To understand the motivation behind this package, you might want to read about fail fast.

What this package does is to make sure you are reading all the environment variables at startup.

Consider that you have a folder with the following structure:

app/
├── __init__.py
└── main.py

Inside of main.py you have:

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def index():
    name = os.environ["APP_NAME"]
    return {"message": f"Hello, {name}!"}

If you run this application, it will run without any problem, but if you forget to set the APP_NAME environment variable, you will get an error when you try to access the / endpoint.

To avoid this, you can use this package.

If you decide to use it, your folder structure will look like this:

app/
├── __init__.py
├── main.py
└── config.py

Your config.py will look like this:

from pydantic import BaseSettings

class Settings(BaseSettings):
    APP_NAME: str

settings = Settings()

And your main.py will look like this:

from fastapi import FastAPI
from app.config import settings

app = FastAPI()

@app.get("/")
def index():
    name = settings.APP_NAME
    return {"message": f"Hello, {name}!"}

You can install load-env-vars-at-startup via pip:

pip install load-env-vars-at-startup

levas DIR

Where DIR is the directory of your application.

This project is licensed under the terms of the MIT license.