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NodeJS SDK

Introduction​

Welcome to the developer documentation for the Kameleoon NodeJS SDK! Our SDK gives you the possibility of running experiments and activating feature flags on your server application. Integrating our SDK into your server is easy, and its footprint (in terms of memory and network usage) is low.

note

Before you begin installing our NodeJS SDK, we recommend that you read our technical considerations article to gain an understanding of the fundamental technological concepts behind our SDKs. This will help you to better understand the SDK and ensure a successful integration.

Changelog​

Latest version description of NodeJS SDK can be found here.

Installation​

Use preferred package manager to install NodeJS SDK from npm repository.

Npm:

npm install @kameleoon/nodejs-sdk

Yarn:

yarn add @kameleoon/nodejs-sdk

Pnpm:

pnpm add @kameleoon/nodejs-sdk

Deno:

deno.json
{
  "imports": {
    "@kameleoon/nodejs-sdk": "npm:@kameleoon/nodejs-sdk@^2.4"
  }
}

Contents​

To configure your NodeJS server and start running feature experiments and deploying new features to your users, please follow the instructions provided in the Main usage section. This section contains all the main steps for proper Kameleoon NodeJS SDK configuration as well as main tools for development.

  1. Initializing the Kameleoon Client
  2. Getting access to feature flags and variations
  3. Using Kameleoon Client methods

We highly recommend that you take a look at the Methods section, which includes useful information on every method that is introduced in NodeJS SDK.

Explore additional sections with some useful information on Kameleoon:

Main Usage​

Here is a step-by-step guide for configuring NodeJS SDK for your application.

1. Initializing the Kameleoon Client​

import {
  Environment,
  KameleoonClient,
  SDKConfigurationType,
} from '@kameleoon/nodejs-sdk';

// -- Optional configuration
const configuration: Partial<SDKConfigurationType> = {
  updateInterval: 20,
  environment: Environment.Production,
};

const client = new KameleoonClient({ siteCode: 'my_site_code', configuration });

// -- Waiting for the client initialization using `async/await`
async function init(): Promise<void> {
  await client.initialize();
}

init();

// -- Waiting for the client initialization using `Promise.then()`
client
  .initialize()
  .then(() => {})
  .catch((error) => {});

For the start developers will need to create an entry point for NodeJS SDK by creating a new instance of Kameleoon Client.

KameleoonClient is used to run experiments and retrieve the status of feature flag and its variables using concerned methods.

KameleoonClient initialization is done asynchronously in order to make sure that Kameleoon API call was successful for that method initialize() is used. You can use async/await, Promise.then() or any other method to handle asynchronous client initialization.

note

In order to add NodeJS SDK to an Edge environment please refer to Integration with Edge providers.

Arguments​
NameTypeDescription
siteCode (required)stringclient's site code defined on Kameleoon platform
configuration (optional)Partial<SDKConfigurationType>client's configuration
integrations (optional)IntegrationTypecompute edge integrations, see Integration with Edge providers
credentials (optional)CredentialsTypeclient API credentials, see Tracking Rate Limit
note

configuration consists of following parameters:

NameTypeDescriptionDefault Value
updateInterval (optional)numberupdate interval in minutes for sdk configuration, minimum value is 1 minute60
environment (optional)Environmentfeature flag environmentEnvironment.Production
targetingDataCleanupInterval (optional)number or undefinedinterval in minutes for cleaning up targeting data, minimum value is 1 minute30

2. Getting access to feature flags and variations​

note

To implement a feature flag in your code, you must first create a feature flag in your Kameleoon account.

After the SDK has been initialized, you can obtain a feature flag configuration. Subsequently, all methods will require you to specify the User ID or visitor code associated with the request.

note

If you are using Kameleoon in Hybrid mode with mixed front-end and back-end environments, you can call the KameleoonUtils.getVisitorCode helper method to obtain the Kameleoon visitorCode for the current visitor. Alternatively, if you provide your own user ID, you must ensure its uniqueness on your end.

3. Using Kameleoon Client methods​

Now your setup is done! You can use KameleoonClient methods to run experiments and manage feature flags.

To associate various data points with the current user, you can use the addData method. This method requires the visitorCode as the first parameter and accepts several additional parameters. These additional parameters represent the various Data Types allowed in Kameleoon.

import {
  KameleoonClient,
  KameleoonUtils,
  CustomData,
} from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Get visitor code using server `request` and `response`
  const visitorCode = KameleoonUtils.getVisitorCode({
    domain: 'www.example.com',
    request: req,
    response: res,
  });

  // -- Trigger an experiment
  const experimentId = 100;
  const variationId = client.triggerExperiment(visitorCode, experimentId);

  // -- Add user data
  const customDataIndex = 0;
  client.addData(visitorCode, new CustomData(customDataIndex, 'my_data'));

  // -- Check if the feature is active for visitor
  const isMyFeatureActive = client.isFeatureFlagActive(
    visitorCode,
    'my_feature_key',
  );

  // -- Track conversion
  client.trackConversion({ visitorCode, revenue: 20000, goalId: 123 });
}

init();

Feature flags can be very useful for implementing ON/OFF switches with optional but advanced user targeting rules. However, you can also use feature flags to run feature experiments with several variations of your feature flag. Check out our documentation on creating feature experiments for more information.

note

See Methods section for detailed guide for each KameleoonClient method available.

