Initialization

To create a VWO Client instance, you need to initialize the VWO FME Node SDK. This client instance serves as the core interface for conducting feature management and experimentation(A/B and personalization) within your application.

Usage

const { init } = require('vwo-fme-node-sdk');

const vwoClient = await init({
  accountId: '123456', // VWO Account ID
  sdkKey: '32-alpha-numeric-sdk-key', // SDK Key,
});

The init() function is called with the sdkKeyand accountId. It initializes and returns a VWO Client ObjectvwoClient, which can be used to perform feature
This client object allows you to run experiments, track events, and enable/disable feature flags.

Parameter Definitions

Parameter	Type	Description
accountId Required	Integer	Your VWO application's Account ID.
sdkKey Required	String	A unique environment key is provided to you inside the Websites & Apps section in the VWO application, under Default Project.
pollInterval Optional	Integer	Time (in milliseconds) at which VWO should check with the server for any updates to the feature flag or rules in the VWO Dashboard. Useful to keep your VWO Client instance up-to-date with any changes made in the VWO Application. For more details, please check -Polling
logger Optional	Object	An optional logger object that defines the logging behavior. For more details, please check - Logger
storage Optional	Object	Storage Service, if required, can be implemented using this parameter. For more details, please check - Storage Service
gatewayService Optional	Object	If using the FME Gateway Service, this object will specify the location and port of where the gateway service is deployed on your servers.
integrations Optional	Object	A callback function that receives data which can be pushed to any external tool that you need to integrate with. For more details, please check - Integrations

Poll Interval (Keeping VWO client up-to-date)

When you initialize the vwoClient on your server, it pulls the latest configurations you've done in the VWO application.
If/when you make any changes to the feature flags or rules within VWO after the vwoClient has been initialized in your server, there needs to be some way to update your vwoClient with the latest settings from VWO. This can be done via polling.

The poll interval is an optional parameter that allows the SDK to automatically fetch and update settings from the VWO server at specified intervals. Setting this parameter ensures your application always uses the latest configuration.

// Init options with poll_interval
const vwoClient = await init({
  accountId: '123456',
  sdkKey: '32-alpha-numeric-sdk-key',
  pollInterval: 60000,
});

Logger

VWO by default logs all ERROR level messages to your server console. To gain more control over VWO's logging behavior, you can use the logger parameter in the init configuration.

// Init options with logger
const vwoClient1 = await init({
  accountId: '123456',
  sdkKey: '32-alpha-numeric-sdk-key',
  logger: {
    level: 'DEBUG',
  },
});

Please click here for more advanced logger options.

Storage

By default, the SDK operates in stateless mode, evaluating flags on each getFlag call. To improve performance and consistency, you can use a custom storage mechanism to cache decisions, ensuring stable user experiences and reducing application load.

// Init options with storage
const vwoClient = await init({
  accountId: '123456',
  sdkKey: '32-alpha-numeric-sdk-key',
  storage: StorageConnector,
});

Please click here to learn more about storage implementation.

Gateway Service

The VWO FME Gateway Service enhances Feature Management and Experimentation (FME) SDKs by enabling pre-segmentation based on user location and user agent. It ensures minimal latency and improved security. The service can be customized via the gateway_service parameter during initialization.

// Init options with gateway_service
const vwoClient = await init({
  accountId: '123456',
  sdkKey: '32-alpha-numeric-sdk-key',
  gatewayService: {
    url: 'https://custom.gateway.com',
  },
});

Please click here to learn more about gateway service.

Integrations

VWO FME SDKs provide seamless integration with third-party tools like analytics platforms, monitoring services, customer data platforms (CDPs), and messaging systems. This is achieved through a simple yet powerful callback mechanism that receives VWO-specific properties and can forward them to any third-party tool of your choice.

// Init options with integrations
const vwoClient = await vwo.init({
    sdkKey: 'bfce67fb74a7a59264045347f650dd2c', //replace with the SDK key for your environment
    accountId: '917741', //replace with your VWO account ID
    integrations: {
      callback (properties) {
        console.log('Integrations callback', properties); // list of keys
      }
    }
})

Please click here to learn more about Integrations,.