Can someone point me to a good technical 101 for Mastodon? Or OStatus? Trying to understand: When I make a post, how does another instance find out about it to show to my followers there or the federated timeline?

So I think it's the PubSubHubbub portion that does what I'm looking for.

Current understanding: I make a post & my instance pushes that post to each instance where someone follows me.

Which means if some single-user instance's user follows me, but no one on my instance (including me) follows them, then my instance is "aware" of theirs, but not in a way that their posts would show up on our federated timeline.

Anybody poke holes in that?

I'm chasing this because someone mentioned the idea of a new privacy setting where your instance would more closely federate with a short list of other instances (forming a slightly larger community). Basically a list of other instances your posts would go to that wasn't Just Everyone in the Federation:tm:. I'm trying to understand how that might work on a technical level and it doesn't sound super hard or breakey.

@benhamill It depends on who runs the servers and how close you want them to be...

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You could fork the main code, and create a p2p pipeline between the instances so that all toots from one are assured to end up on the other two...

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That only works if the admins of the servers are willing to all use the same codebase.