diff --git a/backend/open_webui/routers/chats.py b/backend/open_webui/routers/chats.py
index 88801fa00f..4b5e6c237b 100644
--- a/backend/open_webui/routers/chats.py
+++ b/backend/open_webui/routers/chats.py
@@ -735,7 +735,7 @@ async def create_new_chat(
             subject_id=chat.id,
             data={'title': chat.title, 'folder_id': chat.folder_id},
         )
-        return ChatResponse(**chat.model_dump())
+        return ChatResponse.model_validate(chat, from_attributes=True)
     except Exception as e:
         log.exception(e)
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=ERROR_MESSAGES.DEFAULT())
@@ -820,7 +820,17 @@ async def search_user_chats(
     search_text = chat_search_content_text(text)
     chat_list = []
     for chat in await Chats.get_chats_by_user_id_and_search_text(user.id, text, skip=skip, limit=limit, db=db):
-        chat_list.append(ChatTitleIdResponse(**chat.model_dump(), snippet=chat_search_snippet(chat.chat, search_text)))
+        # Explicit fields: model_dump() would deep-copy the entire chat blob per row
+        chat_list.append(
+            ChatTitleIdResponse(
+                id=chat.id,
+                title=chat.title,
+                updated_at=chat.updated_at,
+                created_at=chat.created_at,
+                last_read_at=chat.last_read_at,
+                snippet=chat_search_snippet(chat.chat, search_text),
+            )
+        )
 
     # Delete tag if no chat is found
     words = text.strip().split(' ')
@@ -849,7 +859,7 @@ async def get_chats_by_folder_id(
         folder_ids.extend([folder.id for folder in children_folders])
 
     return [
-        ChatResponse(**chat.model_dump())
+        ChatResponse.model_validate(chat, from_attributes=True)
         for chat in await Chats.get_chats_by_folder_ids_and_user_id(folder_ids, user.id, db=db)
     ]
 
@@ -915,7 +925,7 @@ async def generate_chat_export_ndjson(user_id: str):
 
         for chat in result.items:
             try:
-                yield ChatResponse(**chat.model_dump()).model_dump_json() + '\n'
+                yield ChatResponse.model_validate(chat, from_attributes=True).model_dump_json() + '\n'
             except Exception as e:
                 log.exception(f'Error serializing chat {chat.id}: {e}')
 
@@ -940,7 +950,7 @@ async def get_user_chats(user=Depends(get_verified_user)):
 
 @router.get('/all/archived', response_model=list[ChatResponse])
 async def get_user_archived_chats(user=Depends(get_verified_user), db: AsyncSession = Depends(get_async_session)):
-    return [ChatResponse(**chat.model_dump()) for chat in await Chats.get_archived_chats_by_user_id(user.id, db=db)]
+    return [ChatResponse.model_validate(chat, from_attributes=True) for chat in await Chats.get_archived_chats_by_user_id(user.id, db=db)]
 
 
 ############################
@@ -967,7 +977,7 @@ async def get_all_user_tags(user=Depends(get_verified_user), db: AsyncSession =
 async def get_all_user_chats_in_db(user=Depends(get_admin_user), db: AsyncSession = Depends(get_async_session)):
     if not ENABLE_ADMIN_EXPORT:
         raise HTTPException(status.HTTP_401_UNAUTHORIZED, detail=ERROR_MESSAGES.ACCESS_PROHIBITED)
-    return [ChatResponse(**chat.model_dump()) for chat in await Chats.get_chats(db=db)]
+    return [ChatResponse.model_validate(chat, from_attributes=True) for chat in await Chats.get_chats(db=db)]
 
 
 ############################
@@ -1133,7 +1143,7 @@ async def get_shared_chat_by_id(
         ):
             chat = await Chats.get_chat_by_share_id(share_id, db=db)
             if chat:
-                return ChatResponse(**chat.model_dump())
+                return ChatResponse.model_validate(chat, from_attributes=True)
 
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
@@ -1145,7 +1155,7 @@ async def get_shared_chat_by_id(
     if user is not None and user.role == 'admin' and ENABLE_ADMIN_CHAT_ACCESS:
         chat = await Chats.get_chat_by_id(share_id, db=db)
         if chat:
-            return ChatResponse(**chat.model_dump())
+            return ChatResponse.model_validate(chat, from_attributes=True)
 
     raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail=ERROR_MESSAGES.NOT_FOUND)
 
