Calling event on stream target parent

1

Hi all,
I have a couple of controllers, 1 nested in the other:

<div data-controller="counter toggle" data-counter-counted-class="item">
  <span data-counter-value="2">2</span>
  
  <div class="counted_items" data-toggle-target="items" data-controller="user-items" data-action="counter#recount">
    <div class="item">item 1</div>
    <div class="item">item 2</div>
  </div>
</div>

.counted_items is a stream target and has new rows appended to it over a socket. Is there a turbo event that I can add to the user-items controller it so so that counter#recount is called, or will I need a mutation observer?

thanks!