diff --git a/lib/Federation/BackendNotifier.php b/lib/Federation/BackendNotifier.php
index db891f07c92..1ae56366c6f 100644
--- a/lib/Federation/BackendNotifier.php
+++ b/lib/Federation/BackendNotifier.php
@@ -560,4 +560,29 @@ protected function getServerRemoteUrl(): string {
 
 		return $server;
 	}
+
+	public function sendReactionNotification(
+		string $remoteServer,
+		int $localAttendeeId,
+		string $accessToken,
+		string $localToken,
+		array $reactionData
+	): ?bool {
+		$remote = $this->prepareRemoteUrl($remoteServer);
+	
+		$notification = $this->cloudFederationFactory->getCloudFederationNotification();
+		$notification->setMessage(
+			FederationManager::NOTIFICATION_REACTION_ADDED,
+			FederationManager::TALK_ROOM_RESOURCE,
+			(string)$localAttendeeId,
+			[
+				'remoteServerUrl' => $this->getServerRemoteUrl(),
+				'sharedSecret' => $accessToken,
+				'remoteToken' => $localToken,
+				'reactionData' => $reactionData,
+			]
+		);
+	
+		return $this->sendUpdateToRemote($remote, $notification);
+	}
 }
diff --git a/lib/Federation/FederationManager.php b/lib/Federation/FederationManager.php
index 4c3706b9d51..05b2f07f051 100644
--- a/lib/Federation/FederationManager.php
+++ b/lib/Federation/FederationManager.php
@@ -46,6 +46,7 @@ class FederationManager {
 	public const NOTIFICATION_PARTICIPANT_MODIFIED = 'PARTICIPANT_MODIFIED';
 	public const NOTIFICATION_ROOM_MODIFIED = 'ROOM_MODIFIED';
 	public const NOTIFICATION_MESSAGE_POSTED = 'MESSAGE_POSTED';
+	public const NOTIFICATION_REACTION_ADDED = 'talk-reaction-added';
 	public const TOKEN_LENGTH = 64;
 
 	public function __construct(
diff --git a/lib/Federation/Proxy/TalkV1/Notifier/MessageSentListener.php b/lib/Federation/Proxy/TalkV1/Notifier/MessageSentListener.php
index 7f54abb095d..e9eb0a70b27 100644
--- a/lib/Federation/Proxy/TalkV1/Notifier/MessageSentListener.php
+++ b/lib/Federation/Proxy/TalkV1/Notifier/MessageSentListener.php
@@ -37,6 +37,8 @@ public function __construct(
 		protected MessageParser $messageParser,
 		protected IFactory $l10nFactory,
 		protected ChatManager $chatManager,
+		protected IUserManager $userManager,
+		protected IAppConfig $appConfig,
 	) {
 	}
 
@@ -57,6 +59,14 @@ public function handle(Event $event): void {
 		$chatMessage = $this->messageParser->createMessage($event->getRoom(), null, $event->getComment(), $l);
 		$this->messageParser->parseMessage($chatMessage);
 
