Canton Architecture

Overview

Canton's defining architectural move: separate coordination from storage. Synchronizers coordinate transaction ordering and consensus; participant nodes (validators) store data only for their hosted parties. No node holds global state, and the coordination layer never sees transaction content.

Core components

Validators (participant nodes) — the private, self-sovereign compute+storage unit for an entity. They host parties, run the Daml engine, validate transactions for their shard, and expose the Ledger API. Each keeps a localized Active Contract Set; stores only contracts where its hosted parties are stakeholders; can connect to multiple synchronizers.

Synchronizers coordinate without decrypting:

• Sequencer — totally orders and distributes encrypted messages; guarantees all participants see the same order. Does not see content.
• Mediator — runs the confirmation protocol: collects participant verdicts, checks the threshold, declares commit/reject. Does not see content.

Both are run as distributed sets of nodes on the Global Synchronizer (operated by Super Validators).

The synchronizer is a coordination layer, not a state-storage layer — it only ever handles encrypted messages and confirmation results.