Opens WebSocketClient on /v2/updates. SubscribeToUpdates.connect returns Promise<void>: resolves when the socket closes cleanly, rejects on Canton error frames or transport failures.
Bounded mode: both beginExclusive and endInclusive → replay stops at endInclusive. Unbounded: omit endInclusive ( beginExclusive defaults from getLedgerEnd when omitted).
Receiver: await canton.ledger.subscribeToUpdates(params)
Setup
import { Canton, TransactionShape } from '@fairmint/canton-node-sdk';
const canton = new Canton({
network: 'devnet',
provider: '5n',
partyId: 'OWN_PARTY_ID',
});Minimal example
await canton.ledger.subscribeToUpdates({
beginExclusive: 0,
parties: [canton.getPartyId()],
transactionShape: TransactionShape.TRANSACTION_SHAPE_LEDGER_EFFECTS,
onMessage: (msg) => {
if ('update' in msg) console.log(msg.update);
},
});Parameters — SubscribeToUpdatesParams
Core (schema): optional parties, templateIds, includeCreatedEventBlob, beginExclusive, endInclusive, includeReassignments (default true), includeTopologyEvents (default false), transactionShape.
Callbacks (extended): optional onMessage (UpdatesWsMessage union { update }, JsCantonError, WsCantonError), onTokenExpiring, onTokenRefreshNeeded ( WebSocketOptions — closes socket after refresh hint).
Returns
Promise<void>. No subscription handle on LedgerJsonApiClient (promise lifecycle only).
Errors
Canton error payloads routed through onMessage also reject the promise (ApiError wrapping diagnostics).
Auth and party
Defaults parties via buildPartyList() when omitted—needs read-as rights matching parties.