According to some simple Googling [0] seems to be the oldest occurrence of this.
[0] http://athena.ecs.csus.edu/~brodyr/jokes/engr/sign-engr.html
67 karma · joined July 14, 2021
[0] http://athena.ecs.csus.edu/~brodyr/jokes/engr/sign-engr.html
Apps that support it: https://unifiedpush.org/users/apps/
(not affiliated just a big fan)
(I'm unaffiliated, just sharing)
AFAIK from an above comment by @rozzie the protocol is open and the domain can be changed. So it should be possible for someone to write a self hostable server
https://dev.blues.io/reference/notecard-api/hub-requests/#hu... https://github.com/blues/note
With a proper UI there would be different messages when a cert mismatches compared to when a new cert is seen or the previous cert was about to expire. (Quite like Gemini browsers)