I was wondering, did I miss the federated authentication service? When a user has a mastadon account on one of the federated services, it is possible to follow and post on mastodon, react on lemmy and follow lemmy users, but creating a lemmy post isn’t possible. When a user has a lemmy account, interaction with mastodon is possible, but to follow you need a mastodon account.
Isn’t there an authentication service, so you can create user@fediverse.domain and interact wuth all services?
Authentication, no. That’s not how ActivityPub works. But if you are looking to be able to do both microblogging (Mastodon/Twitter) and link aggregation (Lemmy/Reddit) on one account, check out Kbin. I’ve also heard Friendica can do all that plus more, but it doesn’t seem to be as popular in the Threadiverse.