fedidev

Slowly developing the in depth testing of the same functionality at different levels in the #GoActivityPub stack.

*A hand picked list of fediverse events put together by @liaizon@social.wake.st*, if you want an event added to this list please reply to this post, or you can DM me.

I was updating this list for much of 2026. I thought the page was getting too long so figured I would split it into past and present.

When I started the work on ActivityPub projects I fully embraced Maslow's Hammer adage. I wanted as much as possible in my services to go through the #ActivityPub vocabulary and I fully embraced the client to server API.

I'm surprised at how many issues my new integration tests are finding.

For anyone who might find it useful, here's some stats on the note (posts) table from two real-world Sharkey instances:Instance A (3 years old, 12 users (2 active), 472 pub and 491 sub connections):+---------------+------------+--------+------------------------------+ |Metric |Value |Percent |Metric | +---------------+------------+--------+------------------------------+ |total | 25,326,479| 100.00%|All notes | |isSilencedUser | 604,310| 2.39%|Notes by a silenced user | |isSilencedHost | 2,940,100| 11.61%|Notes from a silenced instance| |isSuspendedUser| 282,627| 1.12%|Notes by a suspended user | |isSuspendedHost| 85,733| 0.34%|Notes from a blocked instance | |isPublic | 11,910,305| 47.03%|Public notes | |isHome | 10,244,218| 40.45%|Home-only / unlisted notes | |isFollowers | 3,155,757| 12.46%|Followers-only notes | |isSpecified | 16,199| 0.06%|Specified / DM notes | |isPoll | 53,258| 0.21%|Polls | |isMedia | 2,382,441| 9.41%|Notes w/ media | |isReply | 9,541,477| 37.67%|Replies | |isReplyToSelf | 2,058,518| 8.13%|Self-replies | |isBoost | 6,192,622| 24.45%|Boosts | |isBoostOfSelf | 190,660| 0.75%|Self-boosts | |isQuote | 225,201| 0.89%|Quotes | |isQuoteOfSelf | 70,205| 0.28%|Self-quotes | |isChannel | 2| 0.00%|Notes in a channel | |isRemote | 25,259,313| 99.73%|Remote notes | |isLocal | 67,166| 0.27%|Local notes | |isLocalOnly | 311| 0.00%|Local-only (defederated) notes| +---------------+------------+--------+------------------------------+Instance B (3 years old, 2,731 users (130 active), 1,872 pub and 2,149 sub connections):+---------------+------------+--------+------------------------------+ |Metric |Value |Percent |Metric | +---------------+------------+--------+------------------------------+ |total | 87,276,701| 100.00%|All notes | |isSilencedUser | 1,018,657| 1.17%|Notes by a silenced user | |isSilencedHost | 13,408,299| 15.36%|Notes from a silenced instance| |isSuspendedUser| 414,901| 0.48%|Notes by a suspended user | |isSuspendedHost| 819,842| 0.94%|Notes from a blocked instance | |isPublic | 40,977,139| 46.95%|Public notes | |isHome | 28,991,756| 33.22%|Home-only / unlisted notes | |isFollowers | 17,205,922| 19.71%|Followers-only notes | |isSpecified | 101,884| 0.12%|Specified / DM notes | |isPoll | 298,023| 0.34%|Polls | |isMedia | 9,727,324| 11.15%|Notes w/ media | |isReply | 26,004,182| 29.80%|Replies | |isReplyToSelf | 5,551,978| 6.36%|Self-replies | |isBoost | 32,734,600| 37.51%|Boosts | |isBoostOfSelf | 577,841| 0.66%|Self-boosts | |isQuote | 398,429| 0.46%|Quotes | |isQuoteOfSelf | 133,203| 0.15%|Self-quotes | |isChannel | 34| 0.00%|Notes in a channel | |isRemote | 86,199,472| 98.77%|Remote notes | |isLocal | 1,077,229| 1.23%|Local notes | |isLocalOnly | 2,009| 0.00%|Local-only (defederated) notes| +---------------+------------+--------+------------------------------+#FediDev #Fedi #ActivityPub #AP #Sharkey

#Mastodon’s #ActivityPub inbox treats object types in tiers. Note and Question are supported directly. A second tier, Article, Page, Image, Audio, Video, and Event, gets converted to a title, a summary, and a link; content itself doesn’t show. Anything outside both tiers is dropped on delivery, which is a large part of why so much of the fediverse federates as Note regardless of what the object actually is.

