$ cat style.less
@color-red: red;
@color-green: green;

a {
  color: @color-red;

  .green {
    color: @color-green;
  }
}

$ curl -X POST --data-binary @style.less -H "Content-Type: text/less" http://webassets.herokuapp.com/api/
a {
  color: #ff0000;
}
a .green {
  color: #008000;
}

$ curl -X POST --data-binary @style.less -H "Content-Type: text/less" http://webassets.herokuapp.com/api/?compress=true
a{color:#ff0000;}a .green{color:#008000;}

$ npm install
$ npm test