添加回调前，首先看下常规 API 应用是什么样子。

常规 API 应用包含接收 `Invoice` 请求体的*路径操作*，还有包含回调 URL 的查询参数 `callback_url`。

这部分代码很常规，您对绝大多数代码应该都比较熟悉了：

```Python hl_lines="10-14  37-54"
{!../../docs_src/openapi_callbacks/tutorial001.py!}
```

/// tip | "提示"

`callback_url` 查询参数使用 Pydantic 的 <a href="https://pydantic-docs.helpmanual.io/usage/types/#urls" class="external-link" target="_blank">URL</a> 类型。

///

    }
}
```

/// tip | "Dica"

Perceba o servidor gerado automaticamente com um valor `url` de `/api/v1`, retirado do `root_path`.

///

Na interface de documentação em <a href="http://127.0.0.1:9999/api/v1/docs" class="external-link" target="_blank">http://127.0.0.1:9999/api/v1/docs</a> parecerá:

<img src="/img/tutorial/behind-a-proxy/image03.png">

/// tip | "Dica"

                        var tip = \$("<small>").text("Use the 'bin.cmp.report.severity.filter' property to set the default severity filter");
                        tip.css({ padding: "20px" });
                        var menu = \$("ul .dropdown-menu");
                        menu.css({ width: "480px" });
                        menu.append(divider);
                        menu.append(tip);
                    });

<div class="termy">

```console
$ python -m pip install --upgrade pip

---> 100%
```

</div>

/// tip | "Подсказка"

Каждый раз, перед установкой новой библиотеки в виртуальное окружение при помощи `pip`, не забудьте активировать это виртуальное окружение.

#         integration-tests/gradle/gradlew
#         integration-tests/gradle/gradlew.bat
# Please commit your changes or stash them before you switch branches.

GRADLE_TEMP="$(mktemp -d)"
trap 'rm -rf "${GRADLE_TEMP}"' EXIT

# The Gradle tests need the pom.xml only to read its version number.
# (And the file needs to be two directory levels up from the Gradle build file.)

⚫️ 🔜 ✔️ *➡ 🛠️* 👈 🔜 📨 `Invoice` 💪, & 🔢 🔢 `callback_url` 👈 🔜 🔌 📛 ⏲.

👉 🍕 📶 😐, 🌅 📟 🎲 ⏪ 😰 👆:

```Python hl_lines="9-13  36-53"
{!../../docs_src/openapi_callbacks/tutorial001.py!}
```

/// tip

`callback_url` 🔢 🔢 ⚙️ Pydantic <a href="https://docs.pydantic.dev/latest/concepts/types/#urls" class="external-link" target="_blank">📛</a> 🆎.

///

```

////

//// tab | Python 3.10+ non-Annotated

/// tip | Заметка

Рекомендуется использовать версию с `Annotated`, если это возможно.

///

```Python hl_lines="18-23"
{!> ../../docs_src/schema_extra_example/tutorial003_py310.py!}
```

////

//// tab | Python 3.8+ non-Annotated

/// tip | Заметка

Рекомендуется использовать версию с `Annotated`, если это возможно.

/// tip | Dica

## 🔃 ⏬

📄 ⚛ 🛠️ 🏛, 🙆 ⏬ 🔛 `1.0.0` 💪 ⚠ 🚮 💔 🔀.

FastAPI ⏩ 🏛 👈 🙆 "🐛" ⏬ 🔀 🐛 🔧 & 🚫-💔 🔀.

/// tip

"🐛" 🏁 🔢, 🖼, `0.2.3`, 🐛 ⏬ `3`.

///

, 👆 🔜 💪 📌 ⏬ 💖:

```txt
fastapi>=0.45.0,<0.46.0
```

💔 🔀 &amp; 🆕 ⚒ 🚮 "🇺🇲" ⏬.

/// tip

"🇺🇲" 🔢 🖕, 🖼, `0.2.3`, 🇺🇲 ⏬ `2`.

///

## ♻ FastAPI ⏬

👆 🔜 🚮 💯 👆 📱.

```

////

//// tab | Python 3.8+

```Python hl_lines="2  7  11"
{!> ../../docs_src/security/tutorial006_an.py!}
```

////

//// tab | Python 3.8+ non-Annotated

/// tip

尽可能选择使用 `Annotated` 的版本。

///

```Python hl_lines="2  6  10"
{!> ../../docs_src/security/tutorial006.py!}
```

////

第一次打开 URL（或在 API 文档中点击 **Execute** 按钮）时，浏览器要求输入用户名与密码：