Health checks

Health checks

Use health checks when an application needs to verify Canton services before submitting commands or when a LocalNet boot sequence needs to wait for services to finish starting.

One-shot checks

Validator health probes call the Canton Network Quickstart validator endpoints:

await canton.validator.isReady();
await canton.validator.isLive();

The endpoints are unauthenticated and map to:

/api/validator/readyz
/api/validator/livez

The unified client exposes a non-blocking health summary:

const canton = new Canton({ network: 'localnet', provider: 'app-provider' });
const health = await canton.checkHealth();

if (!health.ok) {
  console.log(health.services);
}

checkHealth() does not throw for partial service failures. It returns per-service status for:

Service	Probe
ledger	JSON Ledger API version endpoint
validator	Validator readyz and livez
scan	Scan readyz, livez, and status endpoint

Limit the check to selected services when an application only depends on part of the stack:

const health = await canton.checkHealth({ services: ['validator'] });

Wait for readiness

Use waitForReady() when startup should block until selected services are healthy:

import { Canton, waitForReady } from '@fairmint/canton-node-sdk';

const canton = new Canton({ network: 'localnet', provider: 'app-provider' });

await waitForReady(canton, {
  healthCheck: { services: ['validator'] },
  timeout: 300_000,
  interval: 5_000,
});

The default timeout is five minutes because LocalNet can take several minutes to become ready. Override timeout, interval, and timeoutMessage for shorter application-specific probes.

Source reference

Digital Asset's CN Quickstart project structure documents validator health checks on ports ending in 903, with empty successful responses from /api/validator/readyz.