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Comment by m52go | Hacker News Reader

Can anyone explain, in simple terms, how interoperability and migration works with ActivityPub (or point to resources that do)?

If I create an account on a Mastodon instance, and want to move it to another instance, do I lose everything?

And how does integration among the various platforms currently out (e.g., Mastodon, Plume, Pixelfed, etc) actually work? Is there some tool to see feeds aggregated from all these implementations? Or does it work differently?

I ask these questions as someone used Mastodon for a bit, has explored a handful of ActivityPub implementations. It all sounds very cool to me, but I still don't quite "get it".

Personally I prefer the approach of Secure Scuttlebutt, but I realize their P2P workings are probably unrealistic and impractical for the vast majority of people.

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I want to see a hybrid federation/p2p approach (Secure Scuttlebutt pubs/rooms are close this). As far as I understand it ActivityPub is just a standard for interop between social network services. The social networks still own your data and while they do offer tools for migrating between them you are still essentially at their mercy. You could run your own instance but you'll run into the same problems as you would running your own email server. Not every one will have to ability to do that and you could still run into the 'gmail problem' where large instances refuse to federate with small user instances.

It would be cool if there was a protocol that was fundamentally p2p but with a federated 'tracker' layer that is basically indistinguishable from normal social media sites to casual users. The social media sites would help propagate the content and if one went down or refuses to track your content you can just peer with another one (or just continue to share content with your personal network of followers over a gossip protocol like SSB without the need for a tracker)

ActivityPub can be used in a P2P situation. The biggest problem for that right now is that we use DNS for finding other instances, so you will need something with a domain name.

Thanks! I would like to know if there are any projects working on this. I found this thread discussing how it could be done over SSB

https://github.com/ssbc/ssb-db/issues/202

> If I create an account on a Mastodon instance, and want to move it to another instance, do I lose everything?

You can send a `Move` activity that will tell other instances that you moved, so people will (depending on their server) refollow you automatically. We (= people working on ActivityPub systems) are thinking about ways to create identities that don't belong to any one server, so you wouldn't lose your account even if your server went down.

> And how does integration among the various platforms currently out (e.g., Mastodon, Plume, Pixelfed, etc) actually work? Is there some tool to see feeds aggregated from all these implementations? Or does it work differently?

In general, systems display what they can. Pixelfed, Mastodon and Plume mostly send `Note`s and `Article`s around, which are easy to display in any of their respective interfaces. Other types like `Video`s will usually be displayed as good as possible, with a link to the originating instance. Unknown activities are usually just thrown away by the receiving server.

> ...systems display what they can. Pixelfed, Mastodon and Plume mostly send `Note`s and `Article`s around, which are easy to display in any of their respective interfaces. Other types like `Video`s will usually be displayed as good as possible...

(Not the person you replied to) Thanks, this was helpful. The fact that there's a common activity vocabulary helps me understand the usefulness of an ecosystem of ActivityPub apps which focus on different ways to write and view posts.

Thanks! Integrations don't sound perfect, but I guess it would be unrealistic to expect perfection given the nature of the implementations.

Identities that could be somehow owned independent of servers would be a game-changer, I think.

Thank you for your work, and congratulations on 2.0 ;)

From what I've been able to ascertain, it's just not a _thing_ unless you want to roll-your-own migration tool. There's a few-years-old issue that's now closed: https://github.com/tootsuite/mastodon/issues/177 but links to this currently open issue, which mostly reiterates that this is problematic for a number of reasons: https://github.com/tootsuite/mastodon/issues/12423

From what I understand, it's fairly trivial to post to _multiple_ ActivityPub accounts, but true _migration_ just doesn't exist per se.

You can move between Mastodon instances, but you will lose all your posts https://docs.joinmastodon.org/user/moving/

You can't import your posts, but they will still exist at your old account: if I move from foo@social.example to bar@social.example, then all the posts I made as @foo are still visible on @foo's timeline, rather than getting moved to @bar. (You would have two copies of all your posts otherwise, since people can still fav/boost/interact with the post made when you were still @foo.) Moving accounts will redirect your followers to the new account, and you can import all your old follows/likes/&c to the new account.

Also, you can still export your own posts to preserve them. You could even use that to reimport them (just as said without the ability to migrate faves/boosts/replies/other interactions).

The email analogy isn't always great with ActivityPub federation, but it's still a useful analogy as email is our most common federated service, and here ActivityPub migration is no worse than email address migration, and certainly at this point in some ways already better (follower migration is something email could have used; updating your email contacts list is still a very manual process).

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