One thing I keep coming back to when comparing #ActivityPub and AT Protocol: ActivityPub is basically a convention on top of the web stuff we already have. An actor is a JSON-LD document you GET. An inbox is an endpoint you POST to. If you already run a website, you can bolt this on without changing the site’s basic shape. Ghost didn’t set out to join the fediverse, and then years later it could, just by adding an endpoint.

RE: techhub.social/@fedicon/116665🎟️ Today is the last day to get DISCOUNTED EARLY BIRD tickets for FediCon 2026 — don't miss your chance to grab a discounted pass!(Tickets will be regularly priced after today.)📅 August 6–9, 2026📍 UBC campus, Vancouver, BC🎫 Get your FOSSY ticket, which gets you into FediCon:2026.fossy.ca/attend/tickets/#FediCon #FediCon2026 #FOSSY #FOSSY2026 #FediDev #Fediverse

You would not believe the amount of energy in the #fedidev community right now. It’s incredible.

My Hollo instance has been updated to 0.9.1 if you wanna take a peek. It's shaking off the early UI look and feel for something more professional.

- https://github.com/mastodon/mastodon/releases/tag/v4.5.10- https://hollo.social/@fedify/019e4675-05bc-7725-bcf4-aa51d6af70a0- https://shrimp.meow.company/notes/amhmis327j0wve4w- https://shrimp.meow.company/notes/amhmiqtsbwgmt158- https://activitypub.software/TransFem-org/Sharkey/-/releases/2025.4.7- https://hubzilla.org/item/53f3509f-d63d-494c-a431-ac84df9c6a57- https://w.on-t.work/activitypub/may-2026-vulnerability

@hollo releases a new major version update, 0.90. Too many changes to hit in a single post! Skimming, the most notable to users will be the switch from Pico CSS (my weekend hobbyist fave) to Uno CSS. At least in screenshots, the new UI is taking on a polished look.

RE: mastodon.social/@reiver/116597More on a resume / CV on the Fediverse on Social Web.Another option could be to use something like "JSON resume":jsonresume.org/github.com/jsonresume/resume-sIt seems to be popular. It isn't JSON-LD. Although I think it would be straightforward to translate it to JSON-LD, if that was desired.#ActivityPub #ActivityStreams #FediDev #ProToGo #JSONLD #JSONresume

On Tags (including Hash-Tags) in ActivityPub.

RE: mastodon.social/@reiver/116597There is also the other question of — would the resume / CV be JSON-LD.On one hand, if it was in JSON-LD, it would make it machine-legible similar to ActivityPub.On the other hand, I don't think anyone is going to write JSON-LD (especially HTML embedded in a JSON string value) by hand. But, I do think some people will want to write their resume by hand.It feels like user-experience is fighting with JSON-LD based machine-legibility.#ActivityPub #ActivityStreams #FediDev #ProToGo #JSONLD

How could you represent a resume / CV on the Fediverse and Social Web? Where would you put it? Etc?

ActivityPub being treated as JSON is a good thing.

Internet domain name (ex: example.com) are a reasonable option for making identity on the Internet more human-friendly.

In ActivityPub, these are all equivalent:

RE: mastodon.social/@reiver/1129211/The Fediverse would be better off if if back-end servers and front-end clients were separate projects.I have been arguing that for a while.(I know I am not the only one.)With respect to server, there are different types you might want, depending on your needs. And, it would be nice if you could pick and choose (separate from your choice of front-end).For example, is it single-user or mutli-user? Should it be light-weight, or deal with high-scale? Etc?#FediDev #Microdon

RE: jaz.co.uk/2026/05/12/there-areOnce again, Jaz lays out a fantastic vision for Fediverse design. Chronological feeds are better than rage-bait algorithms, but they give give loudmouths too much real estate.- Design for people, not protocols-Community, not one person’s stream of consciousness- Community notes (from trusted sources) on divisive issuesRead his posts and support his work!about.iftas.org/donate/It’s time for #Fedidev’s to figure out how to get this done.

