* The router dependencies are executed first, then the [`dependencies` in the decorator](dependencies/dependencies-in-path-operation-decorators.md), and then the normal parameter dependencies.
    * You can also add [`Security` dependencies with `scopes`](../advanced/security/oauth2-scopes.md).

/// tip

    public static final int ACB_PWNOTREQ = 4;
    /** Account control bit flag: Temporary duplicate account */
    public static final int ACB_TEMPDUP = 8;
    /** Account control bit flag: Normal user account */
    public static final int ACB_NORMAL = 16;
    /** Account control bit flag: MNS logon user account */
    public static final int ACB_MNS = 32;
    /** Account control bit flag: Interdomain trust account */

    public static final int ACB_PWNOTREQ = 4;
    /** Account control bit flag: Temporary duplicate account */
    public static final int ACB_TEMPDUP = 8;
    /** Account control bit flag: Normal user account */
    public static final int ACB_NORMAL = 16;
    /** Account control bit flag: MNS logon user account */
    public static final int ACB_MNS = 32;
    /** Account control bit flag: Interdomain trust account */

例で見ていきます。

あなたが請求書を作成できるアプリを開発していると想像してください。

これらの請求書は `id`、`title`（任意）、`customer`、`total` を持ちます。

あなたの API の利用者（外部開発者）は、POST リクエストであなたの API に請求書を作成します。

その後、あなたの API は（仮にこうしましょう）:

* 外部開発者の顧客に請求書を送ります。
* 代金を回収します。
* API 利用者（外部開発者）に通知を送り返します。
    * これは（あなたの API から）外部開発者が提供する *外部 API* に POST リクエストを送ることで行われます（これが「コールバック」です）。

## 通常の FastAPI アプリ { #the-normal-fastapi-app }

まず、コールバックを追加する前の通常の API アプリがどうなるか見てみましょう。

  fun nextFrame(
    requireSettings: Boolean,
    handler: Handler,
  ): Boolean {
    try {
      source.require(9) // Frame header size.
    } catch (e: EOFException) {
      return false // This might be a normal socket close.
    }

    //  0                   1                   2                   3
    //  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

  /**
   * Returns the stack trace of {@code throwable}, possibly providing slower iteration over the full
   * trace but faster iteration over parts of the trace. Here, "slower" and "faster" are defined in
   * comparison to the normal way to access the stack trace, {@link Throwable#getStackTrace()
   * throwable.getStackTrace()}. Note, however, that this method's special implementation is not

  }

  /**
   * An instance created in {@link #readObject} to be returned from {@link #readResolve}. This field
   * is used only by those methods, and it is never set in a "normal" instance.
   *
   * <p>For more background, see {@code ConcurrentHashMultiset.deserializationReplacement}.
   */
  private transient @Nullable ImmutableListMultimap<?, ?> deserializationReplacement;

            path = "../";
        }
        out.println(dirCount + fileCount + " objects (" + dirCount + " directories, " + fileCount + " files)<br>");
        out.println("<b><a class=\"plain\" href=\".\">normal</a> | <a class=\"plain\" href=\"?fmt=detail\">detailed</a></b>");
        out.println("<p><table border='0' cellspacing='0' cellpadding='0'><tr><td>");

        out.print("<A style=\"width: " + maxLen);

Apenas um processo no servidor pode se conectar a uma porta em um endereço IP. Poderiam existir outros processos conectados em outras portas desse mesmo endereço IP, mas apenas um para cada combinação de endereço IP e porta.

TLS (HTTPS) usa a porta `443` por padrão. Então essa é a porta que precisamos.

Como apenas um único processo pode se comunicar com essa porta, o processo que faria isso seria o Proxy de Terminação TLS.

## Özel Doğrulama { #custom-validation }

Yukarıdaki parametrelerle yapılamayan bazı **özel doğrulama** ihtiyaçlarınız olabilir.

Bu durumlarda, normal doğrulamadan sonra (ör. değerin `str` olduğunun doğrulanmasından sonra) uygulanacak bir **custom validator function** kullanabilirsiniz.