Bridging SPARQL endpoints and scholarly infrastructures: an interoperability suite for RDF cultural heritage data

Abstract

RDF knowledge graphs and SPARQL endpoints are widely adopted in the Cultural Heritage and Digital Humanities domains to model semantically rich research metadata. However, SPARQL-based access remains poorly aligned with the interoperability requirements of large scholarly aggregation infrastructures and with developer practices centered on RESTful services, limiting the integration and reuse of RDF-native repositories. This paper presents the interoperability suite developed within the DH-ATLAS project, which produced an ontology and a knowledge graph describing Digital Humanities research on Italian Cultural Heritage. The suite includes two complementary components. A configurable OAI-PMH publisher exposes RDF metadata as records compliant with the OpenAIRE Guidelines v4, enabling the harvesting and ingestion of DH-ATLAS resources into aggregators such as the OpenAIRE Graph. In addition, a RESTful API based on the RAMOSE framework offers simplified, developer-friendly access to RDF content, reducing the need for SPARQL expertise. Beyond technical interoperability, the paper illustrates how the DH-ATLAS Knowledge Graph can support thematic aggregation at scale. We describe the knowledge-graph-driven process used to define a subcommunity on Italian Cultural heritage within the OpenAIRE CONNECT Gateway on Digital Humanities and Cultural Heritage, combining expert curation with scalable named-entity-based extraction techniques. The proposed approach enhances the accessibility, interoperability, and reuse of RDF cultural heritage data and provides a reusable model for Digital Humanities initiatives integrating with large-scale scholarly infrastructures.