# Node.js

Node.js `>= 16.0.0` required

## 1. Install the library

Insights library can be used on the backend as a Node.js module.

```bash
npm install search-insights
# or
yarn add search-insights
```

## 2. Initialize the library

Initializing the library is optional, as you can specify the [credentials for each event](https://www.algolia.com/doc/api-reference/api-methods/send-events/#method-param-additionalparams) when sending them.
This gives you the flexibility to manage your Algolia credentials on a per-event basis, without having to configure them upfront.

```js
const aa = require("search-insights");

// Optional: configure default Algolia credentials for events
aa("init", {
  appId: "APPLICATION_ID",
  apiKey: "SEARCH_API_KEY"
});
```

## 3. Add `userToken`

On the Node.js environment, unlike the browser environment, a [user token](https://www.algolia.com/doc/guides/sending-events/concepts/usertoken) (required `userToken` and optional `authenticatedUserToken`) must be specified when sending any event.

```js
// Anonymous user ID
aa("clickedObjectIDs", {
  userToken: "ANONYMOUS_ID"
  // ...
});

// Authenticated user ID
aa("clickedObjectIDs", {
  userToken: "ANONYMOUS_ID",
  authenticatedUserToken: "USER_ID"
  // ...
});
```

## (Optional) Customize the client

If you want to customize the way to send events, you can create a custom Insights client.

```js
// via ESM
import { createInsightsClient } from "search-insights";
// OR in commonJS
const { createInsightsClient } = require("search-insights");
// OR via the UMD
const createInsightsClient = window.AlgoliaAnalytics.createInsightsClient;

function requestFn(url, data) {
  const serializedData = JSON.stringify(data);
  const { protocol, host, path } = require("url").parse(url);
  const options = {
    protocol,
    host,
    path,
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "Content-Length": serializedData.length
    }
  };

  const { request: nodeRequest } =
    url.indexOf("https://") === 0 ? require("https") : require("http");
  const req = nodeRequest(options);

  req.on("error", (error) => {
    console.error(error);
  });

  req.write(serializedData);
  req.end();
}

const aa = createInsightsClient(requestFn);
```