**Spoiler alert**: the tutorial - user guide includes:

* Declaration of **parameters** from other different places as: **headers**, **cookies**, **form fields** and **files**.
* How to set **validation constraints** as `maximum_length` or `regex`.

    operation_ids: Set[str] = set()
    all_fields = get_fields_from_routes(list(routes or []) + list(webhooks or []))
    model_name_map = get_compat_model_name_map(all_fields)
    schema_generator = GenerateJsonSchema(ref_template=REF_TEMPLATE)
    field_mapping, definitions = get_definitions(
        fields=all_fields,
        schema_generator=schema_generator,
        model_name_map=model_name_map,

    # in case a sub-dependency is evaluated with a single unique body field
    # That is combined (embedded) with other body fields
    for param in flat_dependant.body_params:
        setattr(param.field_info, "embed", True)  # noqa: B010
    model_name = "Body_" + name
    BodyModel = create_body_model(
        fields=flat_dependant.body_params, model_name=model_name
    )

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient

from ...utils import needs_py310


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

    client = TestClient(app)
    return client


@needs_py310
def test_items_5(client: TestClient):
    response = client.put("/items/5", json={"item": {"name": "Foo", "price": 3.0}})

        )[0]

    def get_compat_model_name_map(fields: List[ModelField]) -> ModelNameMap:
        models = get_flat_models_from_fields(fields, known_models=set())
        return get_model_name_map(models)  # type: ignore[no-any-return]

    def get_definitions(
        *,
        fields: List[ModelField],
        schema_generator: GenerateJsonSchema,
        model_name_map: ModelNameMap,

    ```

For example, in one of the ways the OAuth2 specification can be used (called "password flow") it is required to send a `username` and `password` as form fields.

The <abbr title="specification">spec</abbr> requires the fields to be exactly named `username` and `password`, and to be sent as form fields, not JSON.

### Model for Output Response Data

If you interact with the docs and check the response, even though the code didn't add anything in one of the `description` fields, the JSON response contains the default value (`null`):

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image02.png">
</div>

## Typhinweise mit Metadaten-Annotationen

Python bietet auch die Möglichkeit, **zusätzliche Metadaten** in Typhinweisen unterzubringen, mittels `Annotated`.

                response_field = create_response_field(name=response_name, type_=model)
                response_fields[additional_status_code] = response_field
        if response_fields:
            self.response_fields: Dict[Union[int, str], ModelField] = response_fields
        else:
            self.response_fields = {}

        assert callable(endpoint), "An endpoint must be a callable"

            Pydantic's `include` parameter, passed to Pydantic models to set the
            fields to include.
            """
        ),
    ] = None,
    exclude: Annotated[
        Optional[IncEx],
        Doc(
            """
            Pydantic's `exclude` parameter, passed to Pydantic models to set the
            fields to exclude.
            """
        ),
    ] = None,
    by_alias: Annotated[