provided in one of multiple optional ways (for example, in HTTP Basic
                authentication or in an HTTP Bearer token).
                """
            ),
        ] = True,
    ):
        self.model = HTTPBaseModel(scheme="basic", description=description)
        self.scheme_name = scheme_name or self.__class__.__name__
        self.realm = realm
        self.auto_error = auto_error

### OpenAPI

**FastAPI** generates a "schema" with all your API using the **OpenAPI** standard for defining APIs.

#### "Schema"

A "schema" is a definition or description of something. Not the code that implements it, but just an abstract description.

#### API "schema"

Alternatively, if you don't have a way to provide a command line option like `--root-path` or equivalent, you can set the `root_path` parameter when creating your FastAPI app:

```Python hl_lines="3"
{!../../../docs_src/behind_a_proxy/tutorial002.py!}
```

Passing the `root_path` to `FastAPI` would be the equivalent of passing the `--root-path` command line option to Uvicorn or Hypercorn.

### About `root_path`

In this case, it would be better to get **one extra server** and run some processes on it so that they all have **enough RAM and CPU time**.

You do that with standard modern Python types.

You don't have to learn a new syntax, the methods or classes of a specific library, etc.

Just standard **Python**.

For example, for an `int`:

```Python
item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```

...and with that single declaration you get:

# Settings and Environment Variables

In many cases your application could need some external settings or configurations, for example secret keys, database credentials, credentials for email services, etc.

Most of these settings are variable (can change), like database URLs. And many could be sensitive, like secrets.

For this reason it's common to provide them in environment variables that are read by the application.

## Environment Variables

!!! tip

# If running behind a proxy like Nginx or Traefik add --proxy-headers
# CMD ["fastapi", "run", "app/main.py", "--port", "80", "--proxy-headers"]
```

</details>

## What is a Container

Containers (mainly Linux containers) are a very **lightweight** way to package applications including all their dependencies and necessary files while keeping them isolated from other containers (other applications or components) in the same system.

You do that with standard modern Python types.

You don't have to learn a new syntax, the methods or classes of a specific library, etc.

Just standard **Python**.

For example, for an `int`:

```Python
item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```

...and with that single declaration you get:

有關更多功能的完整範例，可以參考 <a href="https://fastapi.tiangolo.com/tutorial/">教學 - 使用者指南</a>。

**劇透警告**： 教學 - 使用者指南內容有：

- 對來自不同地方的**參數**進行宣告：像是 **headers**, **cookies**, **form 表單**以及**上傳檔案**。
- 如何設定 **驗證限制** 像是 `maximum_length` or `regex`。
- 簡單且非常容易使用的 **<abbr title="也被稱為元件、資源、提供者、服務或是注入">依賴注入</abbr>** 系統。
- 安全性和身份驗證，包含提供支援 **OAuth2**、**JWT tokens** 和 **HTTP Basic** 驗證。
- 更進階 (但同樣簡單) 的宣告 **多層次的巢狀 JSON 格式** (感謝 Pydantic)。