The HDAI API is designed to support researchers, practitioners, administrators, and data scientists throughout healthcare. The HDAI API offers privileged access to selected analytic models. Upon approval, users may use the API to the models using widely available, structured inputs (demographics, billing codes). Categories include adverse events, utilization, cost, interventions, and chronic conditions and can be run for inpatient and community settings. These models are updated and augmented regularly throughout the year. For each predictor, we provide a range of performance characteristics, including measures of accuracy and calibration and information about populations and subpopulations to which the models apply.