+		$messageType = $chatMessage->getMessageType();
+
+		// Handle reaction events
+		if ($messageType === ChatManager::VERB_REACTION) {
+			$this->createReactionNotification($event->getRoom(), $event->getComment());
+			return;
+		}
+
 		$systemMessage = $chatMessage->getMessageType() === ChatManager::VERB_SYSTEM ? $chatMessage->getMessageRaw() : '';
 		if ($systemMessage !== 'message_edited'
 			&& $systemMessage !== 'message_deleted'
@@ -124,4 +134,84 @@ public function handle(Event $event): void {
 			}
 		}
 	}
+
+	private function createReactionNotification(Room $chat, IComment $reaction): void {
+		$originalCommentId = $reaction->getObjectId();
+		$originalComment = $this->chatManager->getCommentById($originalCommentId);
+
+		if ($originalComment === null) {
+			return;
+		}
+
+		// Check if the original comment's author should be notified
+		if ($originalComment->getActorType() === Attendee::ACTOR_USERS || $originalComment->getActorType() === Attendee::ACTOR_FEDERATED_USERS) {
+			try {
+				$participant = $this->participantService->getParticipant($chat, $originalComment->getActorId(), false);
+			} catch (ParticipantNotFoundException $e) {
+				return;
+			}
+
+			$notificationLevel = $participant->getAttendee()->getNotificationLevel();
+			if ($notificationLevel === Participant::NOTIFY_DEFAULT) {
+				if ($chat->getType() === Room::TYPE_ONE_TO_ONE) {
+					$notificationLevel = Participant::NOTIFY_ALWAYS;
+				} else {
+					$notificationLevel = $this->getDefaultGroupNotification();
+				}
+			}
+
+			if ($notificationLevel === Participant::NOTIFY_ALWAYS) {
+				$this->sendReactionNotification(
+					$participant,
+					$chat,
+					$reaction,
+					$originalComment
+				);
+			}
+		}
+	}
+
+	private function sendReactionNotification(
+		Participant $participant,
+		Room $room,
+		IComment $reaction,
+		IComment $originalComment
+	): void {
+		$attendee = $participant->getAttendee();
+		$cloudId = $this->cloudIdManager->resolveCloudId($attendee->getActorId());
+
+		$notificationData = [
+			'remoteMessageId' => (int)$originalComment->getId(),
+			'reaction' => $reaction->getMessage(),
+			'reactorType' => $reaction->getActorType(),
+			'reactorId' => $reaction->getActorId(),
+			'reactorDisplayName' => $this->getDisplayName($reaction->getActorType(), $reaction->getActorId()),
+			'creationDatetime' => $reaction->getCreationDateTime()->format(\DateTime::ATOM),
+		];
+
+		// Send the notification using BackendNotifier
+		$success = $this->backendNotifier->sendReactionNotification(
+			$cloudId->getRemote(),
+			$attendee->getId(),
+			$attendee->getAccessToken(),
+			$room->getToken(),
+			$notificationData
+		);
+
+		if ($success === null) {
+			$this->participantService->removeAttendee($room, $participant, AAttendeeRemovedEvent::REASON_LEFT);
+		}
+	}
+
+	private function getDisplayName(string $actorType, string $actorId): string {
+		if ($actorType === Attendee::ACTOR_USERS) {
+			$user = $this->userManager->get($actorId);
+			return $user ? $user->getDisplayName() : $actorId;
+		} elseif ($actorType === Attendee::ACTOR_FEDERATED_USERS) {
+			$cloudId = $this->cloudIdManager->resolveCloudId($actorId);
+			return $cloudId->getDisplayName() ?? $actorId;
+		}
+		return $actorId;
+	}
+
 }
diff --git a/tests/integration/features/federation/chat.feature b/tests/integration/features/federation/chat.feature
index 5550308477d..e959cc3182d 100644
--- a/tests/integration/features/federation/chat.feature
+++ b/tests/integration/features/federation/chat.feature
@@ -509,3 +509,44 @@ Feature: federation/chat
       | actorType       | actorId                    | actorDisplayName         | reaction |
       | users           | participant1               | participant1-displayname | 🚀       |
       | federated_users | participant2@{$REMOTE_URL} | participant2-displayname | 🚀       |
+
+  # Scenario: Verifying Notifications for Local Participants
+
+  #   Given the following "spreed" app config is set
+  #     | federation_enabled | yes |
+  #   And user "participant1" creates room "room" (v4)
+  #     | roomType | 2 |
+  #     | roomName | room |
+  #   And user "participant1" adds federated_user "participant3" to room "room" with 200 (v4)
+  #   And user "participant1" adds user "participant2" to room "room" with 200 (v4)
+  #   And user "participant3" has the following invitations (v1)
+  #     | remoteServerUrl | remoteToken | state | inviterCloudId                     | inviterDisplayName       |
+  #     | LOCAL           | room        | 0     | participant1@http://localhost:8080 | participant1-displayname |
+  #   And user "participant3" accepts invite to room "room" of server "LOCAL" with 200 (v1)
+  #     | id          | name | type | remoteServer | remoteToken |
+  #     | LOCAL::room | room | 2   | LOCAL        | room        |
+
+  #   # Enable Notifications for Local User
+  #   And user "participant2" sets notifications to all for room "room" (v4)
+
+  #   #fed user
+  #   #And user "participant3" sets notifications to all for room "room" (v4)
+  #   And user "participant3" sets notifications to all for room "LOCAL::room" (v4)
+
+  #   # Sending a Message
+  #   When user "participant1" sends message "Message 1" to room "room" with 201
+
+  #   And user "participant1" react with "🚀" on message "Message 1" to room "room" with 201
+  #     | actorType       | actorId                  | actorDisplayName         | reaction |
+  #     | users           | participant1             | participant1-displayname | 🚀       |
+
+  #   # Verification for Message Notification
+  #   Then user "participant2" has the following notifications
+  #     | app    | object_type | object_id             | subject                                                             | message   |
+  #     | spreed | chat        | room/Message 1        | participant1-displayname sent a message in conversation room        | Message 1 |
+  #     | spreed | room        | room                  | participant1-displayname invited you to a group conversation: room  |           |
+
+  #   Then user "participant3" has the following notifications
+  #     | app    | object_type | object_id             | subject                                                             | message   |
+  #     | spreed | chat        | LOCAL::room/Message 1        | participant1-displayname sent a message in conversation room        | Message 1 |
+  #     #| spreed | room        | LOCAL::room                  | participant1-displayname invited you to a group conversation: room  |           |
\ No newline at end of file