Harshit Srivastava enhanced the harness-go-sdk repository by developing support for SessionTokenRef within AWS Manual Config, addressing the need for more secure and flexible credential management. He updated the Go data models to incorporate the new SessionTokenRef field, ensuring that session tokens could be referenced securely rather than stored directly. Alongside these model changes, Harshit revised the Markdown documentation to clearly describe the new configuration option and its usage. His work included integration tests and a fix-tagged commit to guarantee proper functionality. This focused contribution demonstrated depth in Go development and documentation, improving operational security for AWS manual configurations.