<i>BSxCuBE-Web</i> – a web application for bioSAXS high-throughput collection and experimental control

The biological small-angle X-ray scattering (bioSAXS) beamline BM29 at the ESRF, operated by the ESRF-EMBL Joint Structural Biology and bioImaging Group (JSBIG), resumed user operation in September 2020 following the ESRF extremely brilliant source (EBS) upgrade. To exploit the high quality of X-ray beam delivered by this new fourth-generation synchrotron source, BM29 underwent significant refurbishment, including source optimization, instrument upgrades, and a complete redesign of the whole experimental control system. Here, we introduce the BioSAXS Customized Beamline Environment (BSxCuBE-Web), a new open-source, web-based platform designed to streamline, automate and enhance bioSAXS data collection. BSxCuBE-Web offers an intuitive and user-friendly interface for expert and non-expert users alike, to easily define and run bioSAXS experiments, as well as to monitor both raw and processed data. Its adaptable architecture facilitates its deployment on beamlines beyond the ESRF. In 2025 alone, BSxCuBE-Web supported more than 97 experiments involving over 256 users at BM29. The interface has been successfully validated using a wide range of biological samples and continues to be actively developed in response to bioSAXS user feedback and evolving experimental requirements. User experience reports have been overwhelmingly positive, highlighting significant improvements in efficiency, accessibility, and reliability during data collection.