Background knowledge about Mastodon, the dominant federated microblogging platform and de facto reference implementation for ActivityPub social networking. Covers Mastodon's JSON-LD @context structure (three-element array: activitystreams, security/v1, inline object defining toot: http://joinmastodon.org/ns# with Emoji/discoverable/featured/featuredTags/ blurhash/votersCount/indexable/memorial/suspended/attributionDomains, schema: http://schema.org# with PropertyValue/value, as: with Hashtag/manuallyApprovesFollowers/movedTo/sensitive), content-type and Accept header requirements (application/activity+json or application/ ld+json with ActivityStreams profile, content negotiation for actor discovery), HTTP signature requirements (RSA-SHA256, Digest header mandatory for POST, signed headers include request-target/host/date/ digest), authorized fetch / secure mode (AUTHORIZED_FETCH env var, requires signatures on GET requests too, breaks unsigned federation), supported object types (Note and Question first-class
Background knowledge about WriteFreely, the open-source federated blogging platform written in Go (AGPL-3.0) by Matt Baer / Musing Studio. Covers the origin story (Write.as anonymous writing platform launched 2014, open-sourced as WriteFreely November 2018 after adding ActivityPub), the write-only/broadcast federation model (blogs can be followed but cannot follow others, no incoming comments/replies displayed, no moderation), the actor model (each blog/collection is a Person actor with handle @blog@instance.com), the Article vs Note object type distinction (double-line break heuristic, notes_only config option), supported activities (outbound Create/Update/Delete, inbound Follow/Undo/Like), RSA-SHA256 HTTP signatures with per-blog keypairs, the tech stack (Go/MySQL or SQLite/single binary deployment/256 MB RAM/Raspberry Pi), configuration (single-user vs multi-user modes, federation toggle, .ini config file), NodeInfo with WriteFreely-specific metadata, the RESTful API (Posts/Collections/Users with token aut
Background knowledge about Mbin, the federated content aggregator and microblogging platform (active community fork of Kbin). Covers the hybrid dual content model (threads as Page + microblogs as Note in one platform), magazines as Group actors with Announce relay, the three actor types (Application instance actor at /i/actor, Person user at /u/username, Group magazine at /m/name), the full activity reference (Create, Update, Delete, Like, Dislike, Announce, Follow, Accept, Block, Flag, Lock, Add, Remove), the voting system (Like for upvotes, Dislike for downvotes with historical federation issues, Announce for boosts — boosts and votes are separate unlike Lemmy), the hybrid thread+microblog model and why it enables superior Mastodon integration, the tech stack (PHP 8.3+/Symfony 7.4/ PostgreSQL/RabbitMQ/Redis, AGPL-3.0), the async message processing architecture (Symfony Messenger with 15 inbox + 15 outbox message types), the REST API with OAuth2 and Swagger docs, the Mbin fork history (forked from Kbin Octob
Background knowledge about NodeBB, the modern open-source forum software built on Node.js with native ActivityPub federation (core feature since v4.0.0, January 2025). Covers the three actor types (Person user at /u/username, Group category at /category/<cid> implementing FEP-1b12 Group Federation with Announce relay pattern, Application instance actor), the two-level content hierarchy (category as audience → topic as context → post), how topics map to resolvable OrderedCollection contexts per FEP-7888 and posts are Note/Article objects, extensive FEP support (12 implemented: FEP-1b12 Group Federation, FEP-7888 context property, FEP-f228 Backfilling Conversations, FEP-4f05 Soft Deletion, FEP-9098 Custom emojis, FEP-b2b8 Long-form Text, FEP-fe34 Origin-based security, FEP-ae0c Relay Protocols, FEP-11dd Context Ownership, FEP-f15d Context Relocation, FEP-fb2a Actor metadata, FEP-0151 NodeInfo), the tech stack (Node.js/WebSocket/Socket.IO/ MongoDB or Redis or PostgreSQL, GPL-3.0), content discovery (follow- base