Methods​

Get Visitor Code / Use Own Visitor ID​

KameleoonUtils getVisitorCode​

import { KameleoonClient, KameleoonUtils } from '@kameleoon/nodejs-sdk';
import { IncomingMessage, ServerResponse } from 'http';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

// -- Get visitor code using native `NodeJS/NextJS/Deno` `request` and `response`
const visitorCode = KameleoonUtils.getVisitorCode({
  domain: 'www.example.com',
  request: req,
  response: res,
});

// -- Get visitor code using `Express`s `request`, `response` and optionally providing
//    default visitor code
const visitorCode = KameleoonUtils.getVisitorCode({
  domain: 'www.example.com',
  request: req as IncomingMessage,
  response: res as ServerResponse,
  defaultVisitorCode: 'my_default_visitor_code',
});

Static method getVisitorCode called on KameleoonUtils obtains visitor code from the request headers cookie, if the visitor code doesn't yet exist generates a random visitor code (or uses a provided default) and sets a new visitor code to response headers cookie

note

getVisitorCode utilizes native NodeJS types for request and response, which are IncomingMessage and ServerResponse imported from http module. However if you are using express framework, the types of request and response will not match. This could be easily overcome using type cast as in example, it will produce identical result.

Parameters​

NameTypeDescription
domain (required)stringdomain which cookie belongs to
request (required)IncomingMessageserver request
response (required)ServerResponseserver response
defaultVisitorCode (optional)stringvisitor code to be used in case there is no visitor code in cookies
note

If defaultVisitorCode wasn't provided and there is no visitor code stored in cookie it will be randomly generated

Returns​

string - result visitor code

Get Kameleoon Client Configuration URL​

KameleoonUtils getClientConfigurationUrl​

import { KameleoonUtils } from '@kameleoon/nodejs-sdk';

// -- Get Kameleoon Client Configuration URL
const uri = KameleoonUtils.getClientConfigurationUrl('my_site_code');

The static method getClientConfigurationUrl called on KameleoonUtils obtains the Kameleoon Client Configuration URL. Use this URL to retrieve a JSON representation of your feature flags. The JSON data contains all the information you need to activate your feature flags.

Parameters​

NameTypeDescription
siteCode (required)stringclient's siteCode defined on Kameleoon platform

Returns​

string - Kameleoon Client Configuration URL

Initialize Kameleoon Client​

initialize​

import {
  KameleoonClient,
  KameleoonError,
  KameleoonException,
} from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  try {
    await client.initialize();
  } catch (err) {
    if (err instanceof KameleoonError) {
      switch (err.type) {
        case KameleoonException.StorageWrite:
        // -- Handle error case
        case KameleoonException.ClientConfiguration:
        // -- Handle error case
        default:
          break;
      }
    }
  }
}

init();

An asynchronous method for KameleoonClient initialization by fetching Kameleoon SDK related data from server or by retrieving data from local source if data is up-to-date or update interval has not been reached.

Returns​

Promise<boolean> - A promise resolved to a boolean indicating a successful sdk initialization. Generally initialize will throw an error if the something that can not be handled will happen, so the boolean value will almost always be true and won't give as much useful information.

Throws​

TypeDescription
KameleoonException.StorageWriteCouldn't update storage data
KameleoonException.ClientConfigurationCouldn't retrieve client configuration from Kameleoon API
KameleoonException.MaximumRetriesReachedMaximum retries reached, request failed

Add associated client data​

addData​

import {
  KameleoonClient,
  BrowserType,
  CustomData,
  Browser,
} from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Create Kameleoon Data Types
  const browserData = new Browser(BrowserType.Chrome);
  const customData = new CustomData(0, 'my_data');

  // -- Add one Data item to Storage
  client.addData('my_visitor_code', browserData);

  // -- Add Data to Storage using variadic style
  client.addData('my_visitor_code', browserData, customData);

  // -- Add Data to Storage in array
  const dataArr = [browserData, customData];
  client.addData('my_visitor_code', ...dataArr);
}

init();

Method for adding targeting data to the storage so that other methods could decide whether the current visitor is targeted or not.

note

The addData() method does not return any value and does not interact with Kameleoon back-end servers on its own. Instead, all the declared data is saved for future transmission via the flush method .This approach helps reduce the number of server calls made, as the data is typically grouped into a single server call triggered by the execution of flush.

