```Python hl_lines="5  12-16"
    {!> ../../../docs_src/security/tutorial002.py!}
    ```

## Create a `get_current_user` dependency

Let's create a dependency `get_current_user`.

Remember that dependencies can have sub-dependencies?

`get_current_user` will have a dependency with the same `oauth2_scheme` we created before.

    And Pydantic's `Field` returns an instance of `FieldInfo` as well.

    `Body` also returns objects of a subclass of `FieldInfo` directly. And there are others you will see later that are subclasses of the `Body` class.

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

!!! tip

    {!> ../../../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.

!!! info

For example:

* 200: `status.HTTP_200_OK`
* 403: `status.HTTP_403_FORBIDDEN`
* etc.

It can be convenient to quickly access HTTP (and WebSocket) status codes in your app, using autocompletion for the name without having to remember the integer status codes by memory.

Read more about it in the [FastAPI docs about Response Status Code](https://fastapi.tiangolo.com/tutorial/response-status-code/).

## Example

```python

When you run **multiple processes** of the same API program, they are commonly called **workers**.

### Worker Processes and Ports

Remember from the docs [About HTTPS](https.md){.internal-link target=_blank} that only one process can be listening on one combination of port and IP address in a server?

This is still true.

## Shortcut to remember the names

Let's see the previous example again:

```Python hl_lines="6"
{!../../../docs_src/response_status_code/tutorial001.py!}
```

`201` is the status code for "Created".

* and from it, import the function `get_token_header`.

But that file doesn't exist, our dependencies are in a file at `app/dependencies.py`.

Remember how our app/file structure looks like:

<img src="/img/tutorial/bigger-applications/package.svg">

---

The two dots `..`, like in:

```Python
from ..dependencies import get_token_header
```

But you can use this space in `Annotated` to provide **FastAPI** with additional metadata about how you want your application to behave.

The important thing to remember is that **the first *type parameter*** you pass to `Annotated` is the **actual type**. The rest, is just metadata for other tools.

For now, you just need to know that `Annotated` exists, and that it's standard Python. 😎

loop` when integrating asynchronous function calls in your tests (e.g. when using <a href="https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop" class="external-link" target="_blank">MongoDB's MotorClient</a>) Remember to instantiate objects that need an event loop only within async functions, e.g. an `'@app.on_event("startup")` callback....

## Response Status Code

You can define the (HTTP) `status_code` to be used in the response of your *path operation*.

You can pass directly the `int` code, like `404`.

But if you don't remember what each number code is for, you can use the shortcut constants in `status`:

=== "Python 3.10+"

    ```Python hl_lines="1  15"
    {!> ../../../docs_src/path_operation_configuration/tutorial001_py310.py!}
    ```