Remote

Julian Fietkau

@julian@fietkau.social

mastodon 4.7.3

Human-computer interaction #HCI, computer science & programming, home server & self-hosting, games and other fun stuff.

Fediverse tool builder: @encyclia@fietkau.social, @canary, FediRoster, Pinhole, ... see https://fietkau.software/tag/fediverse for more. I also help out with @fedidevs@fosstodon.org. If you do HCI-related research, check out https://directory.hci.social.

He/him. Posting mostly in English, but you might see the occasional German boost.

1365 Followers

1712 Following

50 Posts

Joined November 03, 2022

Website:

https://fietkau.me

Job:

https://shield.tib.eu

Matrix:

https://matrix.fietkau.social/to/#/@julian:fietkau.social

ORCID:

https://encyclia.pub/0000-0001-7264-8496

Julian Fietkau @julian@fietkau.social

· 1w ago

Boosted by @fedicat@pc.cafe

RE: https://berlin.social/@berlinfediday/117337512329875864 Yep, here's my presentation at Berlin FediDay 2026, where I talked about SciOp and its federation plans. 🙂 That was a really nice environment and audience for this exchange. Good Q&A too. I'm looking forward to the recording of the “research on the fediverse” panel at the end of the session. #FediDay #ActivityPub #SciOp

Quoting

@berlinfediday@berlin.social

🧪 @julian@fietkau.social — SciOp & decentralised research data rescue https://fair.tube/w/uQCVZArwr6BitUCbmTfeWJ 📢 Have a look, share the videos and help carry the ideas and discussions from #Fediday further into the Fediverse! 🚀 ❤️ And: Fediday should continue! If you would like to support #Fediday2027: https://digitalegesellschaft.de/weitermachen/ #Fediverse

Open quoted post

Berlin FediDay: "🧪 @julian@fietkau.social — SciOp & decentralised …" - berlin.social

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Julian Fietkau @julian@fietkau.social

· 3w ago

Boosted by @fedicat@pc.cafe

Had a pretty calm day 1 of Berlin #FediDay, got to meet @lavaeolus@fedihum.org, @mkljczk@twojstary.gay, @liaizon@social.wake.st, @_elena@mastodon.social and @tommi@pan.rent and probably some people I've forgotten. 🙂

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Julian Fietkau @julian@fietkau.social

· 2w ago

Replying to on activitypub.space

@julian@activitypub.space Thank you! Yes, the context-level interaction controls (we talked about them briefly near the start of the year) will most likely not be part of v1 of my document. I am still curious whether a FEP-c0d0 lock and the interaction policy you posted are indeed equivalent given these conditions: https://docs.gotosocial.org/en/latest/federation/interaction_controls/#implicit-assumptions I'm assuming no. In my draft text I leave it open whether an interaction constraint is imposed by the post author or a moderator. Maybe this distinction should be explicit.

docs.gotosocial.org

Interaction Controls - GoToSocial Documentation

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@lina Actually, after sleeping on it, I think I'm going to put my big boy pants on and tag some of the current team about this: @mellifluousbox @haubles @imanijoy Mastodon has recently been positioning itself as more proactive regarding trust and safety, and, well, here's a T&S win on a silver platter if I dare say. I don't know whatever internal conversation may have taken place about this years ago, but it might be time to revisit it? I don't know, just an innocent nudge by an outsider. 🤔

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@lina There is a longstanding PR to remove replies by blocked users from a post's context: https://github.com/mastodon/mastodon/pull/18468 Reading the conversation in there leaves me with several questions, but also feeling unsure which ones of them to ask out loud.

Hide subthreads by blocked users when looking at a post's descendants by ClearlyClaire · Pull Request #18468 · mastodon/mastodon

This is about the server not returning known subthreads started by people blocked by the post's author, not the viewer. e.g., if we have A → B → C → D → E, where a → b means “b replies to a”, a...

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Julian Fietkau @julian@fietkau.social

· 3mo ago

Boosted by @fedicat@pc.cafe

Re-sharing a small open source project I just finished polishing: PoseViz, my browser-based pose recording data visualizer/player. https://fietkau.software/poseviz When I left my previous employer, we discussed what would remain there and what I would take with me. PoseViz is one of our bespoke research tools now in my private custody. I put a bit of effort into making it presentable and fun to play with. Try opening some of the different demo recordings! 🙂 #OpenSource #PoseTracking #threejs

PoseViz

PoseViz

This is a web-based viewer for 3D body tracking recordings. It was created for the research project HoPE and uses its own native file format.

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Julian Fietkau @julian@fietkau.social

· 3mo ago

RE: https://ecscw.eusset.eu/2026/2026/07/04/ecscw-2026-has-ended/

.. and I basically collapsed and slept 11 hours. 😴

Waiting for a few late payments and invoices to balance the books, having a handful of follow-on email conversations, then the “Julian organizes a conference” chapter can be over, at least for a while.