The trackConversion method also sends out any previously associated data, just like the flush. The same holds true for getFeatureFlagVariationKey and getFeatureFlagVariable methods if an experimentation rule is triggered.

tip

Each visitor can only have one instance of associated data for most data types. However, CustomData is an exception. Visitors can have one instance of associated CustomData per customDataIndex.

note

Check the list of supported conditions to know what data types can be used for targeting

Parameters​

NameTypeDescription
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length
kameleoonData (optional)KameleoonDataType[]number of instances of any type of KameleoonData, can be added solely in array or as sequential arguments
note

kameleoonData is variadic argument it can be passed as one or several arguments (see the example)

note

The index or ID of the custom data can be found in your Kameleoon account. It is important to note that this index starts at 0, which means that the first custom data you create for a given site will be assigned 0 as its ID, not 1.

Throws​

TypeDescription
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty
KameleoonException.StorageWriteCouldn't update storage data
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient
note

Check Data Types reference for more details of how to manage different data types

Trigger an Experiment (without feature flags)​

triggerExperiment​

note

The triggerExperiment() method will be deprecated as SDK and Hybrid type experiments are being merged with feature experimentation in September 2023. Use feature experimentation methods instead.

import { KameleoonClient, KameleoonUtils } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  const experimentId = 123;
  // -- Get visitor code using server `request` and `response`
  const visitorCode = KameleoonUtils.getVisitorCode({
    domain: 'www.example.com',
    request: req,
    response: res,
  });

  await client.initialize();

  // -- Trigger Experiment and obtain variation id
  const variationId = client.triggerExperiment(visitorCode, experimentId);
}

init();

The triggerExperiment() method triggers an experiment by assigning the specified variation to the user with the specified visitorCode. If the variation is already assigned, the method returns the variation ID and sends the tracking request.

The triggerExperiment() method allows you to run server-side or hybrid experiments without the need to configure feature flags.

note

Returned id 0 indicates default variation.

Parameters​

NameTypeDescription
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length
experimentId (required)numberid of experiment running for the current visitor

Returns​

number - associated variationId which is successfully found in storage or newly assigned

Throws​

TypeDescription
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty
KameleoonException.ExperimentConfigurationNotFoundNo configuration found for provided experimentId
KameleoonException.StorageReadCouldn't find associated experiment by provided experimentId and visitorCode inside the storage
KameleoonException.NotTargetedCurrent visitor is not targeted
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient

Track Conversion​

trackConversion​

import { KameleoonClient, KameleoonUtils } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  const experimentId = 123;
  // -- Get visitor code using server `request` and `response`
  const visitorCode = KameleoonUtils.getVisitorCode({
    domain: 'www.example.com',
    request: req,
    response: res,
  });

  await client.initialize();

  // -- Track conversion
  client.trackConversion({ visitorCode, revenue: 20000, goalId: 123 });
}

init();

The method trackConversion() creates and adds Conversion data to the visitor with the specified parameters and executes flush.

note

It's a helper method for the quick and convenient conversion tracking, however creating and adding Conversion manually allows more flexible Conversion with negativeparameter

Parameters​

Parameters object consisting of:

NameTypeDescription
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length
goalId (required)numbergoal to be sent in tracking request
revenue (optional)numberrevenue to be sent in tracking request

Throws​

TypeDescription
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty
KameleoonException.StorageWriteCouldn't update storage data

Flush tracking data​

flush​

import { KameleoonClient, KameleoonUtils } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  // -- Get visitor code using server `request` and `response`
  const visitorCode = KameleoonUtils.getVisitorCode({
    domain: 'www.example.com',
    request: req,
    response: res,
  });

  await client.initialize();

  const customData = new CustomData(0, 'my_data');
  client.addData(visitorCode, customData);

  // -- Flush added custom data
  client.flush(visitorCode);
}

init();

The method flush() takes the Kameleoon data associated with the visitor and sends the data tracking request along with all of the data that's been added previously using the addData method.

note

If a visitorCode isn't provided, the SDK flushes all of its stored data to the remote Kameleoon servers.

note

Previously, this method was named flushData, which has been deprecated since 2.5.0.

Parameters​

NameTypeDescription
visitorCode (optional)stringunique visitor identification string, can't exceed 255 characters length, if not passed all the data will be flushed (sent to the remote Kameleoon servers)

Throws​

TypeDescription
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient

Get list of all experiments​

getExperiments​

note

The getExperiments() method will be deprecated as SDK and Hybrid type experiments are being merged with feature experimentation in September 2023. Use feature experimentation methods instead.

import { KameleoonClient } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Get experiment list
  const experiments = client.getExperiments();
}

init();

Method getExperiments() returns a list of experiments stored in the client configuration

Returns​

ExperimentType[] - list of experiments, each experiment item contains id and name

Throws​

TypeDescription
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient

Get list of experiments for a certain visitor​

getVisitorExperiments​

note

The getVisitorExperiments() method will be deprecated as SDK and Hybrid type experiments are being merged with feature experimentation in September 2023. Use feature experimentation methods instead.

