app.py

import os
from langchain import hub
from langchain.agents import AgentExecutor, create_openai_tools_agent
from langchain_community.tools.tavily_search import TavilySearchResults
from langchain_openai import ChatOpenAI
import streamlit as st

# Securely set API keys (e.g., in a .streamlit/secrets.toml file or environment variables)
OPENAI_API_KEY = os.getenv('OPENAI_API_KEY')
TAVILY_API_KEY = os.getenv('TAVILY_API_KEY')

if not OPENAI_API_KEY or not TAVILY_API_KEY:
    st.error("API keys for OpenAI and Tavily are not set. Please configure them properly.")
    st.stop()

# Create GPT-3.5 instance
llm = ChatOpenAI(model_name="gpt-4o", temperature=0.7, max_tokens=4096)

# Use Tavily as the tool for web searching
tools = [TavilySearchResults(max_results=1)]

# Retrieve the agent prompt from LangChain Hub
try:
    prompt = hub.pull("hwchase17/openai-tools-agent")
except Exception as e:
    st.error(f"Failed to load prompt from hub: {e}")
    st.stop()

# Construct the OpenAI tools agent
agent = create_openai_tools_agent(llm, tools, prompt)

# Create the agent executor by passing in the agent and tools
agent_executor = AgentExecutor(agent=agent, tools=tools, verbose=True)

# Build the Streamlit web app
st.title("ChatGPT ")

user_input = st.text_input("What do you want to know?")

# Process input and display response
if user_input:
    try:
        response = agent_executor.invoke({"input": user_input})
        st.write(response.get("output", "No output received. Please try again."))
    except Exception as e:
        st.error(f"Error processing your request: {e}")