#AcademicChatter #ECSCW2026

ecscw.eusset.eu

ECSCW 2026 has ended – ECSCW 2026

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@Profpatsch As confusing as the situation is, I'm trying to avoid fostering outrage in this conversation. The Mastodon team composition has changed recently, and odds are none of the people I tagged have seen this before. I do think there is something here that may not have been as big a priority in the project strategy in 2022, but could fit what Mastodon is trying to prioritize now. Or, I hope that it's a mere communication issue, which might be solved by a renewed internal conversation.

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@tante@tldr.nettime.org I've heard of https://ibis.wiki I haven't tried it out and don't know how mature it is by now.

Main Page — ibis.wiki

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Julian Fietkau @julian@fietkau.social

· 6mo ago

My ongoing #ActivityPub projects in order of priority, for anyone waiting for something:

– Interaction policy / reply controls FEP: highest priority, stalled for the past few weeks due to other responsibilities
– @encyclia@fietkau.social: probably migrating from Deno+Fresh to Node+Hono for @fedify@hollo.social 2.0, boring infra work
– Updating @fedidevs@fosstodon.org starter packs for compatibility with @loops and @Mastodon@mastodon.social packs: on warm hold, will get to it, but vainly hoping someone will write a Python lib for it before I have to 🙃

fietkau.social

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

So yeah, I have a bit over a month left with my Munich team. The reason I've had my head mostly underwater in recent weeks is I'm working like mad to get all my projects finished up or into a shape to be handed over. Should get one or two public “look what I made” posts out of that process before June as well. My current boss @kochm@hci.social will be hiring to replace me! If you would like to do human-computer interaction research in Munich, ideally with the goal of a PhD, drop us (or just him) a line. 👍

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Julian Fietkau @julian@fietkau.social

· 3mo ago

Big day tomorrow! 🤫 @ecscw2026

#ecscw2026 #conference #AcademicChatter

ecscw.eusset.eu

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

Interestingly enough, even though the job posting doesn't really shine a spotlight on it, this is kind of an ActivityPub job! That's because SciOp has decided to use AP for some of its server interactions. I don't know yet how my time will be divided between internal responsibilities and public open source work, but I'm hoping I'll be able to lend a hand with SciOp itself, and maybe do some “on the clock” FEP writing and other protocol-related work. 😎

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Julian Fietkau @julian@fietkau.social

· 4mo ago

Replying to

@xjasminelu@hci.social Hey 👋 That sounds like a very worthwhile topic, wish you the best!

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Julian Fietkau @julian@fietkau.social

· 6mo ago

RE: https://mastodon.social/@bagder/116359048796181736 Could 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@hollo.social, or at least scripts/aliases. Speaking of RFC 9421, which notable fediverse implementations can't handle it yet? Anyone keeping track? #ActivityPub #FediDev #RFC9421

Quoting

@bagder@mastodon.social

RFC 9421 HTTP Message Signatures support in #curl maybe?

https://github.com/curl/curl/pull/21239

Open quoted post

mastodon.social

daniel:// stenberg://: "RFC 9421 HTTP Message Signatures support in #curl…" - Mastodon

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Julian Fietkau @julian@fietkau.social

· 7mo ago

Replying to

@raphael@mastodon.communick.com Sounds like a worthwhile project, best of luck! I assume you know @newsmast@backend.newsmast.org? I doubt they're drowning in money either, but they exist, have a team, etc., plus your missions sound aligned. Maybe they'll have contacts. Definitely 📌 for ActivityPub in Django, could speed up https://github.com/anze3db/fedidevs/issues/208 for me, which I want/need to get back to this summer. /cc @anze3db@fosstodon.org

Roadmap to Mastodon starter pack compatibility · Issue #208 · anze3db/fedidevs

Mastodon just released the draft FEP for their starter pack implementation – see also the corresponding blog post. It seems we might see the feature in versioned releases toward the end of the year...

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

Oh, one more thing, I'm still going to be general chair of @ecscw2026. Not a chance that would be a viable job to hand over on two months notice. 😅 So if you're coming to Munich for that, you will still meet me. 🙂

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Julian Fietkau @julian@fietkau.social

· 7mo ago

Replying to

(Disclosure: Using the name and logo of Encyclia – symbolically, since Encyclia is not a legal entity – I have an active monthly donation to @fedify@hollo.social on OpenCollective. However, I do not believe that this is getting me any preferential treatment, and in my observation the Fedify project treats all contributors and downstream implementers with equal respect.)

