Update app.py

app.py

@@ -13,6 +13,9 @@ IBM_PROJECT_ID = "a0659778-f4ce-4da1-ba01-43b4f43a026f"
 IBM_URL_TOKEN = "https://iam.cloud.ibm.com/identity/token"
 IBM_URL_CHAT = "https://us-south.ml.cloud.ibm.com/ml/v1/text/chat?version=2023-10-25"
 
+if "messages" not in st.session_state:
+    st.session_state.messages = []
+    
 ##############################################
 ##
 ##   IBM API