Update app.py

app.py

@@ -282,18 +282,20 @@ with gr.Blocks(css="""#chatbot { font-size: 14px; min-height: 1200; }""") as dem
     def respond(message, chat_history, url_value, file_value, key_value, model_value):
         if message.strip() == "":
             return "", chat_history  # Return empty message if no input
-        
+
         try:
+            # Ensure chat_history is initialized properly
+            if chat_history is None:
+                chat_history = []
+
             if key_value.strip() == '':
-                chat_history = chat_history + [
-                    [message, '[ERROR]: Please enter your OpenAI API key']
-                ]
+                chat_history.append({"role": "user", "content": message})
+                chat_history.append({"role": "assistant", "content": '[ERROR]: Please enter your OpenAI API key'})
                 return "", chat_history
-            
+
             if url_value.strip() == '' and file_value is None:
-                chat_history = chat_history + [
-                    [message, '[ERROR]: Both URL and PDF are empty. Provide at least one']
-                ]
+                chat_history.append({"role": "user", "content": message})
+                chat_history.append({"role": "assistant", "content": '[ERROR]: Both URL and PDF are empty. Provide at least one'})
                 return "", chat_history
 
             # Process PDF and generate answer
@@ -307,16 +309,15 @@ with gr.Blocks(css="""#chatbot { font-size: 14px; min-height: 1200; }""") as dem
                 load_recommender(file_name)
 
             answer = generate_answer(message, key_value, model_value)
-            
-            # Update chat history with the new message pair
-            chat_history = chat_history + [[message, answer]]
-            
+
+            chat_history.append({"role": "user", "content": message})
+            chat_history.append({"role": "assistant", "content": answer})
+
             return "", chat_history
 
         except Exception as e:
-            chat_history = chat_history + [
-                [message, f'[ERROR]: {str(e)}']
-            ]
+            chat_history.append({"role": "user", "content": message})
+            chat_history.append({"role": "assistant", "content": f'[ERROR]: {str(e)}'})
             return "", chat_history
 
     submit_btn.click(