## The normal **FastAPI** app { #the-normal-fastapi-app }

Let's first see how the normal API app would look like before adding the callback.

It will have a *path operation* that will receive an `Invoice` body, and a query parameter `callback_url` that will contain the URL for the callback.

This part is pretty normal, most of the code is probably already familiar to you:

 * ever be considered dead, and no DeadEvents will be generated. Accordingly, while DeadEvent
 * extends {@link Object}, a subscriber registered to receive any Object will never receive a
 * DeadEvent.
 *
 * <p>This class is safe for concurrent use.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/EventBusExplained">{@code EventBus}</a>.

You can "watch" FastAPI in GitHub (clicking the "watch" button at the top right): [https://github.com/fastapi/fastapi](https://github.com/fastapi/fastapi). 👀

There you can select "Releases only".

By doing it, you will receive notifications (in your email) whenever there's a new release (a new version) of **FastAPI** with bug fixes and new features.

## Connect with the author { #connect-with-the-author }

Channel communication is the main method of synchronization
between goroutines.  Each send on a particular channel
is matched to a corresponding receive from that channel,
usually in a different goroutine.
</p>

<p class="rule">
A send on a channel is synchronized before the completion of the
corresponding receive from that channel.
</p>

<p>
This program:
</p>

<pre>
var c = make(chan int, 10)
var a string

description: Suggest an idea for this project
labels: [ "a:feature", "to-triage" ]
assignees: [ ]
body:
  - type: markdown
    attributes:
      value: |
        Please follow the instructions below.
        We receive dozens of issues every week, so to stay productive, we will close issues that don't provide enough information.

        Please open Android-related issues on [the Android Issue Tracker](https://source.android.com/source/report-bugs)

    // client to fail at 1500ms when it's time to send ping 3 because pong 2 hasn't been received.
    taskFaker.advanceUntil(ns(1000L))
    taskFaker.advanceUntil(ns(1500L))
    client.listener.assertFailure(
      SocketTimeoutException::class.java,
      "sent ping but didn't receive pong within 500ms (after 1 successful ping/pongs)",
    )
  }

  @Test

     * instead of send/receive.
     *
     * @return threshold in bytes
     */
    int getRdmaReadWriteThreshold();

    /**
     * Get maximum RDMA send size
     *
     * @return max send size in bytes
     */
    int getRdmaMaxSendSize();

    /**
     * Get maximum RDMA receive size
     *
     * @return max receive size in bytes
     */

## Query parameter list / multiple values { #query-parameter-list-multiple-values }

When you define a query parameter explicitly with `Query` you can also declare it to receive a list of values, or said in another way, to receive multiple values.

For example, to declare a query parameter `q` that can appear multiple times in the URL, you can write:

/// note | 技術細節

`Request` 具有 `request.scope` 屬性，它其實就是一個 Python 的 `dict`，包含與該請求相關的中繼資料。

`Request` 也有 `request.receive`，那是一個用來「接收」請求本文的函式。

`scope` 這個 `dict` 與 `receive` 函式都是 ASGI 規格的一部分。

而 `scope` 與 `receive` 這兩者，就是建立一個新的 `Request` 實例所需的資料。

想了解更多 `Request`，請參考 [Starlette 的 Request 文件](https://www.starlette.dev/requests/)。

///

          # retainVersions: 5 # keep the latest 5 versions of the object including delete markers.

  notify:
    endpoint: https://notify.endpoint # notification endpoint to receive job completion status
    token: Bearer xxxxx # optional authentication token for the notification endpoint
  
  retry:
    attempts: 10 # number of retries for the job before giving up