body:
  - type: markdown
    attributes:
      value: |
        Thanks for your interest in FastAPI! 🚀

        If you are not @tiangolo or he didn't ask you directly to create an issue here, please start the conversation in a [Question in GitHub Discussions](https://github.com/fastapi/fastapi/discussions/categories/questions) instead.
  - type: checkboxes
    id: privileged
    attributes:
      label: Privileged issue

Use the chat only for other general conversations.

///

### Don't use the chat for questions

Keep in mind that as chats allow more "free conversation", it's easy to ask questions that are too general and more difficult to answer, so, you might not receive answers.

            return true;
        }

        // Check for identity or widening reference conversion
        if (actual != null && formal.isAssignableFrom(actual)) {
            return true;
        }

        // Check for boxing with widening primitive conversion. Note that
        // actual parameters are never primitives.
        if (formal.isPrimitive()) {

/// tip

`JSONResponse` itself is a sub-class of `Response`.

///

And when you return a `Response`, **FastAPI** will pass it directly.

It won't do any data conversion with Pydantic models, it won't convert the contents to any type, etc.

This gives you a lot of flexibility. You can return any data type, override any data declaration or validation, etc.

        "name": "The Foo live"
    }
}
```

Again, doing just that declaration, with **FastAPI** you get:

* Editor support (completion, etc.), even for nested models
* Data conversion
* Data validation
* Automatic documentation

## Special types and validation

Apart from normal singular types like `str`, `int`, `float`, etc. you can use more complex singular types that inherit from `str`.

* `int`
* `float`
* `str`
* `bool`

But you can also use more complex data types.

And you will still have the same features as seen up to now:

* Great editor support.
* Data conversion from incoming requests.
* Data conversion for response data.
* Data validation.
* Automatic annotation and documentation.

## Other data types

Here are some of the additional data types you can use:

* `UUID`:

/// tip | Consejo

`JSONResponse` en sí misma es una subclase de `Response`.

///

Y cuando devuelves una `Response`, **FastAPI** la pasará directamente.

No hará ninguna conversión de datos con modelos Pydantic, no convertirá el contenido a ningún tipo, etc.

Esto te da mucha flexibilidad. Puedes devolver cualquier tipo de dato, sobrescribir cualquier declaración de datos o validación, etc.

/// note | "Remarque"

`JSONResponse` est elle-même une sous-classe de `Response`.

///

Et quand vous retournez une `Response`, **FastAPI** la transmet directement.

Elle ne fera aucune conversion de données avec les modèles Pydantic, elle ne convertira pas le contenu en un type quelconque.

///

/// info

To declare headers, you need to use `Header`, because otherwise the parameters would be interpreted as query parameters.

///

## Automatic conversion

`Header` has a little extra functionality on top of what `Path`, `Query` and `Cookie` provide.

Most of the standard headers are separated by a "hyphen" character, also known as the "minus symbol" (`-`).

     * requirement) for the preprocessor to resolve the value to a compatible value or a (string) value than can be
     * unmarshalled into that type. The preprocessor is not required to perform any type conversion but should rather
     * filter out incompatible values from its result.
     *
     * @param value The configuration value to preprocess, must not be {@code null}.