import { KameleoonClient, KameleoonUtils } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  // -- Get visitor code using server `request` and `response`
  const visitorCode = KameleoonUtils.getVisitorCode({
    domain: 'www.example.com',
    request: req,
    response: res,
  });

  await client.initialize();

  // -- Get all visitor experiments
  const experiments = client.getVisitorExperiments(visitorCode, false);

  // -- Get only allocated visitor experiments
  const experiments = client.getVisitorExperiments(visitorCode);
}

init();

Method getVisitorExperiments() returns a list of experiments that the visitor with visitorCode is targeted by and that are active for the visitor

note

Visitor will have one of the variations allocated if the experiment was triggered

Parameters​

NameTypeDescriptionDefault Value
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length-
isAllocated (optional)booleanboolean value indicating that only experiments allocated for visitor will be returnedtrue

Returns​

ExperimentType[] - list of experiments, each experiment item contains id and name

Throws​

TypeDescription
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty

Get experiment variation data​

getExperimentVariationData​

import { KameleoonClient, KameleoonUtils } from '@kameleoon/javascript-sdk';

const client = new KameleoonClient('my_site_code');

async function init(): Promise<void> {
  await client.initialize();

  // -- Get experiment variation data
  const variationId = 100;
  const variationDataJson = client.getExperimentVariationData(variationId);
}

init();

Method getExperimentVariationData returns variation data in JSON format for the variation with variationId

Parameters​

NameTypeDescription
variationId (required)numberid of a variation

Returns​

JSONType - variation data in JSON format

Throws​

TypeDescription
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient
KameleoonException.JSONParseCouldn't parse retrieved data to JSON format
KameleoonException.VariationNotFoundNo variation found for provided variationId

Get list of all feature flags​

getFeatureFlags​

import { KameleoonClient } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Get all feature flags
  const experiments = client.getFeatureFlags();
}

init();

Method getFeatureFlags() returns a list of feature flags stored in the client configuration

Returns​

FeatureFlagType[] - list of feature flags, each experiment item contains id and key

Throws​

TypeDescription
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient

Get list of feature flags for a certain visitor​

getVisitorFeatureFlags​

import { KameleoonClient, KameleoonUtils } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  // -- Get visitor code using server `request` and `response`
  const visitorCode = KameleoonUtils.getVisitorCode({
    domain: 'www.example.com',
    request: req,
    response: res,
  });

  await client.initialize();

  // -- Get active feature flags for visitor
  const featureFlags = client.getVisitorFeatureFlags(visitorCode);
}

init();

Method getVisitorFeatureFlags() returns a list of feature flags that the visitor with visitorCode that is targeted by and that are active for the visitor (visitor will have one of the variations allocated).

Parameters​

NameTypeDescription
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length

Returns​

FeatureFlagType[] - list of feature flags, each experiment item contains id and key

Throws​

TypeDescription
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty
KameleoonException.NotTargetedCurrent visitor is not targeted

Check if the feature is active for visitor​

isFeatureFlagActive​

import {
  KameleoonClient,
  KameleoonUtils,
  CustomData,
} from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  // -- Get visitor code using server `request` and `response`
  const visitorCode = KameleoonUtils.getVisitorCode({
    domain: 'www.example.com',
    request: req,
    response: res,
  });

  await client.initialize();

  // -- Add CustomData with index `0` containing visitor id to check the targeting
  client.addData(visitorCode, new CustomData(0, 'visitor_id'));

  // -- Check if the feature flag is active for visitor
  const isActive = client.isFeatureFlagActive(visitorCode, 'my_feature_key');
}

init();

Method isFeatureFlagActive() returns a boolean indicating whether the visitor with visitorCode has featureKey active for him, this method includes targeting check, finding the according variation exposed to the visitor and saving it to storage along with sending tracking request.

note

Visitor must be targeted to has feature flag active

Parameters​

NameTypeDescription
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length
featureKey (required)stringa unique key for feature flag

Returns​

boolean - a boolean indicator of whether the feature flag with featureKey is active for visitor with visitorCode

Throws​

TypeDescription
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty
KameleoonException.NotTargetedCurrent visitor is not targeted
KameleoonException.FeatureFlagConfigurationNotFoundNo feature flag was found for provided visitorCode and featureKey
KameleoonException.FeatureFlagVariableNotFoundNo feature variable was found for provided visitorCode and variableKey
KameleoonException.DataInconsistencyAllocated variation was found, but there is no feature flag with according featureKey.

