This is the source code for the DA-FDM API. The API provides access to a backend model that generated automated subject indexing suggestions for research data based on textual input such as full texts, abstracts, or description fields. The API itself handles the communication and data exchange, while the underlying model performed the semantic analysis and concept mapping. The model suggested relevant concepts and classifications from established knowledge systems DFG Classification System, GND and Wikidata. This dataset includes the source code as well as the corresponding documentation.