How does Wishlist Hero work under the hood?

This page explains how Wishlist Hero fits together: where the wishlist lives, how settings reach your storefront, what happens when a shopper acts, and where the data ends up. Read it once and you can answer most “how does the app do that” questions yourself.

The three parts of the app

Wishlist Hero runs as three cooperating pieces:

1. The storefront app. A script loaded by the App Configuration embed on your theme. It draws the buttons, the popup or page, and the notifications, and talks to the wishlist service.
2. The wishlist service. Cloud storage, one wishlist document per shopper per store, reachable by the storefront and by the admin.
3. The admin app. The screens you see inside Shopify: settings, dashboard, reports, and billing.

Settings you save in the admin are published to your store as a Shopify metafield. The storefront app reads that metafield on every page, which is why a settings change is live on your store within moments and why the embed must stay enabled.

The life of a wishlist

• A guest saves an item. The app creates a wishlist in the cloud and keeps a reference to it in the shopper’s browser. No account is needed.
• The shopper returns. The browser reference reconnects to the same list, even days later.
• The shopper logs in. The guest list merges into their account list. Duplicate items collapse, so the union of both lists survives.
• The shopper shops on another device. Once logged in, the account list follows them everywhere.

Every step in that journey records an action: added to wishlist, removed from wishlist, new wishlist, and added to cart. Those actions power your dashboard, reports, and exports. See How activity is tracked.

What happens on an action

When a shopper adds an item, several things can fire at once:

• The wishlist document in the cloud updates, and the activity feed records the action
• The notification popup and header count update in place
• If the shopper is logged in and reminders are on, the item becomes eligible for price drop and low stock emails
• Any enabled trackers fire: Klaviyo events, Meta Pixel AddToWishlist, GA4 add_to_wishlist, TikTok AddToWishlist

Reminders are evaluated by scheduled jobs three times a day, with guardrails so a shopper never gets repeated emails about the same item. See Price drop reminder and Low stock alert.

Where customization lives

You can customize the app at three levels, and each level overrides the last:

1. App settings. Colors, icons, texts, animations, and behavior for the whole store.
2. Theme blocks. Per theme overrides for button colors, fonts, and placement.
3. Theme code and the SDK. Custom CSS, custom HTML, and scripted buttons for full control. These survive theme updates because they live in app owned blocks and settings rather than edited theme files.

Data and privacy

• Wishlists are stored per store in the cloud; shopper emails and names are encrypted at rest
• Lists have no expiry; a guest list keeps until the shopper clears their browser storage and never logs in
• Deleting a customer through Shopify’s GDPR process deletes their wishlist and activity
• Uninstalling keeps your data so a reinstall picks up where you left off

Details: How wishlists persist and Guest wishlists and merge.

Quotas and plans

Plan quotas count wishlist additions per month. When the quota is reached the storefront widget pauses until the next month or an upgrade; everything else keeps working. See Wishlist item quotas.