Get variation key for a certain feature flag​

getFeatureFlagVariationKey​

import {
  KameleoonClient,
  KameleoonUtils,
  CustomData,
} from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  // -- Get visitor code using server `request` and `response`
  const visitorCode = KameleoonUtils.getVisitorCode({
    domain: 'www.example.com',
    request: req,
    response: res,
  });

  await client.initialize();

  // -- Add CustomData with index `0` containing visitor id to check the targeting
  client.addData(new CustomData(0, 'visitor_id'));

  // -- Get visitor feature flag variation key
  const variationKey = client.getFeatureFlagVariationKey(
    visitorCode,
    'my_feature_key',
  );
}

init();

Method getFeatureFlagVariationKey() returns variation key for the visitor under visitorCode in the found feature flag, this method includes targeting check, finding the according variation exposed to the visitor and saving it to storage along with sending tracking request.

note

If the user has never been associated with the feature flag, the SDK returns a variation key randomly, following the feature flag rules. If the user is already registered with the feature flag, the SDK detects the previous variation key value. If the user doesn't match any of the rules, the default value defined in Kameleoon's feature flag delivery rules will be returned. It's important to note that the default value may not be a variation key, but a boolean value or another data type, depending on the feature flag configuration.

Parameters​

NameTypeDescription
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length
featureKey (required)stringa unique key for feature flag

Returns​

string a string containing variable key for the allocated feature flag variation for the provided visitor

Throws​

TypeDescription
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty
KameleoonException.NotTargetedCurrent visitor is not targeted
KameleoonException.FeatureFlagConfigurationNotFoundNo feature flag was found for provided visitorCode and featureKey

Get a variable of a certain feature flag​

getFeatureFlagVariable​

import {
  KameleoonClient,
  VariableType,
  JSONType,
} from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Get feature variable
  const result = client.getFeatureFlagVariable({
    visitorCode,
    featureKey: 'my_feature_key'
    variableKey: 'my_variable_key'
  });

  // -- Infer the type of variable by it's `type`
  switch (result.type) {
    case VariableType.BOOLEAN:
      const myBool: boolean = result.value;
      break;
    case VariableType.NUMBER:
      const myNum: number = result.value;
      break;
    case VariableType.JSON:
      const myJson: JSONType = result.value;
      break;
    case VariableType.STRING:
      const myStr: string = result.value;
      break;
    default:
      break;
  }
}

init();

Method getFeatureFlagVariable() returns a variable for the visitor under visitorCode in the found feature flag, this method includes targeting check, finding the according variation exposed to the visitor and saving it to storage along with sending tracking request.

Parameters​

Parameters object of a type GetFeatureFlagVariableParamsType containing the following fields:

NameTypeDescription
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length
featureKey (required)stringa unique key for feature flag
variableKey (required)stringkey of the variable to be found for a feature flag with provided featureKey, can be found on Kameleoon Platform

Returns​

FeatureVariableResultType a variable object containing type and value fields, type can be checked against FeatureVariableType enum, if the type is FeatureVariableType.BOOLEAN then the value type will be boolean and so on

Throws​

TypeDescription
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty
KameleoonException.NotTargetedCurrent visitor is not targeted
KameleoonException.FeatureFlagConfigurationNotFoundNo feature flag was found for provided visitorCode and featureKey
KameleoonException.JSONParseCouldn't pass JSON value
KameleoonException.NumberParseCouldn't pass Number value

Obtain data from Kameleoon remote source​

getRemoteData​

import { KameleoonClient } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Get remote data
  const jsonData = await getRemoteData('my_data_key');

  const data = JSON.parse(jsonData);
}

init();

Method getRemoteData() returns a data which is stored for specified site code on a remote Kameleoon server

For example, you can use this method to retrieve user preferences, historical data, or any other data relevant to your application's logic. By storing this data on our highly scalable servers using our Data API, you can efficiently manage massive amounts of data and retrieve it for each of your visitors or users.

Parameters​

NameTypeDescription
key (required)stringunique key that the data you try to get is associated with

Returns​

JSONType - promise with data retrieved for specific key

Throws​

TypeDescription
KameleoonException.RemoteDataCouldn't retrieve data from Kameleoon server

Define an action for realt time configuration update​

onConfigurationUpdate​

import { KameleoonClient } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Define logic to be executed on client configuration update
  client.onConfigurationUpdate(() => {
    // -- My Logic
  });
}

init();

Method onConfigurationUpdate() fires a callback on client configuration update.

note

This method only works for server sent events of real time update

Parameters​

NameTypeDescription
callback (required)() => voidcallback function with no parameters that will be called upon configuration update

Throws​

TypeDescription
KameleoonException.InitializationMethod was executed before initialize was done for kameleoonClient

Obtain custom data from Kameleoon Data API​

getRemoteVisitorData​

import { KameleoonClient, KameleoonDataType } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient('my_site_code');

async function init(): Promise<void> {
  await client.initialize();

  // -- Get remote visitor data and add it to storage
  const customDataList: KameleoonDataType[] = await getRemoteVisitorData(
    'my_visitor_code',
  );

  // -- Get remote visitor data without adding it to storage
  const customDataList: KameleoonDataType[] = await getRemoteVisitorData(
    'my_visitor_code',
    false,
  );
}

init();

getRemoteVisitorData() is an asynchronous method for retrieving custom data for the latest visit of visitorCode from Kameleoon Data API and adding it to the storage so that other methods could decide whether the current visitor is targeted or not.

note

getRemoteVisitorData automatically attaches the latest custom data entry with scope=Visitor to the visitor without calling addData. You can use this data for Synchronizing custom data across devices.

