You don't even have to check if the token exists to return an error. You can be sure that if your function is executed, it will have a `str` in that token.

You can try it already in the interactive docs:

<img src="/img/tutorial/security/image03.png">

We are not verifying the validity of the token yet, but that's a start already.

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

* Ezután kattints az "Execute" gompra, a felhasználói felület kommunikálni fog az API-oddal. Elküldi a paramétereket és a visszakapott választ megmutatja a képernyődön.

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png)

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

* Luego haz click en el botón de "Execute". La interfaz de usuario se comunicará con tu API, enviará los parámetros y recibirá los resultados para mostrarlos en pantalla:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png)

- "Try it out" বাটনে চাপুন, এটি আপনাকে পেরামিটারগুলো পূরণ করতে এবং API এর সাথে সরাসরি ক্রিয়া-কলাপ করতে দিবে:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

- তারপরে "Execute" বাটনে চাপুন, ব্যবহারকারীর ইন্টারফেস আপনার API এর সাথে যোগাযোগ করবে, পেরামিটার পাঠাবে, ফলাফলগুলি পাবে এবং সেগুলি পর্রদায় দেখাবে:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png)

### Autres fonctions utilitaires

This was designed this way mainly to allow using the same objects "yielded" by dependencies inside of background tasks, because the exit code would be executed after the background tasks were finished.

# Primeiros Passos

O arquivo FastAPI mais simples pode se parecer com:

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

Copie o conteúdo para um arquivo `main.py`.

Execute o servidor:

<div class="termy">

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

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)

    ```

These dependencies will be executed/solved the same way as normal dependencies. But their value (if they return any) won't be passed to your *path operation function*.

!!! tip
    Some editors check for unused function parameters, and show them as errors.

    Using these `dependencies` in the *path operation decorator* you can make sure they are executed while avoiding editor/tooling errors.

        code ->> function: say_hi(name="Rick")
        function ->> execute: führe Code der Funktion aus
        execute ->> code: gib das Resultat zurück
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick", salutation="Mr.")
        function ->> execute: führe Code der Funktion aus
        execute ->> code: gib das Resultat zurück
    end

    rect rgba(0, 255, 255, .1)

        test_db.unlink()
    # Import while creating the client to create the DB after starting the test session
    from docs_src.sql_databases.sql_app_py310.tests import test_sql_app

    # Ensure import side effects are re-executed
    importlib.reload(test_sql_app)
    test_sql_app.test_create_user()
    if test_db.is_file():  # pragma: nocover
        test_db.unlink()