See: Description
| Interface | Description | 
|---|---|
| KafkaPublishTimestampFunction<T> | An interface for providing custom timestamp for elements written to Kafka. | 
| TimestampPolicyFactory<KeyT,ValueT> | An extendable factory to create a  TimestampPolicyfor each partition at runtime by
 KafkaIO reader. | 
| Class | Description | 
|---|---|
| CustomTimestampPolicyWithLimitedDelay<K,V> | A policy for custom record timestamps where timestamps within a partition are expected to be
 roughly monotonically increasing with a cap on out of order event delays (say 1 minute). | 
| KafkaCheckpointMark | Checkpoint for a  KafkaUnboundedReader. | 
| KafkaCheckpointMark.PartitionMark | A tuple to hold topic, partition, and offset that comprise the checkpoint for a single
 partition. | 
| KafkaIO | An unbounded source and a sink for Kafka topics. | 
| KafkaIO.Read<K,V> | A  PTransformto read from Kafka topics. | 
| KafkaIO.Read.External | Exposes  KafkaIO.TypedWithoutMetadataas an external transform for cross-language
 usage. | 
| KafkaIO.Read.External.Configuration | Parameters class to expose the Read transform to an external SDK. | 
| KafkaIO.TypedWithoutMetadata<K,V> | A  PTransformto read from Kafka topics. | 
| KafkaIO.Write<K,V> | A  PTransformto write to a Kafka topic with KVs . | 
| KafkaIO.Write.External | Exposes  KafkaIO.Writeas an external transform for cross-language usage. | 
| KafkaIO.Write.External.Configuration | Parameters class to expose the Write transform to an external SDK. | 
| KafkaIO.WriteRecords<K,V> | A  PTransformto write to a Kafka topic with ProducerRecord's. | 
| KafkaRecord<K,V> | KafkaRecord contains key and value of the record as well as metadata for the record (topic name,
 partition id, and offset). | 
| KafkaRecordCoder<K,V> | CoderforKafkaRecord. | 
| ProducerRecordCoder<K,V> | CoderforProducerRecord. | 
| TimestampPolicy<K,V> | A timestamp policy to assign event time for messages in a Kafka partition and watermark for it. | 
| TimestampPolicy.PartitionContext | The context contains state maintained in the reader for the partition. | 
| TimestampPolicyFactory.LogAppendTimePolicy<K,V> | Assigns Kafka's log append time (server side ingestion time) to each record. | 
| TimestampPolicyFactory.ProcessingTimePolicy<K,V> | A simple policy that uses current time for event time and watermark. | 
| TimestampPolicyFactory.TimestampFnPolicy<K,V> | Internal policy to support deprecated withTimestampFn API. | 
| Enum | Description | 
|---|---|
| KafkaTimestampType | This is a copy of Kafka's  TimestampType. |