Skip to content

Architecture

Architecture

Cbox Nexus separates the decision (which it owns) from the data (which it sources behind contracts):

Seam (contract) Supplies Default binding
NexusThresholdSource each state's threshold + measurement rules the us-tax-data dataset
SalesLedger the seller's cumulative sales/transactions per state empty (host binds it)
PhysicalNexus states with asserted physical presence empty
NexusRegistrations states the seller already registered in empty

DefaultNexusEngine composes them and produces a NexusEvaluation per state, or a NexusReport across many.

Principles:

  • Contracts-first. Depend on the interfaces; rebind any of them.
  • Deny-by-default. No threshold or no activity → no economic claim (Below). No physical/registration assertion → none is assumed.
  • Never infers from one supply. The engine compares host-supplied cumulative totals to thresholds; it does not accumulate sales or watch invoices.