Within the framework of this project, a technical infrastructure will be created with which publication costs can be comprehensively recorded and made openly accessible with the help of standardised interfaces. Therefore, a metadata schema is to be developed with which the publication costs can be recorded and retrieved in a structured form. This metadata format should be suitable for as many of the publication costs incurred by a scientific institution as possible and thus include not only Open Access publication fees, so-called Article Processing Charges (APCs), but also costs from transformation contracts, memberships and similar. Such a standardised data format makes it possible to use the data in an automated form for cost evaluations. This promotes cost transparency within an institution as well as a cost comparison between different institutions. The metadata format for publication fees is to be developed in cooperation with national and international partners, as it must meet different requirements depending on the purpose of the cost evaluation. In a further focus of work, an OAI interface will be developed and implemented exemplarily in the systems of the applicants, in which the publication costs are included. This OAI interface should be able to be used by other systems, e.g. institutional repositories of other institutions. By means of such an interface the data can be merged within an institution and across institutions or can be queried for different purposes. Via OAI-PMH, aggregators, such as the service OpenAPC at Bielefeld University Library, should also be able to collect publication output directly from the institutions.The third project focus is to extend the Electronic Journals Library (EZB) with special functions for the administration and display of information on Open Access publication costs or the assumption of publication costs. The data model of the EZB is to be supplemented in such a way that institution-specific agreements such as memberships or regulations from transformation agreements can be recorded and displayed in the EZB. In addition, a possibility to enter information on the assumption of publication costs for a selected journal by a specific institution will be created. This information should be displayed in the EZB with the individual journals. Furthermore, this information should be made available in a machine-readable format in an API. The EZB could thus be used by all participating institutions as a central platform for communicating this information to researchers. Furthermore, it is planned to create an interface to OpenAPC in order to be able to use the data aggregated in this service for the EZB.
