W3C-ACTIVITYPUB

W3C ActivityPub Fediverse federation social.

Définition

ActivityPub 2 sides : (1) Client-to-Server (C2S) : user app communicates with home server via Inbox + Outbox HTTP endpoints. (2) Server-to-Server (S2S) : home servers federate avec other servers via HTTP POST Activity JSON-LD AS2 to remote inbox. Actor objects : ~/actor.json (Person, Service, Application, Group, Organization) + properties inbox URL + outbox URL + followers + following + liked + streams. Patterns key : (a) Follow Activity : POST Follow activity to target actor inbox, target server responds Accept Activity to follower inbox. (b) Create Activity : POST Create activity (envelopes new Note, Article, Image, Video) to target inbox(es). (c) Like, Announce (boost/retweet), Block, Update, Delete activities. Signature : HTTP Signatures spec (draft-cavage-http-signatures) signe HTTP requests + JSON-LD signatures (Linked Data Proofs) data integrity. Mastodon largest implementation ~12M users 8000+ instances 2024. Threads Meta partial ActivityPub support 2024+.

Origine

ActivityPub specification draft 2014 par Christine Lemmer-Webber + Jessica Tallon W3C Social Web WG ; W3C Recommendation 23 janvier 2018 ; Mastodon adopts 2017 v1.6 (avant W3C Rec final) ; Threads Meta partial 2024.

Exemple en contexte

Mastodon.social user @alice follows PeerTube channel @bob@video.example.com : POST Follow activity AS2 vers bob inbox, video.example.com server processes, responds Accept Activity to alice inbox, alice now subscribed to bob video uploads federated cross-instance.

Termes liés

• W3C AS2 — vocabulary base.