diff --git a/chromeos/services/libassistant/grpc/assistant_client.h b/chromeos/services/libassistant/grpc/assistant_client.h
index 3abc1d62e55d87..7b8cd88ea0bd4b 100644
--- a/chromeos/services/libassistant/grpc/assistant_client.h
+++ b/chromeos/services/libassistant/grpc/assistant_client.h
@@ -24,6 +24,7 @@ class OnAssistantDisplayEventRequest;
 class OnConversationStateEventRequest;
 class OnDeviceStateEventRequest;
 class OnDisplayRequestRequest;
+class OnMediaActionFallbackEventRequest;
 class OnSpeakerIdEnrollmentEventRequest;
 class StartSpeakerIdEnrollmentRequest;
 class UpdateAssistantSettingsResponse;
@@ -78,6 +79,8 @@ class AssistantClient {
   // Media:
   using MediaStatus = ::assistant::api::events::DeviceState::MediaStatus;
   using OnDeviceStateEventRequest = ::assistant::api::OnDeviceStateEventRequest;
+  using OnMediaActionFallbackEventRequest =
+      ::assistant::api::OnMediaActionFallbackEventRequest;
 
   // Conversation:
   using OnConversationStateEventRequest =
@@ -137,9 +140,10 @@ class AssistantClient {
   // Sets the current media status of media playing outside of libassistant.
   // Setting external state will stop any internally playing media.
   virtual void SetExternalPlaybackState(const MediaStatus& status_proto) = 0;
-
   virtual void AddDeviceStateEventObserver(
       GrpcServicesObserver<OnDeviceStateEventRequest>* observer) = 0;
+  virtual void AddMediaActionFallbackEventObserver(
+      GrpcServicesObserver<OnMediaActionFallbackEventRequest>* observer) = 0;
 
   // Conversation methods.
   virtual void SendVoicelessInteraction(
diff --git a/chromeos/services/libassistant/grpc/assistant_client_impl.cc b/chromeos/services/libassistant/grpc/assistant_client_impl.cc
index b3c354458f1870..d8b176df044e19 100644
--- a/chromeos/services/libassistant/grpc/assistant_client_impl.cc
+++ b/chromeos/services/libassistant/grpc/assistant_client_impl.cc
@@ -175,6 +175,11 @@ void AssistantClientImpl::AddDeviceStateEventObserver(
   grpc_services_.AddDeviceStateEventObserver(observer);
 }
 
+void AssistantClientImpl::AddMediaActionFallbackEventObserver(
+    GrpcServicesObserver<OnMediaActionFallbackEventRequest>* observer) {
+  grpc_services_.AddMediaActionFallbackEventObserver(observer);
+}
+
 void AssistantClientImpl::SendVoicelessInteraction(
     const ::assistant::api::Interaction& interaction,
     const std::string& description,
diff --git a/chromeos/services/libassistant/grpc/assistant_client_impl.h b/chromeos/services/libassistant/grpc/assistant_client_impl.h
index de2ebe17667cf9..6e2793f79a1711 100644
--- a/chromeos/services/libassistant/grpc/assistant_client_impl.h
+++ b/chromeos/services/libassistant/grpc/assistant_client_impl.h
@@ -54,6 +54,9 @@ class AssistantClientImpl : public AssistantClientV1 {
       GrpcServicesObserver<OnAssistantDisplayEventRequest>* observer) override;
   void AddDeviceStateEventObserver(
       GrpcServicesObserver<OnDeviceStateEventRequest>* observer) override;
+  void AddMediaActionFallbackEventObserver(
+      GrpcServicesObserver<OnMediaActionFallbackEventRequest>* observer)
+      override;
   void SendVoicelessInteraction(
       const ::assistant::api::Interaction& interaction,
       const std::string& description,
diff --git a/chromeos/services/libassistant/grpc/assistant_client_v1.cc b/chromeos/services/libassistant/grpc/assistant_client_v1.cc
index 533a72c747f80c..a757da88f69e68 100644
--- a/chromeos/services/libassistant/grpc/assistant_client_v1.cc
+++ b/chromeos/services/libassistant/grpc/assistant_client_v1.cc
@@ -29,6 +29,7 @@
 #include "chromeos/assistant/internal/proto/shared/proto/v2/speaker_id_enrollment_interface.pb.h"
 #include "chromeos/services/assistant/public/cpp/features.h"
 #include "chromeos/services/libassistant/callback_utils.h"
+#include "chromeos/services/libassistant/grpc/assistant_client.h"
 #include "chromeos/services/libassistant/grpc/utils/media_status_utils.h"
 #include "chromeos/services/libassistant/grpc/utils/settings_utils.h"
 #include "chromeos/services/libassistant/grpc/utils/timer_utils.h"
@@ -443,6 +444,17 @@ void AssistantClientV1::AddDeviceStateEventObserver(
   device_state_event_observer_list_.AddObserver(observer);
 }
 