Parameters​

NameTypeDescriptionDefault Value
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length-
shouldAddData (optional)booleanboolean flag identifying whether the retrieved custom data should be set to the storage like addData method doestrue

Returns​

KameleoonDataType[] - promise with list of custom data retrieved

Throws​

TypeDescription
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty
KameleoonException.RemoteDataCouldn't retrieve data from Kameleoon server

Sending exposure events to external tools​

Kameleoon offers built-in integrations with various analytics and CDP solutions, such as Mixpanel, GA4, Segment.... To ensure that you can track and analyze your server-side experiments, Kameleoon provides a method getEngineTrackingCode() that returns the JavasScript code to be inserted in your page to automatically send the exposure events to the analytics solution you are using. For more information about hybrid experimentation, please refer to this documentation.

note

To benefit from this feature, you will need to implement both the NodeJS SDK and our Kameleoon JavaScript tag. We recommend you implement the Kameleoon Asynchronous tag, which you can install before your closing <body> tag in your HTML page, as it will be only used for tracking purposes.

getEngineTrackingCode​

import { KameleoonClient } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Trigger an experiment
  const experimentId = 100;
  // -- E.g. result `variationId` is `200`
  const variationId = client.triggerExperiment('visitor_code', experimentId);

  // -- Get tracking code
  const engineCode = client.getEngineTrackingCode('visitor_code');

  // -- Result engine code will look like this
  // `
  // window.kameleoonQueue = window.kameleoonQueue || [];
  // window.kameleoonQueue.push(['Experiments.assignVariation', 100, 200]);
  // window.kameleoonQueue.push(['Experiments.trigger', 100, true]);
  // `
}

init();

Method getEngineTrackingCode() returns Kameleoon tracking code for the current visitor. Tracking code is built based the experiments that were triggered during the last 5 seconds

note

Result tracking code can be inserted directly into html <script> tag

For example:

<!DOCTYPE html>
<html lang="en">
  <body>
    <script>
      const engineTrackingCode = `
        window.kameleoonQueue = window.kameleoonQueue || [];
        window.kameleoonQueue.push(['Experiments.assignVariation', 100, 200]);
        window.kameleoonQueue.push(['Experiments.trigger', 100, true]);
      `;
      const script = document.createElement('script');

      script.textContent = engineTrackingCode;
      document.body.appendChild(script);
    </script>
  </body>
</html>

Parameters​

NameTypeDescription
visitorCode (required)stringunique visitor identification string, can't exceed 255 characters length

Returns​

string containing engine tracking code

Throws​

TypeDescription
KameleoonException.VisitorCodeMaxLengthThe visitor code length was exceeded
KameleoonException.VisitorCodeEmptyThe visitor code is empty

Data Types​

Kameleoon Data types are helper classes used for storing data in storage in predefined forms. During the flush execution, the SDK collects all the data and sends it along with the tracking request.

Browser​

import { KameleoonClient, BrowserType, Browser } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Add new browser data to client
  const browser = new Browser(BrowserType.Chrome, 86.1);
  client.addData('my_visitor_code', browser);
}

init();

Browser contains browser information.

Parameters​

NameTypeDescription
browser (required)BrowserTypepredefined browser type (Chrome, InternetExplorer, Firefox, Safari, Opera, Other)
version (optional)numberversion of the browser, floating point number represents major and minor version of the browser

Conversion​

import {
  KameleoonClient,
  ConversionParametersType,
  Conversion,
} from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Defined conversion parameters
  const conversionParameters: ConversionParametersType = {
    goalId: 123,
    revenue: 10000,
    negative: true,
  };

  // -- Add new conversion data to client
  const conversion = new Conversion(conversionParameters);
  client.addData('my_visitor_code', conversion);
}

init();

Conversion contains information about your conversion.

note

goalId can be found on Kameleoon Platform

Parameters​

ConversionParametersType conversionParameters - an object with conversion parameters described below

NameTypeDescriptionDefault Value
goalId (required)numberan id of a goal to track-
revenue (optional)numberan optional parameter for revenue0
negative (optional)booleanan optional parameter identifying whether the conversion should be removedfalse

CustomData​

import { KameleoonClient, CustomData } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  const dataItemOne = 'abc';
  const dataItemTwo = JSON.stringify(100);
  const dataItemThree = JSON.stringify({ a: 200, b: 300 });

  const customDataIndex = 0;

  // -- Create custom data using single parameter
  const customData = new CustomData(customDataIndex, dataItemOne);

  // -- Create custom data using variadic number of parameters
  const customData = new CustomData(customDataIndex, dataItemOne, dataItemTwo);

