/// note | Technische Details

Sie könnten auch `from starlette.middleware.cors import CORSMiddleware` verwenden.

```CSS hl_lines="4"
{!../../docs_src/templates/static/styles.css!}
```

而且因為你使用了 `StaticFiles`，該 CSS 檔案會由你的 **FastAPI** 應用程式在 URL `/static/styles.css` 自動提供。

## 更多細節 { #more-details }

Aber aus Sicherheitsgründen, da der Server nicht weiß, dass er hinter einem vertrauenswürdigen Proxy läuft, wird er diese Header nicht interpretieren.

/// note | Technische Details

Die Proxy-Header sind:

* [X-Forwarded-For](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-For)

// SlashSeparatorChar - slash separator.
const SlashSeparatorChar = '/'

// retainSlash - retains slash from a path.
func retainSlash(s string) string {
	if s == "" {
		return s
	}
	return strings.TrimSuffix(s, SlashSeparator) + SlashSeparator
}

// pathsJoinPrefix - like pathJoin retains trailing SlashSeparator
// for all elements, prepends them with 'prefix' respectively.

// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"bufio"
	"bytes"
	"context"

// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"bytes"
	"context"

## Einen `websocket` erstellen { #create-a-websocket }

Erstellen Sie in Ihrer **FastAPI**-Anwendung einen `websocket`:

{* ../../docs_src/websockets_/tutorial001_py310.py hl[1,46:47] *}

/// note | Technische Details

Sie könnten auch `from starlette.websockets import WebSocket` verwenden.

**FastAPI** stellt den gleichen `WebSocket` direkt zur Verfügung, als Annehmlichkeit für Sie, den Entwickler. Er kommt aber direkt von Starlette.

Mas, seguindo os passos acima, ele será capaz de fazer algumas otimizações de performance.

## Detalhes Técnicos { #technical-details }

Versões modernas de Python têm suporte para **"código assíncrono"** usando algo chamado **"corrotinas"**, com sintaxe **`async` e `await`**.

Vamos ver aquela frase por partes nas seções abaixo:

// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"bytes"
	"context"

Це корисно для протоколів на кшталт [MCP](https://modelcontextprotocol.io), які транслюють SSE через `POST`:

{* ../../docs_src/server_sent_events/tutorial005_py310.py hl[14] *}

## Технічні деталі { #technical-details }

FastAPI реалізує деякі найкращі практики SSE «з коробки».