Der erste Teil der Kommunikation besteht lediglich darin, die Verbindung zwischen dem Client und dem Server herzustellen und die zu verwendenden kryptografischen Schlüssel usw. zu vereinbaren.

<img src="/img/deployment/https/https02.svg">

Diese Interaktion zwischen dem Client und dem Server zum Aufbau der TLS-Verbindung wird als **<abbr title="TLS-Handschlag">TLS-Handshake</abbr>** bezeichnet.

    The HTTP authorization header value is split by the first space.

    The first part is the `scheme`, the second part is the `credentials`.

    For example, in an HTTP Bearer token scheme, the client will send a header
    like:

    ```
    Authorization: Bearer deadbeef12346
    ```

    In this case:

    * `scheme` will have the value `"Bearer"`

* Add a **JSON Schema** for the response, in the OpenAPI *path operation*.
    * This will be used by the **automatic docs**.
    * It will also be used by automatic client code generation tools.

But most importantly:

* It will **limit and filter** the output data to what is defined in the return type.
    * This is particularly important for **security**, we'll see more of that below.

## `response_model` Parameter

* Được thiết kế xung quanh các tiêu chuẩn này sau khi nghiên cứu tỉ mỉ thay vì chỉ suy nghĩ đơn giản và sơ xài.
* Điều này cho phép tự động hóa **trình sinh code client** cho nhiều ngôn ngữ lập trình khác nhau.

### Tự động hóa tài liệu

Ils seront convertis vers leurs valeurs correspondantes (chaînes de caractères ici) avant d'être transmis au client :

```Python hl_lines="18  21  23"
{!../../../docs_src/path_params/tutorial005.py!}
```

Le client recevra une réponse JSON comme celle-ci :

```JSON
{
  "model_name": "alexnet",
  "message": "Deep Learning FTW!"
}
```

It would actually be common to use Requests *inside* of a FastAPI application.

But still, FastAPI got quite some inspiration from Requests.

**Requests** is a library to *interact* with APIs (as a client), while **FastAPI** is a library to *build* APIs (as a server).

They are, more or less, at opposite ends, complementing each other.

Tornando al precedente esempio, **FastAPI**:

* Validerà che esiste un `item_id` nel percorso delle richieste `GET` e `PUT`.
* Validerà che `item_id` sia di tipo `int` per le richieste `GET` e `PUT`.
    * Se non lo è, il client vedrà un errore chiaro e utile.
* Controllerà se ci sia un parametro opzionale chiamato `q` (per esempio `http://127.0.0.1:8000/items/foo?q=somequery`) per le richieste `GET`.

В обоих случаях она будет иметь:

* Необязательный параметр запроса `q`, представляющий собой `str`.
* Параметр запроса `skip`, представляющий собой `int`, по умолчанию `0`.
* Параметр запроса `limit`, представляющий собой `int`, по умолчанию равный `100`.

В обоих случаях данные будут конвертированы, валидированы, документированы по схеме OpenAPI и т.д.

## Как это использовать

flint.png...

    )


def test_main_depends_q_foo():
    response = client.get("/main-depends/?q=foo")
    assert response.status_code == 200
    assert response.json() == {
        "in": "main-depends",
        "params": {"q": "foo", "skip": 0, "limit": 100},
    }


def test_main_depends_q_foo_skip_100_limit_200():
    response = client.get("/main-depends/?q=foo&skip=100&limit=200")
    assert response.status_code == 200