---

"_If you're looking to learn one **modern framework** for building REST APIs, check out **FastAPI** [...] It's fast, easy to use and easy to learn [...]_"

"_We've switched over to **FastAPI** for our **APIs** [...] I think you'll like it [...]_"

**FastAPI** provides several tools to help you deal with **Security** easily, rapidly, in a standard way, without having to study and learn all the security specifications.

But first, let's check some small concepts.

## In a hurry?

If you don't care about any of these terms and you just need to add security with authentication based on username and password *right now*, skip to the next chapters.

## OAuth2

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-03-swagger-02.png)

* Haz click en el botón de "Try it out" que te permite llenar los parámetros e interactuar directamente con la API:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

Таким образом, вы пишете общий код один раз, и **FastAPI** позаботится о его вызове для ваших *операций с путями*.

!!! check "Проверка"
    Обратите внимание, что вы не создаёте специальный класс и не передаёте его куда-то в **FastAPI** для регистрации, или что-то в этом роде.

common_parameters --> read_items
common_parameters --> read_users
```

Auf diese Weise schreiben Sie gemeinsam genutzten Code nur einmal, und **FastAPI** kümmert sich darum, ihn für Ihre *Pfadoperationen* aufzurufen.

!!! check
    Beachten Sie, dass Sie keine spezielle Klasse erstellen und diese irgendwo an **FastAPI** übergeben müssen, um sie zu „registrieren“ oder so ähnlich.

read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

この方法では、共有されるコードを一度書き、**FastAPI** が*path operations*のための呼び出しを行います。

!!! check "確認"
    特別なクラスを作成してどこかで **FastAPI** に渡して「登録」する必要はないことに注意してください。

    `Depends`を渡すだけで、**FastAPI** が残りの処理をしてくれます。

## `async`にするかどうか

依存関係は **FastAPI**（*path operation関数*と同じ）からも呼び出されるため、関数を定義する際にも同じルールが適用されます。

---

"_If you're looking to learn one **modern framework** for building REST APIs, check out **FastAPI** [...] It's fast, easy to use and easy to learn [...]_"

"_We've switched over to **FastAPI** for our **APIs** [...] I think you'll like it [...]_"

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-03-swagger-02.png)

* Click on the button "Try it out", it allows you to fill the parameters and directly interact with the API:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

Most of these ideas would be more or less **independent**, and in most cases you should only need to study them if they apply directly to **your project**.

If something seems interesting and useful to your project, go ahead and check it, but otherwise, you might probably just skip them.

!!! tip

---

"_If you're looking to learn one **modern framework** for building REST APIs, check out **FastAPI** [...] It's fast, easy to use and easy to learn [...]_"

"_We've switched over to **FastAPI** for our **APIs** [...] I think you'll like it [...]_"