  // -- Create custom data using an array of values
  const dataList = [dataItemOne, dataItemTwo, dataItemThree];
  const customData = new CustomData(customDataIndex, ...dataList);

  // -- Add custom data
  client.addData('my_visitor_code', customData);
}

init();

CustomData is usually used together with custom data targeting condition on Kameleoon Platform to determine whether the visitor is targeted or not

note

The index or ID of the custom data can be found in your Kameleoon account. It is important to note that this index starts at 0, which means that the first custom data you create for a given site will be assigned 0 as its ID, not 1.

note

To prevent the SDK from flushing the data with the selected index to the Kameleoon servers, check the Only save this data in Local Storage on the user's device, not on a server option when creating a new custom data entry on the Custom Data dashboard.

It's a useful option if you only want to utilize your private custom data for targeting.

Parameters​

NameTypeDescription
index (required)numberan index of custom data to be stored under in a state, an index of custom data can be specified in Advanced Tools section of Kameleoon Application
value (optional)string[]custom value to store under the specified id, value can be anything but has to be stringified to match the string type. Note value is variadic parameter and can be used as follows

Device​

import { KameleoonClient, DeviceType, Device } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Add device data
  const device = new Device(DeviceType.Desktop);
  client.addData('my_visitor_code', device);
}

init();

Device contains information about your device.

Parameters​

NameTypeDescription
deviceType (required)DeviceTypepossible variants for device type (PHONE, TABLET, DESKTOP)

PageView​

import {
  KameleoonClient,
  PageViewParametersType,
  PageView,
} from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Define page view parameters
  const pageViewParameters: PageViewParametersType = {
    urlAddress: 'www.example.com',
    title: 'my example',
    referrers: [123, 456],
  };

  // -- Add page view data
  const pageView = new PageView(pageViewParameters);
  client.addData('my_visitor_code', pageView);
}

init();

PageView contains information about your web page.

Parameters​

PageViewParametersType pageViewParameters - an object with page view parameters described below

NameTypeDescription
urlAddress (required)stringurl address of the page to track
title (required)stringtitle of the web page
referrer (optional)number[]an optional parameter containing a list of referrers Indices, has no default value
note

The index or ID of the referrer can be found in your Kameleoon account. It is important to note that this index starts at 0, which means that the first acquisition channel you create for a given site will be assigned 0 as its ID, not 1.

UserAgent​

import { KameleoonClient, UserAgent } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Add user agent data
  const userAgent = new UserAgent('my_unique_value');
  client.addData('my_visitor_code', userAgent);
}

init();

UserAgent has a special meaning, if added to client it will be used provided value for filtering out bots during tracking requests

caution

Since NodeJS doesn't automatically provide the user agent header, you must provide UserAgent data when using the bot-filtering option in your NodeJS SDK project. Otherwise, all tracking calls will be disabled.

Parameters​

NameTypeDescription
value (required)stringvalue used for comparison
caution

Server-side experiments are more vulnerable to bot traffic than client-side experiments. To address this, Kameleoon uses the IAB/ABC International Spiders and Bots List to identify known bots and spiders. We recommend that you pass the user agent to be filtered by Kameleoon when running server-side experiments for each visitor browsing your website, to avoid counting bots in your analytics.

If you use internal bots, we suggest that you pass the value curl/8.0 of the userAgent to exclude them from our analytics.

tip

If you run Kameleoon in hybrid mode, your server-side experiments will be automatically protected against bot traffic. This is because Kameleoon collects the user-agent automatically on the front-end side. Therefore, you don't need to pass the user-agent or any other parameter to filter bots and spiders.

List of supported targeting conditions​

Targeting conditions can be defined in the Kameleoon App on the Segment Dashboard.

The following list of conditions are supported by the SDK along with the data checked on the SDK side:

Condition TypeDescriptionAssociated SDK Data
Exclusive ExperimentCheck if only one certain experiment was triggered for visitorInternal data saved after some experiments were triggered
Target ExperimentCheck if certain experiment was triggered for visitorInternal data saved after some experiments were triggered
BrowserCheck if browser type or/and version matches parametersBrowser added by addData() method
DeviceCheck if device type matches parametersDevice added by addData() method
ConversionCheck if conversion goalId matches parametersConversion added by addData() method
Custom DataCheck if custom data values matches parametersCustomData added by addData() method
Page TitleCheck if page title value matches parametersPageView added by addData() method
Page UrlCheck if page url value matches parametersPageView added by addData() method
SDK LanguageCheck if the current SDK language matches parametersA type of the current SDK (NodeJS)
Visitor CodeCheck if visitor code matches parametersvisitorCode passed as an argument to a method

Error Handling​

import {
  KameleoonError,
  KameleoonClient,
  KameleoonException,
} from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  try {
    await client.initialize();

    const customData = new CustomData(0, 'my_data');
    client.addData(visitorCode, customData);
  } catch (error) {
    // -- Type guard for inferring error type as native JavaScript `catch`
    //    only infers `unknown`
    if (error instanceof KameleoonError) {
      switch (error.type) {
        case KameleoonException.VisitorCodeMaxLength:
          // -- Handle an error
          break;
        case KameleoonException.StorageWrite:
          // -- Handle an error
          break;
        case KameleoonException.Initialization:
          // -- Handle an error
          break;
        default:
          break;
      }
    }
  }
}

init();

Almost every KameleoonClient method may throw an error at some point, these errors are not just caveats but rather deliberately predefined KameleoonErrors that extend native JavaScript Error class providing useful messages and special type field with a type KameleoonException.

