnabled]) {
+    if ([self.delegate respondsToSelector:@selector(messaging:didReceiveRegistration:)]) {
+      [self.delegate messaging:self didReceiveRegistration:self.tokenManager.defaultFCMToken];
+    }
+  } else {
+    if ([self.delegate respondsToSelector:@selector(messaging:didReceiveRegistrationToken:)]) {
+      [self.delegate messaging:self didReceiveRegistrationToken:self.tokenManager.defaultFCMToken];
+    }
   }
 
   // Should always trigger the token refresh notification when the delegate method is called
@@ -646,6 +680,57 @@
                         object:self.tokenManager.defaultFCMToken];
 }
 
+#pragma mark - FID
+
+- (void)register {
+  if (!self.isInstallationIdEnabled) {
+    FIRMessagingLoggerError(kFIRMessagingMessageCodeInstallationIdDisabled,
+                            @"FirebaseMessagingInstallationIdEnabled is not set to YES, so "
+                            @"FID operations are not supported.");
+    return;
+  }
+  if (!FIRApp.defaultApp.options.GCMSenderID.length) {
+    FIRMessagingLoggerError(kFIRMessagingMessageCodeSenderIDNotSuppliedForTokenFetch,
+                            @"No Sender ID is available to register");
+    return;
+  }
+  [self.tokenManager tokenAndRequestIfNotExist];
+}
+
+- (void)unregister {
+  if (!self.isInstallationIdEnabled) {
+    FIRMessagingLoggerError(kFIRMessagingMessageCodeInstallationIdDisabled,
+                            @"FirebaseMessagingInstallationIdEnabled is not set to YES, so "
+                            @"FID operations are not supported.");
+    return;
+  }
+  NSString *senderID = FIRApp.defaultApp.options.GCMSenderID;
+  if (!senderID.length) {
+    FIRMessagingLoggerError(kFIRMessagingMessageCodeSenderIDNotSuppliedForTokenDelete,
+                            @"No Sender ID is available to unregister");
+    return;
+  }
+
+  FIRMessaging_WEAKIFY(self);
+  [self.installations installationIDWithCompletion:^(NSString *_Nullable identifier,
+                                                     NSError *_Nullable error) {
+    FIRMessaging_STRONGIFY(self);
+    if (error) {
+      FIRMessagingLoggerError(kFIRMessagingErrorCodeInvalidIdentity,
+                              @"Failed to get installation ID.");
+    } else {
+      [self.tokenManager deleteTokenWithAuthorizedEntity:senderID
+                                                   scope:kFIRMessagingDefaultTokenScope
+                                              instanceID:identifier
+                                                 handler:^(NSError *_Nullable error) {
+                                                   if (!error && [self isAutoInitEnabled]) {
+                                                     [self.tokenManager tokenAndRequestIfNotExist];
+                                                   }
+                                                 }];
+    }
+  }];
+}
+
 #pragma mark - Topics
 
 + (NSString *)normalizeTopic:(NSString *)topic {
@@ -814,8 +899,14 @@
     });
     return;
   }
-  if ([self.delegate respondsToSelector:@selector(messaging:didReceiveRegistrationToken:)]) {
-    [self.delegate messaging:self didReceiveRegistrationToken:self.tokenManager.defaultFCMToken];
+  if ([self isInstallationIdEnabled]) {
+    if ([self.delegate respondsToSelector:@selector(messaging:didReceiveRegistration:)]) {
+      [self.delegate messaging:self didReceiveRegistration:self.tokenManager.defaultFCMToken];
+    }
+  } else {
+    if ([self.delegate respondsToSelector:@selector(messaging:didReceiveRegistrationToken:)]) {
+      [self.delegate messaging:self didReceiveRegistrationToken:self.tokenManager.defaultFCMToken];
+    }
   }
   // Should always trigger the token refresh notification when the delegate method is called
   NSNotificationCenter *center = [NSNotificationCenter defaultCenter];

FirebaseMessaging/Sources/FIRMessagingCode.h

@@ -48,6 +48,9 @@ typedef NS_ENUM(NSInteger, FIRMessagingMessageCode) {
   kFIRMessagingMessageCodeTopicFormatIsDeprecated = 2024,
   kFIRMessagingMessageCodeDirectChannelConnectionFailed = 2025,
   kFIRMessagingMessageCodeInvalidClient = 2026,  // no longer used
+  kFIRMessagingMessageCodeInstallationIdEnabled = 2027,
+  kFIRMessagingMessageCodeInstallationIdDisabled = 2028,
+  kFIRMessagingMessageCodeDebug = 2029,
 
