This can make it a lot easier for your users to **implement their APIs** to receive your **webhook** requests, they might even be able to autogenerate some of their own API code.

/// info

Webhooks are available in OpenAPI 3.1.0 and above, supported by FastAPI `0.99.0` and above.

///

## An app with webhooks

Note that the go_darwin_$GOARCH_exec wrapper uninstalls any existing app identified by
the bundle id before installing a new app. If the uninstalled app is the last app by
the developer identity, the device might also remove the permission to run apps from
that developer, and the exec wrapper will fail to install the new app. To avoid that,
install another app with the same developer identity but with a different bundle id.

   */
  /*
   * TODO(cpovirk): or we could make HOLES_FORBIDDEN a feature. Or we could declare that
   * implementations are permitted to throw IAE if a hole is requested, and we could update
   * test*Hole to permit IAE. (But might this ignore genuine bugs?) But see the TODO above
   * testLower, which could make this all unnecessary
   */
  public static Method[] getHoleMethods() {
    return new Method[] {

      /*
       * If another handleException() caller created the set, we need to use that copy in case yet
       * other callers have added to it.
       *
       * This read is guaranteed to get us the right value because we only set this once (here).
       *
       * requireNonNull is safe because either our compareAndSet succeeded or it failed because
       * another thread did it for us.
       */

        adapterExecutor.execute(
            () -> {
              try {
                /*
                 * Threads from our private pool are never interrupted. Threads from a
                 * user-supplied executor might be, but... what can we do? This is another reason
                 * to return a proper ListenableFuture instead of using listenInPoolThread.
                 */
                getUninterruptibly(delegate);

     *
     *            k * k <= x          <  (k + 1) * (k + 1)
     * (double) (k * k) <= (double) x <= (double) ((k + 1) * (k + 1))
     *          since casting to double is nondecreasing.
     *          Note that the right-hand inequality is no longer strict.
     * Math.sqrt(k * k) <= Math.sqrt(x) <= Math.sqrt((k + 1) * (k + 1))
     *          since Math.sqrt is monotonic.

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## Forbid Extra Headers

In some special use cases (probably not very common), you might want to **restrict** the headers that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

//// tab | Python 3.10+

```Python hl_lines="10"

} text += "</tr>"; } rows = content.split(";"); for (i = 0; i < rows.length; i++) { if (rows[i].length > 0) { columns = rows[i].split(","); text += "<tr>"; for (j = 0; j < columns.length; j++) { text += "<td" + (number.test(columns[j]) ? " align=\"right\">" : ">") + columns[j] + "</td>"; } text += "</tr>"; } } text += "</table>"; } showText(text); } function showText(text) { list = window.open("", "list", "dependent=yes,location=no,menubar=yes,resizable=yes,toolbar=no,scrollbars=yes,width=500,height=400");...

                            <la:message key="labels.dict_protwords_title"/>
                        </h1>
                    </div>
                    <div class="col-sm-6">
                        <ol class="breadcrumb float-sm-right">
                            <li class="breadcrumb-item"><la:link href="/admin/dict">
                                <la:message key="labels.dict_list_link"/>
                            </la:link></li>

                            <la:message key="labels.dict_stopwords_title"/>
                        </h1>
                    </div>
                    <div class="col-sm-6">
                        <ol class="breadcrumb float-sm-right">
                            <li class="breadcrumb-item"><la:link href="/admin/dict">
                                <la:message key="labels.dict_list_link"/>
                            </la:link></li>