Report of I.FAST Workshop on Stability of Storage Ring Based Light Sources

The I.FAST workshop on the stability of storage ring-based light sources, organized by SOLEIL and KIT, took place from March 17th to 21st, 2025. The workshop took place at KIT campus north and featured 26 scientific presentations from institutes and universities in Europe, the Americas, and the Asia-Pacific region. The workshop was a great success in networking the accelerator community, especially between the fields of beam dynamics and hardware. This document summarizes the workshop's objectives and scientific program, including the abstracts. The presentations are published on the following Indico website: https://indico.kit.edu/event/4809/.