diff --git a/api/core/app/apps/advanced_chat/app_generator.py b/api/core/app/apps/advanced_chat/app_generator.py
index 5a1e5973cd..80d2694fc9 100644
--- a/api/core/app/apps/advanced_chat/app_generator.py
+++ b/api/core/app/apps/advanced_chat/app_generator.py
@@ -4,7 +4,7 @@ import os
 import threading
 import uuid
 from collections.abc import Generator
-from typing import Union
+from typing import Any, Literal, Union, overload
 
 from flask import Flask, current_app
 from pydantic import ValidationError
@@ -39,6 +39,26 @@ logger = logging.getLogger(__name__)
 
 
 class AdvancedChatAppGenerator(MessageBasedAppGenerator):
+    @overload
+    def generate(
+        self, app_model: App,
+        workflow: Workflow,
+        user: Union[Account, EndUser],
+        args: dict,
+        invoke_from: InvokeFrom,
+        stream: Literal[True] = True,
+    ) -> Generator[str, None, None]: ...
+
+    @overload
+    def generate(
+        self, app_model: App,
+        workflow: Workflow,
+        user: Union[Account, EndUser],
+        args: dict,
+        invoke_from: InvokeFrom,
+        stream: Literal[False] = False,
+    ) -> dict: ...
+
     def generate(
         self, app_model: App,
         workflow: Workflow,
diff --git a/api/core/app/apps/agent_chat/app_generator.py b/api/core/app/apps/agent_chat/app_generator.py
index 53780bdfb0..cf6d829256 100644
--- a/api/core/app/apps/agent_chat/app_generator.py
+++ b/api/core/app/apps/agent_chat/app_generator.py
@@ -3,7 +3,7 @@ import os
 import threading
 import uuid
 from collections.abc import Generator
-from typing import Any, Union
+from typing import Any, Literal, Union, overload
 
 from flask import Flask, current_app
 from pydantic import ValidationError
@@ -28,6 +28,24 @@ logger = logging.getLogger(__name__)
 
 
 class AgentChatAppGenerator(MessageBasedAppGenerator):
+    @overload
+    def generate(
+        self, app_model: App,
+        user: Union[Account, EndUser],
+        args: Any,
+        invoke_from: InvokeFrom,
+        stream: Literal[True] = True,
+    ) -> Generator[dict, None, None]: ...
+
+    @overload
+    def generate(
+        self, app_model: App,
+        user: Union[Account, EndUser],
+        args: Any,
+        invoke_from: InvokeFrom,
+        stream: Literal[False] = False,
+    ) -> dict: ...
+
     def generate(self, app_model: App,
                  user: Union[Account, EndUser],
                  args: Any,
diff --git a/api/core/app/apps/chat/app_generator.py b/api/core/app/apps/chat/app_generator.py
index 5b896e2845..bf4e6083b6 100644
--- a/api/core/app/apps/chat/app_generator.py
+++ b/api/core/app/apps/chat/app_generator.py
@@ -3,7 +3,7 @@ import os
 import threading
 import uuid
 from collections.abc import Generator
-from typing import Any, Union
+from typing import Any, Literal, Union, overload
 
 from flask import Flask, current_app
 from pydantic import ValidationError
@@ -28,6 +28,24 @@ logger = logging.getLogger(__name__)
 
 
 class ChatAppGenerator(MessageBasedAppGenerator):
+    @overload
+    def generate(
+        self, app_model: App,
+        user: Union[Account, EndUser],
+        args: Any,
+        invoke_from: InvokeFrom,
+        stream: Literal[True] = True,
+    ) -> Generator[dict, None, None]: ...
+
+    @overload
+    def generate(
+        self, app_model: App,
+        user: Union[Account, EndUser],
+        args: Any,
+        invoke_from: InvokeFrom,
+        stream: Literal[False] = False,
+    ) -> dict: ...
+
     def generate(
         self, app_model: App,
         user: Union[Account, EndUser],
diff --git a/api/core/app/apps/completion/app_generator.py b/api/core/app/apps/completion/app_generator.py
index c4e1caf65a..b14568480f 100644
--- a/api/core/app/apps/completion/app_generator.py
+++ b/api/core/app/apps/completion/app_generator.py
@@ -3,7 +3,7 @@ import os
 import threading
 import uuid
 from collections.abc import Generator
-from typing import Any, Union
+from typing import Any, Literal, Union, overload
 
 from flask import Flask, current_app
 from pydantic import ValidationError
@@ -30,12 +30,31 @@ logger = logging.getLogger(__name__)
 
 
 class CompletionAppGenerator(MessageBasedAppGenerator):
-    def generate(self, app_model: App,
-                 user: Union[Account, EndUser],
-                 args: Any,
-                 invoke_from: InvokeFrom,
-                 stream: bool = True) \
-            -> Union[dict, Generator[dict, None, None]]:
+    @overload
+    def generate(
+        self, app_model: App,
+        user: Union[Account, EndUser],
+        args: Any,
+        invoke_from: InvokeFrom,
+        stream: Literal[True] = True,
+    ) -> Generator[dict, None, None]: ...
+
+    @overload
+    def generate(
+        self, app_model: App,
+        user: Union[Account, EndUser],
+        args: Any,
+        invoke_from: InvokeFrom,
+        stream: Literal[False] = False,
+    ) -> dict: ...
+
+    def generate(
+        self, app_model: App,
+        user: Union[Account, EndUser],
+        args: Any,
+        invoke_from: InvokeFrom,
+        stream: bool = True
+    ) -> Union[dict, Generator[dict, None, None]]:
         """
         Generate App response.