*,
        endpoint_ctx: Optional[EndpointContext] = None,
    ) -> None:
        super().__init__(errors, endpoint_ctx=endpoint_ctx)


class ResponseValidationError(ValidationException):
    def __init__(
        self,
        errors: Sequence[Any],
        *,
        body: Any = None,
        endpoint_ctx: Optional[EndpointContext] = None,
    ) -> None:
        super().__init__(errors, endpoint_ctx=endpoint_ctx)

# Without aliases


@app.post("/optional-str", operation_id="optional_str")
async def read_optional_str(p: Annotated[Optional[str], Body(embed=True)] = None):
    return {"p": p}


class BodyModelOptionalStr(BaseModel):
    p: Optional[str] = None


@app.post("/model-optional-str", operation_id="model_optional_str")
async def read_model_optional_str(p: BodyModelOptionalStr):
    return {"p": p.p}

But if you have specified a custom response class with `None` as its media type, FastAPI will use `application/json` for any additional response that has an associated model.

///

## Combining information { #combining-information }

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int = Path(title="The ID of the item to get", ge=0, le=1000),
    q: str | None = None,
    item: Item | None = None,
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

    url: HttpUrl
    name: str


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None
    tags: set[str] = set()
    images: Union[list[Image], None] = None


class Offer(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    items: list[Item]


@app.post("/offers/")

async def read_optional_list_bytes(p: Annotated[Optional[list[bytes]], File()] = None):
    return {"file_size": [len(file) for file in p] if p else None}


@app.post("/optional-list-uploadfile")
async def read_optional_list_uploadfile(
    p: Annotated[Optional[list[UploadFile]], File()] = None,
):
    return {"file_size": [file.size for file in p] if p else None}


@pytest.mark.parametrize(
    "path",
    [

from fastapi.params import Body, Cookie, Header, Param, Path, Query

test_data: list[Any] = ["teststr", None, ..., 1, []]


def get_user():
    return {}  # pragma: no cover


def test_param_repr_str():
    assert repr(Param("teststr")) == "Param(teststr)"


def test_param_repr_none():
    assert repr(Param(None)) == "Param(None)"


def test_param_repr_ellipsis():
    assert repr(Param(...)) == "Param(PydanticUndefined)"

            "axisLabel": "",
            "axisPlacement": "auto",
            "barAlignment": 0,
            "drawStyle": "line",
            "fillOpacity": 10,
            "gradientMode": "none",
            "hideFrom": {
              "legend": false,
              "tooltip": false,
              "viz": false
            },
            "insertNulls": false,
            "lineInterpolation": "linear",

    url: HttpUrl
    name: str


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()
    images: list[Image] | None = None


class Offer(BaseModel):
    name: str
    description: str | None = None
    price: float
    items: list[Item]


@app.post("/offers/")
async def create_offer(offer: Offer):

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


@app.put("/items/{item_id}")
async def update_item(
    item_id: Annotated[int, Path(title="The ID of the item to get", ge=0, le=1000)],
    q: str | None = None,
    item: Item | None = None,
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})