user@maas2-controller:~$ maas maas2 version read -d
200 OK

  -Content-Encoding: gzip
     Content-Length: 221
   Content-Location: http://192.168.150.2/MAAS/api/2.0/version/
       Content-Type: application/json; charset=utf-8
               Date: Thu, 21 Apr 2016 15:58:01 GMT
             Server: TwistedWeb/16.0.0
             Status: 200
               Vary: Authorization,Accept-Encoding
    X-Frame-Options: SAMEORIGIN
    X-Maas-Api-Hash: efafc387b05a52b28e09c6d71b0d13bf10ada5f6

Success.
Machine-readable output follows:
{"version": "2.0.0", "subversion": "alpha3+bzr4810", "capabilities": ["networks-management", "static-ipaddresses", "ipv6-deployment-ubuntu", "devices-management", "storage-deployment-ubuntu", "network-deployment-ubuntu"]}