In this tutorial, we will build a small microblog that implements the ActivityPub protocol, similar to Mastodon or Misskey, using Fedify, an ActivityPub server framework.

I just finished reviewing my 2025 predictions (how do you think I did grading myself?) www.timothychambers.net/2024/12/2… Now it’s time to make some bets for 2026. I do this not to prove how great my prognostication muscles are, but to shine a spotlight on trends I think are vital, spur discussions, and give some attention to projects that have earned it. As always, I try to make these as quantifiable, verifiable and crisp as I can. Here goes: 🌱 MILD Safe bets — would be surprising if these DON’T happen. ▶️ Bluesky will cross 60 million registered users in 2026. Growth will slow from 2024’s explosive pace but remain steady, driven by continued X dissatisfaction and improved features. ▶️ The ActivityPub Fediverse (excluding Threads) will cross 15 million registered users, monthly active users (excluding will plateau around 2-3 million. Another good year in terms of stable base, but no big waves of new users. Both Bluesky and Fediverse growth won’t come from big waves of migration this year. ▶️ Any smaller waves from X/Twitter or from a newly bought TikTok will benefit Meta (Threads/IG), BlueSky, and Fediverse in that order. I see nothing that would change that prediction that was true last year, too. ▶️ Threads will pass 500 million monthly active users and remain the largest ActivityPub-adjacent platform by a wide margin. But see the next prediction: ▶️ Threads federation will remain partial, and opt-in through all of 2026. Full two-way federation will NOT ship in 2026 but may move from about 90 percent there, to 95 percent done, inching forward but not finalized and prioritized as a feature. As Manton wrote, that’s better than fully closed, and better than them stripping it out. (which they might do but I’m predicting not) My bet: the status quo continues. www.manton.org/2025/12/1… ▶️ Ghost’s ActivityPub integration will bring 75,000+ new federated accounts to the Fediverse and Ghost will finish 2026 in the top 10 Fediverse server software by MAU. ▶️ WordPress-based federated accounts will cross 50,000 as measured by FediDB. Currently at approximately 26,000 accounts across 12,700 servers, the WordPress-to-Fediverse pipeline becomes a meaningful growth contributor. 🔥 MEDIUM-SPICEY Plausible bets — could go either way, but evidence points toward yes. ▶️ BridgyFed will shift to “opt-out” for Bluesky users bridging to ActivityPub — and the discourse will be far less contentious than the 2024 debates predicted. Cross-protocol interoperability quietly normalizes. ▶️ At least one fully independent ATProto stack — PDS, Relay, and AppView operating without dependency on Bluesky PBC infrastructure — will achieve viability in 2026, meaning it has paying customers or sustainable funding. This will be the year ATProto proves (or fails to prove) it can exist beyond Bluesky-the-company. ▶️ Mastodon gGmbH will hit key sustainability milestones in 2026. Their hosting revenue model will exceed internal targets, the new organizational structure will unlock additional grant funding (beyond NGI/NLnet), and the pace of Mastodon development will noticeably accelerate — shipping more significant features in 2026 than in the previous two years combined. ▶️ Bluesky PBC will raise another round of funding in 2026 and announce more details on a proposed business model. Following their $15M Series A (October 2024), the company will close a larger round to extend runway. The announced business model will NOT be advertising-based. I’d expect subscriptions, marketplace fees, or enterprise services. ▶️ The first “ATProto-native” social app that is NOT microblogging will cross 100,000 users. Whether it’s Frontpage (link aggregation), Leaflet (long-form), Smoke Signal, or something new — the ATmosphere diversifies beyond Bluesky-the-app. ▶️ Flipboard’s Surf app will launch its 1.0 version in 2026 and cross 1 million downloads across iOS and Android by year end, with 100,000+ monthly active users. It will become the most-downloaded dedicated Open Social Web client, surpassing Mastodon’s official app and Graysky. ▶️ Fedify will power the federation layer for at least one mid-sized social platform (500K+ users) that adds ActivityPub support in 2026. The “build vs. buy” calculation for federation shifts decisively toward “just use Fedify.” ▶️ Fediscovery will ship in a stable Mastodon release in 2026, moving from behind feature flags to production-ready. The specifications for pluggable discovery providers — covering account search, follow recommendations, and trends — will reach 1.0 status, and at least one public Fediscovery-compatible provider will launch for general use. Small instance operators will finally have a real option