This paper introduces ADISS, a generic search system designed to integrate heterogeneous authority file providers. Authority data is used to unambiguously identify entities such as persons, places, and organizations. As single data providers do not offer both quantity and quality of data, a combined access to multiple datasets is often required to support real-world use cases. In the context of Digital Humanities this combination improves the resolution of ambiguities in data curation processes. Our work is mainly motivated by two projects that require semi-automatic retrieval, as well as user-centered search scenarios for different authority file providers. Instead of using multiple existing endpoints to access the various datasets, we gather the heterogeneous data and make it accessible via integrated query and result models. In this paper, we present our highly configurable search API, which offers a diverse range of search and filtering options. We show that by its generic and highly configurable nature, our system is adaptable and reusable for a diverse set of use cases and conclude the paper with ideas for further steps and improvements.