FEP-521a and FEP-8b32. Every persona has an Ed25519 key of its own (Avatar.SigningKey; migration 014 gives the earlier
ones theirs), named in its actor's assertionMethod as a Multikey, the terms defined in the actor's own context. A
persona's activity going to a relay carries an eddsa-jcs-2022 proof (JSON canonicalised by RFC 8785, Jcs), so what
Activity-Relay forwards reaches Mastodon, which verifies it with its own code. Nothing else carries one: Mitra takes a
proof over the HTTP signature and refuses one by a key it has not read, without reading the actor again. Received: an
actor's own Multikeys are kept, and a forwarded activity whose proof one of them verifies is taken as it came instead of
being read again from its origin.
Discovery: WebFinger for the server's origin links its instance actor (FEP-d556), NodeInfo links it as the application
actor (FEP-2677), and actors name RFC 9421 under implements (FEP-844e).
Checked live: relay 16 (Activity-Relay's forward of alice's post reaches Mastodon), Mitra, GoToSocial and Mastodon
unchanged (165 in all).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw
A thread's server passes on what happens in it, signed with its own key: Mastodon forwards the replies to its
accounts' posts and their deletions, Friendica every activity in its threads. PrivaPub answered them 401, which also
tells a sender its signature failed. Now they get 202 and nothing in them is believed: a forwarded Create or Update is
taken as its object reads at the actor's origin, a Delete of a public or unlisted copy once that origin answers 404 or
410 (RemoteActorService.IsGone; FederationHttp remembers the status of a refusal), anything else is let go, and our own
activities coming back are ignored. A forwarded copy has its own dedupe key, so one that failed never hides the
author's own delivery.
A reply in the thread of someone followed here is kept, as Mastodon keeps them. Mastodon delivers a reply to the
followers of the account it answers; PrivaPub dropped those as unaddressed, which the pasture showed: the outsider's
reply its Mastodon scenario said was never delivered had been, and was thrown away.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw
thepraandClaude Opus 5.5