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Main concepts

The LiveConnect module offers a convenient solution for generating and collecting first-party identifiers based on your preferences and sending this information to a designated endpoint. With LiveConnect, you gain a straightforward interface that facilitates the collection of identifiers from web pages, as well as capturing user interactions alongside these identifiers. If you're interested in reviewing the type of data being sent, please check what is being sent section of this documentation.

Quick start

To quickly get started with the LiveConnect module, perform the following steps via the command line interface.

  • Dependency installation: Begin by installing the dependencies using npm. Run the following command: npm install.
  • Code formatting: Ensure your code adheres to the provided ESLint file for consistent formatting. Use the command npm run fix-js to automatically format your code.
  • Unit testing: Validate the functionality of your code by running the unit tests. Execute the command npm run test:unit to initiate the tests.
  • Integration testing: Verify the integration of LiveConnect by running the integration tests against a dockerized Chrome browser. Use the command npm run test:it:docker:chrome to perform these tests.
  • Cross-browser testing: For a comprehensive evaluation, conduct full integration tests on multiple browsers. Please ensure you have valid Browserstack credentials configured. Run the command npm run test:it:browserstack to execute the tests across various browsers.


We welcome ideas, fixes, and improvements from the community. Discover how you can contribute by visiting our contribution guidelines.


Running Unit tests

Unit tests are written using Mocha and Chai. Check Quick Start how to run them.

Running Browserstack tests

Tests set the cookies on eTLD+1 domain. For that, execute the following command: echo "" | sudo tee -a /etc/hosts && echo "" | sudo tee -a /etc/hosts && echo "" | sudo tee -a /etc/hosts && echo "" | sudo tee -a /etc/hosts && echo "" | sudo tee -a /etc/hosts && echo "" | sudo tee -a /etc/hosts && echo "" | sudo tee -a /etc/hosts

Add Browserstack keys to your env, where the setup would be as follows:

user: process.env.BS_USER,
key: process.env.BS_KEY,

or, to run Browserstack tests locally, run: BS_USER=${User} BS_KEY=${Key} npm run test:it:browserstack

The browsers used in these tests are defined in test-config/wdio.browserstack.conf.js and should correlate to the transpiled code for supported browsers, listed in .browserslistrc.


The initialization part should be straightforward, considering the snippet:

import { LiveConnect } from 'live-connect-js'
const lc = LiveConnect(configOptions)

The object returned after initialization (lc in the snippet above) is exposing the following functions:

  • push accepts a custom event one would like to keep track of.
  • fire just fires a pixel, and can be considered as a simple page view.
  • peopleVerifiedId returns the most likely first party cookie that can be used for identity resolution.
  • ready flag, saying that the LC was loaded and ready, can be used when including LiveConnect as a global var on the window object.
  • resolve function accepts a success callback, an error callback and an additional object with key value pairs. Of course, errors during resolution will be emitted on the EventBus and sent to the collector. The third parameter is additionalParameters which is an object and will be attached to the IdentityResolution request, split into key-value pairs. The purpose of this object is to include key-value pairs in the request, e.g. for identifiers that cannot be found in the cookie jar, or in LocalStorage, or simply there's a requirement for a certain identifier to be represented under a specific key which doesn't match its name in the cookie jar, or LocalStorage key.
  • resolutionCallUrl function returns the URL to be called in order to receive the resolution to a stable identifier.

Overriding the StorageHandler and CallHandler

LiveConnect is initialized in a way so that it does not manipulate storage and call on the device on its own.

The StorageHandler is an object with functions that adhere to the signature:

  • function localStorageIsEnabled ()
  • function getCookie (key)
  • function getDataFromLocalStorage (key)
  • function findSimilarCookies (keyLike)
  • function setCookie (key, value, expires, sameSite, domain)
  • function removeDataFromLocalStorage (key)
  • function setDataInLocalStorage (key, value)

The CallHandler is another object with functions:

  • function ajaxGet (uri, responseHandler, fallback, timeout) where the responseHandler is a function(body, response), and the fallback is a function()
  • function pixelGet (uri, onload) where the onload is a function()

If one of the functions is not available in the external handler, LiveConnect will fall back to stubs to ensure that the overall functionality isn't being affected. It is recommended to provide full implementations of the interfaces. Default implementations of the handlers can be found in the live-connect-handlers project.

