Issue on docs: how to use the Environment Variables for Public Apps

[cuicaihao]

how to use the Public Apps & Environment Variables

• langchain == 0.2.0
• openai == 1.30.1

Path: /backend/env-variables
https://docs.chainlit.io/backend/env-variables

Public Apps & Environment Variables
If you want to share your app to a broader audience, you should not put your own OpenAI API keys in the .env file. Instead, you >should use user_env in the Chainlit config to ask each user to provide their own keys.
You can then access the user’s keys in your code using:

user_env = cl.user_session.get("env")

Code and Python and Pkgs

I don't fully understand the above settings.
Here is my sample code:

"""Python file to serve as the frontend"""
import os
import sys
sys.path.append(os.path.abspath('.'))

from openai import AsyncOpenAI
import chainlit as cl
 
from dotenv import load_dotenv
load_dotenv()

# user_env = cl.user_session.get("OPENAI_API_KEY")
# os.environ["OPENAI_API_KEY"] = user_env["OPENAI_API_KEY"]

api_key = os.environ.get("OPENAI_API_KEY")
client = AsyncOpenAI(api_key=api_key)

# Instrument the OpenAI client
cl.instrument_openai()

settings = {
    "model": "gpt-3.5-turbo",
    "temperature": 0,
    # ... more settings
}


# @cl.on_chat_start
# async def on_start():
#     await cl.Message("Hello world from Caihao Cui!").send()

@cl.on_settings_update
async def on_settings_update(settings: dict):
    print("Settings updated:", settings)


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

    user_env = cl.user_session.get("user_env")
    api_key = user_env["OPENAI_API_KEY"]
    open.api_key = api_key
    
    # Instrument the OpenAI client
    cl.instrument_openai()
    response = await client.chat.completions.create(
        messages=[
            {
                "content": "You are a helpful bot, you always reply in English",
                "role": "system"
            },
            {
                "content": message.content,
                "role": "user"
            }
        ],
        **settings
    )
    await cl.Message(content=response.choices[0].message.content).send()


if __name__ == "__main__":
    from chainlit.cli import run_chainlit
    run_chainlit(__file__)

moreover in the '.chainlit/config.toml' I made this change.

...
# List of environment variables to be provided by each user to use the app.
user_env = ["OPENAI_API_KEY"]
...

Environment Setting (Python 3.11.9):

chainlit == 1.1.101
langchain == 0.2.0
openai == 1.30.1
streamlit == 1.34.0
streamlit-chat == 0.1.1

Issue / Error message

2024-05-19 16:09:34 - Loaded .env file
2024-05-19 16:09:35 - Your app is available at http://localhost:8000
2024-05-19 16:09:36 - Translation file for en not found. Using default translation en-US.
2024-05-19 16:09:37 - Translated markdown file for en not found. Defaulting to chainlit.md.
2024-05-19 16:09:40 - 'NoneType' object is not subscriptable
Traceback (most recent call last):
  File "/Users/PROJECTG_ROOT/.venv/lib/python3.11/site-packages/chainlit/utils.py", line 40, in wrapper
    return await user_function(**params_values)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/UsersPROJECTG_ROOT/demo_app/main.py", line 41, in on_message
    api_key = user_env["OPENAI_API_KEY"]
              ~~~~~~~~^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not subscriptable
2024-05-19 16:09:48 - Translation file for en not found. Using default translation en-US.
^C% 

[jefflavallee]

Your user_env = cl.user_session.get("user_env") should be user_env = cl.user_session.get("env")