So, data validation, serialization, and documentation, have to be done in code, not automatically. Or they have to be implemented as a framework on top of Falcon, like Hug. This same distinction happens in other frameworks that are inspired by Falcon's design, of having one request object and one response object as parameters.

!!! check "Inspired **FastAPI** to"
    Find ways to get great performance.

        bool,
        Doc(
            """
            When `embed` is `True`, the parameter will be expected in a JSON body as a
            key instead of being the JSON body itself.

            This happens automatically when more than one `Body` parameter is declared.

            Read more about it in the

```Python
    first_name="john", last_name="doe"
```

It's a different thing.

We are using colons (`:`), not equals (`=`).

And adding type hints normally doesn't change what happens from what would happen without them.

But now, imagine you are again in the middle of creating that function, but with type hints.

At the same point, you try to trigger the autocomplete with `Ctrl+Space` and you see:

# OpenAPI Callbacks

You could create an API with a *path operation* that could trigger a request to an *external API* created by someone else (probably the same developer that would be *using* your API).