That's why in this example we have to declare it in the `response_model` parameter.

...but continue reading below to see how to overcome that.

## Return Type and Data Filtering

Let's continue from the previous example. We wanted to **annotate the function with one type** but return something that includes **more data**.

### <a href="https://webargs.readthedocs.io/en/latest/" class="external-link" target="_blank">Webargs</a>

Another big feature required by APIs is <abbr title="reading and converting to Python data">parsing</abbr> data from incoming requests.

Webargs is a tool that was made to provide that on top of several frameworks, including Flask.

!!! check "😮 **FastAPI** "
    ⚙️ 📟 🔬 "🔗" 👈 🚚 💽 🆎 & 🔬, 🔁.

### <a href="https://webargs.readthedocs.io/en/latest/" class="external-link" target="_blank">Webarg</a>

➕1️⃣ 🦏 ⚒ ✔ 🔗 <abbr title="reading and converting to Python data">✍</abbr> 📊 ⚪️➡️ 📨 📨.

Webarg 🧰 👈 ⚒ 🚚 👈 🔛 🔝 📚 🛠️, 🔌 🏺.

⚫️ ⚙️ 🍭 🔘 💽 🔬. &amp; ⚫️ ✍ 🎏 👩‍💻.

⚫️ 👑 🧰 &amp; 👤 ✔️ ⚙️ ⚫️ 📚 💁‍♂️, ⏭ ✔️ **FastAPI**.

!!! info

# Reference - Code API

Here's the reference or code API, the classes, functions, parameters, attributes, and
all the FastAPI parts you can use in your applications.

If you want to **learn FastAPI** you are much better off reading the

## Dependencies for groups of *path operations*

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

But let's save you the time of reading the full long specification just to find those little pieces of information you need.

Let's use the tools provided by **FastAPI** to handle security.

## How it looks

## 🔑 👨‍💼

### ⚫️❔ "🔑 👨‍💼"

"🔑 👨‍💼" 🙆 👈 🐍 🎚 👈 👆 💪 ⚙️ `with` 📄.

🖼, <a href="https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files" class="external-link" target="_blank">👆 💪 ⚙️ `with` ✍ 📁</a>:

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

## 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

    * PR [#593](https://github.com/tiangolo/fastapi/pull/593).
* Improve handling of custom classes for `Request`s and `APIRoute`s.
    * This helps to more easily solve use cases like:
        * Reading a body before and/or after a request (equivalent to a middleware).
        * Run middleware-like code only for a subset of *path operations*.

    ```Python hl_lines="9  14"
    {!> ../../../docs_src/dependencies/tutorial006.py!}
    ```

## Dependencies for a group of *path operations*