C'est du travail "synchrone", vous être "synchronisés" avec le serveur/cuisinier 👨‍🍳. Vous devez attendre 🕙 et être présent au moment exact où le serveur/cuisinier 👨‍🍳 finira les burgers 🍔 et vous les donnera, sinon quelqu'un risque de vous les prendre.

Puis le serveur/cuisinier 👨‍🍳 revient enfin avec vos burgers 🍔, après un long moment d'attente 🕙 devant le comptoir.

Vous prenez vos burgers 🍔 et allez à une table avec votre crush 😍

Uvicorn est un serveur ASGI rapide comme l'éclair, basé sur uvloop et httptools.

Il ne s'agit pas d'un framework web, mais d'un serveur. Par exemple, il ne fournit pas d'outils pour le routing. C'est
quelque chose qu'un framework comme Starlette (ou **FastAPI**) fournirait par-dessus.

C'est le serveur recommandé pour Starlette et **FastAPI**.

</details>

### Lancez

Lancez le serveur avec :

<div class="termy">

```console
$ uvicorn main:app --reload

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [28720]
INFO:     Started server process [28722]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
```

[19515] [INFO] Booting worker with pid: 19515
[19511] [INFO] Started server process [19511]
[19511] [INFO] Waiting for application startup.
[19511] [INFO] Application startup complete.
[19513] [INFO] Started server process [19513]
[19513] [INFO] Waiting for application startup.
[19513] [INFO] Application startup complete.
[19514] [INFO] Started server process [19514]
[19514] [INFO] Waiting for application startup.

    * Ganz gleich, wie groß Ihr Server ist oder wie klein die einzelnen Anwendungen darauf sind.
    * Hierfür gibt es jedoch eine **Lösung**.
* Es gibt eine **Erweiterung** zum **TLS**-Protokoll (dasjenige, das die Verschlüsselung auf TCP-Ebene, vor HTTP, verwaltet) namens **<a href="https://en.wikipedia.org/wiki/Server_Name_Indication" class="external-link" target="_blank"><abbr title="Server Name Indication – Angabe des Servernamens">SNI</abbr></a>**.

browser("Browser")
proxy["Proxy on http://0.0.0.0:9999/api/v1/app"]
server["Server on http://127.0.0.1:8000/app"]

browser --> proxy
proxy --> server
```

!!! tip
    The IP `0.0.0.0` is commonly used to mean that the program listens on all the IPs available in that machine/server.

The docs UI would also need the OpenAPI schema to declare that this API `server` is located at `/api/v1` (behind the proxy). For example:

* <a href="https://pgjones.gitlab.io/hypercorn/" class="external-link" target="_blank">Hypercorn</a>: an ASGI server compatible with HTTP/2 and Trio among other features.
* <a href="https://github.com/django/daphne" class="external-link" target="_blank">Daphne</a>: the ASGI server built for Django Channels.

## Server Machine and Server Program

The hierarchy is like:

* **Uvicorn**: an ASGI server
    * **Starlette**: (uses Uvicorn) a web microframework
        * **FastAPI**: (uses Starlette) an API microframework with several additional features for building APIs, with data validation, etc.

* **Uvicorn**:
    * Will have the best performance, as it doesn't have much extra code apart from the server itself.

Uvicorn is a lightning-fast ASGI server, built on uvloop and httptools.

It is not a web framework, but a server. For example, it doesn't provide tools for routing by paths. That's something that a framework like Starlette (or **FastAPI**) would provide on top.

It is the recommended server for Starlette and **FastAPI**.

!!! check "**FastAPI** recommends it as"
    The main web server to run **FastAPI** applications.

</details>

### Esegui il server

Puoi far partire il server così:

<div class="termy">

```console
$ uvicorn main:app --reload

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [28720]
INFO:     Started server process [28722]
INFO:     Waiting for application startup.