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@fasterandworse Understandable, conflating low engagement with harassment is doing the discussion no favors. 🫤

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@thisismissem@hachyderm.io Who would be the target audience for FediMod FIRES? Is it anyone who moderates a fediverse server, or are you looking strictly for admins who can set up software integrations? Is there a minimum server size or moderation workload? Is anything about it limited to Mastodon or is it applicable to all or most ActivityPub social platforms? (🫢 Don't tell anyone, but I already know the answers to most of these, I just think it would be helpful to know for others reading this thread.)

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@liaizon@social.wake.st @mro@digitalcourage.social Yeah, you got it! The causal ambiguity of 404 (due to how easy it is to serve accidentally, as a server operator) is even having ripple effects in the ActivityPub ecosystem. For example if you read https://swicg.github.io/activitypub-http-signature/#handling-deletes-of-actors it goes into how if you access a previously known profile and you get a 404, that can either mean the profile was deleted, or the server has been taken down for maintenance by someone who did not realize they ought to put an HTTP 503 in place while they work.

swicg.github.io

ActivityPub and HTTP Signatures

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@liaizon@social.wake.st @mro@digitalcourage.social Something something “HTTP is stateless” 🤪 404 means you requested a document that doesn't exist, meaning that the error is not related to server connection capacity or anything like that which may solve itself by waiting. If you want to see something, you need to change your approach. That's what 4xx says. You may have been directed to a 404 from a link on a different page on the server, but that's unrelated to the HTTP error. It doesn't take into account where you came from.

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@gameboycamera@pocketpixels.club Eyyyy, I missed you! 🙂

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@Lambo@openbiblio.social I'm looking forward to it, and I'm happy I can say that with 100% sincerity. 😀 Shame @fediforum@mastodon.social is so soon, maybe this will be the last time I'll miss chunks of it because my current job would prefer I do other things during work hours. 😉

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Julian Fietkau @julian@fietkau.social

· 7mo ago

Replying to

@fabio@manganiello.eu Right, and my server seems to have gotten the corresponding Accept. 👍 But if you look at https://social.wake.st/@liaizon/116205306320048221 and scroll down, you see that @liaizon@social.wake.st can't see the quote in my reply (and neither can people on any other server looking at this thread). This is because the QuoteAuthorization needs to be publicly resolvable: https://fediverse.codeberg.page/fep/fep/044f/#verifying-third-party-quote-posts

wakest ⁂: "@fabio@manganiello.eu cc @julian@fietkau.social l…" - wakest's server

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@silverpill@mitra.social Good to know, thank you! IMO there should be no restrictions on the two domains – I use two subdomains for convenience reasons, but platforms should support two completely different domains as well. At least in my opinion. The vocal opponents of split-domain handles say that a user's handle should tell you where their profile is hosted, and there are nuances around things like domain blocks. But if you ask me, I should be able to set a custom handle domain in my profile settings. 😄

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@mitra @silverpill Congrats on the split-domain support! I have added Mitra to https://correct.webfinger-canary.fietkau.software/#implementation-status The only feature it's missing for an all-green table row is per-user custom WebFinger domains. I am on a long-term side mission to advocate for ActivityPub platforms to enable personal custom handle domains this way. ☺️

correct.webfinger-canary.fietkau.software

WebFinger Split-Domain Canary

A detailed summary of split-domain WebFinger setups: how do they work and what do they mean for ActivityPub implementers?

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@FRiaK Hmm @pascoda @vollkorn @glamcode who else do you all think should see the parent post? 🤔

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Julian Fietkau @julian@fietkau.social

· 7mo ago

Replying to

@fabio@manganiello.eu @liaizon@social.wake.st New quote test, wooo! https://blog.fabiomanganiello.com/article/Madblog-federated-blogging-from-markdown Edit: Yep, looks to be working! 😀

Madblog: A Markdown Folder That Federates Everywhere

Fabio Manganiello

Madblog: A Markdown Folder That Federates Everywhere

A lightweight blogging engine based on text files, with native Fediverse and IndieWeb support

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Julian Fietkau @julian@fietkau.social

· 7mo ago

Replying to

@silverpill@mitra.social @julian@activitypub.space I believe @hollo@hollo.social does it as well. @general

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Julian Fietkau @julian@fietkau.social

· 7mo ago

Replying to

@fabio@manganiello.eu @liaizon@social.wake.st Oh excellent! Please let me know when the new version is live on your blog and I'll test again. 🙂

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Julian Fietkau @julian@fietkau.social

· 7mo ago

Replying to

@nele @Linzspiration Meine Antwort war glaube ich gefärbt durch den letzten Satz in deinem Post. 🙂 Ich habe persönlich noch nie ein Relay verwendet (ich folge nicht vielen Hashtags und spare mir lieber die zusätzlichen Kosten für Speicherplatz), aber @FediTips hat etwas zu dem Thema: https://fedi.tips/using-relays-to-quickly-expand-a-servers-view-of-the-fediverse/ Ich weiß außerdem, dass es https://relay.fedi.buzz schon eine Weile gibt, was auf einen stabilen Betrieb hindeutet.

