diff --git a/src/memos/api/client.py b/src/memos/api/client.py
index 581076cb2..0beebab9a 100644
--- a/src/memos/api/client.py
+++ b/src/memos/api/client.py
@@ -31,7 +31,12 @@
 class MemOSClient:
     """MemOS API client"""
 
-    def __init__(self, api_key: str | None = None, base_url: str | None = None, is_global: str | bool = "false"):
+    def __init__(
+        self,
+        api_key: str | None = None,
+        base_url: str | None = None,
+        is_global: str | bool = "false",
+    ):
         # Priority:
         # 1. base_url argument
         # 2. MEMOS_BASE_URL environment variable (direct URL)
@@ -44,11 +49,9 @@ def __init__(self, api_key: str | None = None, base_url: str | None = None, is_g
             if final_is_global
             else "https://memos.memtensor.cn/api/openmem/v1"
         )
-        
 
         self.base_url = base_url or os.getenv("MEMOS_BASE_URL") or default_url
 
-
         api_key = api_key or os.getenv("MEMOS_API_KEY")
 
         if not api_key:
diff --git a/src/memos/api/handlers/chat_handler.py b/src/memos/api/handlers/chat_handler.py
index fe250bbd6..58a271f34 100644
--- a/src/memos/api/handlers/chat_handler.py
+++ b/src/memos/api/handlers/chat_handler.py
@@ -1514,12 +1514,14 @@ def run_async_in_thread():
             )
             # Add exception handling for the background task
             task.add_done_callback(
-                lambda t: self.logger.error(
-                    f"Error in background post-chat processing for user {user_id}: {t.exception()}",
-                    exc_info=True,
+                lambda t: (
+                    self.logger.error(
+                        f"Error in background post-chat processing for user {user_id}: {t.exception()}",
+                        exc_info=True,
+                    )
+                    if t.exception()
+                    else None
                 )
-                if t.exception()
-                else None
             )
         except RuntimeError:
             # No event loop, run in a new thread with context propagation
@@ -1581,12 +1583,14 @@ def run_async_in_thread():
                 )
             )
             task.add_done_callback(
-                lambda t: self.logger.error(
-                    f"Error in background add to memory for user {user_id}: {t.exception()}",
-                    exc_info=True,
+                lambda t: (
+                    self.logger.error(
+                        f"Error in background add to memory for user {user_id}: {t.exception()}",
+                        exc_info=True,
+                    )
+                    if t.exception()
+                    else None
                 )
-                if t.exception()
-                else None
             )
         except RuntimeError:
             thread = ContextThread(
diff --git a/src/memos/mem_os/product.py b/src/memos/mem_os/product.py
index 77a5e70c9..b2c74c384 100644
--- a/src/memos/mem_os/product.py
+++ b/src/memos/mem_os/product.py
@@ -798,12 +798,14 @@ def run_async_in_thread():
             )
             # Add exception handling for the background task
             task.add_done_callback(
-                lambda t: logger.error(
-                    f"Error in background post-chat processing for user {user_id}: {t.exception()}",
-                    exc_info=True,
+                lambda t: (
+                    logger.error(
+                        f"Error in background post-chat processing for user {user_id}: {t.exception()}",
+                        exc_info=True,
+                    )
+                    if t.exception()
+                    else None
                 )
-                if t.exception()
-                else None
             )
         except RuntimeError:
             # No event loop, run in a new thread with context propagation
diff --git a/src/memos/mem_os/product_server.py b/src/memos/mem_os/product_server.py
index 758f2794d..80aefea85 100644
--- a/src/memos/mem_os/product_server.py
+++ b/src/memos/mem_os/product_server.py
@@ -437,12 +437,14 @@ def run_async_in_thread():
             )
             # Add exception handling for the background task
             task.add_done_callback(
-                lambda t: logger.error(
-                    f"Error in background post-chat processing for user {user_id}: {t.exception()}",
-                    exc_info=True,
+                lambda t: (
+                    logger.error(
+                        f"Error in background post-chat processing for user {user_id}: {t.exception()}",
+                        exc_info=True,
+                    )
+                    if t.exception()
+                    else None
                 )
-                if t.exception()
-                else None
             )
         except RuntimeError:
             # No event loop, run in a new thread with context propagation