## Resource Utilization

Your server(s) is (are) a **resource**, you can consume or **utilize**, with your programs, the computation time on the CPUs, and the RAM memory available.

!!! info

* Jak ustawić **ograniczenia walidacyjne** takie jak `maksymalna długość` lub `regex`.
* Potężny i łatwy w użyciu system **<abbr title="znane jako komponenty, resources, providers, services, injectables">Dependency Injection</abbr>**.
* Zabezpieczenia i autentykacja, wliczając wsparcie dla **OAuth2** z **tokenami JWT** oraz autoryzacją **HTTP Basic**.

* Come stabilire **vincoli di validazione** come `maximum_length` o `regex`.
* Un sistema di **<abbr title="detto anche components, resources, providers, services, injectables">Dependency Injection</abbr>** facile da usare e molto potente.
e potente.
* Sicurezza e autenticazione, incluso il supporto per **OAuth2** con **token JWT** e autenticazione **HTTP Basic**.

    ```Python
    from main import app
    ```

!!! warning
    Uvicorn and others support a `--reload` option that is useful during development.

    The `--reload` option consumes much more resources, is more unstable, etc.

    It helps a lot during **development**, but you **shouldn't** use it in **production**.

## Hypercorn with Trio

### Dependency Injection

FastAPI bao gồm một hệ thống <abbr title='cũng biết đến như là "components", "resources", "services", "providers"'><strong>Dependency Injection</strong></abbr> vô cùng dễ sử dụng nhưng vô cùng mạnh mẽ.

For example, you might want to try <a href="https://speakeasyapi.dev/?utm_source=fastapi+repo&utm_medium=github+sponsorship" class="external-link" target="_blank">Speakeasy</a>.

There are also several other companies offering similar services that you can search and find online. 🤓

...the path would be:

```
/items/foo
```

!!! info
    A "path" is also commonly called an "endpoint" or a "route".

While building an API, the "path" is the main way to separate "concerns" and "resources".

#### Operation

"Operation" here refers to one of the HTTP "methods".

One of:

* `POST`
* `GET`
* `PUT`
* `DELETE`

...and the more exotic ones:

* `OPTIONS`

**剧透警告**： 教程 - 用户指南中的内容有：

* 对来自不同地方的参数进行声明，如：**请求头**、**cookies**、**form 表单**以及**上传的文件**。
* 如何设置**校验约束**如 `maximum_length` 或者 `regex`。
* 一个强大并易于使用的 **<abbr title="也被称为 components, resources, providers, services, injectables">依赖注入</abbr>** 系统。
* 安全性和身份验证，包括通过 **JWT 令牌**和 **HTTP 基本身份认证**来支持 **OAuth2**。
* 更进阶（但同样简单）的技巧来声明 **多层嵌套 JSON 模型** （借助 Pydantic）。
* 许多额外功能（归功于 Starlette）比如：
    * **WebSockets**

## `fastapi dev`

When you run `fastapi dev`, it will run on development mode.

By default, it will have **auto-reload** enabled, so it will automatically reload the server when you make changes to your code. This is resource intensive and could be less stable than without it, you should only use it for development.

By default it will listen on the IP address `127.0.0.1`, which is the IP for your machine to communicate with itself alone (`localhost`).