# LaunchDarkly Server-Side SDK for Node.js

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The LaunchDarkly Server-Side SDK for Node.js is designed primarily for use in multi-user systems such as web servers and applications. It follows the server-side LaunchDarkly model for multi-user contexts. It is not intended for use in desktop and embedded systems applications.

For using LaunchDarkly in _client-side_ Node.js applications, refer to our [Client-side Node.js SDK](https://github.com/launchdarkly/node-client-sdk).

This SDK is a beta version and should not be considered ready for production use while this message is visible.

## LaunchDarkly overview

[LaunchDarkly](https://www.launchdarkly.com) is a feature management platform that serves over 100 billion feature flags daily to help teams build better software, faster. [Get started](https://docs.launchdarkly.com/home/getting-started) using LaunchDarkly today!

[![Twitter Follow](https://img.shields.io/twitter/follow/launchdarkly.svg?style=social&label=Follow&maxAge=2592000)](https://twitter.com/intent/follow?screen_name=launchdarkly)

## Supported Node versions

This version of the LaunchDarkly SDK is compatible with Node.js versions 14 and above.

## Getting started

Refer to the [SDK reference guide](https://docs.launchdarkly.com/sdk/server-side/node-js) for instructions on getting started with using the SDK.

## Learn more

Check out our [documentation](http://docs.launchdarkly.com) for in-depth instructions on configuring and using LaunchDarkly. You can also head straight to the [complete reference guide for this SDK](https://docs.launchdarkly.com/sdk/server-side/node-js).

The authoritative description of all properties and methods is in the [TypeScript documentation](https://launchdarkly.github.io/node-server-sdk/).

## 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](CONTRIBUTING.md) 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. Check out [our documentation](https://docs.launchdarkly.com/sdk) for a complete list.
- Explore LaunchDarkly
  - [launchdarkly.com](https://www.launchdarkly.com/ 'LaunchDarkly Main Website') for more information
  - [docs.launchdarkly.com](https://docs.launchdarkly.com/ 'LaunchDarkly Documentation') for our documentation and SDK reference guides
  - [apidocs.launchdarkly.com](https://apidocs.launchdarkly.com/ 'LaunchDarkly API Documentation') for our API documentation
  - [blog.launchdarkly.com](https://blog.launchdarkly.com/ 'LaunchDarkly Blog Documentation') for the latest product updates

[sdk-server-node-ci-badge]: https://github.com/launchdarkly/js-core/actions/workflows/server-node.yml/badge.svg
[sdk-server-node-ci]: https://github.com/launchdarkly/js-core/actions/workflows/server-node.yml

[sdk-server-node-npm-badge]: https://img.shields.io/npm/v/@launchdarkly/node-server-sdk.svg?style=flat-square
[sdk-server-node-npm-link]: https://www.npmjs.com/package/@launchdarkly/node-server-sdk