---

"_Nous avons adopté la bibliothèque **FastAPI** pour créer un serveur **REST** qui peut être interrogé pour obtenir des **prédictions**. [pour Ludwig]_"

const (
	jwtAlgorithm = "Bearer"

	// Default JWT token for web handlers is one day.
	defaultJWTExpiry = 24 * time.Hour

	// Inter-node JWT token expiry is 100 years approx.
	defaultInterNodeJWTExpiry = 100 * 365 * 24 * time.Hour
)

var (
	errInvalidAccessKeyID = errors.New("The access key ID you provided does not exist in our records")
	errAccessKeyDisabled  = errors.New("The access key you provided is disabled")

You have already seen how to test your **FastAPI** applications using the provided `TestClient`. Up to now, you have only seen how to write synchronous tests, without using `async` functions.

Pendant que vous discutez avec votre crush 😍, de temps en temps vous jetez un coup d'oeil au nombre affiché au-dessus du comptoir pour savoir si c'est à votre tour d'être servis.

Jusqu'au moment où c'est (enfin) votre tour. Vous allez au comptoir, récupérez vos burgers 🍔 et revenez à votre table.

<img src="/img/async/concurrent-burgers/concurrent-burgers-06.png" class="illustration">

Do you want to have an `id` and `email` and not have any `username` in your model? Sure. You can use these same tools.

Do you want to just have a `str`? Or just a `dict`? Or a database class model instance directly? It all works the same way.

You actually don't have users that log in to your application but robots, bots, or other systems, that have just an access token? Again, it all works the same.

     *   <li>If this field's value is some other thread object, we know that it's not our thread.
     *   <li>If this field's value == null because it originally belonged to another thread and that
     *       thread cleared it, we still know that it's not associated with our thread
     *   <li>If this field's value == null because it was associated with our thread and was
     *       cleared, we know that we're not executing inline any more

* Use that `security` with a dependency in your *path operation*.
* It returns an object of type `HTTPBasicCredentials`:
    * It contains the `username` and `password` sent.

{* ../../docs_src/security/tutorial006_an_py39.py hl[4,8,12] *}

When you try to open the URL for the first time (or click the "Execute" button in the docs) the browser will ask you for your username and password:

## Use it { #use-it }

Now you can declare your dependency using this class.

{* ../../docs_src/dependencies/tutorial002_an_py310.py hl[19] *}

**FastAPI** calls the `CommonQueryParams` class. This creates an "instance" of that class and the instance will be passed as the parameter `commons` to your function.

## Type annotation vs `Depends` { #type-annotation-vs-depends }

```hl_lines="4"
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

That line shows the URL where your app is being served, in your local machine.

### Check it { #check-it }

Open your browser at <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

You will see the JSON response as:

```JSON

If you open the automatic API docs, your extension will show up at the bottom of the specific *path operation*.

<img src="/img/tutorial/path-operation-advanced-configuration/image01.png">

And if you see the resulting OpenAPI (at `/openapi.json` in your API), you will see your extension as part of the specific *path operation* too:

```JSON hl_lines="22"
{