Update app.py

app.py

@@ -39,21 +39,20 @@ from langchain.memory import ConversationBufferMemory
 from streamlit_extras.add_vertical_space import add_vertical_space
 from streamlit_extras.chat_elements import message
 
-# Set OpenAI API Key
-os.environ["OPENAI_API_KEY"] = ""
-
-# Initialize the chatbot
-@st.cache_resource
-def init_chatbot():
+# Set OpenAI API Key (Ensure you add it in Streamlit Secrets)
+if "openai_api_key" in st.secrets:
+    os.environ["OPENAI_API_KEY"] = st.secrets["openai_api_key"]
+else:
+    st.error("🔑 OpenAI API Key is missing! Please add it to Streamlit secrets.")
+    st.stop()
+
+# Initialize chatbot
+def init_chatbot(model="gpt-4o-mini"):
     memory = ConversationBufferMemory()
-    chatbot = ConversationChain(
-        llm=ChatOpenAI(model="gpt-4o-mini"),
-        memory=memory,
-        verbose=False
-    )
-    return chatbot
+    return ConversationChain(llm=ChatOpenAI(model=model), memory=memory, verbose=False)
 
-chatbot = init_chatbot()
+if "chatbot" not in st.session_state:
+    st.session_state.chatbot = init_chatbot()
 
 # Custom Styling
 st.markdown("""
@@ -74,13 +73,13 @@ st.markdown("""
 st.sidebar.title("⚙️ Settings")
 model_choice = st.sidebar.radio("Select Model", ("gpt-4o-mini", "gpt-4", "gpt-3.5-turbo"))
 
-# Update model based on user selection
-if model_choice:
-    chatbot.llm = ChatOpenAI(model=model_choice)
+# Update chatbot model if changed
+if model_choice != st.session_state.chatbot.llm.model_name:
+    st.session_state.chatbot = init_chatbot(model_choice)
 
 # Title and Description
 st.title("💬 LangChain AI Chatbot")
-st.write("### Hi, I'm a chatbot built with Langchain powered by GPT. How can I assist you today?")
+st.write("### Hi, I'm a chatbot built with LangChain powered by GPT. How can I assist you today?")
 
 # Chat history
 if "chat_history" not in st.session_state:
@@ -92,9 +91,10 @@ user_input = st.text_input("You:", placeholder="Ask me anything...")
 # Process input
 if user_input:
     with st.spinner("Thinking..."):
-        response = chatbot.run(user_input)
-        st.session_state.chat_history.append(("user", user_input))
-        st.session_state.chat_history.append(("bot", response))
+        response = st.session_state.chatbot.run(user_input)
+        if response:
+            st.session_state.chat_history.append(("user", user_input))
+            st.session_state.chat_history.append(("bot", response))
 
 # Display chat history
 st.write("### 🗨️ Conversation")