koa-scss

$ npm install koa-scss

var scss = require('koa-scss'),
    serve = require('koa-static'),
    koa = require('koa'),
    app = koa();

app.use(scss({
    src: __dirname + '/public/scss/',
    dest: __dirname + '/public/css/'
}));

app.use(serve('./public'));

app.listen(8000);