{!../../docs_src/first_steps/tutorial001.py!}
```

Aquí la variable `app` será un instance de la clase `FastAPI`.

Este será el punto de interacción principal para crear todo tu API.

Esta `app` es la misma a la que nos referimos cuando usamos el comando de `uvicorn`:

<div class="termy">

```console
$ uvicorn main:app --reload

import org.codelibs.core.crypto.CachedCipher;
import org.codelibs.core.misc.DynamicProperties;
import org.codelibs.fess.api.WebApiManagerFactory;
import org.codelibs.fess.auth.AuthenticationManager;
import org.codelibs.fess.cors.CorsHandlerFactory;
import org.codelibs.fess.crawler.client.CrawlerClientCreator;
import org.codelibs.fess.crawler.client.CrawlerClientFactory;
import org.codelibs.fess.crawler.entity.EsAccessResult;

* **セキュアなパスワード** ハッシュ化 (デフォルトで)。
* **JWTトークン** 認証。
* **SQLAlchemy** モデル (Flask用の拡張と独立しているので、Celeryワーカーと直接的に併用できます)。
* 基本的なユーザーモデル (任意の修正や削除が可能)。
* **Alembic** マイグレーション。
* **CORS** (Cross Origin Resource Sharing (オリジン間リソース共有))。
* **Celery** ワーカー。バックエンドの残りの部分からモデルとコードを選択的にインポートし、使用可能。

    ReverseConverter(Converter<A, B> original) {
      this.original = original;
    }

    /*
     * These gymnastics are a little confusing. Basically this class has neither legacy nor
     * non-legacy behavior; it just needs to let the behavior of the backing converter shine
     * through. So, we override the correctedDo* methods, after which the do* methods should never
     * be reached.
     */

    ./gradlew :distributions-full:binDistributionZip

This will create a minimal distribution at `subprojects/distributions-full/build/distributions/gradle-<version>-bin.zip`, just what's needed to run Gradle (i.e. no sources nor docs).

You can then use it as a Gradle Wrapper local distribution in a Gradle based project by using a `file:/` URL pointing to the built distribution:

* Nhiều tính năng mở rộng (cảm ơn Starlette) như:
    * **WebSockets**
    * kiểm thử vô cùng dễ dàng dựa trên HTTPX và `pytest`
    * **CORS**
    * **Cookie Sessions**
    * ...và nhiều hơn thế.

## Hiệu năng

* 安全性和身份验证，包括通过 **JWT 令牌**和 **HTTP 基本身份认证**来支持 **OAuth2**。
* 更进阶（但同样简单）的技巧来声明 **多层嵌套 JSON 模型** （借助 Pydantic）。
* 许多额外功能（归功于 Starlette）比如：
    * **WebSockets**
    * **GraphQL**
    * 基于 HTTPX 和 `pytest` 的极其简单的测试
    * **CORS**
    * **Cookie Sessions**
    * ......以及更多

## 性能

copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
   * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

	uint32max = (1 << 32) - 1

	// Extra header IDs.
	//
	// IDs 0..31 are reserved for official use by PKWARE.
	// IDs above that range are defined by third-party vendors.
	// Since ZIP lacked high precision timestamps (nor an official specification
	// of the timezone used for the date fields), many competing extra fields
	// have been invented. Pervasive use effectively makes them "official".
	//

But now you know how it works, so you can use relative imports in your own apps no matter how complex they are. 🤓

### Add some custom `tags`, `responses`, and `dependencies`

We are not adding the prefix `/items` nor the `tags=["items"]` to each *path operation* because we added them to the `APIRouter`.