Your contract says 'Open Access', but does it say 'Open Metadata'?

This is the authors' abstract. We don't add key points for this paper.

Publisher contracts usually contain many specific clauses around open access publishing and full text access. But what is said about (open) metadata in these contracts, and how does this differ across publishers and consortia? To get a better overview on this, it is useful to systematically collect information on how metadata are currently included in publisher contracts. This information can provide examples of current practice, including differences among how publishers and consortia approach this topic. Looking forward, this can inform future negotiations around open metadata in publisher contracts. The ESAC Registry of Open Publishing Agreements, maintained by OA2020, provided access to a large corpus of publisher contracts, many of which are available in full text. This allows for a systematic analysis of the extent to which open metadata are currently included in such contracts, and for the resulting data to be publicly shared. As of December 2025, the ESAC registry contained 635 current contracts (i.e. valid in 2025), of which 230 included a link to the full text of the contract. In total, full text contracts are available for 23 countries (or groups of countries) and 48 publishers. Initially, we looked at contracts from two library consortia, Jisc (UK) and Bibsam (Sweden) as well as publisher contracts across Germany (DEAL, TIB and SUB Göttingen).