ShopperDB is a distributed barcode inventory management system built around a fleet of Raspberry Pi 5 scanner stations. Each Pi connects a standard USB barcode scanner and reports scans to this central server over a private WireGuard VPN tunnel - no manual network configuration is needed at any deployment site. Items are organized in a hierarchical category tree with custom attributes per category, and inventory is tracked per store location. On the client side, scanner stations handle barcode input headlessly using a piezo buzzer for audio feedback, queue scans locally if the server is unreachable, and automatically flush the queue once reconnected. Each Pi provisions and registers itself automatically on first boot, and VPN keys are rotated transparently in the background. The server provides per-location store portals for browsing and adjusting inventory, an admin interface for managing items, categories, clients, and stores, and a public category browser for general lookup.