```console
$ npm run generate-client

frontend-app@1.0.0 generate-client /home/user/code/frontend-app
> openapi-ts --input http://localhost:8000/openapi.json --output ./src/client --client axios
```

</div>

That command will generate code in `./src/client` and will use `axios` (the frontend HTTP library) internally.

### Try Out the Client Code

```console
$ npm run generate-client

frontend-app@1.0.0 generate-client /home/user/code/frontend-app
> openapi-ts --input http://localhost:8000/openapi.json --output ./src/client --client axios
```

</div>

Dieser Befehl generiert Code in `./src/client` und verwendet intern `axios` (die Frontend-HTTP-Bibliothek).

### Den Client-Code ausprobieren

frontend-app@1.0.0 generate-client /home/user/code/frontend-app
> openapi-ts --input http://localhost:8000/openapi.json --output ./src/client --client axios
```

</div>

👈 📋 🔜 🏗 📟 `./src/client` &amp; 🔜 ⚙️ `axios` (🕸 🇺🇸🔍 🗃) 🔘.

### 🔄 👅 👩‍💻 📟

🔜 👆 💪 🗄 &amp; ⚙️ 👩‍💻 📟, ⚫️ 💪 👀 💖 👉, 👀 👈 👆 🤚 ✍ 👩‍🔬:

<img src="/img/tutorial/generate-clients/image02.png">

👆 🔜 🤚 ✍ 🚀 📨:

frontend-app@1.0.0 generate-client /home/user/code/frontend-app
> openapi-ts --input http://localhost:8000/openapi.json --output ./src/client --client axios
```

</div>

此命令将在 `./src/client` 中生成代码，并将在其内部使用 `axios`（前端HTTP库）。

### 尝试客户端代码

现在您可以导入并使用客户端代码，它可能看起来像这样，请注意，您可以为这些方法使用自动补全：

<img src="/img/tutorial/generate-clients/image02.png">

您还将自动补全要发送的数据：

<img src="/img/tutorial/generate-clients/image03.png">

With a FastAPI application, using a server program like Uvicorn, running it once in **one process** can serve multiple clients concurrently.

But in many cases, you will want to run several worker processes at the same time.

### Multiple Processes - Workers

* Schreiben Sie Nachrichten in den Tabs.
* Schließen Sie dann einen der Tabs.

Das wird die Ausnahme `WebSocketDisconnect` auslösen und alle anderen Clients erhalten eine Nachricht wie:

```
Client #1596980209979 left the chat
```

!!! tip "Tipp"

                * **FastAPI** ajoute ici une référence aux schémas JSON globaux à un autre endroit de votre OpenAPI au lieu de l'inclure directement. De cette façon, d'autres applications et clients peuvent utiliser ces schémas JSON directement, fournir de meilleurs outils de génération de code, etc.

Les réponses générées au format OpenAPI pour cette *opération de chemin* seront :

```JSON hl_lines="3-12"
{

    ```

!!! tip "Tipp"
    Bedenken Sie, dass JSON nur `str` als Schlüssel unterstützt.

    Aber Pydantic hat automatische Datenkonvertierung.

    Das bedeutet, dass Ihre API-Clients nur Strings senden können, aber solange diese Strings nur Zahlen enthalten, wird Pydantic sie konvertieren und validieren.

    Und das `dict` welches Sie als `weights` erhalten, wird `int`-Schlüssel und `float`-Werte haben.

And there are dozens of alternatives, all based on OpenAPI. You could easily add any of those alternatives to your application built with **FastAPI**.

You could also use it to generate code automatically, for clients that communicate with your API. For example, frontend, mobile or IoT applications.

## Recap, step by step

### Step 1: import `FastAPI`

```Python hl_lines="1"
{!../../../docs_src/first_steps/tutorial001.py!}

To try it out:

* Open the app with several browser tabs.
* Write messages from them.
* Then close one of the tabs.

That will raise the `WebSocketDisconnect` exception, and all the other clients will receive a message like:

```
Client #1596980209979 left the chat
```

!!! tip
    The app above is a minimal and simple example to demonstrate how to handle and broadcast messages to several WebSocket connections.