to improve discovery without running their own infrastructure. ▶️ The new “ActivityRank” algorithm in Loops will prove that ethical recommendations and decentralization can coexist. Dan Supernault’s approach — where each instance trains its own algorithm while surfacing content across the ActivityPub network — will be recognized as a breakthrough in solving the fediverse’s discoverability problem. By the end of 2026, the pattern will be studied or adopted by at least two other ActivityPub platforms. ▶️ Fediscovery will ship in a stable Mastodon release in 2026, moving from behind feature flags to production-ready. Fediscovery is a Mastodon gGmbH-led project building open specifications for pluggable, privacy-respecting discovery providers — covering account search, follow recommendations, and trending content. The specifications will reach 1.0 status, and at least one non-Mastodon platform will adopt the spec. ▶️ ATProto will advance from Internet Drafts to an official IETF Working Group in 2026. Following the September 2025 submission of initial specifications, Bluesky will secure enough support and independent implementers to form a dedicated Working Group — moving from “proposal being discussed” to “standard being formally developed.” 🌶️ SPICY Hot takes - a bit more risky - but I’m calling my shot. ▶️ A well-known digital-native media publication (10M+ monthly visitors) will federate via ActivityPub in 2026 and publicly share positive results. Whether through Ghost, WordPress, or custom implementation, this outlet will report that federated followers drove meaningful engagement — making the business case for federation legible to other publishers for the first time. By year end, at least two additional publications will announce federation plans, citing this pioneer as proof of concept. ▶️ At least one major news organization (top 50 US by traffic) will announce it is leaving X/Twitter entirely and making Bluesky or the Fediverse its primary social distribution channel. The “institutional exodus” begins. ▶️ At least one major national government or major city will launch an official presence on BOTH Bluesky AND the ActivityPub Fediverse in 2026 — and it will be a European government. Expect surprising additional early adopters after this from Latin America, Asia-Pacific, or Africa to follow that lead and make moves that year to do the same. This is the year the move to “digital sovereignty" from US tech will benefit the open social web. Eurosky will inch along with some promise. ▶️ Nostr ↔ ATProto ↔ ActivityPub three-way bridging becomes functional via BridgyFed or another service by end of 2026. The “protocol wars” narrative collapses into “just pick your client.” ▶️ AltStore will be live with Federation features in at least 5 countries by end of 2026 (currently EU + Japan, with Brazil, Australia, UK announced). AltStore is an independent iOS app marketplace created by Riley Testut and Shane Gill — the first major alternative to Apple’s App Store, made possible by the EU’s Digital Markets Act. The federated app marketplace model will prove viable outside Europe, challenging Apple’s App Store dominance in multiple regulatory regimes simultaneously. Their ActivityPub integration — where app updates flow to Mastodon, Threads, and Bluesky — will become the most compelling non-social-media use case for decentrlized social features, proving definitively that such protocols extends beyond microblogging. ▶️ Loops will become the third most-used Fediverse software by MAU by end of 2026, trailing only Mastodon and Pixelfed. The short-form video platform will cross 100,000 monthly active users, with Loops-originated content generating significant federated engagement from non-Loops clients — proving that ActivityPub can power video-centric social experiences. ▶️ PieFed will emerge as the most feature-rich Threadiverse platform by end of 2026, surpassing Lemmy and Mbin in moderation tools, user experience, and federation capabilities. The platform will cross 10,000 monthly active users and its rapid development pace — shipping major features weekly — will make it the default recommendation for anyone starting a new Reddit-style community in the fediverse. ▶️ More laws akin to Utah’s Digital Choice Act will pass or advance - sparking first steps towards interoperability to mainstream US discourse. The Utah law takes effect July 1, 2026, and several other states will pass similar ones, requiring social media platforms to enable data portability and interoperability. At least one major platform will announce ActivityPub or AT Protocol support to comply. The “Digital Choice” framing will prove more politically viable than “antitrust” for breaking Big Tech’s lock-in. **What did I miss? What did I get wrong? Let me know — and I’ll see you in December 2026 to grade these.**