This is not a limitation of **FastAPI**, it's part of the HTTP protocol.

## Recap

## Recap

Having **HTTPS** is very important, and quite **critical** in most cases. Most of the effort you as a developer have to put around HTTPS is just about **understanding these concepts** and how they work.

You can learn how to use them and how they are integrated into **FastAPI** later in the **Advanced User Guide**.

## Recap

With what you have seen up to now, you can set up a secure **FastAPI** application using standards like OAuth2 and JWT.

In almost any framework handling the security becomes a rather complex subject quite quickly.

    ```Python hl_lines="1"
    async def needy_dependency(fresh_value: str = Depends(get_value, use_cache=False)):
        return {"fresh_value": fresh_value}
    ```

## Recap

Apart from all the fancy words used here, the **Dependency Injection** system is quite simple.

Just functions that look the same as the *path operation functions*.

<img src="/img/tutorial/path-operation-configuration/image04.png">

Check how deprecated and non-deprecated *path operations* look like:

<img src="/img/tutorial/path-operation-configuration/image05.png">

## Recap

But if you need to access variables and objects from the same **FastAPI** app, or you need to perform small background tasks (like sending an email notification), you can simply just use `BackgroundTasks`.

## Recap

You can use simple tools like `htop` to see the CPU and RAM used in your server or the amount used by each process. Or you can use more complex monitoring tools, which may be distributed across servers, etc.

## Recap

You have been reading here some of the main concepts that you would probably need to keep in mind when deciding how to deploy your application:

* Security - HTTPS
* Running on startup
* Restarts

    {!> ../../../docs_src/body_updates/tutorial002_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="35"
    {!> ../../../docs_src/body_updates/tutorial002.py!}
    ```

### Partial updates recap

In summary, to apply partial updates you would:

* (Optionally) use `PATCH` instead of `PUT`.
* Retrieve the stored data.
* Put that data in a Pydantic model.

```
X-Token: foo
X-Token: bar
```

The response would be like:

```JSON
{
    "X-Token values": [
        "bar",
        "foo"
    ]
}
```

## Recap

Declare headers with `Header`, using the same common pattern as `Query`, `Path` and `Cookie`.

    {!> ../../../docs_src/extra_models/tutorial005_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="1  8"
    {!> ../../../docs_src/extra_models/tutorial005.py!}
    ```

## Recap

Use multiple Pydantic models and inherit freely for each case.