Developed a user-facing feature for the ESMValGroup/ESMValCore repository, introducing a session_name parameter to the ESMValTool.run command-line interface. This addition enables users to customize output subdirectory names, improving organization and reproducibility for session-based workflows. The implementation involved API design in Python, with comprehensive unit testing to ensure the override functionality worked as intended and to safeguard against regressions. Documentation was updated to reflect the new parameter, and contributor metadata was revised for accurate attribution. The work streamlined output management for forecasts and experiments, reducing manual intervention and maintaining stability by introducing no breaking changes to existing workflows.