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

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

    You can combine it with Gunicorn, to have an asynchronous multi-process server.

    Check more details in the [Deployment](deployment/index.md){.internal-link target=_blank} section.

## Benchmarks and speed

⚫️ ⚙️ 📚 🏢 ✅ 🦎, 🟥 👒 & 🎟.

⚫️ 🕐 🥇 🖼 **🏧 🛠️ 🧾**, & 👉 🎯 🕐 🥇 💭 👈 😮 "🔎" **FastAPI**.

!!! note
    ✳ 🎂 🛠️ ✍ ✡ 🇺🇸🏛. 🎏 👼 💃 & Uvicorn, 🔛 ❔ **FastAPI** ⚓️.


!!! check "😮 **FastAPI** "
    ✔️ 🏧 🛠️ 🧾 🕸 👩‍💻 🔢.

### <a href="https://flask.palletsprojects.com" class="external-link" target="_blank">🏺</a>

🏺 "🕸", ⚫️ 🚫 🔌 💽 🛠️ 🚫 📚 👜 👈 👟 🔢 ✳.

Check the in-code annotation tips above to see more specific details.

## Learn More

You can also combine `dataclasses` with other Pydantic models, inherit from them, include them in your own models, etc.

```Python hl_lines="7"
{!../../../docs_src/path_params/tutorial002.py!}
```

In this case, `item_id` is declared to be an `int`.

!!! check
    This will give you editor support inside of your function, with error checks, completion, etc.

## Data <abbr title="also known as: serialization, parsing, marshalling">conversion</abbr>

    Check the docs about <a href="https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/about-pull-request-reviews" class="external-link" target="_blank">adding a pull request review</a> to approve it or request changes.

Вы можете объявить тип параметра пути в функции, используя стандартные аннотации типов Python.

```Python hl_lines="7"
{!../../../docs_src/path_params/tutorial002.py!}
```

Здесь, `item_id` объявлен типом `int`.

!!! check "Заметка"
    Это обеспечит поддержку редактора внутри функции (проверка ошибок, автодополнение и т.п.).

## <abbr title="Или сериализация, парсинг">Преобразование</abbr> данных

{!../../../docs_src/path_params/tutorial002.py!}
```

本例把 `item_id` 的类型声明为 `int`。

!!! check "检查"

    类型声明将为函数提供错误检查、代码补全等编辑器支持。

## 数据<abbr title="也称为：序列化、解析">转换</abbr>

运行示例并访问 <a href="http://127.0.0.1:8000/items/3" class="external-link" target="_blank">http://127.0.0.1:8000/items/3</a>，返回的响应如下：

```JSON
{"item_id":3}
```

!!! check "检查"

    注意，函数接收并返回的值是 `3`（ `int`），不是 `"3"`（`str`）。

Most of these ideas would be more or less **independent**, and in most cases you should only need to study them if they apply directly to **your project**.

If something seems interesting and useful to your project, go ahead and check it, but otherwise, you might probably just skip them.

!!! tip

### Check the docs UI

But here's the fun part. ✨

The "official" way to access the app would be through the proxy with the path prefix that we defined. So, as we would expect, if you try the docs UI served by Uvicorn directly, without the path prefix in the URL, it won't work, because it expects to be accessed through the proxy.

```Python hl_lines="7"
{!../../../docs_src/path_params/tutorial002.py!}
```

Ici, `item_id` est déclaré comme `int`.

!!! check "vérifier"
    Ceci vous permettra d'obtenir des fonctionnalités de l'éditeur dans votre fonction, telles
    que des vérifications d'erreur, de l'auto-complétion, etc.