ActivityPub over ATProto (2023)

by albuic • 13 days ago

60 41 13 days ago

rapnie3• 13 days ago

(2023) but worth being reposted, never got a good HN discussion. Between 8 and 12 July there's DWebCamp [0] and many experts and devs on both protocols are present, so opportunity for some good cross-pollination here.

[0] https://dwebcamp.org

toomuchtodo• 13 days ago

Will content from dwebcamp be online for those unable to make it?

rapnie3• 13 days ago

I think so, yes. The videos of the last camp are online as well at https://dwebcamp.org/videos

inigyou2• 13 days ago

Damn, I could've been there, if I'd known about it

nekusar• 13 days ago

I can easily install an ActivityPub server, with Glitch.

Show me the ATProto server that can integrate with BlueSky.

master-lincoln2• 13 days ago

here https://blog.bront.rodeo/setting-up-your-own-pds/

Hoodedcrow3• 13 days ago

The answer here would be "there's no such thing as a generic "server" like in ActivityPub because it's split into different components, of which a PDS is only one".

Honestly my main question here is "If you disagree with various ActivityPub instances' defederations, you can get around this by starting your own instance that federates with everything; is there an equivalent for bypassing Bluesky's moderation decisions?"

madeofpalk3• 13 days ago

I can easily install an ActivityPub server, with Glitch.

Can you? The same Glitch that shut down last year? https://blog.glitch.com/post/goodbye-glitch

Regardless, ActivityPub and ATProto have different designs and goals. Your question is akin to comparing a helicopter and an airplane.

There's no such thing as a "ATProto server". How complicated it is, and the trade-offs it made are valid criticisms of it. It all depends on what exactly your goal is as a participant of a distributed social network.

inigyou2• 13 days ago

What does ATProto run on, if not servers? Is it fully decentralised mesh P2P that runs on phones?

riffraff• 13 days ago

Never used it, but I've seen some praise for Snac as an easy to deploy activitypub server

https://codeberg.org/grunfink/snac2

spankalee4• 13 days ago

There is no "AT Proto server" - https://overreacted.io/there-are-no-instances-in-atproto/

fsflover3• 13 days ago

Which is a misleading message, according to the recent HN discussion, https://news.ycombinator.com/item?id=48599515.

jimmydoe2• 12 days ago

Is run your own pds good enough? Or you want your own view?

4lx872• 13 days ago

RSS/webmention > ActivityPub > ATProto

jayemar• 13 days ago

I don't disagree with the sentiment as I love RSS, but doesn't it have a different use case than ActivityPub or ATProto?

madeofpalk3• 13 days ago

I mean, conceptually ActivityPub is quite similar to RSS. You might be able to call it Less Simple Syndication.

spankalee4• 13 days ago

And how does RSS let you move your data to a new host while preserving your identity like AT Proto does?

mort96• 12 days ago

Change the DNS record?

danielspace23• 12 days ago

This is an apples-to-oranges comparison

gnashxyz• 13 days ago

Huge fan of this concept.

kmeisthax4• 12 days ago

Ok, since everyone's here, I'll ask: what is the credible exit from Bluesky - as in, not ATProto as a whole, but specifically the Bluesky PDS/AppView/etc - right now, in 2026?

I have a Bluesky identity that I registered primarily to follow someone that I happened to meet in person while stumping for the Rio Grande Plan[0]. I only have like five posts on it, but I would like to migrate that over to the same domain I already self-host Mastodon on. Bluesky has an option to have your handle on a custom domain, but that involves publishing a DNS record containing a did:plc whose keys are custodially owned by Bluesky. This is not so much an exit as it is an overcomplicated verification scheme.

My assumption is that if Bluesky wanted a better credible exit than ActivityPub, then we would need some way to rotate keys so that I could have my own PDS publish new posts on my existing identity and have other AppViews recognize that as the same kmeisthax that was previously using Bluesky as a PDS. The Mastodon exit is woefully inadequate, but at least if the admin cooperates, you can redirect your account and export your data. Everyone else on any other ActivityPub instance will see the same thing. As it currently stands, ATProto has a great way to migrate between AppViews[1], but no way to migrate off an uncompliant PDS.

[0] The Rio Grande Plan is a citizen-led movement calling for burying the heavy rail corridor going through Salt Lake City.

[1] ActivityPub is actually really lousy at cross-app interaction. If you're on a Mastodon instance, there is no way to participate in a Lemmy forum. Mastodon does not understand how to send the correct ActivityPub messages that Lemmy expects; and there's no protocol for Lemmy to tell Mastodon to publish certain ActivityPub messages on its behalf.

jimmydoe2• 12 days ago

Google did:web

kmeisthax4• 12 days ago

There is no mechanism to migrate a did:plc identity to a did:web one (or vice versa). The DID string is morally an SQL primary key.

jsmith45• 12 days ago

The PLC keys are normally intended to be held by your current PDS. Not a hard protocol requirement, but without it, certain things like migrating to a custom domain handle cannot be done cleanly though the app, and would need to be done manually. It might be a requirement of the bluesky hosted PDSes though, as those have some extra requirements beyond the reference self-hosted PDS.

