The original content will be surrounded by triple percentage signs («%%%»). Do not include the triple percentage signs in the translation.


### Technical terms in English

For technical terms in English that don't have a common translation term, use the original term in English.


### Content of code snippets

Erstellen Sie einen echten JWT-Zugriffstoken und geben Sie ihn zurück.

{* ../../docs_src/security/tutorial004_an_py310.py hl[118:133] *}

### Technische Details zum JWT-„Subjekt“ `sub` { #technical-details-about-the-jwt-subject-sub }

Die JWT-Spezifikation besagt, dass es einen Schlüssel `sub` mit dem Subjekt des Tokens gibt.

#### Technische Details zu `lru_cache` { #lru-cache-technical-details }

`@lru_cache` ändert die Funktion, die es dekoriert, dahingehend, denselben Wert zurückzugeben, der beim ersten Mal zurückgegeben wurde, anstatt ihn erneut zu berechnen und den Code der Funktion jedes Mal auszuführen.

你也可以用它自動生成程式碼，讓前端、手機應用程式或物聯網設備等與你的 API 進行通訊。

## 逐步回顧

### 第一步：引入 `FastAPI`

{* ../../docs_src/first_steps/tutorial001.py h1[1] *}

`FastAPI` 是一個 Python 類別，提供所有 API 的全部功能。

/// note | Technical Details

`FastAPI` 是一個直接繼承自 `Starlette` 的類別。

你同樣可以透過 `FastAPI` 來使用 <a href="https://www.starlette.dev/" class="external-link" target="_blank">Starlette</a> 所有的功能。

///

### 第二步：建立一個 `FastAPI` 「實例」

Crea un verdadero token de acceso JWT y devuélvelo.

{* ../../docs_src/security/tutorial004_an_py310.py hl[118:133] *}

### Detalles técnicos sobre el "sujeto" `sub` de JWT { #technical-details-about-the-jwt-subject-sub }

La especificación de JWT dice que hay una clave `sub`, con el sujeto del token.

For more info about <abbr title="Cross-Origin Resource Sharing">CORS</abbr>, check the <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS" class="external-link" target="_blank">Mozilla CORS documentation</a>.

/// note | Technical Details

You could also use `from starlette.middleware.cors import CORSMiddleware`.

And the calls to the client are also normal calls, not using `await`.

This allows you to use `pytest` directly without complications.

///

/// note | Technical Details

You could also use `from starlette.testclient import TestClient`.

## Available responses { #available-responses }

Here are some of the available responses.

Keep in mind that you can use `Response` to return anything else, or even create a custom sub-class.

/// note | Technical Details

You could also use `from starlette.responses import HTMLResponse`.

This **proxy** would normally set some HTTP headers on the fly before transmitting the request to the **application server**, to let the application server know that the request is being **forwarded** by the proxy.

/// note | Technical Details

The proxy headers are:

* <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-For" class="external-link" target="_blank">X-Forwarded-For</a>

This simplicity and flexibility allow doing things like using NoSQL databases as the main data storage system.

As it is very simple, it's relatively intuitive to learn, although the documentation gets somewhat technical at some points.