This sea is what lets different companies, different individuals, and different software meet in one timeline. Following someone on hollo from Mastodon, a hackers.pub article flowing into Misskey—all of it happens thanks to one shared rite: ActivityPub.
The diplomatic documents the ships carry are JSON-LD parcels called Activities. "I follow you (Follow)," "I made this (Create)." The wax seal is an HTTP signature—so the receiver can verify that it truly came from that island's keeper.
Highlights
- Resolving a destination always begins at the Webfinger Gate. A name like @handle@host is first resolved to an actor's URL.
- The documents are JSON-LD, not plain JSON. The meaning of the vocabulary is carried by
@context—so the ship carries the dictionary along with it. - The wax seal (HTTP signature) has two etiquettes, new and old, and fedify's Chamber of Rites picks between them to match the other party.
- No reply is the norm (fire-and-forget). Whether it arrived is told only by the HTTP response code.