4 ms·

There is no mention of "identities" or "identity" in the spec either. So if a person is available via ActivityPub, how do they reference their "identity"? When

by mg 3y ago

There is no mention of "identities" or "identity" in the spec either. So if a person is available via ActivityPub, how do they reference their "identity"? When you want to say "Follow me via ActivityPub: ..." - what is "..."? The most common form I see is @username@hostname. Is there a more universal form? How does a Pixelfed user do it?

vidarh 3y ago
The most common form is @username@hostname, sure, because it's convenient, and also because doing a webfinger lookup of that is more generic - a webfinger response can include far more than AcrivityPub endpoints. But specifically for ActivityPub the URL works just fine (try pasting it in the Mastodon search box, for example, and up pops the user details exactly as if you'd used @user@host)
- mg 3y ago
  You say "the url works" as if there is a clearly defined url for every Fediverse user. But the way I read the specs, that is not the case. Some servers link you to hostname/users/username, some use hostname/@username, some use hostname/username when you look up a user via webfinger. And the way I read the specs, those don't have to be permanent. A server could change their scheme from hostname/users/username to hostname/u/username and would not violate the protocol. Because the way to identify the user is via a webfinger lookup. Maybe the only way to say who you are on the Fediverse is "I am <username> on <hostname>. Look me up through Webfinger"? That might be the equivalent of saying "I am https://masto.ai/.well-known/webfinger?resource=acct%3Amg%40masto.ai https://masto.ai/.well-known/webfinger?resource=acct%3Amg%40..."
  - vidarh 3y ago
    > You say "the url works" as if there is a clearly defined url for every Fediverse user. But the way I read the specs, that is not the case. There is a clearly defined URL for every Fediverse user, but not in the sense you mean (there isn't a static or predictable mapping from user@host to URL). The Fediverse is a graph of Person actor urls, not @user@host ids. The Webfinger lookup functionality is used because it makes things more flexible for users and because webfinger allows for a single identity to refer to multiple different types of services and resources, but my followers servers and the servers of those I'm following knows me as https://m.galaxybound.com/users/vidar https://m.galaxybound.com/users/vidar even though @vidar@galaxybound.com is what I use. > And the way I read the specs, those don't have to be permanent. A server could change their scheme from hostname/users/username to hostname/u/username and would not violate the protocol. Because the way to identify the user is via a webfinger lookup. See my other comment. A user is identified via a webfinger lookup when trying to determine which Person Actor @mg@masto.ai refers to. But in almost every other context the only thing that is stored is the URI of the Person actor. If that changes without using the (not in ActivityPub; new) move functionality, you're effectively creating a new identity, and quite a few servers do not yet support the move functionality, so while you can change @mg@masto.ai at a whim and nothing will break, changing the URL is what you need to be careful about (too careful, as I've noted elsewhere; the better support for migrating your data is pretty much the only thing I like about Bluesky)

by mg 3y ago

vidarh 3y ago

The most common form is @username@hostname, sure, because it's convenient, and also because doing a webfinger lookup of that is more generic - a webfinger response can include far more than AcrivityPub endpoints. But specifically for ActivityPub the URL works just fine (try pasting it in the Mastodon search box, for example, and up pops the user details exactly as if you'd used @user@host)

mg 3y ago
You say "the url works" as if there is a clearly defined url for every Fediverse user. But the way I read the specs, that is not the case. Some servers link you to hostname/users/username, some use hostname/@username, some use hostname/username when you look up a user via webfinger. And the way I read the specs, those don't have to be permanent. A server could change their scheme from hostname/users/username to hostname/u/username and would not violate the protocol. Because the way to identify the user is via a webfinger lookup. Maybe the only way to say who you are on the Fediverse is "I am <username> on <hostname>. Look me up through Webfinger"? That might be the equivalent of saying "I am https://masto.ai/.well-known/webfinger?resource=acct%3Amg%40masto.ai https://masto.ai/.well-known/webfinger?resource=acct%3Amg%40..."
- vidarh 3y ago
  > You say "the url works" as if there is a clearly defined url for every Fediverse user. But the way I read the specs, that is not the case. There is a clearly defined URL for every Fediverse user, but not in the sense you mean (there isn't a static or predictable mapping from user@host to URL). The Fediverse is a graph of Person actor urls, not @user@host ids. The Webfinger lookup functionality is used because it makes things more flexible for users and because webfinger allows for a single identity to refer to multiple different types of services and resources, but my followers servers and the servers of those I'm following knows me as https://m.galaxybound.com/users/vidar https://m.galaxybound.com/users/vidar even though @vidar@galaxybound.com is what I use. > And the way I read the specs, those don't have to be permanent. A server could change their scheme from hostname/users/username to hostname/u/username and would not violate the protocol. Because the way to identify the user is via a webfinger lookup. See my other comment. A user is identified via a webfinger lookup when trying to determine which Person Actor @mg@masto.ai refers to. But in almost every other context the only thing that is stored is the URI of the Person actor. If that changes without using the (not in ActivityPub; new) move functionality, you're effectively creating a new identity, and quite a few servers do not yet support the move functionality, so while you can change @mg@masto.ai at a whim and nothing will break, changing the URL is what you need to be careful about (too careful, as I've noted elsewhere; the better support for migrating your data is pretty much the only thing I like about Bluesky)