diff --git a/api/controllers/console/app/audio.py b/api/controllers/console/app/audio.py
index 43b41903f60..b66c97c274c 100644
--- a/api/controllers/console/app/audio.py
+++ b/api/controllers/console/app/audio.py
@@ -30,6 +30,7 @@ from controllers.console.wraps import (
     setup_required,
 )
 from core.errors.error import ModelCurrentlyNotSupportError, ProviderTokenNotInitError, QuotaExceededError
+from extensions.ext_database import db
 from graphon.model_runtime.errors.invoke import InvokeError
 from libs.login import login_required
 from models import App, AppMode
@@ -142,6 +143,7 @@ class ChatMessageTextApi(Resource):
 
             response = AudioService.transcript_tts(
                 app_model=app_model,
+                session=db.session,
                 text=payload.text,
                 voice=payload.voice,
                 message_id=payload.message_id,
diff --git a/api/controllers/console/explore/audio.py b/api/controllers/console/explore/audio.py
index 756dfe84f6c..c2104ccfc61 100644
--- a/api/controllers/console/explore/audio.py
+++ b/api/controllers/console/explore/audio.py
@@ -20,6 +20,7 @@ from controllers.console.app.error import (
 )
 from controllers.console.explore.wraps import InstalledAppResource
 from core.errors.error import ModelCurrentlyNotSupportError, ProviderTokenNotInitError, QuotaExceededError
+from extensions.ext_database import db
 from graphon.model_runtime.errors.invoke import InvokeError
 from models.model import InstalledApp
 from services.audio_service import AudioService
@@ -99,7 +100,13 @@ class ChatTextApi(InstalledAppResource):
             text = payload.text
             voice = payload.voice
 
-            response = AudioService.transcript_tts(app_model=app_model, text=text, voice=voice, message_id=message_id)
+            response = AudioService.transcript_tts(
+                app_model=app_model,
+                session=db.session,
+                text=text,
+                voice=voice,
+                message_id=message_id,
+            )
             return response
         except services.errors.app_model_config.AppModelConfigBrokenError:
             logger.exception("App model config broken.")
diff --git a/api/controllers/console/explore/trial.py b/api/controllers/console/explore/trial.py
index ad98dd303fb..6aef9129780 100644
--- a/api/controllers/console/explore/trial.py
+++ b/api/controllers/console/explore/trial.py
@@ -419,7 +419,13 @@ class TrialChatTextApi(TrialAppResource):
             app_id = app_model.id
             user_id = current_user.id
 
-            response = AudioService.transcript_tts(app_model=app_model, text=text, voice=voice, message_id=message_id)
+            response = AudioService.transcript_tts(
+                app_model=app_model,
+                session=db.session,
+                text=text,
+                voice=voice,
+                message_id=message_id,
+            )
             RecommendedAppService.add_trial_app_record(db.session, app_id, user_id)
             return response
         except services.errors.app_model_config.AppModelConfigBrokenError:
diff --git a/api/controllers/service_api/app/audio.py b/api/controllers/service_api/app/audio.py
index 2b5a9ba83a1..59ed4b4a4b1 100644
--- a/api/controllers/service_api/app/audio.py
+++ b/api/controllers/service_api/app/audio.py
@@ -23,6 +23,7 @@ from controllers.service_api.app.error import (
 from controllers.service_api.schema import binary_response, expect_with_user, multipart_file_params
 from controllers.service_api.wraps import FetchUserArg, WhereisUserArg, validate_app_token
 from core.errors.error import ModelCurrentlyNotSupportError, ProviderTokenNotInitError, QuotaExceededError
+from extensions.ext_database import db
 from graphon.model_runtime.errors.invoke import InvokeError
 from models.model import App, EndUser
 from services.audio_service import AudioService
@@ -177,7 +178,12 @@ class TextApi(Resource):
             text = payload.text
             voice = payload.voice
             response = AudioService.transcript_tts(
-                app_model=app_model, text=text, voice=voice, end_user=end_user.external_user_id, message_id=message_id
+                app_model=app_model,
+                session=db.session,
+                text=text,
+                voice=voice,
+                end_user=end_user.external_user_id,
+                message_id=message_id,
             )
 
             return response
diff --git a/api/controllers/web/audio.py b/api/controllers/web/audio.py
index c762c914861..801c1f5a629 100644
--- a/api/controllers/web/audio.py
+++ b/api/controllers/web/audio.py
@@ -22,6 +22,7 @@ from controllers.web.error import (
 )
 from controllers.web.wraps import WebApiResource
 from core.errors.error import ModelCurrentlyNotSupportError, ProviderTokenNotInitError, QuotaExceededError
+from extensions.ext_database import db
 from graphon.model_runtime.errors.invoke import InvokeError
 from libs.helper import uuid_value
 from models.model import App, EndUser
@@ -130,7 +131,12 @@ class TextApi(WebApiResource):
             text = payload.text
             voice = payload.voice
             response = AudioService.transcript_tts(
-                app_model=app_model, text=text, voice=voice, end_user=end_user.external_user_id, message_id=message_id
+                app_model=app_model,
+                session=db.session,
+                text=text,
+                voice=voice,
+                end_user=end_user.external_user_id,
+                message_id=message_id,
             )
 