How much Fediverse software would fail if the "to" or "cc" of an activity contained:

ActivityPub specifications don't seem to provide a way to do Idempotent POSTs to your outbox.

I just migrated my personally hosted PDS to Northsky.social because I was tired of paying Hetzner form something I rarely use.

#Hashtags don’t scale

🌐 FediCon 2026 is coming up — and Early Bird (discounted) tickets are still available!

I have been thinking about payments on the Fediverse (for a while).

There is a comparison that can be made between ActivityPub and Event-Sourcing.

Drafting a proposal to add API support in #Fedify for the ActivityPub Media Upload extension, the SocialCG-incubated #C2S companion that lets clients upload media via a dedicated endpoints.uploadMedia endpoint, separate from the outbox.

It seems as if the uploadMedia ActivityPub extension does not provide a way to resume an upload that didn't previously compete.

What do you think about JSON-LD language maps for "preferredUsername"?

Mastodon now has a table with size limits in its FEDERATION.md:

Divine, a short video Vine-like experience, had their app go live this week. It includes vintage vines previously archived from the original platform. Instant nostalgia is a great hook.

I've lost a lot of work in @moshidon because it doesn't save my half-written post as a draft when the app is being closed, or crashes, or the OS is shutting down.

Both Mastodon and Pixelfed seem to attach images as ActivityPub/ActivityStreams "type" = 'Document'.

I think it would be better if instead of Fediverse software outputting the following for ActivityPub/ActivityStreams Notes, Articles, etc:

Thought here … #fediforum, #fedidev, #atproto builders who are deeper in the architecture than I can get…

Was the original intent of the ActivityPub / ActivityStreams "name" field to be a title?

What should the file-extension for ActivityPub / ActivityStreams documents be.

If you’d like to preview the #tutorial I’m writing on building a small federated image sharing service, similar to @pixelfed@mastodon.social, with @fedify@hollo.social and @nuxt@webtoo.ls, here it is:

RE: mastodon.social/@reiver/116471If an ActivityPub Actor is something that has an "inbox" or an "outbox" (i.e., it could have just one or both) then —Perhaps we should also be talking about "sources" and "sinks", too. Where —An ActivityPub Source is an Actor with just an "outbox" (and no "inbox").And, an ActivityPub Sink is an Actor with just an "inbox" (and no "outbox").#ActivityPub #ActivityStreams #FediDev

What makes an ActivityPub Actor and Actor?

Can an ActivityPub 'Place' also be an Actor?

Should an ActivityPub 'Place' be used to represent a fictional place?

FEP-8b32 (Object Integrity Proofs) is getting updated: https://codeberg.org/fediverse/fep/pulls/839

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RE: mastodon.social/@reiver/116460I think Mastodon will strip image attachments from ActivityPub 'Question' objects.That is too bad.That means even if you create an 'Question' with 'Image' attachments elsewhere, you still won't see them in Mastodon (or in the Mastodon client-server API)...I guess the work-around is to post a 'Note' with an 'Image' attachment(s), and then reply to it with a 'Question'. That feels clunkier, but doable#ActivitiyPub #ActivityStream #FediDev #FediGames #Games #Mastodon #MastoDev #VideoGames

RE: mastodon.social/@reiver/116456If one was to create a Fediverse Game using the ActivityPub 'Question' —It would be nice if people could play it from a regular Fediverse client.But, you could also offer a game-specific client that allows for a richer game experience.#ActivitiyPub #ActivityStream #FediDev #FediGames #Games #VideoGames

RE: mastodon.social/@reiver/116456One decision to make if one was to create a Fediverse Game using the ActivityPub 'Question' —Do you just create a bot that connect to a Fediverse server (such as a Mastodon server)?Or, do you create the Fediverse server, too?...There are pros and cons each way.The former is simpler to build in many ways.The latter lets you add as many poll choices as you want, and even add extra JSON-LD name-spaces.#ActivitiyPub #ActivityStream #FediDev #FediGames #Games #VideoGames

We’re working on a new #tutorial for #Fedify: Building a Federated Blog with Astro!

Holos Discover added a couple of new filters to its API search - minimum likes and minimum boosts. Additionally, although not documented, you can pass contentType=image|video|audio|text|all|none to the `/api/search` endpoint and it works.

