How to pass variable from app.js to routes/index.js?

I'm using shrinkroute https://npmjs.org/package/shrinkroute to make links in nodejs. I get error 500 ReferenceError: shrinkr is not defined

How to pass shrinkroute to routes/index.js? Is there a better way to create url by passing query string args?

//app.js
var app = express();

var shrinkr = shrinkroute( app, {
    "user": {
        path: "/user/:id?",
        get: routes.showOrListUsers
    }
});
//url method works in app.js    
var url = shrinkr.url( "user", { id: 5, page:40, type:'a' } );
console.log(url);

app.use( shrinkr.middleware );

//routes/index.js
exports.showOrListUsers = function(req, res, next) {                       
    console.log(req.params); 
    //shrinkr errors out in index.js                                      
    var url2 = shrinkr.url( "users", {name: "foo"});                       
    console.log(url2);                                                                         
}