1. The Producer API allows applications to send streams of data to topics in the Kafka cluster.
2. The Consumer API allows applications to read streams of data from topics in the Kafka cluster.
3. The Streams API allows transforming streams of data from input topics to output topics.
4. The Connect API allows implementing connectors that continually pull from some source system or application into Kafka or push from Kafka into some sink system or application.

2.1 Producer API

Examples showing how to use the producer are given in the javadocs.

To use the producer, you can use the following maven dependency:

	<dependency>
	    <groupId>org.apache.kafka</groupId>
	    <artifactId>kafka-clients</artifactId>
	    <version>0.10.0.0</version>
	</dependency>

2.2 Consumer API

Examples showing how to use the consumer are given in the javadocs.

To use the consumer, you can use the following maven dependency:

	<dependency>
	    <groupId>org.apache.kafka</groupId>
	    <artifactId>kafka-clients</artifactId>
	    <version>0.10.0.0</version>
	</dependency>

Streams API

Examples showing how to use this library are given in the javadocs

Additional documentation on using the Streams API is available here.

To use Kafka Streams you can use the following maven dependency:

	<dependency>
	    <groupId>org.apache.kafka</groupId>
	    <artifactId>kafka-streams</artifactId>
	    <version>0.10.0.0</version>
	</dependency>

Connect API

Many users of Connect won't need to use this API directly, though, they can use pre-built connectors without needing to write any code. Additional information on using Connect is available here.

Those who want to implement custom connectors can see the javadoc.

Legacy APIs

A more limited legacy producer and consumer api is also included in Kafka. These old Scala APIs are deprecated and only still available for compatability purposes. Information on them can be found here here.