Happy Buyers External API
External REST API for Happy Buyers organization metadata and inventory data. Requests are authenticated with an API key sent in the hca-api-key header and results are scoped to the organization attached to that key. Covers stores, POS brands/categories, universal brands and categories, product and product-line inventory with demand and replenishment metrics, package-level inventory, inventory health (current and historical, by store / POS brand / category), daily sales metadata, blockout dates, and full purchase-order management including order items, invoices and temporary invoice upload/download URLs. List endpoints use limit/offset pagination and return totalCount plus hasMore. Released in beta on 2026-06-05.