# Get Current User

In the previous chapter the security system (which is based on the dependency injection system) was giving the *path operation function* a `token` as a `str`:

=== "Python 3.9+"

    ```Python hl_lines="12"
    {!> ../../../docs_src/security/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="11"
    {!> ../../../docs_src/security/tutorial001_an.py!}
    ```

=== "Python 3.8+ non-Annotated"

        return {"fresh_value": fresh_value}
    ```

## Zusammenfassung

Abgesehen von all den ausgefallenen Wörtern, die hier verwendet werden, ist das **Dependency Injection**-System recht simpel.

Einfach Funktionen, die genauso aussehen wie *Pfadoperation-Funktionen*.

Dennoch ist es sehr mächtig und ermöglicht Ihnen die Deklaration beliebig tief verschachtelter Abhängigkeits-„Graphen“ (Bäume).

    "Operating System :: OS Independent",
    "Programming Language :: Python :: 3",
    "Programming Language :: Python",
    "Topic :: Internet",
    "Topic :: Software Development :: Libraries :: Application Frameworks",
    "Topic :: Software Development :: Libraries :: Python Modules",
    "Topic :: Software Development :: Libraries",
    "Topic :: Software Development",
    "Typing :: Typed",

# About FastAPI versions

**FastAPI** is already being used in production in many applications and systems. And the test coverage is kept at 100%. But its development is still moving quickly.

New features are added frequently, bugs are fixed regularly, and the code is still continuously improving.

    current_user: Annotated[User, Security(get_current_active_user, scopes=["items"])],
):
    return [{"item_id": "Foo", "owner": current_user.username}]


@app.get("/status/")
async def read_system_status(current_user: Annotated[User, Depends(get_current_user)]):

## Dependency Injection

Die Verwendung von `BackgroundTasks` funktioniert auch mit dem <abbr title="Einbringen von Abhängigkeiten">Dependency Injection</abbr> System. Sie können einen Parameter vom Typ `BackgroundTasks` auf mehreren Ebenen deklarieren: in einer *Pfadoperation-Funktion*, in einer Abhängigkeit (Dependable), in einer Unterabhängigkeit usw.

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

## Recap

You can integrate any third party NoSQL database, just using their standard packages.

It can be used by the frontend team (that can also be yourself).

It can be used by third party applications and systems.

And it can also be used by yourself, to debug, check and test the same application.

## The `password` flow

Now let's go back a bit and understand what is all that.

مشخصه OpenAPI روشی برای تعریف چندین "schemes" دارد.

با استفاده از آن‌ها، شما می‌توانید از همه این ابزارهای مبتنی بر استاندارد استفاده کنید، از جمله این سیستم‌های مستندات تعاملی(interactive documentation systems).

استاندارد OpenAPI شیوه‌های امنیتی زیر را تعریف می‌کند:

* شیوه `apiKey`: یک کلید اختصاصی برای برنامه که می‌تواند از موارد زیر استفاده شود:
    * پارامتر جستجو.
    * هدر.
    * کوکی.

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="9"
    {!> ../../../docs_src/cookie_params/tutorial001.py!}
    ```

!!! note "Technical Details"
    `Cookie` is a "sister" class of `Path` and `Query`. It also inherits from the same common `Param` class.

    But remember that when you import `Query`, `Path`, `Cookie` and others from `fastapi`, those are actually functions that return special classes.