LaunchDarkly sample Node.js (server-side) application

We've built a simple console application that demonstrates how LaunchDarkly's SDK works.

Below, you'll find the build procedure. For more comprehensive instructions, you can visit your Quickstart page or the Node.js (server-side) reference guide.

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 a sample application demonstrating how to use LaunchDarkly in client-side Node.js applications, refer to our Client-side Node.js SDK sample application.

Build instructions

1. Set the environment variable LAUNCHDARKLY_SDK_KEY to your LaunchDarkly SDK key. If there is an existing boolean feature flag in your LaunchDarkly project that you want to evaluate, set LAUNCHDARKLY_FLAG_KEY to the flag key; otherwise, a boolean flag of sample-feature will be assumed.

   export LAUNCHDARKLY_SDK_KEY="1234567890abcdef"
   export LAUNCHDARKLY_FLAG_KEY="my-boolean-flag"

2. Install the LaunchDarkly Node.js SDK by running npm install

3. Run node index.js

You should receive the message "The feature flag evaluates to .". The application will run continuously and react to the flag changes in LaunchDarkly.