   // DO NOT USE 4000, 4004 - 4013
   kFIRMessagingMessageCodeClient001 = 4001,  // I-FCM004000

FirebaseMessaging/Sources/FIRMessaging_Private.h

@@ -26,6 +26,7 @@ typedef NS_ENUM(int8_t, FIRMessagingNetworkStatus) {
 };
 
 FOUNDATION_EXPORT NSString *const kFIRMessagingPlistAutoInitEnabled;
+FOUNDATION_EXPORT NSString *const kFIRMessagingPlistInstallationIdEnabled;
 FOUNDATION_EXPORT NSString *const kFIRMessagingUserDefaultsKeyAutoInitEnabled;
 FOUNDATION_EXPORT NSString *const kFIRMessagingUserDefaultsKeyUseMessagingDelegate;
 FOUNDATION_EXPORT NSString *const kFIRMessagingPlistUseMessagingDelegate;

FirebaseMessaging/Sources/Public/FirebaseMessaging/FIRMessaging.h

@@ -155,6 +155,12 @@ NS_SWIFT_NAME(MessagingDelegate)
 - (void)messaging:(FIRMessaging *)messaging
     didReceiveRegistrationToken:(nullable NSString *)fcmToken
     NS_SWIFT_NAME(messaging(_:didReceiveRegistrationToken:));
+
+/// This method is similar to `messaging(_:didReceiveRegistrationToken:)` above, but will be called
+/// instead when `isInstallationIdEnabled` is `YES`.
+- (void)messaging:(FIRMessaging *)messaging
+    didReceiveRegistration:(nullable NSString *)installationId
+    NS_SWIFT_NAME(messaging(_:didReceiveRegistration:));
 @end
 
 /**
@@ -238,6 +244,20 @@ NS_SWIFT_NAME(Messaging)
  */
 @property(nonatomic, assign, getter=isAutoInitEnabled) BOOL autoInitEnabled;
 
+/**
+ * Is Firebase Messaging installation ID enabled? It's the `FirebaseMessagingInstallationIdEnabled`
+ * property in `Info.plist` file. The default value is `NO`.
+ *
+ * When enabled, there are several behavior changes:
+ *
+ *    1. An installation ID, instead of an FCM Registration token, is generated.
+ *    2. All token related operations like `tokenWithCompletion`, `deleteTokenWithCompletion`,
+ *       `retrieveFCMTokenForSenderID`, and `deleteFCMTokenForSenderID` will always fail
+ *       with an error indicating that the operation is not supported.
+ *    3. You should call `register()` and `unregister()` instead.
+ */
+@property(nonatomic, readonly, getter=isInstallationIdEnabled) BOOL installationIdEnabled;
+
 /**
  * The FCM registration token is used to identify this device so that FCM can send notifications to
  * it. It is associated with your APNs token when the APNs token is supplied, so messages sent to
@@ -314,6 +334,25 @@ NS_SWIFT_NAME(Messaging)
                        completion:(void (^)(NSError *_Nullable error))completion
     NS_SWIFT_NAME(deleteFCMToken(forSenderID:completion:));
 
+#pragma mark - FID
+
+/**
+ * Asynchronously registers to the FCM backend.
+ *
+ * Please use the FIRMessaging delegate method
+ * `messaging:didReceiveRegistration:` to receive the registered FID.
+ *
+ * This method works only when `FirebaseMessaging.isInstallationIdEnabled` is set to `YES`.
+ */
+- (void)register;
+
+/**
+ * Asynchronously unregisters from the FCM backend.
+ *
+ * This method works only when `FirebaseMessaging.isInstallationIdEnabled` is set to `YES`.
+ */
+- (void)unregister;
+
 #pragma mark - Topics
 
 /**

FirebaseMessaging/Sources/Token/FIRMessagingFIDRegisterOperation.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "FirebaseMessaging/Sources/Token/FIRMessagingTokenOperation.h"
+
+@class FIRInstallations;
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FIRMessagingFIDRegisterOperation : FIRMessagingTokenOperation
+
+- (instancetype)initWithAuthorizedEntity:(NSString *)authorizedEntity
+                                   scope:(NSString *)scope
+                                 options:(nullable NSDictionary<NSString *, NSString *> *)options
+                              instanceID:(NSString *)instanceID
+                         heartbeatLogger:(id<FIRHeartbeatLoggerProtocol>)heartbeatLogger
+                           installations:(FIRInstallations *)installations;
+
+@end
+
+NS_ASSUME_NONNULL_END