class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50


settings = Settings()
app = FastAPI()


@app.get("/info")
async def info():
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,

client = TestClient(app)


def get_settings_override():
    return Settings(admin_email="******@****.***")


app.dependency_overrides[get_settings] = get_settings_override


def test_app():
    response = client.get("/info")
    data = response.json()
    assert data == {
        "app_name": "Awesome API",
        "admin_email": "******@****.***",
        "items_per_user": 50,

@lru_cache
def get_settings():
    return Settings()


@app.get("/info")
async def info(settings: Settings = Depends(get_settings)):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,

### Ejecutar el servidor { #run-the-server }

Luego, ejecutarías el servidor pasando las configuraciones como variables de entorno, por ejemplo, podrías establecer un `ADMIN_EMAIL` y `APP_NAME` con:

<div class="termy">

```console
$ ADMIN_EMAIL="******@****.***" APP_NAME="ChimichangApp" fastapi run main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

    monkeypatch.setenv("ADMIN_EMAIL", "******@****.***")
    settings = main_mod.get_settings()
    assert settings.app_name == "Awesome API"
    assert settings.admin_email == "******@****.***"
    assert settings.items_per_user == 50


def test_endpoint(main_mod: ModuleType, monkeypatch: MonkeyPatch):
    monkeypatch.setenv("ADMIN_EMAIL", "******@****.***")
    client = TestClient(main_mod.app)

class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50


settings = Settings()
app = FastAPI()


@app.get("/info")
async def info():
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,

    if mod_name in sys.modules:
        del sys.modules[mod_name]
    monkeypatch.setenv("ADMIN_EMAIL", "******@****.***")
    main_mod = importlib.import_module(mod_name)
    return TestClient(main_mod.app)


def test_settings_validation_error(mod_name: str, monkeypatch: MonkeyPatch):
    monkeypatch.delenv("ADMIN_EMAIL", raising=False)
    if mod_name in sys.modules:
        del sys.modules[mod_name]  # pragma: no cover

from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50

from pydantic.v1 import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50

    class Config:

from fastapi import FastAPI

from .config import settings

app = FastAPI()


@app.get("/info")
async def info():
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,