mention has no default — it stays unregistered until you pass items:

Prop

Type

useSlashEditor({
  blockKit: {
    mention: {
      items: (query, { signal }) => yourMentionProvider(query, signal),
    },
  },
});

items is built on @tiptap/suggestion's native async provider support: it accepts MentionItem[] | Promise<MentionItem[]>, and a stale in-flight call is aborted the moment a newer keystroke supersedes it — the signal argument is that abort. A rejection is caught into onError and an empty result set, rather than leaving the menu stuck loading.

See the Mention Menu component for the rendered async search surface, including its loading state.

Mentions