You can now access the source code of AWS Elastic Beanstalk Command Line Interface (EBCLI) on Github. You can contribute to the development of EBCLI by making suggestions, reporting issues, and submitting pull requests. Visit the EBCLI source code in the Github repository to find more details. For more information about the EB CLI, see Using the Elastic Beanstalk Command Line Interface (EB CLI) in the AWS Elastic Beanstalk Developer Guide.

from Recent Announcements: https://aws.amazon.com/about-aws/whats-new/2020/01/aws-elastic-beanstalk-command-line-interface-now-open-source/