@confluentinc/kafka-javascript

Confluent's JavaScript Client for Apache Kafka^TM

confluent-kafka-javascript is Confluent's JavaScript client for Apache Kafka and the Confluent Platform. This is an limited availability library. The goal is to provide an highly performant, reliable and easy to use JavaScript client that is based on node-rdkafka yet also API compatible with KafkaJS to provide flexibility to users and streamline migrations from other clients.

Features:

• High performance - confluent-kafka-javascript is a lightweight wrapper around librdkafka, a finely tuned C client.

• Reliability - There are a lot of details to get right when writing an Apache Kafka client. We get them right in one place (librdkafka) and leverage this work across all of our clients.

• Supported - Commercial support is offered by Confluent.

• Future proof - Confluent, founded by the creators of Kafka, is building a streaming platform with Apache Kafka at its core. It's high priority for us that client features keep pace with core Apache Kafka and components of the Confluent Platform.

This library leverages the work and concepts from two popular Apache Kafka JavaScript clients: node-rdkafka and KafkaJS. The core is heavily based on the node-rdkafka library, which uses our own librdkafka library for core client functionality. However, we leverage a promisified API and a more idiomatic interface, similar to the one in KafkaJS, making it easy for developers to migrate and adopt this client depending on the patterns and interface they prefer. We're very happy to have been able to leverage the excellent work of the many authors of these libraries!

This library is currently in limited-availability

To use Schema Registry, use the existing @confluentinc/schemaregistry library that is compatible with this library. For a simple schema registry example, see sr.js.

Requirements

The following configurations are supported:

• Any supported version of Node.js (The two LTS versions, 18 and 20, and the latest versions, 21 and 22).
• Linux (x64 and arm64) - both glibc and musl/alpine.
• macOS - arm64/m1. macOS (Intel) is supported on a best-effort basis.
• Windows - x64.

Installation on any of these platforms is meant to be seamless, without any C/C++ compilation required.

In case your system configuration is not within the supported ones, a supported version of Python must be available on the system for the installation process. This is required for the node-gyp build tool..

npm install @confluentinc/kafka-javascript

Yarn and pnpm support is experimental.

Getting Started

Below is a simple produce example for users migrating from KafkaJS.

// require('kafkajs') is replaced with require('@confluentinc/kafka-javascript').KafkaJS.
const { Kafka } = require("@confluentinc/kafka-javascript").KafkaJS;

async function producerStart() {
    const kafka = new Kafka({
        kafkaJS: {
            brokers: ['<fill>'],
            ssl: true,
            sasl: {
                mechanism: 'plain',
                username: '<fill>',
                password: '<fill>',
            },
        }
    });

    const producer = kafka.producer();

    await producer.connect();

    console.log("Connected successfully");

    const res = []
    for (let i = 0; i < 50; i++) {
        res.push(producer.send({
            topic: 'test-topic',
            messages: [
                { value: 'v222', partition: 0 },
                { value: 'v11', partition: 0, key: 'x' },
            ]
        }));
    }
    await Promise.all(res);

    await producer.disconnect();

    console.log("Disconnected successfully");
}

producerStart();

• If you're migrating from kafkajs, you can use the migration guide.
• If you're migrating from node-rdkafka, you can use the migration guide.
• If you're starting afresh, you can use the quickstart guide.

An in-depth reference may be found at INTRODUCTION.md.

Contributing

Bug reports and feedback is appreciated in the form of Github Issues. For guidelines on contributing please see CONTRIBUTING.md

Changelog

confluent-kafka-javascript v0.4.0

v0.4.0 is a limited availability feature release. It is supported for all usage.

Enhancements

• Fixes an issue where headers were not passed correctly to the eachBatch callback (#130).
• Add support for an Admin API to list a consumer group's offsets (#49).
• Reduce consumer poll timeout to nil and add wakeups for new messages. This improves the consumer efficiency, and resolves issues while running multiple consumers within the same node process (#135).
• Add pre-built binaries for macOS (Intel).