Disappointing to see this die. I would really like there to be some open, public API with a knowledge engine backend that could be part of an open source alternative to Siri, Cortana, Echo, etc.
some projects like wikidata and dbpedia provide public APIs. You can query them using SPARQL for example.
Having actively looked into using Wikidata as part of a system... Hahaha ... yeah it's great for Wikipedia but pretty useless for anyone else. Don't get me started on how useless SPARQL is for "explorative search".