You can later read more about other middlewares in the [Advanced User Guide: Advanced Middleware](../advanced/middleware.md){.internal-link target=_blank}.

# Concurrency and async / await

Details about the `async def` syntax for *path operation functions* and some background about asynchronous code, concurrency, and parallelism.

## In a hurry?

<abbr title="too long; didn't read"><strong>TL;DR:</strong></abbr>

If you are using third party libraries that tell you to call them with `await`, like:

```Python
results = await some_library()
```

	github.com/valyala/bytebufferpool v1.0.0
	github.com/xdg/scram v1.0.5
	github.com/zeebo/xxh3 v1.0.2
	go.etcd.io/etcd/api/v3 v3.5.16
	go.etcd.io/etcd/client/v3 v3.5.16
	go.uber.org/atomic v1.11.0
	go.uber.org/zap v1.27.0
	goftp.io/server/v2 v2.0.1
	golang.org/x/crypto v0.27.0
	golang.org/x/exp v0.0.0-20240823005443-9b4947da3948
	golang.org/x/oauth2 v0.22.0
	golang.org/x/sync v0.8.0
	golang.org/x/sys v0.25.0

/// tip

💭 🌅 🔃 🔠 👔 📟 &amp; ❔ 📟 ⚫️❔, ✅ <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Status" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">🏇</abbr> 🧾 🔃 🇺🇸🔍 👔 📟</a>.

///

## ⌨ 💭 📛

➡️ 👀 ⏮️ 🖼 🔄:

```Python hl_lines="6"
{!../../docs_src/response_status_code/tutorial001.py!}
```

`201` 👔 📟 "✍".

## Servidores ASGI

Vamos nos aprofundar um pouco mais em detalhes.

FastAPI utiliza um padrão para construir frameworks e servidores web em Python chamado <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr>. FastAPI é um framework web ASGI.

Se você quiser ler mais sobre essas codificações e campos de formulário, vá para a <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">MDN</abbr> web docs para <code>POST</code></a>.

///

/// warning | Aviso

stockage.

Il a été créé pour générer le HTML en backend, pas pour créer des API consommées par un frontend moderne (comme React, Vue.js et Angular) ou par d'autres systèmes (comme les appareils <abbr title="Internet of Things">IoT</abbr>) communiquant avec lui.

### <a href="https://www.django-rest-framework.org/" class="external-link" target="_blank">Django REST Framework</a>

The MIT License (MIT)

Copyright (c) 2014 Ryan Uber

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is

Copyright (c) 2016 Uber Technologies, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is

Copyright (c) 2017-2021 Uber Technologies, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is