Spent some time this morning getting a cursory understanding of #ATProtocol (the open protocol behind #BlueSky). I have a decent understanding of #ActivityPub and I expected AT to have a lot of similarities.
It’s quite different, and this diagram surprised me.
PDS here is “Personal Data Server”. You might think of it as something like a #Mastodon instance where all your data is stored and posts by those you follow are cached.
Except notice that there’s no arrows between PDSes.
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Instead of PDSes sharing their posts with each other, they send exclusively to one or more relay services. These relay services talk to “app views” and "feed generators” which are ultimately the services that provide you your feed of posts.
The relay service is really what is interesting here though. These relays are going to be big and expensive to run. They are meant to aggregate the entirety of as many PDSes as they can.
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@eric you can (could) run a full network relay for 150usd/month:
https://whtwnd.com/bnewbold.net/3kwzl7tye6u2y
will be interesting to see how this figure changes with the new inflow of users, will ping bryan about it once the chaos has died down a little bit
