Unmanaged extensions (UE) are a way to serve content from the Neo4j server but outside of its usual API endpoints. Strictly put, this is YOUR code, running on the server, in order to serve your data. More precisely, this is JAX-RS 2.0 code.
In order to create a Maven-based project, after the initial creation with your favorite IDE, add those two dependencies to the pom.xml file:
<dependency> <groupId>org.neo4j</groupId> <artifactId>neo4j</artifactId>