fix code

app.py

@@ -30,7 +30,7 @@ class BasicAgent:
 
     def __call__(self, question: str) -> str:
         print(f"Agent received question (first 50 chars): {question[:50]}...")
-        answer = self.agent.invoke(inputs = {"messages": [("user", question)]})
+        answer = self.agent.invoke({"messages": [("user", question)]})
         print(f"Agent returning answer: {answer}")
         return answer