Three buy surfaces hang off a thin BDA Cloud spine. Cloud owns identity meaning and the rank gate. Zen owns money, time, and the door signal.
Actors
1 · BDA Cloud — thin spine we build
Durable meaning — not a gym OS clone
We buildbda_athlete_id → rank / pathway → rank booking gate. Maps sit beside the id. Household here is consent, not the family invoice.
Buy — do not build
Field House is the live membership shape: a monthly seat, one preferred weekly class, waitlist, and pro-rate. The Cloud spine does not change.
If Zen cannot restrict class booking by BDA rank (expected), Cloud syncs eligible class types or blocks. It does not write rank into Zen membership nicknames.