How Does Federation Work?

Does it run in allowlist mode by default? Is it connected with ActivityPub yet?

Lemmy federates through activity pub. At the moment it only federates with other lemmy instances but the devs have much longer term plans to federate with other activitypub services. Lemmy uses an allowlist system where you allow instances to federate instead of defaulting to federation with everyone.

@sirl1on
44M

What I haven’t understood and found an answer yet: Are Lemmy instance federation transitive, i.e. A follows C through B? Or are federations only exactly affecting the 2 involved parties?

poVoq
6
edit-2
4M

There is a global timeline (“all”) that shows all posts from the instance specific allow-list. So far federation in Lemmy is AFAIK limited to instances configured, this is contrary to most of the other Fediverse that operates on an automatic allow-list with a configured block-list.

In addition you can subscribe to any community (and soon user, I think. I am not a Lemmy developer) on the allow-list through federation.

Edit: to answer your specific quesion, no there is no chaining, it is an all-connects-to-all type of network (with the allow-list as the limiting factor). Other Fediverse (ActivityPub) software operates similarly, except that you can subscribe to any other instance (Unless on the block-list) and then that instance gets added to the instance wide allow-list of your instance automatically.

Dessalines
admin
5
edit-2
4M

@sirl1on@lemmy.ml poVoq got it but there’s several things going on.

If no one on your instance follows that community, you’re not going to get new posts for it. There are some cases where history / chaining is fetched, for example, lets say you receive a comment, and the parent commenter is from another instance. Or someone from a third instance comments on a post of a community you’re subscribed to. As long as that parent commenter is from an instance thats allowed (IE in the allowlist or open federation), it will pull it.

poVoq
44M

Ah, good point about commenting.

@sirl1on
24M

OK, makes sense. I don’t envy you keeping track of all those edge cases…

Thanks for working on Lemmy and taking time to answer questions!

Dessalines
admin
24M

No probs.

@sirl1on
1
edit-2
4M

Edit: to answer your specific quesion, no there is no chaining, it is an all-connects-to-all type of network (with the allow-list as the limiting factor). Other Fediverse (ActivityPub) software operates similarly, except that you can subscribe to any other instance (Unless on the block-list) and then that instance gets added to the instance wide allow-list of your instance automatically.

Thanks for calrifying this! now I understand :)

A loosely moderated place to ask open ended questions

If your post is

  1. Open ended
  2. Not offensive

it’s welcome here!

  • 0 users online
  • 17 users / day
  • 43 users / week
  • 121 users / month
  • 477 users / 6 months
  • 1557 subscribers
  • 439 Posts
  • 5457 Comments
  • Modlog