@hongminhee@hollo.social ah yes, implements would be a good thing to support. It would allow you to cache the value temporarily (maybe a quick recheck every 7 days or so) so as to avoid needing a double knock at all.
Caching based on first knock success also works.
I wonder if sending HTTP 426 is doable too... 🤔
https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/426