langchain_integration.py

import chainlit as cl
import openai
import os
from langchain import PromptTemplate, OpenAI, LLMChain


template = """Question: {question}

Answer: Let's think step by step."""

@cl.on_chat_start
def main():
    prompt = PromptTemplate(template=template, input_variables = ["question"])
    llm_chain = LLMChain(prompt = prompt,llm=OpenAI(temperature=0,streaming=True),verbose=True)

    cl.user_session.set("llm_chain",llm_chain)

@cl.on_message
async def main(message : str):
    llm_chain = cl.user_session.get("llm_chain")

    res = await llm_chain.acall(message, callbacks=[cl.AsyncLangchainCallbackHandler()])

    await cl.Message(content=res["text"]).send()