```Python hl_lines="61-65"
{!../../../docs_src/async_sql_databases/tutorial001.py!}
```

!!! info
    In Pydantic v1 the method was called `.dict()`, it was deprecated (but still supported) in Pydantic v2, and renamed to `.model_dump()`.

    The examples here use `.dict()` for compatibility with Pydantic v1, but you should use `.model_dump()` instead if you can use Pydantic v2.

!!! note

app = FastAPI(
    servers=[
        {"url": "/", "description": "Default, relative server"},
        {
            "url": "http://staging.localhost.tiangolo.com:8000",
            "description": "Staging but actually localhost still",
        },
        {"url": "https://prod.example.com"},
    ]
)


@app.get("/foo")
def foo():
    return {"message": "Hello World"}


client = TestClient(app)


def test_app():

    ```

=== "Python 3.8+"

    ```Python hl_lines="10"
    {!> ../../../docs_src/query_params_str_validations/tutorial002_an.py!}
    ```

Notice that the default value is still `None`, so the parameter is still optional.

    done_translation_message = f"~There's a new translation PR to be reviewed: #{pr.number} by @{pr.user.login}~ Good job! This is done. 🍰☕"

    # Normally only one language, but still
    for lang in langs:
        if lang not in lang_to_discussion_map:
            log_message = f"Could not find discussion for language: {lang}"
            logging.error(log_message)

When you return a `Response` directly its data is not validated, converted (serialized), nor documented automatically.

But you can still document it as described in [Additional Responses in OpenAPI](additional-responses.md){.internal-link target=_blank}.

    ```Python hl_lines="9  11  16  22  24  29-30  33-35  40-41"
    {!> ../../../docs_src/extra_models/tutorial001.py!}
    ```

!!! info
    In Pydantic v1 the method was called `.dict()`, it was deprecated (but still supported) in Pydantic v2, and renamed to `.model_dump()`.

    The examples here use `.dict()` for compatibility with Pydantic v1, but you should use `.model_dump()` instead if you can use Pydantic v2.

Still, in both situations, chances are that **FastAPI** will [still be faster](index.md#performance){.internal-link target=_blank} than (or at least comparable to) your previous framework.

### Dependencies

That way, you can create a token with an expiration of, let's say, 1 week. And then when the user comes back the next day with the token, you know that user is still logged in to your system.

## Use case

For example, imagine that you want to return an HTTP status code of "OK" `200` by default.

But if the data didn't exist, you want to create it, and return an HTTP status code of "CREATED" `201`.

But you still want to be able to filter and convert the data you return with a `response_model`.

For those cases, you can use a `Response` parameter.

## Use a `Response` parameter

It is being chosen over previous alternatives for suiting many use cases better.

Many developers and teams already depend on **FastAPI** for their projects (including me and my team).

But still, there are many improvements and features to come.

**FastAPI** has a great future ahead.