Synchronizer

A synchronizer is the coordination component of Canton's architecture. Participant nodes hold the data and do the validating, but when a transaction involves parties on different nodes, something neutral must put messages in a definitive order and deliver them reliably. That is the synchronizer's entire job: sequencing and delivery, with the payloads encrypted so the synchronizer cannot read contract contents.

This split of responsibilities is what lets Canton scale and stay private at once. Because synchronizers do not execute or store contract state, they are not a data honeypot, and because ordering is separated from validation, many synchronizers can run in parallel. An organization can operate a private synchronizer for internal applications with its own performance and compliance characteristics.

The Global Synchronizer is the special case that binds the ecosystem together: a public synchronizer operated by many independent super validators, available to any Canton participant that needs to transact across organizational boundaries. A participant node can connect to several synchronizers simultaneously, so private and public workflows coexist on the same infrastructure.

When a OneSwap trade settles, a synchronizer ordered the messages between the participants involved; that ordering is what makes the atomic outcome definitive.