Design and Implementation of a Software System for Digital Product Passport

Digital Product Passports (DPPs) are emerging as foundational tools for transparency, traceability, and sustainability in global supply chains. As regulatory initiatives such as the European Union's Ecodesign for Sustainable Products Regulation (ESPR) gain momentum, there is increasing demand for technical solutions that support decentralised management and retrieval of product lifecycle data. This paper proposes a lightweight, extensible architecture centred on the DPP Protocol - a general-purpose communication mechanism for interoperable access to product information. The approach is particularly suited to fragmented or highly variable production contexts, such as fashion and other sectors characterised by short product lifecycles, complex supply networks, and limited digital infrastructure. We present two complementary implementations: the DPP Software, a server-side system for managing product data, and the DPP Browser, a stateless client for visualising and querying digital passports. Together, these components demonstrate the feasibility and versatility of the proposed protocol. The solution emphasises interoperability, recursive querying, and role-based access control, offering a foundation for scalable adoption across diverse industrial and regulatory settings.