KameleoonException is an enum containing all possible error variants.

To know exactly what variant of KameleoonException the method may throw you can check Throws section of the method description on this page or just hover over the method in your IDE to see jsdocs description.

Overall handling the errors considered a good practice to make your application more stable and avoid technical issues.

Integration with Edge providers​

Kameleoon provides the following starter packs to automate your integration with specific edge providers:

ProviderStarter pack
Fastly Compute@Edgehttps://github.com/Kameleoon/fastly-compute-starter-kit
Cloudfare Workershttps://github.com/Kameleoon/cloudflare-worker-starter-kit
AWS Lambda@Edge Functionhttps://github.com/Kameleoon/aws-lambda-edge-starter-kit

For the other edge providers, you can initialize the Kameleoon Client yourself using externalClientConfiguration. Passing externalClientConfiguration causes the SDK to rely solely on the provided configuration data, instead of making a call to the Kameleoon servers. This gives you greater control and flexibility over the configuration data used in your application. For example:

import rp from 'request-promise';
import { KameleoonClient, KameleoonUtils } from '@kameleoon/nodejs-sdk';

async function init() {
  // -- Get Kameleoon Client Configuration URL
  const uri = KameleoonUtils.getClientConfigurationUrl('my_site_code');

  const clientConfiguration = await rp({
    uri,
    json: true,
  });

  const client = new KameleoonClient({
    siteCode: 'my_site_code',
    integrations: {
      externalClientConfiguration: clientConfiguration,
    },
  });
}

init();

To update the configuration, obtain a fresh copy of the configuration data and re-initialize the client with the updated file.

Tracking Rate Limit​

For the server systems dealing with the heavy load Kameleoon Provides a way to increase tracking request limit for Kameleoon API.

This can be achieved by passing credentials to NodeJS SDK upon client initialization. CredentialsType exported from SDK can be used for convenience in TypeScript

For server systems that deal with a high volume of requests, you can increase the tracking request limit for the Kameleoon API by passing credentials to the NodeJS SDK during client initialization. For convenience, you can import the CredentialsType in TypeScript from the SDK. For example:

import {
  CredentialsType,
  KameleoonClient,
  SDKConfigurationType,
} from '@kameleoon/nodejs-sdk';

// -- Credentials for access to higher request rate limit
const clientCredentials: CredentialsType = {
  clientId: 'my_client_id',
  clientSecret: 'my_client_secret',
};

const configuration: Partial<SDKConfigurationType> = {
  credentials: clientCredentials,
};

const client = new KameleoonClient({ siteCode: 'my_site_code', configuration });
Credentials Types​
NameTypeDescription
clientId (required)stringclient id
clientSecret (required)stringclient secret
note

Follow Credentials Flow for more information

Synchronizing custom data across devices​

If you want to synchronize your Custom Data across multiple devices, Kameleoon provides a Custom Data synchronization mechanism.

To use this feature, in the Custom Data Dashboard, edit the custom data and set the Scope value to Visitor. The custom data will now be permanently associated with a specific visitor as long as getRemoteVisitorData is called before any other actions with the visitor-associated data.

info

The current implementation will change in an upcoming release.

The getRemoteVisitorData method implicitly attaches the latest custom data entry with scope=VISITOR to the visitor, so make sure your app calls this method before any other actions with Kameleoon Data. See the following example:

import { KameleoonClient, CustomData } from '@kameleoon/nodejs-sdk';

const client = new KameleoonClient({ siteCode: 'my_site_code' });

async function init(): Promise<void> {
  await client.initialize();

  // -- Before working with data, make `getRemoteVisitorData` call
  // -- That way visitor will always has latest data with `scope=VISITOR`
  //    associated (even without manually calling `addData`)
  await getRemoteVisitorData("my_visitor_code");

  // -- Let's say that only "Device 1" adds visitor data
  if global.device === "Device 1" {
    // -- Create custom data
    // -- Let's assume index `0` is set to `scope=VISITOR` on Kameleoon Platform
    const customData = new CustomData(0, "my_data");
    // -- Add custom data
    client.addData('my_visitor_code', customData);
  }

  // -- As a result visitor on "Device 1" and the same visitor on other devices will
  //    always have `CustomData(0, "my_data")` associated with them in the storage
}

init();