Update app.py

app.py

@@ -71,7 +71,7 @@ from langchain_openai import ChatOpenAI
 from langchain.callbacks.streaming_stdout import StreamingStdOutCallbackHandler
 
 llm = ChatOpenAI(
-    model="gpt-4o",
+    model="gpt-4o-mini",
     temperature=0,
     max_tokens=None,
     timeout=None,