You only give `Depends` a single parameter.

This parameter must be something like a function.

You **don't call it** directly (don't add the parenthesis at the end), you just pass it as a parameter to `Depends()`.

And that function takes parameters in the same way that *path operation functions* do.

/// tip

            bufferIndex += byteCount;
        }

        /*
         * if there is an andx and it itself is an andx then just recur by
         * calling this method for it. otherwise just read it's parameter words
         * and bytes as usual. Note how we can't just call andx.readWireFormat
         * because there's no header.
         */

        if (errorCode != 0 || andxCommand == (byte) 0xFF) {

* `https://www.googleapis.com/auth/drive` is used by Google.

/// info

In OAuth2 a "scope" is just a string that declares a specific permission required.

It doesn't matter if it has other characters like `:` or if it is a URL.

Those details are implementation specific.

For OAuth2 they are just strings.

///

## Code to get the `username` and `password` { #code-to-get-the-username-and-password }

For that, use the standard Python `typing.List` (or just `list` in Python 3.9 and above):

{* ../../docs_src/extra_models/tutorial004_py39.py hl[18] *}


## Response with arbitrary `dict` { #response-with-arbitrary-dict }

You can also declare a response using a plain arbitrary `dict`, declaring just the type of the keys and values, without using a Pydantic model.

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Just Modern Python { #just-modern-python }

It's all based on standard **Python type** declarations (thanks to Pydantic). No new syntax to learn. Just standard modern Python.

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.

            }
            bufferIndex += this.byteCount;
        }

        /*
         * if there is an andx and it itself is an andx then just recur by
         * calling this method for it. otherwise just read it's parameter words
         * and bytes as usual. Note how we can't just call andx.readWireFormat
         * because there's no header.
         */

        if (this.errorCode != 0 || this.andxCommand == (byte) 0xFF) {

This example doesn't implement the callback itself (that could be just a line of code), only the documentation part.

/// tip

The actual callback is just an HTTP request.

Each "scope" is just a string (without spaces).

They are normally used to declare specific security permissions, for example:

* `users:read` or `users:write` are common examples.
* `instagram_basic` is used by Facebook / Instagram.
* `https://www.googleapis.com/auth/drive` is used by Google.

/// info

In OAuth2 a "scope" is just a string that declares a specific permission required.

**FastAPI** will create the object of type `BackgroundTasks` for you and pass it as that parameter.

## Create a task function { #create-a-task-function }

Create a function to be run as the background task.

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.