Do I have to rebuild my scenes?

No. Your scenes and sources stay as they are in OBS; atme only switches, shows and hides them.

Can I set keys for them?

Yes. In the studio, Keys on the deck, then the button, then the key.

Help · Set up

How to use your own OBS scenes and sources in atme

atme reads your OBS scenes and sources once OBS is connected, and any you pin become buttons on the deck in the studio, the OBS dock and your phone. A scene button switches OBS to it; a source button shows or hides it everywhere it is, groups included. Mark sources "One at a time" and they swap, so pressing a background hides the last one. A pinned source can also go on top of atme's show in OBS, show only in some of atme's scenes, or fill your card for the stranger in Chatroulette with your camera in the corner.

Settings → OBS: connect OBS
Settings → From OBS: Pin the scenes and sources you use
Backgrounds: tick "One at a time" on each, so one press swaps them
Optional: "Add to show" puts a source over atme's show; "Only in" ties it to atme scenes
Chatroulette: the layers button in the dock fills your card with a pinned source

Questions

Do I have to rebuild my scenes?: No. Your scenes and sources stay as they are in OBS; atme only switches, shows and hides them.
Can I set keys for them?: Yes. In the studio, Keys on the deck, then the button, then the key.