Add Button To Top Toolbar in Gutenberg

Question

I would like to add a button that triggers some custom JS code to the top roolbar (not the block level editor toolbar):

Is there an official way to do this? I couldn't find any documentation about extending the top toolbar.

Thanks Aaron

Answer 1

This is presently not offered as an extension point. The source for the post editor's toolbar shows that these items are hard-coded, and do not offer any filters or Slotfills.

Issue #16174 provides a feature request for such extension points.