+void AssistantClientV1::AddMediaActionFallbackEventObserver(
+    GrpcServicesObserver<OnMediaActionFallbackEventRequest>* observer) {
+  media_action_fallback_event_observer_list_.AddObserver(observer);
+
+  // Register handler for media actions.
+  auto callback = base::BindRepeating(&AssistantClientV1::HandleMediaAction,
+                                      weak_factory_.GetWeakPtr());
+  assistant_manager_internal()->RegisterFallbackMediaHandler(
+      ToStdFunctionRepeating(BindToCurrentSequenceRepeating(callback)));
+}
+
 void AssistantClientV1::SendVoicelessInteraction(
     const ::assistant::api::Interaction& interaction,
     const std::string& description,
@@ -536,6 +548,19 @@ void AssistantClientV1::AddMediaManagerListener() {
       media_manager_listener_.get());
 }
 
+void AssistantClientV1::HandleMediaAction(
+    const std::string& action_name,
+    const std::string& media_action_args_proto) {
+  OnMediaActionFallbackEventRequest request;
+  auto* media_action = request.mutable_event()->mutable_on_media_action_event();
+  media_action->set_action_name(action_name);
+  media_action->set_action_args(media_action_args_proto);
+
+  for (auto& observer : media_action_fallback_event_observer_list_) {
+    observer.OnGrpcMessage(request);
+  }
+}
+
 void AssistantClientV1::NotifyConversationStateEvent(
     const OnConversationStateEventRequest& request) {
   for (auto& observer : conversation_state_event_observer_list_) {
diff --git a/chromeos/services/libassistant/grpc/assistant_client_v1.h b/chromeos/services/libassistant/grpc/assistant_client_v1.h
index 693ea5b9335a63..e736ff1cef4d9f 100644
--- a/chromeos/services/libassistant/grpc/assistant_client_v1.h
+++ b/chromeos/services/libassistant/grpc/assistant_client_v1.h
@@ -57,6 +57,9 @@ class AssistantClientV1 : public AssistantClient {
   void SetExternalPlaybackState(const MediaStatus& status_proto) override;
   void AddDeviceStateEventObserver(
       GrpcServicesObserver<OnDeviceStateEventRequest>* observer) override;
+  void AddMediaActionFallbackEventObserver(
+      GrpcServicesObserver<OnMediaActionFallbackEventRequest>* observer)
+      override;
   void SendVoicelessInteraction(
       const ::assistant::api::Interaction& interaction,
       const std::string& description,
@@ -108,6 +111,8 @@ class AssistantClientV1 : public AssistantClient {
   class AssistantManagerDelegateImpl;
 
   void AddMediaManagerListener();
+  void HandleMediaAction(const std::string& action_name,
+                         const std::string& media_action_args_proto);
 
   void NotifyConversationStateEvent(
       const OnConversationStateEventRequest& request);
@@ -141,6 +146,9 @@ class AssistantClientV1 : public AssistantClient {
   base::ObserverList<GrpcServicesObserver<OnDeviceStateEventRequest>>
       device_state_event_observer_list_;
 
+  base::ObserverList<GrpcServicesObserver<OnMediaActionFallbackEventRequest>>
+      media_action_fallback_event_observer_list_;
+
   base::ObserverList<
       GrpcServicesObserver<::assistant::api::OnAlarmTimerEventRequest>>
       timer_event_observer_list_;
diff --git a/chromeos/services/libassistant/grpc/external_services/event_handler_driver.cc b/chromeos/services/libassistant/grpc/external_services/event_handler_driver.cc
index efabe8d6ba62f8..1b604c0e8ffbc4 100644
--- a/chromeos/services/libassistant/grpc/external_services/event_handler_driver.cc
+++ b/chromeos/services/libassistant/grpc/external_services/event_handler_driver.cc
@@ -16,6 +16,7 @@ constexpr char kAlarmTimerEventName[] = "AlarmTimerEvent";
 constexpr char kAssistantDisplayEventName[] = "AssistantDisplayEvent";
 constexpr char kConversationStateEventName[] = "ConversationStateEvent";
 constexpr char kDeviceStateEventName[] = "DeviceStateEvent";
+constexpr char kMediaActionFallbackEventName[] = "MediaActionFallbackEvent";
 constexpr char kHandlerMethodName[] = "OnEventFromLibas";
 
 template <typename EventSelection>
@@ -75,5 +76,16 @@ CreateRegistrationRequest<::assistant::api::DeviceStateEventHandlerInterface>(
   return request;
 }
 
