If you need to serve a static directory from your Sails application you can extend the http.js configuration file.

module.exports.http = {
    middleware: {
        custom: true
    },
    customMiddleware: function(app){
        var express = require('express');
        var dirpath = require('path').join(sails.config.paths.tmp, 'uploads');
        app.use('/uploads', express.static(dirpath));
    }
};