takahe/templates/activities/_boost.html

<span class="post-action">
  {% if post.pk in interactions.boost %}
      <a title="Unboost" class="active" hx-post="{{ post.urls.action_unboost }}" hx-swap="outerHTML">
          <i class="fa-solid fa-retweet"></i> {{ event.boost_count }}
      </a>
  {% else %}
      <a title="Boost" hx-post="{{ post.urls.action_boost }}" hx-swap="outerHTML">
          <i class="fa-solid fa-retweet"></i> {{ event.boost_count }}
      </a>
  {% endif %}
</span>