The official method is to set a TXT record, but apparently their "AT protocol" also lets you confirm a domain by serving `GET your.domainname.com/xrpc/com.atproto.identity.resolveHandle`
and `xrpc` was available as an S3 bucket name :)
https://docs.aws.amazon.com/AmazonS3/latest/userguide/access...
(I don't know anything about this personally, but since a lot of people are indicating an interest in this detail of the story, figured I'd try and surface that link better!)
* ActivityPub -> AT Protocol (https://atproto.com/)
* Mastadon -> Bluesky (https://blueskyweb.xyz/)
Right now, federation is not turned on for the Bluesky instance.
There are differences in both, however. I'm not going to speak about my impressions of the Mastadon vs Bluesky teams because frankly, Mastadon never really caught on with me, so they're probably biased. ('they' being my impressions, that is, I just realized that may be ambiguous.)
At the protocol level, I haven't implemented ActivityPub in a decade, so I'm a bit behind developments there personally, but the mental model for AT Protocol is best analogized as git, honestly. Users have a PDS, a personal data server, that is identified by a domain, and signed. The location of the PDS does not have to match the domain, enabling you to do what you see here: a user with a domain as their handle, yet all the PDS data is stored on bluesky's servers. You can make a backup of your data at any time, and move your PDS somewhere else with ease (again, once federation is actually implemented, the path there is straightforward though). This is analogous to how you have a git repository locally, and on GitHub, and you point people at the GitHub, but say you decide you hate GitHub, and move to GitLab: you just upload your git repo there, and you're good. Same thing, except since identity is on your own domain, you don't even need to do a redirect, everything Just Works.
This analogy is also fruitful for understanding current limitations: "delete a post" is kind of like "git revert" currently: that is, it's a logical deletion, not an actual deletion. Enabling that ("git rebase") is currently underway. Private messaging does not yet exist.
Anyway if you want to know more the high-level aspects of the docs are very good. Like shockingly so. https://atproto.com/guides/overview They fall down a bit once you get into the details, but stuff is still changing and the team has 10,000 things to do, so it's understandable.
[1] If they ever actually turn off path-style addressing, come find me and I'll PayPal you a dollar. I don't think it'll ever happen.
Also to try to avoid having to special-case any logic in terraform etc.
Say you're working on a family of sites for tradespeople like plumber.io, electrician.io, carpenter.io, etc. A fair number of people from India have "occupational surnames" like Miller, Contractor, Builder, Sheriff, etc. Suddenly one Mr. Dev Contractor registers a bucket "contractor-dev" and you have to special-case your bucket names in your terraform.
Other things I think we do better on:
* The account is the top-level thing we publish a cert for. Without knowing the bucket name you can't really do anything. With S3's global namespace, each bucket has a cert published which makes all buckets discovered as soon as they're created.
* Not default open to the world
* The R2-managed public bucket cname is shared and the URL for the bucket is random (i.e. just a UUID). Additionally, if you delete and recreate the bucket with the same name IIRC that random UUID is changed.
* We have a lot of sensible extensions like automatically creating a bucket on upload (granted not possible for S3 since buckets are global), setting per-object TTLs, handling unicode more gracefully (I think normalizing the key name is a saner choice with fewer foot guns even if there's some potential compatibility issues when you try to synchronize from a filesystem where you have two files with different forms but same normalized), etc etc etc.
I think the funniest one I struggle with all the time is “parallel.” I always think it should be “paralell.” I put the two parallel lines in the wrong spot in the word!