Google's new Cast Connect library might sound a bit snore, but it should make casting to Android TV devices a whole lot better. With it, developers can do a few new things, but by far the most important is that it will allow hardware remotes to control 'casted playback, and apps can open Chromecast streams remotely into the same app on your Android TV.
More info on Cast Connect for developers.
Before Cast Connect, content that was 'casted remotely to Android TV devices from your phone or via the Assistant played back in a "web receiver" — basically inside a browser on your Android TV device. It was a lightweight and simple solution, but it meant you couldn't actually control playback locally on the Android TV, you had to use an external device like your phone. This new solution should offer a similar experience, but with the benefit of local hardware controls, plus some other perks like having casting open the applicable app on Android TV for playback. And Cast Connect can always fall back on the old web receiver method for corner cases, like a mismatch in account credentials between the app on your phone and the app on your Android TV.
Of course, developers will need to implement Cast Connect on their end for it to work, and there are a few requirements, like using Jetpack and registering your Android TV app package name on the Cast Developer Console. For more details, developers should set aside the time to watch the video above.
The only caveat right now is that Assistant functionality isn't yet "fully supported" for Cast Connect, but we assume that Google will have that worked out soon.