             return response
diff --git a/api/services/audio_service.py b/api/services/audio_service.py
index a9024eb3bdd..14c5c0111e5 100644
--- a/api/services/audio_service.py
+++ b/api/services/audio_service.py
@@ -5,11 +5,11 @@ from collections.abc import Generator
 from typing import cast
 
 from flask import Response, stream_with_context
+from sqlalchemy.orm import Session, scoped_session
 from werkzeug.datastructures import FileStorage
 
 from constants import AUDIO_EXTENSIONS
 from core.model_manager import ModelManager
-from extensions.ext_database import db
 from graphon.model_runtime.entities.model_entities import ModelType
 from models.enums import MessageStatus
 from models.model import App, AppMode, Message
@@ -77,6 +77,8 @@ class AudioService:
     def transcript_tts(
         cls,
         app_model: App,
+        *,
+        session: Session | scoped_session,
         text: str | None = None,
         voice: str | None = None,
         end_user: str | None = None,
@@ -87,7 +89,7 @@ class AudioService:
             if voice is None:
                 if app_model.mode in {AppMode.ADVANCED_CHAT, AppMode.WORKFLOW}:
                     if is_draft:
-                        workflow = WorkflowService().get_draft_workflow(app_model=app_model)
+                        workflow = WorkflowService().get_draft_workflow(app_model=app_model, session=session)
                     else:
                         workflow = app_model.workflow
                     if (
@@ -132,7 +134,7 @@ class AudioService:
                 uuid.UUID(message_id)
             except ValueError:
                 return None
-            message = db.session.get(Message, message_id)
+            message = session.get(Message, message_id)
             if message is None:
                 return None
             if message.answer == "" and message.status in {MessageStatus.NORMAL, MessageStatus.PAUSED}:
diff --git a/api/services/workflow_service.py b/api/services/workflow_service.py
index 9f8e4b83093..262ccc18f83 100644
--- a/api/services/workflow_service.py
+++ b/api/services/workflow_service.py
@@ -6,7 +6,7 @@ from collections.abc import Callable, Generator, Mapping, Sequence
 from typing import Any, cast
 
 from sqlalchemy import exists, select
-from sqlalchemy.orm import Session, sessionmaker
+from sqlalchemy.orm import Session, scoped_session, sessionmaker
 
 from configs import dify_config
 from core.app.apps.advanced_chat.app_config_manager import AdvancedChatAppConfigManager
@@ -142,7 +142,7 @@ class WorkflowService:
         return db.session.execute(stmt).scalar_one()
 
     def get_draft_workflow(
-        self, app_model: App, workflow_id: str | None = None, session: Session | None = None
+        self, app_model: App, workflow_id: str | None = None, session: Session | scoped_session | None = None
     ) -> Workflow | None:
         """
         Get draft workflow
@@ -169,7 +169,7 @@ class WorkflowService:
         return workflow
 
     def get_published_workflow_by_id(
-        self, app_model: App, workflow_id: str, session: Session | None = None
+        self, app_model: App, workflow_id: str, session: Session | scoped_session | None = None
     ) -> Workflow | None:
         """
         fetch published workflow by workflow_id
diff --git a/api/tests/test_containers_integration_tests/services/test_audio_service_db.py b/api/tests/test_containers_integration_tests/services/test_audio_service_db.py
index 2593b53fe84..c9cf60bcfb1 100644
--- a/api/tests/test_containers_integration_tests/services/test_audio_service_db.py
+++ b/api/tests/test_containers_integration_tests/services/test_audio_service_db.py
@@ -158,6 +158,7 @@ class TestAudioServiceTranscriptTTSMessageLookup:
         with patch("services.audio_service.ModelManager.for_tenant", return_value=mock_model_manager):
             result = AudioService.transcript_tts(
                 app_model=app,
+                session=db_session_with_containers,
                 message_id=message.id,
                 voice="en-US-Neural",
             )
@@ -174,6 +175,7 @@ class TestAudioServiceTranscriptTTSMessageLookup:
 
         result = AudioService.transcript_tts(
             app_model=app,
+            session=db_session_with_containers,
             message_id="invalid-uuid",
         )
 
@@ -185,6 +187,7 @@ class TestAudioServiceTranscriptTTSMessageLookup:
 
         result = AudioService.transcript_tts(
             app_model=app,
+            session=db_session_with_containers,
             message_id=str(uuid4()),
         )
 
