Which endpoint did you use? You could either use the forums/topics or core/search endpoint for this.
Webhooks support this already, BUT I don’t think that they would make you happy in regards to your previous question, bedusle webhooks are used to notify other apps/services about a specific event which happened just now. So an example:
you’ll want to use the REST API to retrieve the recent X topics, files or members by either sending a manual request or polling the data frequently, but you’ll want to use webhooks to get an instant notification which is triggered by your community.
This also means, that the webhook request also contains ONLY the one object (*) which triggered the event, like the topic and not the last x topics!
* there are of course also some cases where’s more then only the item in a hooks payload.
For example the calendarEvent_rsvp webhook will contain the event, the attendee member object and the new state as payload.