launchdarkly-node-client-sdk/README.md

LaunchDarkly Client-Side SDK for Node.js

# LaunchDarkly Client-Side SDK for Node.js

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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](https://github.com/launchdarkly/js-core/tree/main/packages/sdk/server-node).

## LaunchDarkly overview

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

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## 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](https://docs.launchdarkly.com/sdk/client-side/node-js#getting-started) for instructions on getting started with using the SDK.

## Learn more

Read our [documentation](https://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/docs/node-client-sdk-reference).

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