51Degrees Device Detection Node.js  4.4

51Degrees Device Detection for Node.js


This example shows how to use the 51Degrees Cloud service to determine details about a device based on its User-Agent and User-Agent Client Hint HTTP header values.

You will learn:

  1. How to create a Pipeline that uses the 51Degrees cloud service
  2. How to pass input data (evidence) to the Pipeline
  3. How to retrieve the results

This example is available in full on GitHub.

To run this example, you will need to create a resource key. The resource key is used as shorthand to store the particular set of properties you are interested in as well as any associated license keys that entitle you to increased request limits and/or paid-for properties.

You can create a resource key using the 51Degrees Configurator.

Required npm Dependencies:

  • fiftyone.pipeline.cloudrequestengine
  • fiftyone.pipeline.core
  • fiftyone.pipeline.engines
  • fiftyone.pipeline.engines.fiftyone
  • fiftyone.devicedetection.cloud


The flowData.evidence.addFromRequest(request) is used to extract required evidence from a Http request. The Helpers.setResponseHeaders(response, flowData) from fiftyone.pipeline.core package is used to add extra headers to a Http response to request further evidence from the client.

core.Helpers.setResponseHeaders(response, flowData);

The results of detection can be accessed by querying the device property of a FlowData object. This can then be used to interrogate the data.

var flowData = pipeline.createFlowData();
var deviceData = pipeline.device;
var hardwareVendor = deviceData.hardwarevendor;

Results can also be accessed in client-side code by using the fod object. See the JavaScriptBuilderElement for details on available settings such as changing the fod name.

window.onload = function () {
fod.complete(function(data) {
var hardwareName = data.device.hardwarename;
alert(hardwareName.join(", "));


"PipelineOptions": {
"Elements": [
"elementName": "fiftyone.pipeline.cloudrequestengine/cloudRequestEngine",
"elementParameters": {
"resourceKey": "!!YOUR_RESOURCE_KEY!!"
"elementName": "../../../deviceDetectionCloud"
/* *********************************************************************
* This Original Work is copyright of 51 Degrees Mobile Experts Limited.
* Copyright 2022 51 Degrees Mobile Experts Limited, Davidson House,
* Forbury Square, Reading, Berkshire, United Kingdom RG1 3EU.
* This Original Work is licensed under the European Union Public Licence
* (EUPL) v.1.2 and is subject to its terms as set out below.
* If a copy of the EUPL was not distributed with this file, You can obtain
* one at https://opensource.org/licenses/EUPL-1.2.
* The 'Compatible Licences' set out in the Appendix to the EUPL (as may be
* amended by the European Commission) shall be deemed incompatible for
* the purposes of the Work and the provisions of the compatibility
* clause in Article 5 of the EUPL shall not apply.
* If using the Work as, or as part of, a network application, by
* including the attribution notice(s) required under Article 5 of the EUPL
* in the end user terms of the application under an appropriate heading,
* such notice(s) shall fulfill the requirements of that article.
* ********************************************************************* */
const require51 = (requestedPackage) => {
try {
return require('/../' + requestedPackage);
} catch (e) {
return require(requestedPackage);
const path = require('path');
const fs = require('fs');
const http = require('http');
const pug = require('pug');
const compiledFunction = pug.compileFile(path.join(__dirname, '/index.pug'));
const core = require51('fiftyone.pipeline.core');
const ExampleUtils = require(path.join(__dirname, '/../exampleUtils'));
// Pipeline variable to be used
var pipeline;
const setPipeline = (options) => {
const resourceKey = OptionsExtension.getResourceKey(options);
// If we don't have a resource key then log an error
if (!resourceKey) {
throw 'No resource key specified in the configuration file ' +
'\'51d.json\' or the environment variable ' +
`'${ExampleUtils.RESOURCE_KEY_ENV_VAR}'. The 51Degrees cloud ` +
'service is accessed using a \'ResourceKey\'. For more information ' +
'see ' +
'https://51degrees.com/documentation/_info__resource_keys.html. ' +
'A resource key with the properties required by this example can be ' +
'created for free at https://configure.51degrees.com/1QWJwHxl. ' +
'Once complete, populate the config file or environment variable ' +
'mentioned at the start of this message with the key.';
pipeline = new core.PipelineBuilder({
// Enable custom javascript builder
addJavaScriptBuilder: true,
// Settings for javascript builder
javascriptBuilderSettings: {
// Custom endpoint to report client-side evidence
endPoint: '/json'
// Logging of errors and other messages.
// Valid logs types are info, debug, warn, error
pipeline.on('error', console.error);
const server = http.createServer((req, res) => {
// FlowData is a data structure that is used to convey
// information required for detection and the results of the
// detection through the pipeline.
// Information required for detection is called "evidence"
// and usually consists of a number of HTTP Header field
// values, in this case represented by a
// Object of header name/value entries.
const flowData = pipeline.createFlowData();
// Extract required evidence from the Http request.
if (req.url.startsWith('/json')) {
flowData.process().then(function () {
res.statusCode = 200;
res.setHeader('Content-Type', 'application/json');
} else {
flowData.process().then(function () {
res.statusCode = 200;
res.setHeader('Content-Type', 'text/html');
// Some browsers require that extra HTTP headers are explicitly
// requested. So set whatever headers are required by the browser in
// order to return the evidence needed by the pipeline.
// More info on this can be found at
// https://51degrees.com/blog/user-agent-client-hints
core.Helpers.setResponseHeaders(res, flowData);
// Obtain all used evidence
const allEvidence = flowData.evidence.getAll();
const evidences =
const device = flowData.device;
// Compile a response
responseHeaders: res.getHeaders(),
evidenceUsed: evidences,
allEvidence: allEvidence,
fiftyOneJs: flowData.javascriptbuilder.javascript,
hardwareVendor: DataExtension.getValueHelper(device, 'hardwarevendor'),
hardwareName: DataExtension.getValueHelper(device, 'hardwarename'),
deviceType: DataExtension.getValueHelper(device, 'devicetype'),
platformVendor: DataExtension.getValueHelper(device, 'platformvendor'),
platformName: DataExtension.getValueHelper(device, 'platformname'),
platformVersion: DataExtension.getValueHelper(device, 'platformversion'),
browserVendor: DataExtension.getValueHelper(device, 'browservendor'),
browserName: DataExtension.getValueHelper(device, 'browsername'),
browserVersion: DataExtension.getValueHelper(device, 'browserversion'),
screenWidth: DataExtension.getValueHelper(device, 'screenpixelswidth'),
screenHeight: DataExtension.getValueHelper(device, 'screenpixelsheight')
// Don't run the server if under TEST
if (process.env.JEST_WORKER_ID === undefined) {
const args = process.argv.slice(2);
// Use the supplied resource key or try to obtain one
// from the environment variable.
const resourceKey =
args.length > 0 ? args[0] : process.env[ExampleUtils.RESOURCE_KEY_ENV_VAR];
// Load the configuration options from
const options = JSON.parse(fs.readFileSync(path.join(__dirname, '/51d.json')));
// If resource key is not set in the config file, set one from console input
// or from environment variable.
const resourceKeyFromConfig = OptionsExtension.getResourceKey(options);
if (!resourceKeyFromConfig || resourceKeyFromConfig.startsWith('!!')) {
OptionsExtension.setResourceKey(options, resourceKey);
const port = 3001;
console.log('Server listening on port: ' + port);
// Export server object and set pipeline.
module.exports = {
server: server,
setPipeline: setPipeline