Because `Annotated` can have more than one metadata annotation, you could now even use the same function with other tools, like <a href="https://typer.tiangolo.com/" class="external-link" target="_blank">Typer</a>. 🚀

## Add more validations

* After being able to understand the question, you can give them a possible **answer**.

* In many cases, it's better to understand their **underlying problem or use case**, because there might be a better way to solve it than what they are trying to do.

### Ask to close

If they reply, there's a high chance you would have solved their problem, congrats, **you're a hero**! 🦸

* Now, if that solved their problem, you can ask them to:

Import the `Response` class (sub-class) you want to use and declare it in the *path operation decorator*.

For large responses, returning a `Response` directly is much faster than returning a dictionary.

And as you can have parallelism and asynchronicity at the same time, you get higher performance than most of the tested NodeJS frameworks and on par with Go, which is a compiled language closer to C <a href="https://www.techempower.com/benchmarks/#section=data-r17&hw=ph&test=query&l=zijmkf-1" class="external-link" target="_blank">(all thanks to Starlette)</a>.

### Is concurrency better than parallelism?

Nope! That's not the moral of the story.

If you are developing an application with an older non-async framework, and can work with all its defaults, **it can be a great tool**.

But if you need to change some of the defaults, support more than one predefined database, work with an async framework (like FastAPI), etc, you will need to add quite some complex extra code to override those defaults.

In this case, it requires the scope `me` (it could require more than one scope).

!!! note
    You don't necessarily need to add different scopes in different places.

    We are doing it here to demonstrate how **FastAPI** handles scopes declared at different levels.

    assert response.json() == IsDict(
        {
            "detail": [
                {
                    "type": "greater_than",
                    "loc": ["path", "item_id"],
                    "msg": "Input should be greater than 3",
                    "input": "2",
                    "ctx": {"gt": 3.0},
                }
            ]
        }
    ) | IsDict(

Таким образом, `0.5` будет корректным значением. А `0.0` или `0` — нет.

То же самое справедливо и для <abbr title="less than"><code>lt</code></abbr>.

=== "Python 3.9+"

* Memory
* Previous steps before starting

## Memory

If you run **a single process per container** you will have a more or less well-defined, stable, and limited amount of memory consumed by each of those containers (more than one if they are replicated).

    Because of that, versions of FastAPI previous to 0.99.0 still used versions of OpenAPI lower than 3.1.0.

### Pydantic and FastAPI `examples`

When you add `examples` inside a Pydantic model, using `schema_extra` or `Field(examples=["something"])` that example is added to the **JSON Schema** for that Pydantic model.