This could be useful, for example, to expose the same API under different prefixes, e.g. `/api/v1` and `/api/latest`.

This is an advanced usage that you might not really need, but it's there in case you do.

## Include an `APIRouter` in another

!!! tip "Tipp"

* When you install `"fastapi[all]"` it now also includes:
    * <a href="https://docs.pydantic.dev/latest/usage/pydantic_settings/" target="_blank"><code>pydantic-settings</code></a> - for settings management.
    * <a href="https://docs.pydantic.dev/latest/usage/types/extra_types/extra_types/" target="_blank"><code>pydantic-extra-types</code></a> - for extra types to be used with Pydantic.

repos:
-   repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.4.0
    hooks:
    -   id: check-added-large-files
    -   id: check-toml
    -   id: check-yaml
        args:
        -   --unsafe
    -   id: end-of-file-fixer
    -   id: trailing-whitespace
-   repo: https://github.com/charliermarsh/ruff-pre-commit
    rev: v0.2.0
    hooks:
    -   id: ruff
        args:
        - --fix

So, the interactive docs will have all the information from these dependencies too:

<img src="/img/tutorial/dependencies/image01.png">

## Simple usage

If you look at it, *path operation functions* are declared to be used whenever a *path* and *operation* matches, and then **FastAPI** takes care of calling the function with the correct parameters, extracting the data from the request.

# (1)
FROM python:3.9 as requirements-stage

# (2)
WORKDIR /tmp

# (3)
RUN pip install poetry

# (4)
COPY ./pyproject.toml ./poetry.lock* /tmp/

# (5)
RUN poetry export -f requirements.txt --output requirements.txt --without-hashes

# (6)
FROM python:3.9

# (7)
WORKDIR /code

# (8)
COPY --from=requirements-stage /tmp/requirements.txt /code/requirements.txt

    Pydantic 버전 2에서 <a href="https://docs.pydantic.dev/latest/usage/model_config/" class="external-link" target="_blank">Pydantic 공식 문서: Model Config</a>에 나와 있는 것처럼 `dict`를 받는 `model_config` 어트리뷰트를 사용할 것입니다.

    `"json_schema_extra"`를 생성된 JSON 스키마에서 보여주고 싶은 별도의 데이터와 `examples`를 포함하는 `dict`으로 설정할 수 있습니다.

=== "Pydantic v1"

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。

此处唯一比较新的内容是*路径操作装饰器*中的 `callbacks=invoices_callback_router.routes` 参数，下文介绍。

## 存档回调

实际的回调代码高度依赖于您自己的 API 应用。

并且可能每个应用都各不相同。

* <a href="https://docs.pydantic.dev/latest/usage/pydantic_settings/" target="_blank"><code>pydantic-settings</code></a> - parametrlərin idarə edilməsi üçün.
* <a href="https://docs.pydantic.dev/latest/usage/types/extra_types/extra_types/" target="_blank"><code>pydantic-extra-types</code></a> - Pydantic ilə istifadə edilə bilən əlavə tiplər üçün.

* <a href="https://docs.pydantic.dev/latest/usage/pydantic_settings/" target="_blank"><code>pydantic-settings</code></a> - fún ètò ìsàkóso.
* <a href="https://docs.pydantic.dev/latest/usage/types/extra_types/extra_types/" target="_blank"><code>pydantic-extra-types</code></a> - fún àfikún oríṣi láti lọ pẹ̀lú Pydantic.

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