@@ -205,6 +208,7 @@ class TestAudioServiceTranscriptTTSMessageLookup:
 
         result = AudioService.transcript_tts(
             app_model=app,
+            session=db_session_with_containers,
             message_id=message.id,
         )
 
diff --git a/api/tests/unit_tests/controllers/service_api/app/test_audio.py b/api/tests/unit_tests/controllers/service_api/app/test_audio.py
index 1cfe152c864..52d050ff55a 100644
--- a/api/tests/unit_tests/controllers/service_api/app/test_audio.py
+++ b/api/tests/unit_tests/controllers/service_api/app/test_audio.py
@@ -176,6 +176,7 @@ class TestAudioServiceMockedBehavior:
 
         result = AudioService.transcript_tts(
             app_model=mock_app,
+            session=Mock(),
             text="Hello world",
             voice="nova",
             end_user="user_123",
diff --git a/api/tests/unit_tests/services/test_audio_service.py b/api/tests/unit_tests/services/test_audio_service.py
index 5d148974f87..788a47c5c31 100644
--- a/api/tests/unit_tests/services/test_audio_service.py
+++ b/api/tests/unit_tests/services/test_audio_service.py
@@ -398,6 +398,7 @@ class TestAudioServiceTTS:
         # Act
         result = AudioService.transcript_tts(
             app_model=app,
+            session=MagicMock(),
             text="Hello world",
             voice="en-US-Neural",
             end_user="user-123",
@@ -432,6 +433,7 @@ class TestAudioServiceTTS:
         # Act
         result = AudioService.transcript_tts(
             app_model=app,
+            session=MagicMock(),
             text="Test",
         )
 
@@ -465,6 +467,7 @@ class TestAudioServiceTTS:
         # Act
         result = AudioService.transcript_tts(
             app_model=app,
+            session=MagicMock(),
             text="Test",
         )
 
@@ -496,17 +499,52 @@ class TestAudioServiceTTS:
         mock_model_instance = MagicMock()
         mock_model_instance.invoke_tts.return_value = b"draft audio"
         mock_model_manager.get_default_model_instance.return_value = mock_model_instance
+        session = MagicMock()
 
         # Act
         result = AudioService.transcript_tts(
             app_model=app,
+            session=session,
             text="Draft test",
             is_draft=True,
         )
 
         # Assert
         assert result == b"draft audio"
-        mock_workflow_service.get_draft_workflow.assert_called_once_with(app_model=app)
+        mock_workflow_service.get_draft_workflow.assert_called_once_with(app_model=app, session=session)
+
+    @patch("services.audio_service.ModelManager.for_tenant", autospec=True)
+    def test_transcript_tts_message_id_uses_provided_session(
+        self, mock_model_manager_class, factory: AudioServiceTestDataFactory
+    ):
+        """Test TTS message lookup uses the injected session."""
+        # Arrange
+        app = factory.create_app_mock(mode=AppMode.CHAT)
+        message_id = "00000000-0000-0000-0000-000000000001"
+        message = factory.create_message_mock(message_id=message_id, answer="Message answer")
+        session = MagicMock()
+        session.get.return_value = message
+
+        mock_model_manager = mock_model_manager_class.return_value
+        mock_model_instance = MagicMock()
+        mock_model_instance.invoke_tts.return_value = b"message audio"
+        mock_model_manager.get_default_model_instance.return_value = mock_model_instance
+
+        # Act
+        result = AudioService.transcript_tts(
+            app_model=app,
+            session=session,
+            message_id=message_id,
+            voice="message-voice",
+        )
+
+        # Assert
+        assert result == b"message audio"
+        session.get.assert_called_once_with(Message, message_id)
+        mock_model_instance.invoke_tts.assert_called_once_with(
+            content_text="Message answer",
+            voice="message-voice",
+        )
 
     def test_transcript_tts_raises_error_when_text_missing(self, factory: AudioServiceTestDataFactory):
         """Test that TTS raises error when text is missing."""
@@ -515,7 +553,7 @@ class TestAudioServiceTTS:
 
         # Act & Assert
         with pytest.raises(ValueError, match="Text is required"):
-            AudioService.transcript_tts(app_model=app, text=None)
+            AudioService.transcript_tts(app_model=app, session=MagicMock(), text=None)
 
     @patch("services.audio_service.ModelManager.for_tenant", autospec=True)
     def test_transcript_tts_raises_error_when_no_voices_available(
@@ -539,7 +577,7 @@ class TestAudioServiceTTS:
 
         # Act & Assert
         with pytest.raises(ValueError, match="Sorry, no voice available"):
-            AudioService.transcript_tts(app_model=app, text="Test")
+            AudioService.transcript_tts(app_model=app, session=MagicMock(), text="Test")
 
 
 class TestAudioServiceTTSVoices: