If the client requests `http://example.com/items/foo` (an `item_id` `"foo"`), that client will receive an HTTP status code of 200, and a JSON response of:

```JSON
{
  "item": "The Foo Wrestlers"
}
```

But if the client requests `http://example.com/items/bar` (a non-existent `item_id` `"bar"`), that client will receive an HTTP status code of 404 (the "not found" error), and a JSON response of:

```JSON
{

# Request Files

You can define files to be uploaded by the client using `File`.

/// info

To receive uploaded files, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

## Await for messages and send messages

In your WebSocket route you can `await` for messages and send messages.

```Python hl_lines="48-52"
{!../../docs_src/websockets/tutorial001.py!}
```

You can receive and send binary, text, and JSON data.

## Try it

If your file is named `main.py`, run your application with:

<div class="termy">

```console
$ fastapi dev main.py

Ein `Request` hat auch ein `request.receive`, welches eine Funktion ist, die den Hauptteil des Requests empfängt.

Das `scope`-`dict` und die `receive`-Funktion sind beide Teil der ASGI-Spezifikation.

Und diese beiden Dinge, `scope` und `receive`, werden benötigt, um eine neue `Request`-Instanz zu erstellen.

For example, it doesn't receive `datetime` objects, as those are not compatible with JSON.

So, a `datetime` object would have to be converted to a `str` containing the data in <a href="https://en.wikipedia.org/wiki/ISO_8601" class="external-link" target="_blank">ISO format</a>.

The same way, this database wouldn't receive a Pydantic model (an object with attributes), only a `dict`.

# limitations under the License.
# ==============================================================================


# This Workflow updates tensorflow/tools/toolchains/remote_config/configs.bzl
# to reference the most recent versions of the SIG Build Docker images.
name: Update RBE Configs
on:
  workflow_dispatch:

permissions:
  contents: read

jobs:
  rbe:
    name: Update RBE Configs
    runs-on: ubuntu-latest

Para isso, **FastAPI** fornece uma função `jsonable_encoder()`.

## Usando a função `jsonable_encoder`

Vamos imaginar que você tenha um banco de dados `fake_db` que recebe apenas dados compatíveis com JSON.

Por exemplo, ele não recebe objetos `datetime`, pois estes objetos não são compatíveis com JSON.

    you're running the same code that you're testing:

    *   Use an up to date [tf-nightly](https://pypi.org/project/tf-nightly/)
        `pip install -U tf-nightly`
    *   Rebase your pull request onto a recent pull from
        [TensorFlow's](https://github.com/tensorflow/tensorflow) master branch.

2.  If you are changing the code and the docstring of a class/function/method,
    then you will need to

# Form Data

When you need to receive form fields instead of JSON, you can use `Form`.

/// info

To use forms, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

A `Request` also has a `request.receive`, that's a function to "receive" the body of the request.

The `scope` `dict` and `receive` function are both part of the ASGI specification.

And those two things, `scope` and `receive`, are what is needed to create a new `Request` instance.