They've offered that for a long time, e.g. Startpage, Mullvad Leta, and Kagi are supposedly using that API. The pricing isn't public AFAIK, but a revshare like

They've offered that for a long time, e.g. Startpage, Mullvad Leta, and Kagi are supposedly using that API. The pricing isn't public AFAIK, but a revshare like you suggest seems unlikely.