def serialize_a_uuid(self, v):
            return str(v)

    @app.get("/get_custom_class")
    def return_some_user():
        # Test that the fix also works for custom pydantic classes
        return SomeCustomClass(a_uuid=MyUuid("b8799909-f914-42de-91bc-95c819218d01"))

    client = TestClient(app)

    with client:
        response_simple = client.get("/fast_uuid")

/// tip

If you need GraphQL, I still would recommend you check out <a href="https://strawberry.rocks/" class="external-link" target="_blank">Strawberry</a>, as it's based on type annotations instead of custom classes and types.

///

## Learn More { #learn-more }

You can learn more about **GraphQL** in the <a href="https://graphql.org/" class="external-link" target="_blank">official GraphQL documentation</a>.

/// tip | Dica

Se você precisa de GraphQL, eu ainda recomendaria que você desse uma olhada no <a href="https://strawberry.rocks/" class="external-link" target="_blank">Strawberry</a>, pois ele é baseado em anotações de tipo em vez de classes e tipos personalizados.

///

## Saiba Mais { #learn-more }

Você pode aprender mais sobre **GraphQL** na <a href="https://graphql.org/" class="external-link" target="_blank">documentação oficial do GraphQL</a>.

            if route.status_code is not None:
                status_code = str(route.status_code)
            else:
                # It would probably make more sense for all response classes to have an
                # explicit default status_code, and to extract it from them, instead of
                # doing this inspection tricks, that would probably be in the future

### Recap

In summary, you declare **once** the types of parameters, body, etc. as function parameters.

You do that with standard modern Python types.

You don't have to learn a new syntax, the methods or classes of a specific library, etc.

Just standard **Python**.

For example, for an `int`:

```Python
item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```

Example:

    Source (English):

        «««
        <abbr title="Object Relational Mapper: a fancy term for a library where some classes represent SQL tables and instances represent rows in those tables">ORM</abbr>
        »»»

    Result (German):

        «««

## 0.122.0

### Fixes

* 🐛 Use `401` status code in security classes when credentials are missing. PR [#13786](https://github.com/fastapi/fastapi/pull/13786) by [@YuriiMotov](https://github.com/YuriiMotov).

### Recap { #recap }

In summary, you declare **once** the types of parameters, body, etc. as function parameters.

You do that with standard modern Python types.

You don't have to learn a new syntax, the methods or classes of a specific library, etc.

Just standard **Python**.

For example, for an `int`:

```Python
item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```