okay check this out https://grebedoc.dev/
@whitequark why is the webhook HTTP instead of HTTPS? Haven't used webhooks in a while, but that feels strange.
@esoterra it's because i provision TLS on-demand; the first time you fire the webhook i will not have a certificate (and provisioning a cert to anything in a Host: header is not recommended by ACME)
Have you considered getting a wildcard cert? On the face of it I'd expect it to simplify provisioning significantly, but maybe your separation between repositories relies on this (cert transparency logs do show different public keys for different subdomains after all).
@whitequark apparently I can't see robryk's messages so this is all showing up really confusingly in my notifications.
I suspect this is some kind of fallout from instances silencing other instances years ago.
Mechanistically, you get notified when sender's instance sends something to receiver's instance. The sending instance might refuse to do so, or the receiving one might refuse to accept (generally based on either the identity of the sending instance or the sending user).
Whether you can call up a post (by URL) in your Mastodon client[^1] is a question of whether the post's hosting instance is willing to serve it to your (which in practice might be more restricted than viewing it using the sending instance's web UI; how do they know who's fetching? -> Authorized Fetch) and whether yours is willing to contemplate storing the post at all (see the case above).
What appears when you look for replies to a particular post is more mysterious for me.
[^1] I'm less sure about other fedi instance software