Presolicitation notice from the Department of Health and Human Services, National Institutes of Health, for the ARPA-H Biomedical Data Fabric (BDF) Toolbox. This solicitation is seeking innovative proposals for research and development in data integration and usability technologies. The goal is to enable revolutionary advances in the collection and usability of biomedical datasets from various sources, such as research labs and clinical care centers. The proposed software approaches should accelerate technical innovation across the health ecosystem. The solicitation is open for proposals at different scales, including BIT, BYTE, and KILO. All awards will be made in the form of an Other Transaction or Cooperative Agreement.