A common tool is <a href="https://openapi-generator.tech/" class="external-link" target="_blank">OpenAPI Generator</a>.

If you are building a **frontend**, a very interesting alternative is <a href="https://github.com/hey-api/openapi-ts" class="external-link" target="_blank">openapi-ts</a>.

## Client and SDK Generators - Sponsor

            It will affect the generated OpenAPI (e.g. visible at `/docs`).
            """
        ),
    ] = None,
    include_in_schema: Annotated[
        bool,
        Doc(
            """
            To include (or not) this parameter field in the generated OpenAPI.
            You probably don't need it, but it's available.

            This affects the generated OpenAPI (e.g. visible at `/docs`).

```

### `StreamingResponse`

Takes an async generator or a normal generator/iterator and streams the response body.

```Python hl_lines="2  14"
{!../../../docs_src/custom_response/tutorial007.py!}
```

#### Using `StreamingResponse` with file-like objects

If you have a file-like object (e.g. the object returned by `open()`), you can create a generator function to iterate over that file-like object.

    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,
        separate_input_output_schemas=separate_input_output_schemas,
    )

        )
        inputs = [
            (field, override_mode or field.mode, field._type_adapter.core_schema)
            for field in fields
        ]
        field_mapping, definitions = schema_generator.generate_definitions(
            inputs=inputs
        )
        return field_mapping, definitions  # type: ignore[return-value]

    def is_scalar_field(field: ModelField) -> bool:
        from fastapi import params

    ```
    pip install async-exit-stack async-generator
    ```

    これにより<a href="https://github.com/sorcio/async_exit_stack" class="external-link" target="_blank">async-exit-stack</a>と<a href="https://github.com/python-trio/async_generator" class="external-link" target="_blank">async-generator</a>がインストールされます。

!!! note "技術詳細"
    以下と一緒に使用できる関数なら何でも有効です:

And these same full-stack generators were the base of the [**FastAPI** Project Generators](project-generation.md){.internal-link target=_blank}.

!!! info
    Flask-apispec was created by the same Marshmallow developers.

!!! check "Inspired **FastAPI** to"
    Generate the OpenAPI schema automatically, from the same code that defines serialization and validation.

![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png)

### OpenAPI

**FastAPI** generates a "schema" with all your API using the **OpenAPI** standard for defining APIs.

#### "Schema"

A "schema" is a definition or description of something. Not the code that implements it, but just an abstract description.

* Add a **JSON Schema** for the response, in the OpenAPI *path operation*.
    * This will be used by the **automatic docs**.
    * It will also be used by automatic client code generation tools.

But most importantly:

* It will **limit and filter** the output data to what is defined in the return type.
    * This is particularly important for **security**, we'll see more of that below.

                It will be included in the generated OpenAPI (e.g. visible at `/docs`).
                """
            ),
        ] = None,
        description: Annotated[
            Optional[str],
            Doc(
                """
                Security scheme description.

                It will be included in the generated OpenAPI (e.g. visible at `/docs`).
                """