For example, let's say you are using version `0.45.0` in your app.

If you use a `requirements.txt` file you could specify the version with:

```txt
fastapi==0.45.0
```

that would mean that you would use exactly the version `0.45.0`.

Or you could also pin it with:

```txt
fastapi>=0.45.0,<0.46.0
```

    -webkit-animation: blink 1s infinite;
            animation: blink 1s infinite;
}


/* Cursor animation */

@-webkit-keyframes blink {
    50% {
        opacity: 0;
    }
}

@keyframes blink {
    50% {
        opacity: 0;
    }

# Response Status Code

The same way you can specify a response model, you can also declare the HTTP status code used for the response with the parameter `status_code` in any of the *path operations*:

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

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

!!! note

    ```

It will be used in the interactive docs:

<img src="/img/tutorial/path-operation-configuration/image02.png">

## Response description

You can specify the response description with the parameter `response_description`:

=== "Python 3.10+"

    ```Python hl_lines="19"
    {!> ../../../docs_src/path_operation_configuration/tutorial005_py310.py!}
    ```

If you select "Watching" instead of "Releases only" you will receive notifications when someone creates a new issue or question. You can also specify that you only want to be notified about new issues, or discussions, or PRs, etc.

Then you can try and help them solve those questions.

## Ask Questions

        * In responses, the `set` will be converted to a `list`.
        * The generated schema will specify that the `set` values are unique (using JSON Schema's `uniqueItems`).
* `bytes`:
    * Standard Python `bytes`.
    * In requests and responses will be treated as `str`.
    * The generated schema will specify that it's a `str` with `binary` "format".
* `Decimal`:
    * Standard Python `Decimal`.

Let's look at how we can make that work.

## pytest.mark.anyio

If we want to call asynchronous functions in our tests, our test functions have to be asynchronous. AnyIO provides a neat plugin for this, that allows us to specify that some test functions are to be called asynchronously.

## HTTPX

Even if your **FastAPI** application uses normal `def` functions instead of `async def`, it is still an `async` application underneath.

Because this dependency function doesn't have any scope requirements itself, we can use `Depends` with `oauth2_scheme`, we don't have to use `Security` when we don't need to specify security scopes.

We also declare a special parameter of type `SecurityScopes`, imported from `fastapi.security`.

This `SecurityScopes` class is similar to `Request` (`Request` was used to get the request object directly).

}
```

Of course, you will probably find much better ways to take advantage of this than formatting JSON. 😉

## Default response class

When creating a **FastAPI** class instance or an `APIRouter` you can specify which response class to use by default.

The parameter that defines this is `default_response_class`.

```Python hl_lines="16-18  21-22  25-30  34-35  38-39  42-48"
{!../../../docs_src/sql_databases_peewee/sql_app/schemas.py!}
```

!!! tip
    Here we are creating the models with an `id`.

    We didn't explicitly specify an `id` attribute in the Peewee models, but Peewee adds one automatically.

    We are also adding the magic `owner_id` attribute to `Item`.

### Create a `PeeweeGetterDict` for the Pydantic *models* / schemas