+template <>
+::assistant::api::RegisterEventHandlerRequest CreateRegistrationRequest<
+    ::assistant::api::MediaActionFallbackEventHandlerInterface>(
+    const std::string& assistant_service_address) {
+  ::assistant::api::RegisterEventHandlerRequest request;
+  PopulateRequest(assistant_service_address, kMediaActionFallbackEventName,
+                  &request,
+                  request.mutable_media_action_fallback_events_to_handle());
+  return request;
+}
+
 }  // namespace libassistant
 }  // namespace chromeos
diff --git a/chromeos/services/libassistant/grpc/external_services/grpc_services_initializer.cc b/chromeos/services/libassistant/grpc/external_services/grpc_services_initializer.cc
index 2ae8909bd9878e..028c4bb320cef3 100644
--- a/chromeos/services/libassistant/grpc/external_services/grpc_services_initializer.cc
+++ b/chromeos/services/libassistant/grpc/external_services/grpc_services_initializer.cc
@@ -98,6 +98,12 @@ void GrpcServicesInitializer::AddDeviceStateEventObserver(
   device_state_event_handler_driver_->AddObserver(observer);
 }
 
+void GrpcServicesInitializer::AddMediaActionFallbackEventObserver(
+    GrpcServicesObserver<::assistant::api::OnMediaActionFallbackEventRequest>*
+        observer) {
+  media_action_fallback_event_handler_driver_->AddObserver(observer);
+}
+
 ActionService* GrpcServicesInitializer::GetActionService() {
   return action_handler_driver_.get();
 }
@@ -140,6 +146,14 @@ void GrpcServicesInitializer::InitDrivers(grpc::ServerBuilder* server_builder) {
       EventHandlerDriver<::assistant::api::DeviceStateEventHandlerInterface>>(
       &server_builder_, libassistant_client_.get(), assistant_service_address_);
   service_drivers_.emplace_back(device_state_event_handler_driver_.get());
+
+  media_action_fallback_event_handler_driver_ =
+      std::make_unique<EventHandlerDriver<
+          ::assistant::api::MediaActionFallbackEventHandlerInterface>>(
+          &server_builder_, libassistant_client_.get(),
+          assistant_service_address_);
+  service_drivers_.emplace_back(
+      media_action_fallback_event_handler_driver_.get());
 }
 
 void GrpcServicesInitializer::InitLibassistGrpcClient() {
@@ -172,6 +186,7 @@ void GrpcServicesInitializer::RegisterEventHandlers() {
   assistant_display_event_handler_driver_->StartRegistration();
   conversation_state_event_handler_driver_->StartRegistration();
   device_state_event_handler_driver_->StartRegistration();
+  media_action_fallback_event_handler_driver_->StartRegistration();
 }
 
 }  // namespace libassistant
diff --git a/chromeos/services/libassistant/grpc/external_services/grpc_services_initializer.h b/chromeos/services/libassistant/grpc/external_services/grpc_services_initializer.h
index 1f8d7f108a8ec6..2a5d2fdf2cb6bb 100644
--- a/chromeos/services/libassistant/grpc/external_services/grpc_services_initializer.h
+++ b/chromeos/services/libassistant/grpc/external_services/grpc_services_initializer.h
@@ -24,6 +24,7 @@ class AlarmTimerEventHandlerInterface;
 class AssistantDisplayEventHandlerInterface;
 class ConversationStateEventHandlerInterface;
 class DeviceStateEventHandlerInterface;
+class MediaActionFallbackEventHandlerInterface;
 }  // namespace api
 }  // namespace assistant
 
@@ -63,6 +64,9 @@ class GrpcServicesInitializer : public ServicesInitializerBase {
   void AddDeviceStateEventObserver(
       GrpcServicesObserver<::assistant::api::OnDeviceStateEventRequest>*
           observer);
+  void AddMediaActionFallbackEventObserver(
+      GrpcServicesObserver<::assistant::api::OnMediaActionFallbackEventRequest>*
+          observer);
 
   ActionService* GetActionService();
 
