What is one purpose of a customer data JS library?

The customer-data JavaScript library in Adobe Commerce is a core component for managing private content on pages served from a full-page cache. Its primary purpose is to store customer-specific data, such as the number of items in the cart or the customer's name, in the browser's local storage. This allows the frontend to dynamically render personalized information for a user on a cached, generic page, improving performance without sacrificing personalization. The library invalidates and reloads this data via AJAX requests when certain customer actions occur.

A. Storing unencrypted credit card information in browser local storage is a severe security risk and a direct violation of PCI DSS (Payment Card Industry Data Security Standard) compliance.
C. Storing a customer's raw password in local storage is a critical security vulnerability. Authentication is managed through secure server-side sessions and tokens, not by storing credentials on the client-side.

1. Adobe Commerce Developer Documentation, Frontend Developer Guide, UI components, Private content: "To solve this problem, Adobe Commerce uses a mechanism called customer-data... This data is stored in the browser’s local storage under the mage-cache-storage key... Examples of private content include the customer name, the number of items in the cart, and a list of previously ordered items."

2. Adobe Commerce Developer Documentation, Frontend Developer Guide, JavaScript, Customer data: "The customer-data object provides access to the data stored in the browser’s local storage. The main purpose of this object is to prevent extra AJAX requests for the same data." This section details the methods used to get, set, and manage the data stored locally.