I login to lemmy.world using username/password. There is an email address associated with my account.
I just tried to login to mastodon.world using that email address and my existing lemmy.world password and it gives me a “Invalid E-mail address or password” error. Not entirely unexpected… Does this functionality exist? Is there something I’m doing wrong?
You made an account on lemmy.world. You can’t login to mastodon or any other lemmy instances, but you can interact with them.
You can access communities in any other lemmy instances from lemmy.world. So, instead of directly acessing otherlemmy/c/something, you access it from lemmy.world/c/something@otherlemmy
For mastodon, if you want to use mastodon you’ll need to make a separate mastodon account. Meanwhile, you can see your lemmy.world account posts from mastodon. Just login to Mastodon and go t o mastodon.world/@[email protected]
They’re separate servers hosted by the same admin group. The accounts are still separate though, no single sign-on. Make an additional mastodon.world (or pick another mastodon server, there’s no reason you HAVE use use the same one) if you want one.