LaunchDarkly Client-Side SDK for Node.js

The LaunchDarkly Client-Side SDK for Node.js is designed primarily for use by code that is deployed to an end user, such as in a desktop application or a smart device. It follows the client-side LaunchDarkly model for single-user contexts (much like our mobile or JavaScript SDKs). It is not intended for use in multi-user systems such as web servers and applications.

For using LaunchDarkly in server-side Node.js applications, refer to our Server-side Node.js SDK.

LaunchDarkly overview

LaunchDarkly is a feature management platform that serves trillions of feature flags daily to help teams build better software, faster. Get started using LaunchDarkly today!

Supported Node versions

This version of the LaunchDarkly SDK is compatible with Node.js versions 12 and above.

Getting started

Refer to the SDK documentation for instructions on getting started with using the SDK.

Learn more

Read our documentation for in-depth instructions on configuring and using LaunchDarkly. You can also head straight to the complete reference guide for this SDK.

The authoritative description of all properties and methods is in the TypeScript documentation.

Testing

We run integration tests for all our SDKs using a centralized test harness. This approach gives us the ability to test for consistency across SDKs, as well as test networking behavior in a long-running application. These tests cover each method in the SDK, and verify that event sending, flag evaluation, stream reconnection, and other aspects of the SDK all behave correctly.

Contributing

We encourage pull requests and other contributions from the community. Check out our contributing guidelines for instructions on how to contribute to this SDK.

About LaunchDarkly

• LaunchDarkly is a continuous delivery platform that provides feature flags as a service and allows developers to iterate quickly and safely. We allow you to easily flag your features and manage them from the LaunchDarkly dashboard. With LaunchDarkly, you can:
  • Roll out a new feature to a subset of your users (like a group of users who opt-in to a beta tester group), gathering feedback and bug reports from real-world use cases.
  • Gradually roll out a feature to an increasing percentage of users, and track the effect that the feature has on key metrics (for instance, how likely is a user to complete a purchase if they have feature A versus feature B?).
  • Turn off a feature that you realize is causing performance problems in production, without needing to re-deploy, or even restart the application with a changed configuration file.
  • Grant access to certain features based on user attributes, like payment plan (eg: users on the ‘gold’ plan get access to more features than users in the ‘silver’ plan). Disable parts of your application to facilitate maintenance, without taking everything offline.
• LaunchDarkly provides feature flag SDKs for a wide variety of languages and technologies. Read our documentation for a complete list.
• Explore LaunchDarkly
  • launchdarkly.com for more information
  • docs.launchdarkly.com for our documentation and SDK reference guides
  • apidocs.launchdarkly.com for our API documentation
  • blog.launchdarkly.com for the latest product updates