This schema definition includes your API paths, the possible parameters they take, etc.

#### Data "schema"

The term "schema" might also refer to the shape of some data, like a JSON content.

In that case, it would mean the JSON attributes, and data types they have, etc.

#### OpenAPI and JSON Schema

Here are some possible ideas:

* An "Init Container" in Kubernetes that runs before your app container
* A bash script that runs the previous steps and then starts your application
    * You would still need a way to start/restart *that* bash script, detect errors, etc.

!!! tip

```

</div>

That would work for most of the cases. 😎

You could use that command for example to start your **FastAPI** app in a container, in a server, etc.

## ASGI Servers

Let's go a little deeper into the details.

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Resumen

En resumen, declaras los tipos de parámetros, body, etc. **una vez** como parámetros de la función.

Lo haces con tipos modernos estándar de Python.

No tienes que aprender una sintaxis nueva, los métodos o clases de una library específica, etc.

Solo **Python** estándar.

Por ejemplo, para un `int`:

```Python
item_id: int
```

* API keys in:
    * Headers.
    * Query parameters.
    * Cookies, etc.

Plus all the security features from Starlette (including **session cookies**).

All built as reusable tools and components that are easy to integrate with your systems, data stores, relational and NoSQL databases, etc.

### Dependency Injection

In this case, you could want to document how that external API *should* look like. What *path operation* it should have, what body it should expect, what response it should return, etc.

## An app with callbacks

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

These invoices will have an `id`, `title` (optional), `customer`, and `total`.

## Documenting webhooks with **FastAPI** and OpenAPI

With **FastAPI**, using OpenAPI, you can define the names of these webhooks, the types of HTTP operations that your app can send (e.g. `POST`, `PUT`, etc.) and the request **bodies** that your app would send.

This can make it a lot easier for your users to **implement their APIs** to receive your **webhook** requests, they might even be able to autogenerate some of their own API code.

Because `Annotated` is **standard Python**, you still get all the **benefits** from editors and tools, like **autocompletion**, **inline errors**, etc.

    * Fájlok.
* Kimeneti adatok <abbr title=" más néven: serialization, parsing, marshalling">átváltása</abbr>: Python adatok is típusokról hálózati adatokká:
    * válts át Python típusokat (`str`, `int`, `float`, `bool`, `list`, etc).
    * `datetime` csak objektumokat.
    * `UUID` objektumokat.
    * Adatbázis modelleket.
    * ...És sok mást.
* Automatikus interaktív dokumentáció, beleértve két alternatív dokumentációt is:
    * Swagger UI.

Linux containers run using the same Linux kernel of the host (machine, virtual machine, cloud server, etc). This just means that they are very lightweight (compared to full virtual machines emulating an entire operating system).