There are a lot of Cassandra API:s available and usually the programming language preference determines the choice of API.
However, if we take the programming language component out of the equation, what Cassandra API provides the highest level of abstraction?
Definition of "level of abstraction" in this context: An API providing a lot of extra goodies such as index handling, etc would be considered being at a higher abstraction layer than a bare bones "close to Thrift" API.