diff --git a/api/core/app/apps/workflow/app_generator.py b/api/core/app/apps/workflow/app_generator.py
index df40aec154..c5bf35edb6 100644
--- a/api/core/app/apps/workflow/app_generator.py
+++ b/api/core/app/apps/workflow/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 Literal, Union, overload
 
 from flask import Flask, current_app
 from pydantic import ValidationError
@@ -32,6 +32,28 @@ logger = logging.getLogger(__name__)
 
 
 class WorkflowAppGenerator(BaseAppGenerator):
+    @overload
+    def generate(
+        self, app_model: App,
+        workflow: Workflow,
+        user: Union[Account, EndUser],
+        args: dict,
+        invoke_from: InvokeFrom,
+        stream: Literal[True] = True,
+        call_depth: int = 0,
+    ) -> Generator[dict, None, None]: ...
+
+    @overload
+    def generate(
+        self, app_model: App,
+        workflow: Workflow,
+        user: Union[Account, EndUser],
+        args: dict,
+        invoke_from: InvokeFrom,
+        stream: Literal[False] = False,
+        call_depth: int = 0,
+    ) -> dict: ...
+
     def generate(
         self, app_model: App,
         workflow: Workflow,
diff --git a/api/core/tools/tool/tool.py b/api/core/tools/tool/tool.py
index 52513c13f9..68db0d5b2e 100644
--- a/api/core/tools/tool/tool.py
+++ b/api/core/tools/tool/tool.py
@@ -1,5 +1,5 @@
 from abc import ABC, abstractmethod
-from collections.abc import Generator, Mapping
+from collections.abc import Generator
 from copy import deepcopy
 from enum import Enum
 from typing import TYPE_CHECKING, Any, Optional, Union
diff --git a/api/core/tools/tool/workflow_tool.py b/api/core/tools/tool/workflow_tool.py
index 4724c992d2..7a669a4fe4 100644
--- a/api/core/tools/tool/workflow_tool.py
+++ b/api/core/tools/tool/workflow_tool.py
@@ -48,6 +48,8 @@ class WorkflowTool(Tool):
         from core.app.apps.workflow.app_generator import WorkflowAppGenerator
         generator = WorkflowAppGenerator()
 
+        assert self.runtime and self.runtime.invoke_from
+
         result = generator.generate(
             app_model=app, 
             workflow=workflow, 
@@ -154,7 +156,7 @@ class WorkflowTool(Tool):
                     try:
                         file_var_list = [FileVar(**f) for f in file]
                         for file_var in file_var_list:
-                            file_dict = {
+                            file_dict: dict[str, Any] = {
                                 'transfer_method': file_var.transfer_method.value,
                                 'type': file_var.type.value,
                             }