@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. 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!

To use Schema Registry, use the @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, 22 and 23).
• 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.

npm install @confluentinc/kafka-javascript

In case your system configuration is not within the supported ones, check the detailed installation instructions for more information.

Yarn and pnpm support is experimental.

Getting Started

Below is a simple produce example using the promisified API.

const { Kafka } = require('@confluentinc/kafka-javascript').KafkaJS;

async function producerStart() {
    const producer = new Kafka().producer({
        'bootstrap.servers': '<fill>',
        'security.protocol': 'SASL_SSL',
        'sasl.mechanisms': 'PLAIN',
        'sasl.username': '<fill>',
        'sasl.password': '<fill>',
    });

    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: 'v', partition: 0, key: 'x' },
            ]
        }));
    }
    await Promise.all(res);

    await producer.disconnect();
    console.log("Disconnected successfully");
}

producerStart();

There are two variants of the API offered by this library. A promisified API and a callback-based API.

• If you're starting afresh, you should use the promisified API.
• If you're migrating from kafkajs, you can use the migration guide to get started quickly.
• If you're migrating from node-rdkafka, you can use the migration 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

Librdkafka Version

confluent-kafka-javascript	librdkafka
1.0.0	2.6.1

This mapping is applicable if you're using a pre-built binary. Otherwise, you can check the librdkafka version with the following command:

node -e 'console.log(require("@confluentinc/kafka-javascript").librdkafkaVersion)'

Changelog

confluent-kafka-javascript v1.0.0

v1.0.0 is a feature release. It is supported for all usage.

Enhancements

• Add support for an Admin API to fetch topic offsets (#156).
• Add support for Node v23 pre-built binaries (#158).
• Add KafkaJS-compatible errors to promisified Admin API (createTopics, deleteGroups, deleteTopicRecords) (#159).
• Include error types within Type definitions for promisified API (#210).

Fixes

• Fixes an issue where uv_async_init was being called off the event loop thread, causing the node process to hang (#190).