This repository is Confluent's official JavaScript client for Apache Kafka, wrapping the high-performance C library librdkafka via native Node.js addons. It provides two API surfaces: a legacy callback-based API (node-rdkafka) and a modern promisified API compatible with the popular KafkaJS library. The client supports all core Kafka operations: producing and consuming messages (including transactional and exactly-once semantics), admin operations (topic management, consumer groups, offsets), and stream-based interfaces. Additionally, it includes a full Schema Registry client (TypeScript) with serializers/deserializers for Avro, JSON Schema, and Protobuf, along with a rule execution engine supporting CEL (Common Expression Language), JSONata, and field-level encryption via pluggable KMS drivers (AWS, GCP, Azure, HashiCorp Vault, local). The architecture is layered: a C++ binding layer handles the Kafka protocol, while pure JavaScript/TypeScript implements schema management, rule evaluation, and encryption. Key entry points are `lib/index.js` (node-rdkafka), `lib/kafkajs/index.js` (KafkaJS), and `schemaregistry/index.ts` (Schema Registry). External dependencies include librdkafka, protobuf, avsc, axios, and cloud KMS SDKs. The codebase is production-grade with extensive unit, integration, and e2e tests, performance benchmarks, and CI/CD pipelines across multiple platforms.