The openCost project aims to contribute to a fair reform of the scientific publishing system by establishing comprehensive cost transparency in the publishing process.To this end, openCost creates the required technical infrastructure to freely access publication costs and exchange these data via automated, standardized interfaces and formats.Standardized recording and open provision of publication costs associated with articles or contracts is vitally important to improve cost transparency both within institutions as well as inter-institutional and on larger levels (e.g. consortium or national contracts).openCost proposed for easy distribution of data to use the well established and widely available OAI-PMH interface in conjunction with an XML format. This will be implemented exemplarily at the services of the project partners, the Universities of Bielefeld and Regensburg and by DESY for the shared repository infrastructure JOIN², effectively enabling six research centres and another university to provide data.Via OAI-PMH openCost will also enable service providers (e.g. aggregators and research funding agencies) to harvest data directly from institutions. As a sample aggregator within the project’s framework, this is demonstrated by the OpenAPC service (Bielefeld).By implementing a technical interface, the services of the Electronic Journals Library EZB (Regensburg) will also be extended to include detailed information on OA publication costs, to be finally used as a central information platform for communicating OA information to researchers.The project’s view on publication costs not only include article processing charges (APCs), but all publication-related fees, such as submission or color fees, as well as costs resulting from transformation contracts or memberships.With the help of international expertise, openCost develops a standardized, structured metadata schema for publication costs. This schema, including standardized vocabularies, identifiers or consensual definitions, will be presented.To prove the viability of our approach it is constantly integrated in its latest version into the repositories of the project partners and definitions are cross checked with feedback from the community.The openCost metadata schema already exists for costs based on individual scientific articles, while a similar schema for contracts is currently under development. Additionally, metadata schemas for books and book chapters are to be added.Beyond the classical publishing outputs openCost will also tackle costs related to the publication of research data.The publication of data is becoming increasingly important and raises many questions in the publication process, and related costs also require a transparent, standardized approach right from the start.We assume that many of the carefully thought out criteria of the publication types discussed so far are already connectable, hence the extension of the openCost schema seems to be an immediate goal for the near future.This extension, however, will require close collaboration with thecommunity early on to identify relevant parameters. By providing insight into our work at hand, highlight parallels and differences between research data and literature publications, we want to engage in this discussion.Funded by the German Research Foundation (457354095), openCost was launched in 2022 by the project partners Bielefeld University Library, Regensburg University Library and DESY Central Library.

HMC Conference: Better Research Through Better Metadata, HMC 2023, Virtual, Internet, 10 Oct 2023 - 12 Oct 2023