ARI Sync - Inventory (HTNG) SOAP API 10.32 The ARI Sync-Inventory (HTNG) is used to notifiy a booking source of the inventory amount available at a specific hotel property. The ARI Sync-Inventory (HTNG) is used to notifiy a booking source of the inventory amount available at a specific hotel property. Property Connect HTNG Inventory Rooms Data Migration PMS Integration