memory chatbot upgrade

app.py

@@ -468,19 +468,23 @@ async def stream_agent_response(question: str, chat_history: List[List[str]]) ->
             f"3. El modelo de lenguaje esté disponible\n\n"
             f"Error: {agent_error}"
         )
-        return error_msg, None
+        return error_msg, None, None
         
     # Update the agent's memory with the full conversation history
     try:
-        # Rebuild agent memory from chat history pairs
+        # Hydrate agent memory only if it's empty; do NOT clear existing memory.
         if hasattr(agent, 'memory') and agent.memory is not None:
-            agent.memory.clear()
-            for i in range(0, len(messages)-1, 2):  # (user, assistant)
-                if i+1 < len(messages):
-                    agent.memory.save_context(
-                        {"input": messages[i].content},
-                        {"output": messages[i+1].content}
-                    )
+            try:
+                existing_messages = getattr(getattr(agent.memory, 'chat_memory', None), 'messages', []) or []
+            except Exception:
+                existing_messages = []
+            if not existing_messages and chat_history:
+                for pair in chat_history:
+                    try:
+                        user_prev, bot_prev = pair[0], pair[1] if len(pair) > 1 else ""
+                        agent.memory.save_context({"input": user_prev}, {"output": bot_prev})
+                    except Exception:
+                        continue
     except Exception as e:
         logger.error(f"Error updating agent memory: {str(e)}", exc_info=True)
     
@@ -726,7 +730,7 @@ async def stream_agent_response(question: str, chat_history: List[List[str]]) ->
         error_msg = f"## ❌ Error\n\nOcurrió un error al procesar tu solicitud:\n\n```\n{str(e)}\n```"
         logger.error(f"Error in stream_agent_response: {str(e)}", exc_info=True)
         # Return error message and no chart
-        return error_msg, None
+        return error_msg, None, None
 
 # Custom CSS for the app
 custom_css = """