router = APIRouter()

    @app.post("/", response_model=List[Item], responses={404: {"model": List[Message]}})
    def post_root(item1: Item, item2: Item):
        return item1, item2  # pragma: nocover

    @router.post(
        "/router", response_model=List[Item], responses={404: {"model": List[Message]}}
    )
    def post_router(item1: Item, item2: Item):

    client = get_client()
    response = client.get("/openapi.json")
    assert response.status_code == 404, response.text
    response = client.get("/docs")
    assert response.status_code == 404, response.text
    response = client.get("/redoc")
    assert response.status_code == 404, response.text


@needs_pydanticv2
def test_root():
    client = get_client()
    response = client.get("/")

    responses={404: {"description": "Not found"}},
)


fake_items_db = {"plumbus": {"name": "Plumbus"}, "gun": {"name": "Portal Gun"}}


@router.get("/")
async def read_items():
    return fake_items_db


@router.get("/{item_id}")
async def read_item(item_id: str):
    if item_id not in fake_items_db:
        raise HTTPException(status_code=404, detail="Item not found")

class Message(BaseModel):
    message: str


app = FastAPI()


@app.get("/items/{item_id}", response_model=Item, responses={404: {"model": Message}})
async def read_item(item_id: str):
    if item_id == "foo":
        return {"id": "foo", "value": "there goes my hero"}

app = FastAPI()

items = {"foo": "The Foo Wrestlers"}


@app.get("/items/{item_id}")
async def read_item(item_id: str):
    if item_id not in items:
        raise HTTPException(
            status_code=404,
            detail="Item not found",
            headers={"X-Error": "Some custom header"},
        )
    return {"item": items[item_id]}


@app.get("/http-no-body-statuscode-exception")

    assert response.json() == {"id": "foo", "value": "there goes my hero"}


def test_path_operation_not_found():
    response = client.get("/items/bar")
    assert response.status_code == 404, response.text
    assert response.json() == {"message": "Item not found"}


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

                          example: "text/html"
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '500':
          $ref: '#/components/responses/InternalServerError'

  /documents/all:
    get:
      tags:
        - search

    assert response.json() == {"id": "foo", "value": "there goes my hero"}


def test_path_operation_not_found():
    response = client.get("/items/bar")
    assert response.status_code == 404, response.text
    assert response.json() == {"message": "Item not found"}


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

    responses={404: {"description": "Not found"}},
)


fake_items_db = {"plumbus": {"name": "Plumbus"}, "gun": {"name": "Portal Gun"}}


@router.get("/")
async def read_items():
    return fake_items_db


@router.get("/{item_id}")
async def read_item(item_id: str):
    if item_id not in fake_items_db:
        raise HTTPException(status_code=404, detail="Item not found")

**FastAPI** nimmt dieses Modell, generiert dessen JSON-Schema und fügt es an der richtigen Stelle in OpenAPI ein.

Um beispielsweise eine weitere Response mit dem Statuscode `404` und einem Pydantic-Modell `Message` zu deklarieren, können Sie schreiben:

```Python hl_lines="18  22"
{!../../../docs_src/additional_responses/tutorial001.py!}
```

!!! note "Hinweis"