kafka-pub-sub/examples/quickstart/subscribe.js

Enterprise-grade Kafka publish/subscribe library for Node.js — producer pool, batch sending, DLQ, SSL/SASL, multi-broker, and real-world industry examples.

/**
 * QUICKSTART — Subscriber
 *
 * Run this FIRST in Terminal 1, then run publish.js in Terminal 2.
 *
 * Usage:
 *   node examples/quickstart/subscribe.js
 */

require('dotenv').config({ path: require('path').resolve(__dirname, '../../.env') });

const { ConsumeEvent } = require('../../index');

async function main() {
  console.log('Waiting for messages on "quickstart.topic"... (Ctrl+C to stop)\n');

  const stop = await ConsumeEvent(
    'quickstart.topic',
    async (message) => {
      console.log('─'.repeat(40));
      console.log('Received message:');
      console.log('  Key    :', message.key);
      console.log('  Event  :', message.value.event);
      console.log('  Data   :', JSON.stringify(message.value.data, null, 2));
      console.log('  Offset :', message.offset);
      console.log('  At     :', new Date(Number(message.timestamp)).toISOString());
      console.log('─'.repeat(40) + '\n');
    },
    {
      fromBeginning: true, // read from the start so you see every message
      groupId: 'quickstart-group',
    }
  );

  // Keep running until Ctrl+C
  process.on('SIGINT', async () => {
    console.log('\nStopping subscriber...');
    await stop();
    process.exit(0);
  });
}

main().catch((err) => {
  console.error('Subscriber error:', err.message);
  process.exit(1);
});