So, it was a complete additional system.

It is not very popular or used nowadays.

## OpenAPI

OpenAPI (previously known as Swagger) is the open specification for building APIs (now part of the Linux Foundation).

**FastAPI** is based on **OpenAPI**.

## Read the Tutorial first

The next sections assume you already read the main [Tutorial - User Guide: Security](../../tutorial/security/index.md){.internal-link target=_blank}.

* **Standards-based**: Based on (and fully compatible with) the open standards for APIs: <a href="https://github.com/OAI/OpenAPI-Specification" class="external-link" target="_blank">OpenAPI</a> (previously known as Swagger) and <a href="https://json-schema.org/" class="external-link" target="_blank">JSON Schema</a>.

* **<abbr title="Robust">استوار</abbr>**: ایجاد کدی آماده برای استفاده در محیط پروداکشن و تولید خودکار <abbr title="Interactive documentation">مستندات تعاملی</abbr>

    {!> ../../../docs_src/dependencies/tutorial001_02_an.py!}
    ```

!!! tip
    This is just standard Python, it's called a "type alias", it's actually not specific to **FastAPI**.

    But because **FastAPI** is based on the Python standards, including `Annotated`, you can use this trick in your code. 😎

- **簡単**: 簡単に利用、習得できるようにデザインされています。ドキュメントを読む時間を削減します。
- **短い**: コードの重複を最小限にしています。各パラメータからの複数の機能。少ないバグ。
- **堅牢性**: 自動対話ドキュメントを使用して、本番環境で使用できるコードを取得します。