Update agent.py

agent.py

@@ -61,12 +61,8 @@ class BasicAgent():
         """)
         response = self.chat_with_tools.invoke([sys_msg] + state["messages"])
  
-        # Ensure the response is not None
-        if response is None:
-            raise RuntimeError("chat_with_tools.invoke returned None")
-
         return {
-            "messages":  response,            
+            "messages":  state["messages"] + [response],            
         }