KafkaSourceKafka is the canonical entry point: open Kafka and use Kafka.Producer/Kafka.Consumer/Kafka.Error/Kafka.Security instead of the flat Kafka_producer/Kafka_consumer/Kafka_error/ Kafka_security module names those packages still export directly (kept for existing callers — this is a pure alias, not a rename). Kafka_raw is deliberately not aliased here: it is internal to kafka-eio-core and was never meant to be part of the public surface.