With custom implementations, the initialization can look like this:

import { LiveConnect } from 'live-connect-js'

const storageHandler = {
  getCookie: (key) => {
    let m = window.document.cookie.match('(^|;)\\s*' + key + '\\s*=\\s*([^;]*)\\s*(;|$)')
    return m ? decodeURIComponent(m[2]) : null;
  setCookie: (key, value, expires, sameSite, domain) => {
const callHandler = {
  ajaxGet: (url, responseHandler, fallback, timeout) => {
  pixelGet: (url, onload) => {
const lc = LiveConnect(configOptions, storageHandler, callHandler)

Configuration options

Considering the snippet above, LiveConnect accepts a JSON with the config which determines its behaviour. You can learn more about available options here.


The code in the manager folder is responsible for browser state interaction and management, e.g. storage manipulation. It's sometimes important in which order the managers are invoked, as one might depend on the result of another.

Decisions manager

managers/decision.js is responsible for keeping the state in the browser with all the recent li_did parameters picked up from urls where LiveConnect was loaded.

Identifiers manager

managers/identifiers.js takes care of LiveConnect first party identifiers being created (if not present) and picked up so that they can be sent as signal pixels containing that information. Where the LiveConnect identifiers are stored (Cookie vs LocalStorage) depends on the config.storageStrategy option. How long those identifiers will live is configured in the config.expirationDays parameter. In case the storageStrategy is set to Cookie, the browser will ensure that the cookie expires. In case of localStorage, Identifiers Manager and its underlying utils/storage.js helper will ensure that on the next load, the entry is removed from localStorage in case it's obsolete.

People-verified manager

managers/people-verified.js makes sure that either of the selected identifiers is stored as the _li_duid key in local storage, as some integrations are using the information stored there.


The enrichers folder contains code responsible for extracting specific information about the page visit when the module is loaded. It makes sure that the extracted data is stored in the state which contains data that is sent as a single pixel.

Page enrichment

enrichers/page.js holds the logic which determines the real page url on which we're trying to capture user interactions.

Identifiers enrichment

enrichers/identifiers.js is responsible for reading the identifiersToResolve configuration parameter to read any additional identifiers that customers want to share with us.

Messaging between components via EventBus

LiveConnect exposes an object via the field eventBus on the LiveConnect instance which is responsible for communicating various information based on different fields of interest. For example, there are three topics that anyone can hook to, and receive information about:

  • errors, on the li_errors topic
  • whenever the pixel is sent successfully, the lips topic will emit that information
  • just before the pixel is sent, pre_lips topic will contain the information about it.

The following snippets can be used to hook up to one of the topics and receive events as they happen. Here, lc is a reference to a LiveConnect instance.

const lipsLogger = (message) => {'Received a lips message, will continue receiving them', message) }
lc.eventBus.on('lips', lipsLogger)


const lipsLogger = (message) => {'Received a lips message once, it will self destruct now.', message) }
lc.eventBus.once('lips', lipsLogger)

There are two ways this can be achieved:

  • on - will be triggered every time the topic receives a message.
  • once - will be triggered only once, and the handler that is subscribing to that topic will be automatically removed once the event is received and sent.

The bus isn't a pure event listener, as we also want to cover the case where handlers can be attached even after messages have been emitted. An example of how to hook to the topic will be explained in the next section.

Error handling

Vital logic is wrapped in try catch blocks, and where it makes sense, the error message is emitted on the li_errors topic in the eventBus. To start listening to the topic, one can simply implement their own logic. For example, if logging the messages is of interest, the following snippet can be used:

const logger = (message) => {console.error('Error message received on the event bus', message)}
lc.eventBus.on('li_errors', logger)

Receiving errors on the collector

LiveConnect has a handler called events/error-pixel.js which is subscribed on the li_errors topic, and wraps the exceptions into the following format:

    message: e.message,
    stackTrace: e.stack,
    lineNumber: e.lineNumber,
    columnNumber: e.columnNumber,
    fileName: e.fileName

Every time there's an exception in LiveConnect, this handler will create such a message, and LiveConnect will send the base64 url encoded message to the collector containing the details above.

What is being sent?

The user interaction is sent to a url specified in the inbound config, as collectorUrl, only if the information is present. For example, one of the parameters is aid which should send the value of the appId from the config, however, if it is not set, it will not be sent. For more details on requests being sent take a look at collector parameters.




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