SemTK: An Ontology-first, Open Source Semantic Toolkit for Managing and Querying Knowledge Graphs

While the use of knowledge graphs has exploded in recent years, there exist few tools and mechanisms for users to explore, query and manage semantic data in knowledge graphs. A lack of user-friendly tools to construct SPARQL queries has been a barrier preventing the wide adoption of Semantic Web technologies by domain experts and application developers alike. There are a variety of tools and techniques to convert CSV and relational data to RDF, but to the best of our knowledge there is no integrated, user-friendly toolkit for data triplification and ingestion into a triple store. In this paper, we present the Semantics Toolkit (SemTK), an open source project that allows user-friendly querying and semantic data management. Through its user interface, SemTK allows users to convert CSV data into RDF triples and ingest them into a triple store. It also allows users to visually explore the ontology and construct SPARQL queries via a drag-and-drop interface. SemTK also provides novel SQL stored procedurelike support for saving and executing semantic queries with run-time constraints. Additionally, SemTK provides REST APIs for all of its functionality including allowing data ingestion and queries to be executed programmatically, dramatically simplifying the deployment of knowledge-driven applications. The Semantics Toolkit is open-sourced under the Apache License, Version 2.0 and is available at https://github.com/ge-semtk/semtk.