This is your first hands-on lesson with the Node.js SDK: create a client, send an event, and receive it. Make sure you have the SDK installed (see the Node.js SDK overview).

Create a Client

connect.ts

import { KubeMQClient } from 'kubemq-js';

const client = await KubeMQClient.create({ address: 'localhost:50000' });
console.log('Connected to KubeMQ');

Send Your First Event

send_event.ts

import { KubeMQClient, createEventMessage } from 'kubemq-js';

const client = await KubeMQClient.create({ address: 'localhost:50000' });

await client.sendEvent(
  createEventMessage({ channel: 'notifications', body: 'hello kubemq' }),
);
console.log('Event sent!');

Receive Events

receive_events.ts

client.subscribeToEvents({
  channel: 'notifications',
  onEvent: (msg) => console.log('Received:', new TextDecoder().decode(msg.body)),
  onError: (err) => console.error('Error:', err.message),
});

Configuration Options

Option	Type	Default	Description
`address`	`string`	(required)	KubeMQ server address (`host:port`)
`clientId`	`string`	Auto-generated UUID	Unique client identifier
`credentials`	`CredentialProvider \| string`	`undefined`	Auth token or credential provider
`tls`	`TlsOptions \| boolean`	Smart default	TLS configuration
`retry`	`RetryPolicy`	3 retries, 500ms initial	Auto-retry policy
`reconnect`	`ReconnectionPolicy`	Unlimited, 500ms initial	Auto-reconnection
`connectionTimeoutSeconds`	`number`	`10`	Connection timeout
`logger`	`Logger`	`noopLogger`	Structured logging
`tracerProvider`	`unknown`	No-op	OpenTelemetry tracer provider

configuration.ts

import { KubeMQClient, createConsoleLogger } from 'kubemq-js';

const client = await KubeMQClient.create({
  address: 'kubemq-server:50000',
  credentials: 'my-auth-token',
  tls: { enabled: true, caCert: '/path/to/ca.pem' },
  retry: {
    maxRetries: 5,
    initialBackoffMs: 1000,
    maxBackoffMs: 30_000,
    multiplier: 2.0,
    jitter: 'full',
  },
  logger: createConsoleLogger('info'),
});

Error Handling

All SDK errors extend KubeMQError with 19 typed subclasses:

error_handling.ts

import { KubeMQError, ConnectionError, ValidationError } from 'kubemq-js';

try {
  await client.sendEvent(msg);
} catch (err) {
  if (err instanceof ConnectionError) {
    console.log('Server unreachable, will auto-retry');
  } else if (err instanceof ValidationError) {
    console.log('Fix the message:', err.suggestion);
  }
}

The SDK automatically retries transient errors (connection drops, timeouts, throttling) using exponential backoff with jitter.

Next Steps

Node.js SDK Reference — full API documentation
Node.js SDK Examples — complete examples for all patterns
GitHub Repository — source code and issues

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