Hey #FediDev community:

An interesting development happens in funfedidev/schemas project. It's a JSON schema validator for Fediverse:

I've started working on generating RFC9421 compatible HTTP-Signatures in #GoActivityPub about a week and a half ago, but it felt more like a month.

Arnold Schrijver (@smallcircles) just published a fairly long thinkpiece on the future of ActivityPub and the fediverse and how we could achieve a grassroots improvement of the standards. It's well worth a read!

RE: mastodon.social/@bagder/116359Could be potentially nice for fediverse server testing, as more implementations make the jump to final RFC 9421 HTTP signatures.On the flip side, ever more complex curl invocations (here: Accept header plus signature fields plus key file, presumably) suggest use of more specialized CLI tools, such as provided by @fedify, or at least scripts/aliases.Speaking of RFC 9421, which notable fediverse implementations can't handle it yet? Anyone keeping track?#ActivityPub #FediDev #RFC9421

The #CFP for the Fediverse & Social Web track at COSCUP 2026 (Taipei, Aug 8–9) is now open! If you’re working on #ActivityPub, the #fediverse, or anything in the open social web space, we’d love to hear from you. The deadline is May 9. #COSCUP is free to attend.

I am outputting ActivityPub/ActivityStreams content for the listing of what is in a directory.

So, an interesting issue came up in the #Fedify repo that I’ve been thinking about: [#629].

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Just had to add a workaround to #Fedify for http://joinmastodon.org/ns, a JSON-LD context URL that has never actually served a JSON-LD document. Mastodon has always inlined the term definitions, but some implementations put it as a bare URL in their @context, so Fedify’s JSON-LD processor tries to fetch it and gets a 404 Not Found. Now Fedify ships a bundled copy of a context that never existed in the first place.

I used to not like JSON-LD. And then I got exposed to CBOR. And, since then, I ended up liking JSON-LD more than I did before.

I was talking to my marketing guy about integrating a tags-based onboarding workflow for freshly installed forums.

RE: blog.fabiomanganiello.com/artiMadblog by @fabio is really coming along!#fedidev

With ActivityPub / ActivityStreams...

FEP website now displays the number of implementations for each implementable proposal:

RE: mastodon.social/@fediverserepoLaurens Hof is at it again highlighting the problems of our lack of an adequate ActivityPub API and the hurdles that are to come in it getting adoption.#fedidev

#FediDev is there a generic Android intent for sharing to the Fediverse?

RE: mastodon.nzoss.nz/@strypey/116Any thoughts on this idea @silverpill, @julian, or others involved in #FediDev?

I’ve been saying for a while that we need something like FediCon in East Asia. A dedicated conference is still a stretch, but I’ve been thinking about a smaller step:

Today @kopper@not-brain.d.on-t.work shared a post on the fediverse titled *how to not regret c2s*, and I found it genuinely interesting to read, even if I’m not sure its proposed architecture actually solves what it sets out to solve.

When I first started working with #ActivityPub, before #Fedify existed, it felt like writing web apps in Perl and CGI in the late ‘90s. Interesting, even exciting—but never comfortable. That era where your business logic and your protocol plumbing were just… the same thing:

Started laying out a rough plan for implementing FEP-ef61: Portable Objects in #Fedify—server-independent #ActivityPub identities backed by #DIDs, multi-server replication, and client-side signing. It’s going to be a long road (13 tasks across 5 phases, with a few open questions that need answering before we even begin), but I think it’s worth doing right.

RE: planet.moe/@oeee_cafe/11561551Oeee is a Korean federated community drawing app that recently launched mobile apps on iOS and Android. You can follow users there from here in the fediverse already but not sure if you can submit drawings remotely yet.#fedidev

came across a thread by @LiquidParasyte about things they are coming across that need work or are broken on @Bonfireindieweb.studio/post/01KJ0T79K#fedidev #bonfire

Hi #fediverse and #ActivityPub developers!

I've seen an ongoing debate between "Note" versus "Article" in ActivityPub / ActivityStreams.

Your Home Feed is the inbox of an ActivityPub actor — in particular YOUR ActivityPub actor.