@@ -133,6 +137,10 @@ class GrpcServicesInitializer : public ServicesInitializerBase {
   std::unique_ptr<
       EventHandlerDriver<::assistant::api::DeviceStateEventHandlerInterface>>
       device_state_event_handler_driver_;
+
+  std::unique_ptr<EventHandlerDriver<
+      ::assistant::api::MediaActionFallbackEventHandlerInterface>>
+      media_action_fallback_event_handler_driver_;
 };
 
 }  // namespace libassistant
diff --git a/chromeos/services/libassistant/media_controller.cc b/chromeos/services/libassistant/media_controller.cc
index 5d00f6c228c2a7..6de0ede3c31ebd 100644
--- a/chromeos/services/libassistant/media_controller.cc
+++ b/chromeos/services/libassistant/media_controller.cc
@@ -97,14 +97,15 @@ std::string GetWebUrlFromMediaArgs(const std::string& play_media_args_proto) {
 
 }  // namespace
 
-class MediaController::DeviceStateEventObserver
-    : public GrpcServicesObserver<::assistant::api::OnDeviceStateEventRequest> {
+class MediaController::GrpcEventsObserver
+    : public GrpcServicesObserver<::assistant::api::OnDeviceStateEventRequest>,
+      public GrpcServicesObserver<
+          ::assistant::api::OnMediaActionFallbackEventRequest> {
  public:
-  explicit DeviceStateEventObserver(MediaController* parent)
-      : parent_(parent) {}
-  DeviceStateEventObserver(const DeviceStateEventObserver&) = delete;
-  DeviceStateEventObserver& operator=(const DeviceStateEventObserver&) = delete;
-  ~DeviceStateEventObserver() override = default;
+  explicit GrpcEventsObserver(MediaController* parent) : parent_(parent) {}
+  GrpcEventsObserver(const GrpcEventsObserver&) = delete;
+  GrpcEventsObserver& operator=(const GrpcEventsObserver&) = delete;
+  ~GrpcEventsObserver() override = default;
 
   // GrpcServicesObserver:
   // Invoked when a device state event has been received.
@@ -123,37 +124,20 @@ class MediaController::DeviceStateEventObserver
         ConvertMediaStatusToMojomFromV2(new_state.media_status()));
   }
 
- private:
-  mojom::MediaDelegate& delegate() { return *parent_->delegate_; }
-
-  MediaController* const parent_;
-};
+  // Invoked when a media action fallack event has been received.
+  void OnGrpcMessage(const ::assistant::api::OnMediaActionFallbackEventRequest&
+                         request) override {
+    if (!request.event().has_on_media_action_event())
+      return;
 
-class MediaController::LibassistantMediaHandler {
- public:
-  LibassistantMediaHandler(
-      MediaController* parent,
-      assistant_client::AssistantManagerInternal* assistant_manager_internal)
-      : parent_(parent),
-        mojom_task_runner_(base::SequencedTaskRunnerHandle::Get()) {
-#if !BUILDFLAG(IS_PREBUILT_LIBASSISTANT)
-    // Register handler for media actions.
-    assistant_manager_internal->RegisterFallbackMediaHandler(
-        [this](std::string action_name, std::string media_action_args_proto) {
-          HandleMediaAction(action_name, media_action_args_proto);
-        });
-#endif  // !BUILDFLAG(IS_PREBUILT_LIBASSISTANT)
+    auto media_action_event = request.event().on_media_action_event();
+    HandleMediaAction(media_action_event.action_name(),
+                      media_action_event.action_args());
   }
-  LibassistantMediaHandler(const LibassistantMediaHandler&) = delete;
-  LibassistantMediaHandler& operator=(const LibassistantMediaHandler&) = delete;
-  ~LibassistantMediaHandler() = default;
 
  private:
-  // Called from the Libassistant thread.
   void HandleMediaAction(const std::string& action_name,
                          const std::string& media_action_args_proto) {
-    ENSURE_MOJOM_THREAD(&LibassistantMediaHandler::HandleMediaAction,
-                        action_name, media_action_args_proto);
     if (action_name == kPlayMediaClientOp)
       OnPlayMedia(media_action_args_proto);
     else
@@ -229,13 +213,10 @@ class MediaController::LibassistantMediaHandler {
   mojom::MediaDelegate& delegate() { return *parent_->delegate_; }
 
   MediaController* const parent_;
-  scoped_refptr<base::SequencedTaskRunner> mojom_task_runner_;
-  base::WeakPtrFactory<LibassistantMediaHandler> weak_factory_{this};
 };
 
