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

#!/usr/bin/env bash

set -e
set -x

mypy fastapi
ruff check fastapi tests docs_src scripts

⚫️ ⚙️ 📚 🏢 ✅ 🦎, 🟥 👒 & 🎟.

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

## Available versions

You can see the available versions (e.g. to check what is the current latest) in the [Release Notes](../release-notes.md){.internal-link target=_blank}.

## About versions

    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`）。

SQLALCHEMY_DATABASE_URL = "sqlite:///./sql_app.db"
# SQLALCHEMY_DATABASE_URL = "postgresql://user:password@postgresserver/db"

engine = create_engine(
    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)