## Use `CORSMiddleware` { #use-corsmiddleware }

You can configure it in your **FastAPI** application using the `CORSMiddleware`.

* Import `CORSMiddleware`.
* Create a list of allowed origins (as strings).
* Add it as a "middleware" to your **FastAPI** application.

You can also specify whether your backend allows:

* Credentials (Authorization headers, Cookies, etc).

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Waiting for application startup.
     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Application startup complete.
```

</div>

该命令行程序 `fastapi` 就是 **FastAPI CLI**。

FastAPI CLI 接收你的 Python 程序路径，自动检测包含 FastAPI 的变量（通常命名为 `app`）及其导入方式，然后启动服务。

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Waiting for application startup.
     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Application startup complete.
```

</div>

**强烈建议**您在本地编写或复制代码，对其进行编辑并运行。

在编辑器中使用 FastAPI 会真正地展现出它的优势：只需要编写很少的代码，所有的类型检查，代码补全等等。

---

## 安装 FastAPI

                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        }
                    },
                    "summary": "Read Current User",
                    "operationId": "read_current_user_users_me_get",

**FastAPI** позаботится о том, чтобы считать эти данные из нужного места, а не из JSON.

/// note | Технические детали

Данные из форм обычно кодируются с использованием "media type" `application/x-www-form-urlencoded` когда он не включает файлы.

Но когда форма включает файлы, она кодируется как multipart/form-data. Если вы используете `File`, **FastAPI** будет знать, что ему нужно получить файлы из нужной части тела.

  ## https://kubernetes.io/docs/tasks/access-application-cluster/configure-cloud-provider-firewall/#restrict-access-for-loadbalancer-service
  ##
  #loadBalancerSourceRanges:
  #   - 10.10.10.0/24
  loadBalancerSourceRanges: []

  ## service.externalTrafficPolicy minio service external traffic policy
  ## ref http://kubernetes.io/docs/tasks/access-application-cluster/create-external-load-balancer/#preserving-the-client-source-ip

* Password Flow
* Mobile

* deprecated
* designed
* invalid
* on the fly
* standard
* default
* case-sensitive
* case-insensitive

* to serve the application
* to serve the page

* the app
* the application

* the request
* the response
* the error response

* the path operation
* the path operation decorator
* the path operation function

* the body

                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        }
                    },
                    "summary": "Read Current User",
                    "operationId": "read_current_user_users_me_get",

                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        }
                    },
                    "summary": "Read Current User",
                    "operationId": "read_current_user_users_me_get",

                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        }
                    },
                    "summary": "Read Current User",
                    "operationId": "read_current_user_users_me_get",