Abstract: In general, the present disclosure describes inventory management systems and methods which track all inventory of items within a retail supply chain. A computerized system aggregates inventory movement events to produce a common source of truth for the location and disposition of items within a supply chain. Order events and inventory events are received from multiple data sources. Additionally, a current inventory level for each item at each location within the supply chain is provided according to the data source. The computerized system normalizes the information in the event messages before it is stored in the centralized inventory database. The inventory information in the database can be accessed by multiple consumers through an API to obtain the most up-to-date information about the disposition and location of an item.