# 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

    This is what you would probably do once you want to deploy your application to production:

    ```
    pip install fastapi
    ```

    Also install `uvicorn` to work as the server:

    ```
    pip install "uvicorn[standard]"
    ```

    And the same for each of the optional dependencies that you want to use.

## Advanced User Guide

* <a href="https://jinja.palletsprojects.com" target="_blank"><code>jinja2</code></a> - Required if you want to use the default template configuration.

If something seems interesting and useful to your project, go ahead and check it, but otherwise, you might probably just skip them.

!!! tip

And it shows their true commitment to FastAPI and its **community** (you), as they not only want to provide you a **good learning experience** but also want to make sure you have a **good and healthy framework**, FastAPI. 🙇

You might want to try their courses:

* <a href="https://training.talkpython.fm/fastapi-courses" class="external-link" target="_blank">Talk Python Training</a>

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

### En résumé

En résumé, vous déclarez **une fois** les types de paramètres, <abbr title="en anglais : body">le corps</abbr>  de la requête, etc. en tant que paramètres de fonction.

Vous faites cela avec les types Python standard modernes.

Vous n'avez pas à apprendre une nouvelle syntaxe, les méthodes ou les classes d'une bibliothèque spécifique, etc.

And it has the same shape and structure that all your *path operation functions* have.

You can think of it as a *path operation function* without the "decorator" (without the `@app.get("/some-path")`).

And it can return anything you want.

In this case, this dependency expects:

* An optional query parameter `q` that is a `str`.
* An optional query parameter `skip` that is an `int`, and by default is `0`.