> ## Documentation Index
> Fetch the complete documentation index at: https://launchdarkly-preview.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Set up Node.js (server-side) SDK

> Install and initialize the LaunchDarkly Node.js (server-side) SDK

> For the complete documentation index, see [llms.txt](/llms.txt). For the full documentation snapshot, see [llms-full.txt](/llms-full.txt).

<div>
  <ReadmeButton sdk={SDK.NodeServer} />

  <CursorButton sdk={SDK.NodeServer} />
</div>

### Install the package

<CodeGroup>
  ```shell title={"yarn"} theme={null}
    yarn add @launchdarkly/node-server-sdk

  ```

  ```shell title={"npm"} theme={null}
    npm i @launchdarkly/node-server-sdk

  ```

  ```shell title={"pnpm"} theme={null}
    pnpm i @launchdarkly/node-server-sdk

  ```
</CodeGroup>

### Initialize the SDK

```tsx title={"Node.js (server-side) SDK initialization"} theme={null}
import * as LaunchDarkly from '@launchdarkly/node-server-sdk';

// Set your LaunchDarkly SDK key.
// This is inlined as example only for onboarding.
// Never hardcode your SDK key in production.
const client = LaunchDarkly.init('YOUR_SDK_KEY');

client.once('ready', function () {
  // For onboarding purposes only we flush events as soon as
  // possible so we quickly detect your connection.
  // You don't have to do this in practice because events are automatically flushed.
  client.flush();
  console.log('SDK successfully initialized!');
});

```

<Accordion title="Finding your SDK credentials">
  You can find your server-side SDK key, client-side ID, and mobile key in the "Resources" section of the help menu. Click the **help icon** at the bottom left corner of the LaunchDarkly UI, then choose **SDK keys**:

  <Frame caption="The SDK keys option in the help menu.">
    ![The SDK keys option in the help menu.](https://files.buildwithfern.com/https://launchdarkly.docs.buildwithfern.com/docs/28d3e1c568378ea02528db7ba62bfbd742f6f1cad964b5675395e10af5eeeb60/assets/images/auto/help-menu-sdk-keys.auto.png)
  </Frame>
</Accordion>

To learn more, read [Initialize the client](/sdk/server-side/node-js#initialize-the-client) in the Node.js (server-side) SDK reference guide.