Update app.py

app.py

@@ -251,7 +251,7 @@ def generate_response_with_langchain(message, max_retries=3):
             else:
                 return f"I apologize, but I encountered an error while processing your message: {str(e)}"
 
-def chat_response(message, history):
+def chat_response(message, history=None):
     """Process chat message and return response."""
     try:
         # Track metrics with timing context
@@ -272,7 +272,7 @@ def chat_response(message, history):
         logger.error(f"Error in chat_response: {e}")
         return f"I apologize, but I encountered an error while processing your message: {str(e)}"
 
-def respond_with_enhanced_streaming(message, history):
+def respond_with_enhanced_streaming(message, history=None):
     """Enhanced streaming response function."""
     try:
         response = chat_response(message, history)