# Full Stack FastAPI Template

Templates, while typically come with a specific setup, are designed to be flexible and customizable. This allows you to modify and adapt them to your project's requirements, making them an excellent starting point. 🏁

You can use this template to get started, as it includes a lot of the initial set up, security, database and some API endpoints already done for you.

# Path Operation Configuration

There are several parameters that you can pass to your *path operation decorator* to configure it.

!!! warning
    Notice that these parameters are passed directly to the *path operation decorator*, not to your *path operation function*.

## 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`.

    {!> ../../../docs_src/query_params/tutorial002.py!}
    ```

In this case, the function parameter `q` will be optional, and will be `None` by default.

!!! check
    Also notice that **FastAPI** is smart enough to notice that the path parameter `item_id` is a path parameter and `q` is not, so, it's a query parameter.

## Query parameter type conversion

You can also declare `bool` types, and they will be converted:

    "paid": true
}
```

and it would expect a response from that *external API* with a JSON body like:

```JSON
{
    "ok": true
}
```

!!! tip
    Notice how the callback URL used contains the URL received as a query parameter in `callback_url` (`https://www.external.org/events`) and also the invoice `id` from inside of the JSON body (`2expen51ve`).

### Add the callback router

            "name": "The Foo live"
        },
        {
            "url": "http://example.com/dave.jpg",
            "name": "The Baz"
        }
    ]
}
```

!!! info
    Notice how the `images` key now has a list of image objects.

## Deeply nested models

You can define arbitrarily deeply nested models:

=== "Python 3.10+"

    ```Python hl_lines="7  12  18  21  25"

* `@app.get()`
* `@app.post()`
* `@app.put()`
* `@app.delete()`
* etc.

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

!!! note
    Notice that `status_code` is a parameter of the "decorator" method (`get`, `post`, etc). Not of your *path operation function*, like all the parameters and body.

The `status_code` parameter receives a number with the HTTP status code.

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="22"
    {!> ../../../docs_src/dependencies/tutorial005.py!}
    ```

!!! info
    Notice that we are only declaring one dependency in the *path operation function*, the `query_or_cookie_extractor`.

    * Entendre quand je fais des annonces ou que je lance de nouveaux outils.
* <a href="https://www.linkedin.com/in/tiangolo/" class="external-link" target="_blank">Vous connectez à moi sur **LinkedIn**</a>.
    * Etre notifié quand je fais des annonces ou que je lance de nouveaux outils (bien que j'utilise plus souvent Twitter 🤷‍♂).

There you can set:

* The "Item ID", used in the path.
* The "Token" used as a query parameter.

!!! tip
    Notice that the query `token` will be handled by a dependency.

With that you can connect the WebSocket and then send and receive messages:

<img src="/img/tutorial/websockets/image05.png">

read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

This way you write shared code once and **FastAPI** takes care of calling it for your *path operations*.

!!! check
    Notice that you don't have to create a special class and pass it somewhere to **FastAPI** to "register" it or anything similar.

    You just pass it to `Depends` and **FastAPI** knows how to do the rest.