assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


def test_token():
    access_token = get_access_token(scope="me")
    response = client.get(
        "/users/me", headers={"Authorization": f"Bearer {access_token}"}
    )
    assert response.status_code == 200, response.text
    assert response.json() == {
        "username": "johndoe",

async def read_main(item_id: str, x_token: str = Header()):
    if x_token != fake_secret_token:
        raise HTTPException(status_code=400, detail="Invalid X-Token header")
    if item_id not in fake_db:
        raise HTTPException(status_code=404, detail="Item not found")
    return fake_db[item_id]


@app.post("/items/", response_model=Item)
async def create_item(item: Item, x_token: str = Header()):
    if x_token != fake_secret_token:

                        "500": {"description": "Server error level 0"},
                        "501": {"description": "Server error level 1"},
                        "502": {"description": "Server error level 2"},
                        "503": {"description": "Server error level 3"},
                        "504": {"description": "Server error level 4"},
                        "505": {"description": "Server error level 5"},
                    },

browser("Browser")
proxy["Proxy on http://0.0.0.0:9999/api/v1/app"]
server["Server on http://127.0.0.1:8000/app"]

browser --> proxy
proxy --> server
```

!!! tip
    The IP `0.0.0.0` is commonly used to mean that the program listens on all the IPs available in that machine/server.

The docs UI would also need the OpenAPI schema to declare that this API `server` is located at `/api/v1` (behind the proxy). For example:

    assert response.json() == {"detail": "X-Token header invalid"}


def test_items_bar_with_invalid_token(client: TestClient):
    response = client.get("/items/bar?token=jessica", headers={"X-Token": "invalid"})
    assert response.status_code == 400
    assert response.json() == {"detail": "X-Token header invalid"}


def test_items_with_missing_x_token_header(client: TestClient):

    assert response.json() == {"detail": "X-Token header invalid"}


@needs_py39
def test_items_bar_with_invalid_token(client: TestClient):
    response = client.get("/items/bar?token=jessica", headers={"X-Token": "invalid"})
    assert response.status_code == 400
    assert response.json() == {"detail": "X-Token header invalid"}


@needs_py39
def test_items_with_missing_x_token_header(client: TestClient):

    )


def test_internal_server_error():
    from docs_src.dependencies.tutorial008d_an import app

    client = TestClient(app, raise_server_exceptions=False)
    response = client.get("/items/portal-gun")
    assert response.status_code == 500, response.text

    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "Bearer"


def test_token():
    response = client.get("/items", headers={"Authorization": "Bearer testtoken"})
    assert response.status_code == 200, response.text
    assert response.json() == {"token": "testtoken"}


def test_incorrect_token():

@pytest.fixture(name="client")
def get_client():
    from docs_src.header_params.tutorial001_an_py310 import app

    client = TestClient(app)
    return client


@needs_py310
@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"User-Agent": "testclient"}),
        ("/items", {"X-Header": "notvalid"}, 200, {"User-Agent": "testclient"}),

{!../../../docs_src/middleware/tutorial001.py!}
```

!!! tip "Tipp"
    Beachten Sie, dass benutzerdefinierte proprietäre Header hinzugefügt werden können. <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">Verwenden Sie dafür das Präfix 'X-'</a>.