XASDB -- Design and Implementation of an Open-Access Spectral Database

The increasing volume and complexity of X-ray absorption spectroscopy (XAS) data generated at synchrotron facilities worldwide require robust infrastructure for data management, sharing, and analysis. This paper introduces the XAS Database (XASDB), a comprehensive web-based platform developed and hosted by the Canadian Light Source (CLS). The database houses more than 1000 reference spectra spanning 40 elements and 324 chemical compounds. The platform employs a Node.js/MongoDB architecture designed to handle diverse data formats from multiple beamlines and synchrotron facilities. A key innovation is the XASproc JavaScript library, which enables browser-based XAS data processing including normalization, background sub- traction, extended X-ray absorption fine structure (EXAFS) extraction, and preliminary analysis traditionally limited to desktop applications. The integrated XASVue spectral viewer provides installation-free data visualization and analysis with broad accessibility across devices and operating systems. By offering standardized data output, comprehensive metadata, and integrated analytical ca- pabilities, XASDB facilitates collaborative research and promotes FAIR (Findable, Accessible, In- teroperable, and Reusable) data principles. The platform serves as a valuable resource for linear combination fitting (LCF) analysis, machine learning applications, and educational purposes. This initiative demonstrates the potential for web-centric approaches in XAS data analysis, accelerating advances in materials science, environmental research, chemistry, and biology.