Universities are using a multitude of technical systems to support researchers and students. As a result there are new challenges concerning administration and system integration. The University of Bamberg has the requirement that research data from our repository (DSpace-CRIS) should be accessible through a web service to embed the data into a homepage uitilizing Typo3. DSpace-CRIS already features a REST API which supports access to DSpace's core data (publications) but is not conceived to provide data of CRIS entities (projects, research data). Moreover, in a multitude system landscape it is favored to use the same standard for several systems to access data which is implemented by the Open Data Protocol (OData) at the University of Bamberg. The goal of OData is to establish a consistent standard for realizing a RESTful API. In 2017 OData has been approved as a standard for Open Data Exchange by OASIS. In our approach the OData API makes direct use of DSpace-CRIS' underlying search platform (Solr) to access both DSpace's core data and data of CRIS entities by implementing a unified query language. Providing data from several system with the same query language simplifies the integration within other systems and reduces the amount of maintenance.