We're trying to organize a hackathon, and one of the users has a proof of concept gateway running allowing Red Reader (and other 3rd party apps) to switch to Lemmy with no changes (except for the API url). It's basically providing a reddit-compatible api for lemmy.

See https://imgur.com/a/IF5HYGz

And also https://www.reddit.com/r/apihackathon/comments/13yvzg2/rapihackathon_lounge/jmxcq0u/