diff --git a/api/configs/feature/__init__.py b/api/configs/feature/__init__.py
index 5e5ab974b7..4fe6691e4b 100644
--- a/api/configs/feature/__init__.py
+++ b/api/configs/feature/__init__.py
@@ -560,8 +560,10 @@ class RepositoryConfig(BaseSettings):
 
     CORE_WORKFLOW_NODE_EXECUTION_REPOSITORY: str = Field(
         description="Repository implementation for WorkflowNodeExecution. Options: "
-        "'core.repositories.sqlalchemy_workflow_node_execution_repository.SQLAlchemyWorkflowNodeExecutionRepository' (default), "
-        "'core.repositories.celery_workflow_node_execution_repository.CeleryWorkflowNodeExecutionRepository'",
+        "'core.repositories.sqlalchemy_workflow_node_execution_repository."
+        "SQLAlchemyWorkflowNodeExecutionRepository' (default), "
+        "'core.repositories.celery_workflow_node_execution_repository."
+        "CeleryWorkflowNodeExecutionRepository'",
         default="core.repositories.sqlalchemy_workflow_node_execution_repository.SQLAlchemyWorkflowNodeExecutionRepository",
     )
 
diff --git a/api/core/repositories/celery_workflow_execution_repository.py b/api/core/repositories/celery_workflow_execution_repository.py
index 39e0c99337..4d7d518536 100644
--- a/api/core/repositories/celery_workflow_execution_repository.py
+++ b/api/core/repositories/celery_workflow_execution_repository.py
@@ -8,7 +8,7 @@ providing improved performance by offloading database operations to background w
 import logging
 from typing import Optional, Union
 
-from celery.result import AsyncResult
+from celery.result import AsyncResult  # type: ignore[import-untyped]
 from sqlalchemy.engine import Engine
 from sqlalchemy.orm import sessionmaker
 
@@ -40,6 +40,15 @@ class CeleryWorkflowExecutionRepository(WorkflowExecutionRepository):
     - Configurable timeouts for async operations
     """
 
+    _session_factory: sessionmaker
+    _tenant_id: str
+    _app_id: Optional[str]
+    _triggered_from: Optional[WorkflowRunTriggeredFrom]
+    _creator_user_id: str
+    _creator_user_role: CreatorUserRole
+    _async_timeout: int
+    _pending_saves: dict[str, AsyncResult]
+
     def __init__(
         self,
         session_factory: sessionmaker | Engine,
@@ -72,7 +81,7 @@ class CeleryWorkflowExecutionRepository(WorkflowExecutionRepository):
         tenant_id = extract_tenant_id(user)
         if not tenant_id:
             raise ValueError("User must have a tenant_id or current_tenant_id")
-        self._tenant_id = tenant_id
+        self._tenant_id = tenant_id  # type: ignore[assignment]  # We've already checked tenant_id is not None
 
         # Store app context
         self._app_id = app_id
diff --git a/api/core/repositories/celery_workflow_node_execution_repository.py b/api/core/repositories/celery_workflow_node_execution_repository.py
index c18f0c93a1..61d9014794 100644
--- a/api/core/repositories/celery_workflow_node_execution_repository.py
+++ b/api/core/repositories/celery_workflow_node_execution_repository.py
@@ -9,7 +9,7 @@ import logging
 from collections.abc import Sequence
 from typing import Optional, Union
 
-from celery.result import AsyncResult
+from celery.result import AsyncResult  # type: ignore[import-untyped]
 from sqlalchemy.engine import Engine
 from sqlalchemy.orm import sessionmaker
 
@@ -46,6 +46,16 @@ class CeleryWorkflowNodeExecutionRepository(WorkflowNodeExecutionRepository):
     - Batch operations for improved efficiency
     """
 
+    _session_factory: sessionmaker
+    _tenant_id: str
+    _app_id: Optional[str]
+    _triggered_from: Optional[WorkflowNodeExecutionTriggeredFrom]
+    _creator_user_id: str
+    _creator_user_role: CreatorUserRole
+    _async_timeout: int
+    _pending_saves: dict[str, AsyncResult]
+    _workflow_execution_mapping: dict[str, str]
+
     def __init__(
         self,
         session_factory: sessionmaker | Engine,
@@ -78,7 +88,7 @@ class CeleryWorkflowNodeExecutionRepository(WorkflowNodeExecutionRepository):
         tenant_id = extract_tenant_id(user)
         if not tenant_id:
             raise ValueError("User must have a tenant_id or current_tenant_id")
-        self._tenant_id = tenant_id
+        self._tenant_id = tenant_id  # type: ignore[assignment]  # We've already checked tenant_id is not None
 
         # Store app context
         self._app_id = app_id
@@ -132,7 +142,8 @@ class CeleryWorkflowNodeExecutionRepository(WorkflowNodeExecutionRepository):
             self._pending_saves[execution.id] = task_result
             
             # Cache the workflow_execution_id mapping for efficient workflow-specific waiting
-            self._workflow_execution_mapping[execution.id] = execution.workflow_execution_id
+            if execution.workflow_execution_id:
+                self._workflow_execution_mapping[execution.id] = execution.workflow_execution_id
 
             logger.debug(f"Queued async save for workflow node execution: {execution.id}")
 
diff --git a/api/tasks/workflow_execution_tasks.py b/api/tasks/workflow_execution_tasks.py
index 93f3604ed3..76c7faebae 100644
--- a/api/tasks/workflow_execution_tasks.py
+++ b/api/tasks/workflow_execution_tasks.py
@@ -8,7 +8,7 @@ improving performance by offloading storage operations to background workers.
 import json
 import logging
 
-from celery import shared_task
+from celery import shared_task  # type: ignore[import-untyped]
 from sqlalchemy import select
 from sqlalchemy.orm import sessionmaker
 
diff --git a/api/tasks/workflow_node_execution_tasks.py b/api/tasks/workflow_node_execution_tasks.py
index e2b5ff7ab2..58098c681f 100644
--- a/api/tasks/workflow_node_execution_tasks.py
+++ b/api/tasks/workflow_node_execution_tasks.py
@@ -9,7 +9,7 @@ import json
 import logging
 from typing import Optional
 
-from celery import shared_task
+from celery import shared_task  # type: ignore[import-untyped]
 from sqlalchemy import select
 from sqlalchemy.orm import sessionmaker