51Degrees Device Detection Node.js  4.4

51Degrees Device Detection for Node.js


This example shows how to use 51Degrees on-premise device detection 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 51Degrees on-premise device detection
  2. How to pass input data (evidence) to the Pipeline
  3. How to retrieve the results

This example is available in full on GitHub.

This example requires a local data file. The free 'Lite' data file can be acquired by pulling the git submodules under this repository (run `git submodule update --recursive`) or from the device-detection-data GitHub repository.

The Lite data file is only used for illustration, and has limited accuracy and capabilities. Find out about the more capable data files that are available on our pricing page

Required npm Dependencies:

  • fiftyone.pipeline.core
  • fiftyone.pipeline.engines
  • fiftyone.pipeline.engines.fiftyone
  • fiftyone.devicedetection.onpremise


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 fs = require('fs');
const http = require('http');
const path = require('path');
const pug = require('pug');
const compiledFunction =
pug.compileFile(path.join(__dirname, '/index.pug'));
const core = require51('fiftyone.pipeline.core');
const optionsExtension =
const dataExtension =
const { DATA_FILE_AGE_WARNING, ExampleUtils } =
require(path.join(__dirname, '/../exampleUtils'));
// Pipeline variable to be used
var pipeline;
const setPipeline = (options) => {
const dataFilePath = optionsExtension.getDataFilePath(options);
if (!dataFilePath) {
throw 'A data file must be specified in the 51d.json file.';
if (!fs.existsSync(dataFilePath)) {
const newDataFilePath = ExampleUtils.findFile(path.basename(dataFilePath));
if (newDataFilePath !== undefined) {
optionsExtension.setDataFilePath(options, newDataFilePath);
console.warn('Failed to find a device detection data file at ' +
`at the specified path '${dataFilePath}'. Use '${newDataFilePath}' ` +
} else {
throw 'Failed to find a device detection data file at ' +
`'${dataFilePath}'. If using the lite file, then make sure the ` +
'device-detection-data submodule has been updated by running ' +
'\'git submodule update --recursive\'. Otherwise, ensure that the ' +
'filename is correct in 51d.json.';
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.
// Handle report from client side separately
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 =
// Compile a response
dataFilePublishedTime: new Date().getTime(),
dataFileAgeWarning: DATA_FILE_AGE_WARNING,
responseHeaders: res.getHeaders(),
evidenceUsed: evidences,
allEvidence: allEvidence,
dataSourceTier: ExampleUtils.getDataTier(pipeline),
fiftyOneJs: flowData.javascriptbuilder.javascript,
hardwareVendor: dataExtension.getValueHelper(flowData.device, 'hardwarevendor'),
hardwareName: dataExtension.getValueHelper(flowData.device, 'hardwarename'),
deviceType: dataExtension.getValueHelper(flowData.device, 'devicetype'),
platformVendor: dataExtension.getValueHelper(flowData.device, 'platformvendor'),
platformName: dataExtension.getValueHelper(flowData.device, 'platformname'),
platformVersion: dataExtension.getValueHelper(flowData.device, 'platformversion'),
browserVendor: dataExtension.getValueHelper(flowData.device, 'browservendor'),
browserName: dataExtension.getValueHelper(flowData.device, 'browsername'),
browserVersion: dataExtension.getValueHelper(flowData.device, 'browserversion'),
screenWidth: dataExtension.getValueHelper(flowData.device, 'screenpixelswidth'),
screenHeight: dataExtension.getValueHelper(flowData.device, 'screenpixelsheight')
// Don't run the server if under TEST
if (process.env.JEST_WORKER_ID === undefined) {
// Load the configuration options from config file.
const options = JSON.parse(fs.readFileSync(path.join(__dirname, '/51d.json')));
const port = 3001;
console.log('Server listening on port: ' + port);
// Export server object and set pipeline.
module.exports = {
server: server,
setPipeline: setPipeline