1var Fingerprint = require('express-fingerprint') app.use(Fingerprint({ parameters:[ // Defaults Fingerprint.useragent, Fingerprint.acceptHeaders, Fingerprint.geoip, // Additional parameters function(next) { // ...do something... next(null,{ 'param1':'value1' }) }, function(next) { // ...do something... next(null,{ 'param2':'value2' }) }, ]})) app.get('*',function(req,res,next) { // Fingerprint object console.log(req.fingerprint)})