The Cost Center service is built following the agent-centric modular architecture of Carolverse. It leverages agile principles to build or modify software using distinct agent identities, each carrying out a specific activity — here, the financial roll-up that turns every service's sales, costs and profit into one accountable view of the whole economy. It is an early work-in-progress: the intent is set and the owner is in place, but most of the ledger is still being built.