 MediaController::MediaController()
-    : device_state_event_observer_(
-          std::make_unique<DeviceStateEventObserver>(this)) {}
+    : events_observer_(std::make_unique<GrpcEventsObserver>(this)) {}
 
 MediaController::~MediaController() = default;
 
@@ -271,24 +252,9 @@ void MediaController::SetExternalPlaybackState(mojom::MediaStatePtr state) {
 void MediaController::OnAssistantClientRunning(
     AssistantClient* assistant_client) {
   assistant_client_ = assistant_client;
-
-  handler_ = std::make_unique<LibassistantMediaHandler>(
-      this, assistant_client->assistant_manager_internal());
-
-  // |device_state_event_observer_| outlives |assistant_client_|.
-  assistant_client->AddDeviceStateEventObserver(
-      device_state_event_observer_.get());
-}
-
-void MediaController::OnDestroyingAssistantClient(
-    AssistantClient* assistant_client) {
-  assistant_client_ = nullptr;
-}
-
-void MediaController::OnAssistantClientDestroyed() {
-  // Handler can only be unset after the |AssistantManagerInternal| has been
-  // destroyed, as |AssistantManagerInternal| will call the handler.
-  handler_ = nullptr;
+  // `events_observer_` outlives `assistant_client_`.
+  assistant_client->AddDeviceStateEventObserver(events_observer_.get());
+  assistant_client->AddMediaActionFallbackEventObserver(events_observer_.get());
 }
 
 }  // namespace libassistant
diff --git a/chromeos/services/libassistant/media_controller.h b/chromeos/services/libassistant/media_controller.h
index 68c23458c48f27..93e414031a45ad 100644
--- a/chromeos/services/libassistant/media_controller.h
+++ b/chromeos/services/libassistant/media_controller.h
@@ -32,19 +32,15 @@ class MediaController : public mojom::MediaController,
 
   // AssistantClientObserver implementation:
   void OnAssistantClientRunning(AssistantClient* assistant_client) override;
-  void OnDestroyingAssistantClient(AssistantClient* assistant_client) override;
-  void OnAssistantClientDestroyed() override;
 
  private:
-  class DeviceStateEventObserver;
-  class LibassistantMediaHandler;
+  class GrpcEventsObserver;
 
   AssistantClient* assistant_client_ = nullptr;
 
   mojo::Receiver<mojom::MediaController> receiver_{this};
   mojo::Remote<mojom::MediaDelegate> delegate_;
-  std::unique_ptr<DeviceStateEventObserver> device_state_event_observer_;
-  std::unique_ptr<LibassistantMediaHandler> handler_;
+  std::unique_ptr<GrpcEventsObserver> events_observer_;
 };
 
 }  // namespace libassistant
diff --git a/chromeos/services/libassistant/test_support/fake_assistant_client.cc b/chromeos/services/libassistant/test_support/fake_assistant_client.cc
index 1ee6c8c12c1bc7..ccf3377f7587b3 100644
--- a/chromeos/services/libassistant/test_support/fake_assistant_client.cc
+++ b/chromeos/services/libassistant/test_support/fake_assistant_client.cc
@@ -88,6 +88,9 @@ void FakeAssistantClient::StopAssistantInteraction(bool cancel_conversation) {}
 void FakeAssistantClient::AddConversationStateEventObserver(
     GrpcServicesObserver<OnConversationStateEventRequest>* observer) {}
 
+void FakeAssistantClient::AddMediaActionFallbackEventObserver(
+    GrpcServicesObserver<OnMediaActionFallbackEventRequest>* observer) {}
+
 void FakeAssistantClient::SetInternalOptions(const std::string& locale,
                                              bool spoken_feedback_enabled) {}
 
diff --git a/chromeos/services/libassistant/test_support/fake_assistant_client.h b/chromeos/services/libassistant/test_support/fake_assistant_client.h
index f7f4126bff243d..9bfc1af7a5df44 100644
--- a/chromeos/services/libassistant/test_support/fake_assistant_client.h
+++ b/chromeos/services/libassistant/test_support/fake_assistant_client.h
@@ -56,6 +56,9 @@ class FakeAssistantClient : public AssistantClient {
   void SetExternalPlaybackState(const MediaStatus& status_proto) override;
   void AddDeviceStateEventObserver(
       GrpcServicesObserver<OnDeviceStateEventRequest>* observer) override;
+  void AddMediaActionFallbackEventObserver(
+      GrpcServicesObserver<OnMediaActionFallbackEventRequest>* observer)
+      override;
   void SendVoicelessInteraction(
       const ::assistant::api::Interaction& interaction,
       const std::string& description,