Migrating from KCL 1.x to KCL 3.x - Amazon Kinesis Data Streams
This documentation is a draft for private preview for regions in the AWS European Sovereign Cloud. Documentation content will continue to evolve. Published: January 10, 2026.

Migrating from KCL 1.x to KCL 3.x

This topic explains the instructions to migrate your consumer from KCL 1.x to KCL 3.x. KCL 1.x uses different classes and interfaces compared to KCL 2.x and KCL 3.x. You must migrate the record processor, record processor factory, and worker classes to the KCL 2.x/3.x compatible format first, and follow the migration steps for KCL 2.x to KCL 3.x migration. You can directly upgrade from KCL 1.x to KCL 3.x.

Important

Do not use AWS SDK for Java version 2.27.19 to 2.27.23 with KCL 3.x. These versions include an issue that causes an exception error related to KCL's DynamoDB usage. We recommend that you use the AWS SDK for Java version 2.28.0 or later to avoid this issue.