!!! tip
    This is just standard Python, it's called a "type alias", it's actually not specific to **FastAPI**.

    But because **FastAPI** is based on the Python standards, including `Annotated`, you can use this trick in your code. 😎

    return item


@app.get("/items/")
def read_items() -> list[Item]:
    return [
        Item(
            name="Portal Gun",
            description="Device to travel through the multi-rick-verse",
        ),
        Item(name="Plumbus"),

from fastapi import Depends, FastAPI, HTTPException

app = FastAPI()


class InternalError(Exception):
    pass


def get_username():
    try:
        yield "Rick"
    except InternalError:
        print("Oops, we didn't raise again, Britney 😱")


@app.get("/items/{item_id}")
def get_item(item_id: str, username: str = Depends(get_username)):
    if item_id == "portal-gun":
        raise InternalError(

@app.get("/items/")
async def read_items():
    return [{"item": "Portal Gun"}, {"item": "Plumbus"}]


@app.get("/users/")
async def read_users():

    with pytest.raises(InternalError) as exc_info:
        client.get("/items/portal-gun")
    assert (
        exc_info.value.args[0] == "The portal gun is too dangerous to be owned by Rick"
    )


@needs_py39
def test_internal_server_error():
    from docs_src.dependencies.tutorial008d_an_py39 import app

    client = TestClient(app, raise_server_exceptions=False)

    assert response.json() == ["Portal gun", "Plumbus"]


def test_get_users():
    response = client.get("/users/")
    assert response.status_code == 200, response.text
    assert response.json() == ["Rick", "Morty"]


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",

            "X-Token": "fake-super-secret-token",
            "X-Key": "fake-super-secret-key",
        },
    )
    assert response.status_code == 200, response.text
    assert response.json() == [{"username": "Rick"}, {"username": "Morty"}]


@needs_py39
def test_openapi_schema(client: TestClient):
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text

    return client


def test_users_token_jessica(client: TestClient):
    response = client.get("/users?token=jessica")
    assert response.status_code == 200
    assert response.json() == [{"username": "Rick"}, {"username": "Morty"}]


def test_users_with_no_token(client: TestClient):
    response = client.get("/users")
    assert response.status_code == 422
    assert response.json() == IsDict(
        {

                the OpenAPI version. But some tools, even though they might be
                compatible with OpenAPI 3.1.0, might not recognize it as a valid.

                So you could override this value to trick those tools into using
                the generated OpenAPI. Have in mind that this is a hack. But if you
                avoid using features added in OpenAPI 3.1.0, it might work for your
                use case.

    return item


@app.get("/items/")
def read_items() -> list[Item]:
    return [
        Item(
            name="Portal Gun",
            description="Device to travel through the multi-rick-verse",
        ),
        Item(name="Plumbus"),