///

## Add extra information

You can declare extra information in `Field`, `Query`, `Body`, etc. And it will be included in the generated JSON Schema.

You will learn more about adding extra information later in the docs, when learning to declare examples.

/// warning

Extra keys passed to `Field` will also be present in the resulting OpenAPI schema for your application.

        "parameters": [
            {
                "required": False,
                "schema": {"title": "Extra Param 1"},
                "name": "extra_param_1",
                "in": "query",
            },
            {
                "required": True,
                "schema": {"title": "Extra Param 2"},
                "name": "extra_param_2",
                "in": "query",
            },
        ]
    },

        deprecated: Union[deprecated, str, bool, None] = None,
        include_in_schema: bool = True,
        json_schema_extra: Union[Dict[str, Any], None] = None,
        **extra: Any,
    ):
        if example is not _Unset:
            warnings.warn(
                "`example` has been deprecated, please use `examples` instead",
                category=DeprecationWarning,

            Any additional JSON schema data.
            """
        ),
    ] = None,
    **extra: Annotated[
        Any,
        Doc(
            """
            Include extra fields used by the JSON Schema.
            """
        ),
        deprecated(
            """
            The `extra` kwargs is deprecated. Use `json_schema_extra` instead.
            """
        ),
    ],
) -> Any:

        "/login/", data={"username": "Foo", "password": "secret", "extra": "extra"}
    )
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {
                "type": "extra_forbidden",
                "loc": ["body", "extra"],
                "msg": "Extra inputs are not permitted",
                "input": "extra",
            }
        ]
    }


@needs_pydanticv2

    response = client.post(
        "/login/", data={"username": "Foo", "password": "secret", "extra": "extra"}
    )
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {
                "type": "value_error.extra",
                "loc": ["body", "extra"],
                "msg": "extra fields not permitted",
            }
        ]
    }


@needs_pydanticv1

    response = client.post(
        "/login/", data={"username": "Foo", "password": "secret", "extra": "extra"}
    )
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {
                "type": "value_error.extra",
                "loc": ["body", "extra"],
                "msg": "extra fields not permitted",
            }
        ]
    }

    response = client.post(
        "/login/", data={"username": "Foo", "password": "secret", "extra": "extra"}
    )
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {
                "type": "value_error.extra",
                "loc": ["body", "extra"],
                "msg": "extra fields not permitted",
            }
        ]
    }

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## Forbid Extra Headers

In some special use cases (probably not very common), you might want to **restrict** the headers that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

//// tab | Python 3.10+

```Python hl_lines="10"

<div class="screenshot">
<img src="/img/tutorial/query-param-models/image01.png">
</div>

## Forbid Extra Query Parameters

In some special use cases (probably not very common), you might want to **restrict** the query parameters that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

//// tab | Python 3.10+

```Python hl_lines="10"