Private Only Validators that are Just Connected to a Dedicated Synchronizers

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When to choose private-only validators

• Internal enterprise workflows — Your Daml applications run entirely within one organization, and all parties are hosted on validators you operate.
• Consortium with no external dependencies — A closed group of organizations runs shared workflows without needing to perform transactions with the MainNet.
• Regulatory constraints — Rules prevent connecting to external network infrastructure, or all transaction processing must occur on infrastructure within a specific jurisdiction.
• Development and testing — You want to build and test Daml applications without setting up Global Synchronizer connectivity.

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What differs from Global Synchronizer validators

• Full Canton protocol features — sub-transaction privacy, multi-party workflows, Daml smart contracts.
• The Ledger API works identically to a Global Synchronizer-connected validator.
• Simpler network topology for the synchronizer users.

• No Canton Coin — You cannot hold, transfer, or use Canton Coin.
• No wallet connectivity by default — The wallet providers requires Global Synchronizer connectivity.
• No interoperability with Canton Network parties — Your contracts cannot interact with contracts on the Global Synchronizer.
• No validator onboarding process — You manage the full topology yourself.

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Architecture

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Deployment

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Helm deployment

# participant-values.yaml
participant:
  storage:
    type: postgres
    config:
      dataSourceClass: "org.postgresql.ds.PGSimpleDataSource"
      properties:
        serverName: "<postgres-host>"
        portNumber: 5432
        databaseName: "participant_db"
        user: "participant_user"
        password: "<password>"
  ledgerApi:
    port: 5001
    tls:
      certChainFile: "/certs/tls.crt"
      privateKeyFile: "/certs/tls.key"
  synchronizerConnections:
    - alias: "private-sync"
      sequencerConnection: "https://sequencer.private-sync.example.com"

helm install participant canton/canton-participant \
  -f participant-values.yaml \
  --namespace canton

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Connecting to the synchronizer

@ bootstrap.synchronizer(synchronizerName = "private-sync", sequencers = Seq(sequencer1), mediators = Seq(mediator1), synchronizerOwners = Seq(sequencer1), synchronizerThreshold = PositiveInt.one, staticSynchronizerParameters = StaticSynchronizerParameters.defaults(ProtocolVersion.forSynchronizer))
    res1: PhysicalSynchronizerId = private-sync::122032922613...::35-0

@ participant1.synchronizers.list_connected()
    res2: Seq[ListConnectedSynchronizersResult] = Vector(
      ListConnectedSynchronizersResult(
        synchronizerAlias = Synchronizer 'private-sync',
        physicalSynchronizerId = private-sync::122032922613...::35-0,
        healthy = true
      )
    )

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Choosing between private-only and Global Synchronizer-connected

• Do any of your parties need to transact with external Canton Network parties? If yes, you need to transact on the Global Synchronizer. Consider the hybrid pattern instead.
• Do you need Canton Coin for payments or settlement? If yes, you need a Global Synchronizer connection.
• Might you need network connectivity in the future? If possibly, deploy standard validators now and users can connect to the Global Synchronizer later. Adding a synchronizer connection is non-disruptive — see linking to multiple synchronizers.

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Migrating to Global Synchronizer later

1. Complete the Global Synchronizer onboarding process (sponsorship, IP allowlisting, onboarding secret).
2. Add the Global Synchronizer connection to your validators.
3. As needed, reassign contracts that need network-wide visibility from the dedicated synchronizer to the Global Synchronizer.
4. Continue running private workflows on the dedicated synchronizer.