The fact that BlueSky runs the PLC central server is supposed to be fixed by them creating a swiss association to run and control it instead, but while they announced this, it is unclear if it went anywhere.

If you migrate to a self hosted PDS using the all-in-one migration `goat account migrate` command, it will temporarily change your handle to a subdomain of your new PDS, and leave the new PDS managing the PLC. You can instead perform each step manually via goat or raw API calls, either of which would let you transition to direct PLC key management, and/or a new domain based handle as a single atomic plc update, as part of the overall migration process.

See https://atproto.com/guides/account-migration for a discussion of the process at the protocol level. See https://whtwnd.com/bnewbold.net/3l5ii332pf32u for a breakdown of both the automated, and step by step process via `goat`. It does not go into the details of switching to self managed, but it basically requires crafting your new PLC document, sending that one to the old PDS to sign, and then submitting the result. There are manual PLC signing, and submission commands available as `goat plc` subcommands, for use once you have manual control.

kmeisthax4• 12 days ago

This more or less answered my question in exactly the way I was dreading.

The option to register and manage PLC rotation keys should be built into the Bluesky Appview itself, sitting right next to the existing option to verify a domain with your did:plc string. Having the option only exist as a command line tool means most people aren't going to use it and third-party PDS hosts are going to be a pain in the ass to use for people with data already on Bluesky's PDS.

I'm also not happy about the existence of the PLC directory at all, mostly because it's not really explained all that well in the Bluesky interface. I assumed PDSes were just identified by their domain name (like a Mastodon instance is) - and while that is an option with did:web, it's not the default option, and you cannot migrate an identity between PLC and DNS governance. Hopefully that will change.

Hoodedcrow3• 12 days ago

The fact that BlueSky runs the PLC central server is supposed to be fixed by them creating a swiss association to run and control it instead, but while they announced this, it is unclear if it went anywhere.

That I didn't know! So... Basically the whole solution is still "trust me bro"?

kyle-rb• 12 days ago

If you don't like BlueSky managing your keys, the alternative to did:plc is did:web. Unfortunately, afaiu, it's not possible to migrate[0]. If this is something you really care about, and you trust yourself to manage your own private keys, you should probably bite the bullet and do it now. Make a pinned post on the old account to point to the new one.

That's the one part you can't migrate; everything else you can change while retaining your followers, posts, etc.

Setting your handle to a domain name via DNS[1] is intended to be easy for non-technical users (especially with registrars adding one-click forms for doing so) and also decoupled from actual PDS hosting. Many users just want their handle to reflect their identity on the web, and are ok trusting BlueSky to host their PDS for free.

Migrating to a new PDS is possible in both the cooperative case[2] or in the adversarial case[3]. The gist is that A: you should take regular backups by exporting your account data, and B: if you're using did:plc instead of did:web, you should register a backup key that has a higher priority than the key held by your PDS, so a malicious PDS can't simply migrate you back.

[0] https://github.com/bluesky-social/atproto/discussions/2705

[1] Alternatively there's an option for HTTP handle resolution instead via `/.well-known/atproto-did`

[2] https://atproto.com/specs/account#pds-account-migration

[3] https://www.da.vidbuchanan.co.uk/blog/adversarial-pds-migrat...

ChrisArchitect2• 12 days ago

The Fediverse Is Not the Way Forward

https://news.ycombinator.com/item?id=48785077

There are no instances in ATProto

https://news.ycombinator.com/item?id=48599515

ChrisArchitect2• 12 days ago

Feel like alot has happened since (2023). Mastodon/fediverse didn't take off in the way many thought it might at the time, with various silo/controversies, limitations on network effect, and general public uptake dwindling. Acknowledging that a good chunk of the public wants a centralized service is a thing (despite all the problems with that down the road etc etc). Some like it and have found their community on various servers, good. Meanwhile AT Proto has put a lot of work into getting devs on board with building things on the protocol etc and a snazzy new website recently https://atproto.com/. Not arguing that Bluesky is wildly successful, with stagnating growth etc but as with fediverse, many have found community there as well. But again, since 2023, there has been change and developments as far as people interested in external PDS etc putting the work in (Eurosky, Blacksky etc). Not even mentioning Meta's Threads, with again, some finding community there (tho how they even arrived there is one thing (instagram forced) and Fediverse integration or wider instance support is questionable).

All of these things require engineering and social work to grow and it's hit and miss to gather momentum and stickiness.

ActivityPub over ATProto (2023)

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