Background knowledge about Kbin and its active community fork Mbin, the decentralized content aggregator and microblogging platform for the Fediverse (Reddit + Mastodon hybrid). Covers the dual content model (threads/link aggregation via Page objects + microblogging via Note objects in a single platform), magazines as Group actors with Announce relay (same pattern as Lemmy communities), the three actor types (Application instance actor at /i/actor, Person user at /u/username, Group magazine at /m/name), supported activities (Follow, Like, Announce, Create, Update, Delete, Block, Flag, Lock, Add, Remove), the critical detail that downvotes do NOT federate, content object mapping (threads as Page, microblogs as Note, comments as Note with inReplyTo, private messages as ChatMessage), the tech stack (PHP 8.2+/Symfony/PostgreSQL/RabbitMQ/Redis, AGPL-3.0), the REST API with OAuth2 and Swagger docs at /api/docs, the Mbin fork history (Kbin discontinued after creator Ernest Wisniewski's absences, Mbin forked October
Background knowledge about PieFed, the federated link aggregation and discussion platform (Python-based Reddit/Lemmy alternative in the Threadiverse). Covers PieFed's tech stack (Python/Flask, PostgreSQL, Celery/Redis, htmx, Jinja2, AGPL-3.0), the Lemmy-compatible ActivityPub implementation (Community as Group, Post as Page, Comment as Note, Like/Dislike voting, Announce relay pattern, ChatMessage for DMs), the unique Feed actor type (FEP-1d80 for federated multi- community collections), private/anonymous voting via proxy user profiles, additional activity types (EmojiReact, PollVote, ChooseAnswer for Q&A mode, Event objects with startTime/endTime), the 95%-Lemmy-compatible REST API (/api/alpha/ with Swagger docs, enabling Voyager/Interstellar/Blorp/Summit mobile apps), custom JSON-LD extensions (genAI, nsfl, flair, postingWarning, interactionPolicy, lemmy:tagsForPosts compatibility), the federation architecture (Celery async processing, Redis dedup with 90s TTL, RSA-SHA256 HTTP signatures, LD signature fallb
Background knowledge about Misskey, the Japanese-origin federated microblogging platform (created 2014 by syuilo). Covers Misskey's ActivityPub extensions (custom namespace https://misskey-hub.net/ns# with _misskey_content, _misskey_quote, _misskey_reaction for emoji reactions on Like activities, _misskey_votes, _misskey_talk for chat, isCat boolean, _misskey_followedMessage, _misskey_requireSigninToViewContents, _misskey_makeNotesFollowersOnlyBefore, _misskey_makeNotesHiddenBefore, _misskey_license), MFM (Misskey Flavored Markdown) proprietary markup with animations/colors/effects, emoji reactions as primary engagement mechanism (Unicode + custom emoji, federated via Like with _misskey_reaction), the Drive file management system, Antennas (custom filtered feeds), Deck UI, Channels, Pages, Clips, Plugins, Themes, Widgets, isCat mode, the tech stack (Node.js/TypeScript/NestJS/PostgreSQL/Redis/Vue.js 3/Vite, AGPL-3.0), REST API (POST-based) and WebSocket streaming API, Note visibility levels (public/home/follow
Background knowledge about Loops, the federated short-form video sharing platform (TikTok/Vine alternative for the Fediverse). Covers the key federation design decision of using Note objects with video attachments instead of Video objects for maximum cross-platform compatibility, the instance actor and shared inbox implementation, HTTP Signatures with SHA-256 digests, WebFinger discovery, the graph-walking comment validator (rejects top-level Notes, creates Comment and CommentReply objects), cross-platform interactions (follow, comment, like, Announce across Mastodon/Pixelfed/PeerTube), the tech stack (Laravel/PHP, Vue 3, Tailwind, Expo/React Native mobile), features (vertical swipe feed, For You algorithm, duets, 3-minute videos, playlists, threaded comments), the relationship to Pixelfed and creator Daniel Supernault, federation beta status, and comparison with PeerTube (Note vs Video object types, short-form vs long-form). Load when the user asks about Loops; how short-form video federates in the Fediverse