diff --git a/api/core/memory/entities.py b/api/core/memory/entities.py
index 84e6d915b9..26927c7931 100644
--- a/api/core/memory/entities.py
+++ b/api/core/memory/entities.py
@@ -1,5 +1,5 @@
 from enum import Enum
-from typing import Optional, Dict, Any
+from typing import Any, Optional
 from uuid import uuid4
 
 from pydantic import BaseModel, Field
@@ -42,7 +42,7 @@ class MemoryBlockSpec(BaseModel):
     update_turns: int = Field(gt=0, description="Number of turns between updates")
     preserved_turns: int = Field(gt=0, description="Number of conversation turns to preserve")
     schedule_mode: MemoryScheduleMode = Field(description="Synchronous or asynchronous update mode")
-    model: Optional[Dict[str, Any]] = Field(default=None, description="Model configuration for memory updates")
+    model: Optional[dict[str, Any]] = Field(default=None, description="Model configuration for memory updates")
     end_user_visible: bool = Field(default=False, description="Whether memory is visible to end users")
     end_user_editable: bool = Field(default=False, description="Whether memory is editable by end users")
 
@@ -66,7 +66,7 @@ class MemoryBlock(BaseModel):
     value: str
     scope: MemoryScope  # Derived from node_id: None=APP, str=NODE
     term: MemoryTerm  # Derived from conversation_id: None=PERSISTENT, str=SESSION
-    app_id: Optional[str] = None  # None=global(future), str=app-specific
+    app_id: str  # None=global(future), str=app-specific
     conversation_id: Optional[str] = None  # None=persistent, str=session
     node_id: Optional[str] = None  # None=app-scope, str=node-scope
     created_at: Optional[str] = None
diff --git a/api/models/workflow.py b/api/models/workflow.py
index c7b0759b4f..66c64a0fd5 100644
--- a/api/models/workflow.py
+++ b/api/models/workflow.py
@@ -16,8 +16,11 @@ from core.file.models import File
 from core.memory.entities import MemoryBlockSpec
 from core.variables import utils as variable_utils
 from core.variables.variables import FloatVariable, IntegerVariable, StringVariable
-from core.workflow.constants import CONVERSATION_VARIABLE_NODE_ID, SYSTEM_VARIABLE_NODE_ID, \
-    MEMORY_BLOCK_VARIABLE_NODE_ID
+from core.workflow.constants import (
+    CONVERSATION_VARIABLE_NODE_ID,
+    MEMORY_BLOCK_VARIABLE_NODE_ID,
+    SYSTEM_VARIABLE_NODE_ID,
+)
 from core.workflow.nodes.enums import NodeType
 from factories.variable_factory import TypeMismatchError, build_segment_with_type
 from libs.datetime_utils import naive_utc_now