When referring to the remote machine, it's common to call it **server**, but also **machine**, **VM** (virtual machine), **node**. Those all refer to some type of remote machine, normally running Linux, where you run programs.

## Install the Server Program

When you install FastAPI, it comes with a production server, Uvicorn, and you can start it with the `fastapi run` command.

You can define *path operation function* parameters to be of the type `UploadFile` to receive files from the request.

You can import it directly from `fastapi`:

```python
from fastapi import UploadFile
```

::: fastapi.UploadFile
    options:
        members:
            - file
            - filename
            - size
            - headers
            - content_type
            - read
            - write

        "hashed_password": "$2b$12$EixZaYVK1fsbw1ZfbX3OXePaWxn96p36WQoeG6Lruj3vjPGga31lW",
        "disabled": False,
    }
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None

You can customize several metadata configurations in your **FastAPI** application.

## Metadata for API

You can set the following fields that are used in the OpenAPI specification and the automatic API docs UIs:

| Parameter | Type | Description |
|------------|------|-------------|
| `title` | `str` | The title of the API. |
| `summary` | `str` | A short summary of the API. <small>Available since OpenAPI 3.1.0, FastAPI 0.99.0.</small> |

{!../../../docs_src/security/tutorial003.py!}
```

`OAuth2PasswordRequestForm` 是用以下几项内容声明表单请求体的类依赖项：

* `username`
* `password`
* 可选的 `scope` 字段，由多个空格分隔的字符串组成的长字符串
* 可选的 `grant_type`

!!! tip "提示"

    实际上，OAuth2 规范*要求* `grant_type` 字段使用固定值 `password`，但 `OAuth2PasswordRequestForm` 没有作强制约束。

    如需强制使用固定值 `password`，则不要用 `OAuth2PasswordRequestForm`，而是用 `OAuth2PasswordRequestFormStrict`。

* 可选的 `client_id`（本例未使用）

        "hashed_password": "$2b$12$gSvqqUPvlXP2tfVFaWK1Be7DlH.PKZbv5H8KnzzVgXXbVxpva.pFm",
        "disabled": True,
    },
}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: Union[str, None] = None
    scopes: List[str] = []


class User(BaseModel):
    username: str
    email: Union[str, None] = None

    ```

`OAuth2PasswordRequestForm` 🎓 🔗 👈 📣 📨 💪 ⏮️:

*  `username`.
*  `password`.
* 📦 `scope` 🏑 🦏 🎻, ✍ 🎻 🎏 🚀.
* 📦 `grant_type`.

!!! tip
    Oauth2️⃣ 🔌 🤙 *🚚* 🏑 `grant_type` ⏮️ 🔧 💲 `password`, ✋️ `OAuth2PasswordRequestForm` 🚫 🛠️ ⚫️.

    🚥 👆 💪 🛠️ ⚫️, ⚙️ `OAuth2PasswordRequestFormStrict` ↩️ `OAuth2PasswordRequestForm`.

* 📦 `client_id` (👥 🚫 💪 ⚫️ 👆 🖼).

# WebSockets

When defining WebSockets, you normally declare a parameter of type `WebSocket` and with it you can read data from the client and send data to it.

It is provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi import WebSocket
```

!!! tip

    And your *path operation* has a little lock in the top-right corner that you can click.

And if you click it, you have a little authorization form to type a `username` and `password` (and other optional fields):

<img src="/img/tutorial/security/image02.png">

!!! note
    It doesn't matter what you type in the form, it won't work yet. But we'll get there.

```JSON
{
    "detail": [
        {
            "loc": [
                "query",
                "needy"
            ],
            "msg": "field required",
            "type": "value_error.missing"
        }
    ]
}
```

`needy` は必須のパラメータなので、URLにセットする必要があります:

```
http://127.0.0.1:8000/items/foo-item?needy=sooooneedy
```

...これはうまくいくでしょう:

```JSON