@@ -1270,7 +1280,7 @@ async def get_chat_by_id(id: str, user=Depends(get_verified_user), db: AsyncSess
                     chat = candidate
 
     if chat:
-        data = ChatResponse(**chat.model_dump()).model_dump()
+        data = ChatResponse.model_validate(chat, from_attributes=True).model_dump()
         data['context_usage'] = await get_chat_context_usage(chat)
         return data
 
@@ -1316,7 +1326,7 @@ async def update_chat_by_id(
             subject_id=id,
             data={'title': chat.title},
         )
-        return ChatResponse(**chat.model_dump())
+        return ChatResponse.model_validate(chat, from_attributes=True)
     else:
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
@@ -1390,7 +1400,7 @@ async def update_chat_message_by_id(
         subject_id=message_id,
         data={'chat_id': id, 'content_preview': form_data.content[:300]},
     )
-    return ChatResponse(**chat.model_dump())
+    return ChatResponse.model_validate(chat, from_attributes=True)
 
 
 @router.delete('/{id}/messages/{message_id}', response_model=ChatResponse | None)
@@ -1429,7 +1439,7 @@ async def delete_chat_message_by_id(
         subject_id=message_id,
         data={'chat_id': id},
     )
-    return ChatResponse(**chat.model_dump())
+    return ChatResponse.model_validate(chat, from_attributes=True)
 
 
 ############################
@@ -1685,7 +1695,7 @@ async def fork_chat_by_id(
         subject_id=fork.id,
         data={'original_chat_id': id, 'forked_from_message_id': source_message_id},
     )
-    return ChatResponse(**fork.model_dump())
+    return ChatResponse.model_validate(fork, from_attributes=True)
 
 
 @router.post('/{id}/clone', response_model=ChatResponse | None)
@@ -1732,7 +1742,7 @@ async def clone_chat_by_id(
                 subject_id=chat.id,
                 data={'original_chat_id': id},
             )
-            return ChatResponse(**chat.model_dump())
+            return ChatResponse.model_validate(chat, from_attributes=True)
         else:
             raise HTTPException(
                 status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
@@ -1809,7 +1819,7 @@ async def clone_shared_chat_by_id(
 
     if chats:
         chat = chats[0]
-        return ChatResponse(**chat.model_dump())
+        return ChatResponse.model_validate(chat, from_attributes=True)
     else:
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
@@ -1850,7 +1860,7 @@ async def archive_chat_by_id(
             subject_id=id,
             subject_type='chat',
         )
-        return ChatResponse(**chat.model_dump())
+        return ChatResponse.model_validate(chat, from_attributes=True)
     else:
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail=ERROR_MESSAGES.DEFAULT())
 
@@ -1884,7 +1894,7 @@ async def share_chat_by_id(
                 subject_id=id,
                 data={'share_id': chat.share_id, 'updated': True},
             )
-            return ChatResponse(**chat.model_dump())
+            return ChatResponse.model_validate(chat, from_attributes=True)
 
     # Create a new share
     shared = await SharedChats.create(id, user.id, db=db)
@@ -1902,7 +1912,7 @@ async def share_chat_by_id(
         subject_id=id,
         data={'share_id': shared.id},
     )
-    return ChatResponse(**chat.model_dump())
+    return ChatResponse.model_validate(chat, from_attributes=True)
 
 
 # --- Delete Shared Chat ---
@@ -1972,7 +1982,7 @@ async def update_shared_chat_access_by_id(
 
     await AccessGrants.set_access_grants('shared_chat', id, form_data.access_grants, db=db)
 
-    return ChatResponse(**chat.model_dump())
+    return ChatResponse.model_validate(chat, from_attributes=True)
 
 
 ############################
@@ -2047,7 +2057,7 @@ async def update_chat_folder_id_by_id(
             subject_id=id,
             data={'folder_id': form_data.folder_id},
         )
-        return ChatResponse(**chat.model_dump())
+        return ChatResponse.model_validate(chat, from_attributes=True)
     else:
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail=ERROR_MESSAGES.DEFAULT())