Csv Import Via Api?

I thought I read you could import CSV files via the API but I don't see it anywhere in the REST API.

Am I crazy or is it possible to automate that with the current API?

Or even just doing mass updates at once via REST. The current REST scheme is very slow if I want to update several thousand items especially if I want it to happen at a particular time.

I am afraid, it is not possible without additional code modificaitons