May be wrong but as far as I know thrift is still the official API, for now. CQL is in it's first release and still has a few things to be added to it https://issues.apache.org/jira/browse/CASSANDRA-2472 . That said, jump in and try it out :) 

The best documentation I can point you to is 
https://github.com/apache/cassandra/blob/cassandra-0.8.0/doc/cql/CQL.textile

There are Java,  Python and Twisted Python drivers in the source tree under the drivers/ directory. 

Hope that helps. 

-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton

On 5 Jun 2011, at 04:16, Yonder wrote:

Hi,

In Cassandra 0.8, CQL become the primary client interface, but I don't know how to use it in a non-command line env. I could not find out any how-to do docs in Wiki or DataStax's website.

Thanks