And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.
        * At this point is that the API will somehow send a POST request to the
            external API with the notification of the invoice event
            (e.g. "payment successful").
    """

```mermaid
sequenceDiagram
    participant App
    participant Client

    App->>App: Produce Item 1
    App->>Client: Send Item 1
    App->>App: Produce Item 2
    Client->>Client: Process Item 1
    App->>Client: Send Item 2
    App->>App: Produce Item 3
    Client->>Client: Process Item 2
    App->>Client: Send Item 3
    Client->>Client: Process Item 3
    Note over App: Keeps producing...
    Note over Client: Keeps consuming...

///

## Await for messages and send messages { #await-for-messages-and-send-messages }

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

{* ../../docs_src/websockets_/tutorial001_py310.py hl[48:52] *}

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

## Try it { #try-it }

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.
        * At this point is that the API will somehow send a POST request to the
            external API with the notification of the invoice event
            (e.g. "payment successful").
    """

 * its incoming messages.
 *
 * ## Message Queue
 *
 * Messages enqueued with [send] are buffered in an outgoing message queue. This queue has a 16 MiB
 * limit. If a call to [send] would cause the queue to exceed this limit, the web socket will
 * initiate a graceful shutdown (close code 1001) and `send()` will return `false`. No exception is

# Request Body { #request-body }

When you need to send data from a client (let's say, a browser) to your API, you send it as a **request body**.

A **request** body is data sent by the client to your API. A **response** body is the data your API sends to the client.

This is normally called a **webhook**.

## Webhooks steps { #webhooks-steps }

The process normally is that **you define** in your code what is the message that you will send, the **body of the request**.

You also define in some way at which **moments** your app will send those requests or events.

run-name: Notify the IDE Experience team about new RCs for manual testing
on:
  push:
    tags:
      - 'v*.*.*-RC1'

permissions: {}

jobs:
  send-slack-notification:
    runs-on: ubuntu-latest
    steps:
      - name: Send Slack notification about new RCs for manual testing
        id: slack
        uses: slackapi/slack-github-action@v3.0.1
        with:

* The browser thinks it's not sending JSON (because of the missing `Content-Type` header).

Then the malicious website could make the local AI agent send angry messages to the user's ex-boss... or worse. 😅

## Open Internet { #open-internet }

If your app is in the open internet, you wouldn't "trust the network" and let anyone send privileged requests without authentication.

            return message

        return inner

    async def __call__(self, scope, receive, send):
        if scope["type"] != "http" or self.max_content_size is None:
            await self.app(scope, receive, send)
            return

        wrapper = self.receive_wrapper(receive)
        await self.app(scope, wrapper, send)


@router.post("/middleware")