Operationalizing the EU Data Act for Automated Compliance

Abstract

The EU Data Act establishes comprehensive rules governing data access and sharing across business-to-consumer (B2C), business-to-business (B2B), and business-to-government (B2G) contexts. This paper presents a comprehensive ontology for the EU Data Act, enabling reasoning over data-sharing agreements through machine-readable representations. The DAOnt ontology reuses elements from three established ontologies—the Core Ontology of the Legal Knowledge Interchange Format, Open Digital Rights Language, and Data Privacy Vocabulary—to capture the normative structure of the Data Act. The ontology captures the main concepts and relationships in the Regulation, and it also operationalizes three articles to facilitate compliance checking: Article 4(1) (B2C user access rights), Article 8(6) (B2B trade secret exceptions), and Article 19(2)(a) (B2G competitive use prohibitions). The ontology supports compliance checking through SPARQL queries that return obligations, permissions, and prohibitions, allowing organizations to verify whether data-sharing agreements meet the requirements of the EU Data Act and to assess conditions such as FRAND obligations. By representing key legal concepts in Resource Description Framework (RDF), our work helps bridge the gap between the legal provisions of the Data Act and their computational interpretation. The complete ontology, along with example instances and queries, is available online.

Received: 3 May 2026 | Revised: 9 July 2026 | Accepted: 29 July 2026

Conflicts of Interest

Víctor Rodríguez-Doncel is the Editorial Board Member for the Journal of Computational Law and Legal Technology and was not involved in the editorial review or the decision to publish this article. The authors declare that they have no conflicts of interest to this work.

Data Availability Statement

The data that support the findings of this study are openly available on GitHub at https://github.com/oeg-upm/DAOnt, and the DAOnt ontology is published at https://w3id.org/def/daont.

Author Contribution Statement

Sheyla Leyva-Sánchez: Conceptualization, Methodology, Software, Investigation, Data curation, Writing – original draft, Writing – review & editing, Visualization. Fabian Linde: Conceptualization, Methodology, Software, Investigation, Writing – original draft, Writing – review & editing. Meem Arafat Manab: Software, Writing – original draft, Writing – review & editing. María Poveda-Villalón: Conceptualization, Methodology, Writing – review & editing, Supervision, Project administration, Funding acquisition. Víctor Rodríguez-Doncel: Conceptualization, Writing – review & editing, Supervision, Project administration, Funding acquisition.