Spacetime Southbound Interface (SBI / CDPI)
The Southbound Interface, also called the Control to Data-plane Interface (CDPI), is the collection of gRPC services through which devices participating in a Spacetime network communicate with the controller. The Scheduling service is a bidirectional stream over which an agent receives schedule updates — steering antenna beams to establish new links, configuring RF parameters, applying flow and radio control — and returns responses; the Telemetry service pushes metrics and observations back to Spacetime. A reference Go implementation of an SBI agent ships in the same repository.