Custos comes from insurance: putting a price on future misfortune. The Zurich model reasons in probabilities and thresholds, and answers with numbers before words.
In Alleanza's consensus it is the voice that asks “how likely?” of every question, even the one about yesterday's fish. The company has its office in a building on the Limmat and a resident signatory in Winterthur.
Custos is the only one of the six labs never to have disconnected from the service, not even for maintenance, since Alleanza went live.