Tracking transformative agreements through open metadata: method and validation using Dutch Research Council NWO funded papers

Transformative agreements have become an important strategy in the transition to open access, with almost 1,200 such agreements registered by 2025. Despite their prevalence, these agreements suffer from important transparency limitations, most notably article-level metadata that indicates which articles are covered by these agreements. Typically, this data is available to libraries but not openly shared, making it difficult to study the impact of these agreements. In this paper, we present a novel, open, replicable method for analyzing transformative agreements using open metadata, more specifically the Journal Checker tool developed by cOAlition S and OpenAlex. To demonstrate the potential of the approach, it is applied to a subset of publications funded by the Dutch Research Council (NWO). In addition, we validate this open method by comparing with the actual publisher data reported to the Dutch university library consortium UKB. The results show a high precision rate of 89% and a more modest recall of 53%. The 11% false positives shed an interesting light on the limitations of the method. In the absence of hard, openly available article-level data on transformative agreements, we provide researchers and institutions with a powerful tool to critically track and evaluate the impact of these agreements.