> ## Documentation Index
> Fetch the complete documentation index at: https://docs.saytics.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Install the Saytics JavaScript or Node.js SDK
> Install and configure the Saytics JavaScript SDK or server-side library. Covers npm, CDN, and Node.js setup with initialization options.
This page covers how to install Saytics in two environments: as a browser JavaScript library for client-side tracking, and as a Node.js library for server-side event collection. Choose the tab that matches your setup — many teams use both.
Install the Saytics JavaScript SDK with npm:
```bash theme={null}
npm install @saytics/js
```
Alternatively, load Saytics from the CDN by adding this script tag to your HTML ``. The `async` attribute prevents the script from blocking page rendering.
```html theme={null}
```
Once installed, initialize the SDK with your write key. Pass an optional configuration object as the second argument to customize behavior.
```js theme={null}
import Saytics from '@saytics/js';
Saytics.init('YOUR_WRITE_KEY', {
debug: false,
batchSize: 10,
});
```
Install the Saytics Node.js library with npm:
```bash theme={null}
npm install @saytics/node
```
Import or require the library, then create a client instance with your write key. Use the instance to send events from your server.
```js theme={null}
// ES module
import Saytics from '@saytics/node';
// CommonJS
const Saytics = require('@saytics/node');
const saytics = new Saytics('YOUR_WRITE_KEY');
```
You can then call `saytics.track()` from any server-side handler or background job.
## Configuration options
Pass these options as the second argument to `Saytics.init()` (browser) or the constructor options object (Node.js).
Your project's write key from **Settings → API Keys**. Required to authenticate all events.
Enable console logging for every event sent and any SDK errors. Useful during development. Disable in production.
Override the default API endpoint. Use this if you're proxying Saytics traffic through your own domain.
Number of events to accumulate before flushing to the API in a single request. Reducing this value sends events more frequently; increasing it reduces network requests.
Use your write key (not secret key) for client-side code. The write key is safe to expose in browser environments.
## Next steps
* [Quick start guide](/quickstart) — send your first event end-to-end
* [JavaScript SDK reference](/tracking/javascript) — all available methods and advanced options