```Python hl_lines="8"
{!../../../docs_src/first_steps/tutorial001.py!}
```

You can return a `dict`, `list`, singular values as `str`, `int`, etc.

You can also return Pydantic models (you'll see more about that later).

There are many other objects and models that will be automatically converted to JSON (including ORMs, etc). Try using your favorite ones, it's highly probable that they are already supported.

## Recap

### Return a Response Directly

The most common case would be [returning a Response directly as explained later in the advanced docs](../advanced/response-directly.md){.internal-link target=_blank}.

```Python hl_lines="8  10-11"
{!> ../../../docs_src/response_model/tutorial003_02.py!}
```

    # Including PR: https://github.com/encode/httpx/pull/2309
    "ignore:'cgi' is deprecated:DeprecationWarning",
    # For passlib
    "ignore:'crypt' is deprecated and slated for removal in Python 3.13:DeprecationWarning",
    # see https://trio.readthedocs.io/en/stable/history.html#trio-0-22-0-2022-09-28
    "ignore:You seem to already have a custom.*:RuntimeWarning:trio",

    * Code-Vervollständigung.
    * Typprüfungen.
* Validierung von Daten:
    * Automatische und eindeutige Fehler, wenn die Daten ungültig sind.
    * Validierung auch für tief verschachtelte JSON-Objekte.
* <abbr title="auch bekannt als: Serialisierung, Parsen, Marshalling">Konvertierung</abbr> von Eingabedaten: Aus dem Netzwerk kommend, zu Python-Daten und -Typen. Lesen von:
    * JSON.
    * Pfad-Parametern.

We will use `Session` (the one imported from SQLAlchemy) later.

To create the `SessionLocal` class, use the function `sessionmaker`:

```Python hl_lines="11"
{!../../../docs_src/sql_databases/sql_app/database.py!}
```

### Create a `Base` class

Now we will use the function `declarative_base()` that returns a class.

    If you don't want to have those optional dependencies, you can instead install `pip install fastapi-slim`.

## Advanced User Guide

There is also an **Advanced User Guide** that you can read later after this **Tutorial - User guide**.

The **Advanced User Guide**, builds on this, uses the same concepts, and teaches you some extra features.

The first stage will only be used to **install Poetry** and to **generate the `requirements.txt`** with your project dependencies from Poetry's `pyproject.toml` file.

This `requirements.txt` file will be used with `pip` later in the **next stage**.

    In particular, when running on **Kubernetes** you will probably **not** want to use Gunicorn and instead run **a single Uvicorn process per container**, but I'll tell you about it later in that chapter.

## Gunicorn with Uvicorn Workers