> Portal Navigation:
> 
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## Resource: Events



## Article: Introduction

## Article Link: https://dev.wix.com/docs/velo/events-service-plugins/e-commerce/events/introduction.md

## Article Content:

---
title: Introduction
---
# Introduction

Wix eCommerce events are fired on your site's backend when certain events occur related to eCommerce carts, current carts, checkouts, orders, and more. You can write event handlers that react to these events. Event handler functions receive data that corresponds to the event that fired. Use event handlers to create custom responses to eCommerce events.

> **Note:** Backend events don't work when previewing your site.

To add an eCommerce (ecom) event handler, add an **events.js** file to the **Backend** section of your site if one does not already exist. All event handler functions for your site are defined in this file.

Event handler functions are defined using the following pattern:
```javascript
export function <wixAppName>_<eventName>(event) { }
```

For example, an event handler that handles the creation of a cart looks
like this:
```javascript
export function wixEcom_onCartCreated(event) { }
```