fix basic agent

app.py

@@ -23,9 +23,30 @@ class BasicAgent:
         print(f"Agent received question (first 50 chars): {question[:50]}...")
         # Wrap the question in a HumanMessage from langchain_core
         messages = [HumanMessage(content=question)]
-        messages = self.graph.invoke({"messages": messages})
-        answer = messages['messages'][-1].content
-        return answer[14:]
+        # The graph.invoke method returns the final state of the graph.
+        # The state is expected to contain a 'messages' key with a list of messages.
+        result = self.graph.invoke({"messages": messages})
+        # Extract the final answer message from the state
+        # The final message should be the content of the last AIMessage with content
+        submitted_answer = "Could not get answer from agent output." # Default if extraction fails
+
+        # Check if the result is a dictionary and contains a list of messages
+        if isinstance(result, dict) and "messages" in result and isinstance(result["messages"], list):
+            # Iterate through messages in reverse to find the last one from the AI
+            for msg in reversed(result["messages"]):
+                # Check if the message is an AIMessage and has content (non-empty string or non-empty list/dict representation)
+                # The 'content' attribute exists on AIMessage, so hasattr check is redundant.
+                if isinstance(msg, AIMessage) and msg.content is not None:
+                     # Ensure the content is treated as a string for submission.
+                     # LangChain AIMessage content can be str or list[str | dict].
+                     # str() handles conversion for both cases.
+                     submitted_answer = str(msg.content)
+                     break # Found the last AI message with content, stop searching
+
+        # If the loop finishes without finding an AIMessage with content,
+        # submitted_answer remains the default value.
+
+        return submitted_answer
 
 
 def run_and_submit_all( profile: gr.OAuthProfile | None):