How to increase your server’s view of the Fediverse with updates, relays, groups, directories and scripts | Fedi.Tips – An Unofficial Guide to Mastodon and the Fediverse

How to increase your server’s view of the Fediverse with updates, relays, groups, directories and scripts | Fedi.Tips – An Unofficial Guide to Mastodon and the Fediverse

An unofficial guide to using Mastodon and the Fediverse

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@datenteiler@openbiblio.social Hey and thanks! 😄 Be seeing you all soon!

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@tibhannover@openbiblio.social Looking forward to meeting more of the team! 😄

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@smallcircles@social.coop Thank you Arnold! 😀 I'm excited. I'm not usually a big risk taker, but even though some of this might be happening a bit fast, the overall timing feels right.

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@stefan@stefanbohacek.online Thank you! 😁

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@fasterandworse I believe this reply is a misunderstanding of the quoted sentence. The “traction” refers to the development process, AFAIK both in terms of team size (recent hires) and process optimization (doing more with less), not platform market share. My feeling matches Scott's that feature development has sped up considerably. I recommend @mergebot for a finger on the pulse. Scott's larger point is these improvements haven't yet impacted usage numbers visibly, which is another matter.

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@simulo I just supervised a bachelor thesis on that topic, if you feel like giving it a skim: https://fietkau.science/teaching#bsc_szepielewicz Results seemed mostly inconclusive, might need cooperation with someone deeper in the quant world than me to refine.

Teaching

This is an overview of some of my current and past teaching activity. See below for some interesting student projects taught or assisted by me, take a look at theses I supervised, get an overview of my teaching qualifications or refer to a complete list of courses I have taught.

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@stefan Thanks for the tag Stefan, I'm honored!

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@IGVazquez@social.vivaldi.net @encyclia@fietkau.social Yes, I've been working on the Fedify version upgrade. 🙂

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@liaizon@social.wake.st @vincent@r.town @julian@activitypub.space No experience with group actors, sorry! I don't see any obvious issues with the JSON, which makes sense since it loads on Mastodon.

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@liaizon@social.wake.st @fabio That one's a microformat mismatch, Mastodon looks for the class "mention" to skip the link preview and open the profile locally. https://docs.joinmastodon.org/spec/microformats/#mastodon

docs.joinmastodon.org

Microformats - Mastodon documentation

An open data format using CSS classes to structure your already-existing HTML.

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Julian Fietkau @julian@fietkau.social

· 7mo ago

Replying to

@liaizon@social.wake.st @fabio@manganiello.eu Alas, the PR has been merged, so it'll be a long while until I bother Claire again. 🙂 But I'll keep updating my own list. I see in the code where the interaction policy is declared, but not where individual quotes are authorized. If I quote this post here, let's test if both of us will see the quote. https://blog.fabiomanganiello.com/article/Madblog-federated-blogging-from-markdown

Madblog: A Markdown Folder That Federates Everywhere

Fabio Manganiello

Madblog: A Markdown Folder That Federates Everywhere

A lightweight blogging engine based on text files, with native Fediverse and IndieWeb support

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@mczachurski @liaizon Hence all the handwringing and clashing opinions on whether a hypothetical compatibility-breaking ActivityPub 2.0 should get rid of JSON-LD. As you point out, plain JSON parsers have to sort of reinvent JSON-LD canonicalization to be widely compatible. They typically do this not for the general case, but whenever interop bugs pop up, so it never ends. Using a real JSON-LD parser should work in theory, but many platforms also emit canonically broken JSON-LD. 😅

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Julian Fietkau @julian@fietkau.social

· 6mo ago

Replying to

@andypiper If you have the chance, I recommend the Museum for Communication. Could see it being very up your alley! https://www.mfk-nuernberg.de/

mfk-nuernberg.de

Museum für Kommunikation Nürnberg – Kommunikation. Erleben, verstehen, gestalten.

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Julian Fietkau @julian@fietkau.social

· 5mo ago

Replying to

@nsunami Since you're on a (relatively) small server, I additionally recommend following the https://tags.pub accounts for your favorite hashtags, it'll probably give you some posts that you wouldn't otherwise catch.

tags.pub

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Julian Fietkau @julian@fietkau.social

· 7mo ago

Replying to

@liaizon@social.wake.st Yeah, works on my server but not yours. 😅 Hey @fabio@manganiello.eu, congrats on the ActivityPub support! The quote authorization that my server got from your blog for the above post seems to 404: https://manganiello.blog/ap/actor/quote_authorizations/34bcaca1-62d8-4620-b97d-552008426bce

manganiello.blog

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