app.py

import chainlit as cl

@cl.on_chat_start
async def on_chat_start():
    
    await cl.Message(content=f'Hello, How can I help you today?').send()

@cl.on_message
async def on_message(message: cl.Message):

    await cl.Message(
        content=f"Received: {message.content}",
    ).send()