After five years of operation, we are today retiring the Expander service within our data services API.
For now, the Expander endpoint will continue to respond to requests, but will always return an empty result.
We originally built Expander to solve a specific problem around finding conceptually similar phrases to provided words and short phrases. Much has changed in the world of NLP since then, including the arrival of a variety of similar third-party services, as well as easier-to-use libraries like FastText for building your own word co-location algorithms. That, coupled with a decline in usage of our endpoint informed our decision to retire Expander today.
Note that this does not affect Profiler, Matcher, or Warrior, all of which continue to operate as expected and have been recently updated to work with O*NET 2019 SOCs (as discussed in a prior announcement).