Mastodon has a ton of apps and Lemmy app development is going crazy right now. Are there any apps that can use both Lemmy and Mastodon accounts (and preferably Kbin accounts too)? I know the interfaces may need to be different, but the protocols are the same as far as I understand it, so it seems technically possible.
On the surface they do interconnect (which is what federated systems do) because they all use a protocol called ActivityPub in the backend.
However the way apps interact with a service like this is through either an API or some kind of frontend system.
Each of these platform uses a different API to let apps interacts with it, so the app need to figure out which platform it’s connecting to and use the correct API. So it’s not going to magically work with everything else if you make it work for let’s say Lemmy.