Upcart V2.0 migration guide

Overview

Upcart V2.0 modules introduce a complete architectural redesign of the cart system. The update focuses on improved performance, enhanced customization, and better maintainability. This guide will help you understand what changes when migrating from V1.0 to V2.0 modules, what compatibility issues you may encounter, and how to update your existing customizations safely.

Breaking changes - CSS classname changes

V1 Classes (Deprecated)

🚨 The following V1.0 class names are no longer supported in V2.0:

.styles_Header__  
.styles_ProductRow__  
.styles_Rewards__  
.styles_TieredRewards__  
...

The out-of-stock warning classes upcart-quantity-warning and upcart-quantity-warning-text are also unchanged. They come from the cart initializer rather than a versioned module, so they are emitted identically whether your modules are on V1 or V2.

.styles_CartPreview__card__ is not in this list — it is the shared cart-shell wrapper rendered around every module regardless of version, so rules targeting it keep working on V2. The rewards classes are .styles_Rewards__ (simple bar) and .styles_TieredRewards__ (tiered bar); there is no .styles_RewardsModule__.

/*******************  
*** Cart Header ***  
*******************/  
'upcart-header',  
'upcart-header-text',  
'upcart-header-logo',  
'upcart-header-close-button',  
'upcart-header-close-button-icon',  
  
/******************  
*** Line Items ***  
******************/  
'upcart-products-section',  
'upcart-product-item',  
/** > Title */  
'upcart-product-title',  
'upcart-product-title-link',  
/** > Prices */  
'upcart-item-prices-row',  
'upcart-item-price',  
'upcart-item-compare-price',  
'upcart-product-savings',  
/** > Options/Variants */  
'upcart-item-option',  
'upcart-item-option-category',  
'upcart-item-option-value',  
/** > Bundle Item Components */  
'upcart-bundle-item-image-wrapper',  
'upcart-bundle-item-product-title',  
'upcart-bundle-item-variant-title',  
'upcart-bundle-detail-toggle',  
/** > Properties */  
'upcart-item-properties',  
'upcart-item-property',  
'upcart-item-property-subscription',  
/** > Quantity Selector */  
'upcart-product-quantity-input',  
'upcart-product-quantity-minus',  
'upcart-product-quantity-plus',  
/** > Image */  
'upcart-product-image-wrapper',  
  
/*********************  
*** Announcements ***  
*********************/  
'upcart-announcement',  
  
/***************  
*** Rewards ***  
***************/  
'upcart-rewards',  
'upcart-rewards-message',  
'upcart-rewards-bar-background',  
'upcart-rewards-bar-foreground',  
'upcart-rewards-tier',  
'upcart-rewards-tier-circle',  
'upcart-rewards-tier-icon',  
'upcart-rewards-tier-description',  
  
/***************  
*** Upsells & Recommendations ***  
***************/  
'upcart-upsells-module',  
'upcart-upsells-title',  
'upcart-upsells-button',  
'upcart-upsell-item-title',  
'upcart-upsell-item-card',  
'upcart-upsell-item-image-wrapper',  
'upcart-upsell-item-image',  
'upcart-upsell-item-price',  
'upcart-upsell-item-price-row',  
'upcart-upsell-item-compare-price',  
'upcart-upsell-item-variant-selector',  
'upcart-upsells', // deprecated  
'upcart-recommendation-module',  
'upcart-recommendations-title',  
'upcart-recommendations-shop-now-button',  
  
/***************  
*** Add-ons ***  
***************/  
'upcart-addons',  
'upcart-addons-title',  
'upcart-addons-product-description',  
'upcart-addons-price',  
'upcart-addons-compare-price',  
'upcart-addons-toggle',  
'upcart-addons-image-wrapper',  
  
/**********************  
*** Discount Codes ***  
**********************/  
'upcart-discount-code-row',  
'upcart-discount-code-module',  
'upcart-discount-code-button',  
'upcart-discount-code-input',  
'upcart-discount-code-badge',  
'upcart-discount-code-icon',  
'upcart-discount-code-text',  
'upcart-discount-code-input-wrapper',  
  
/*****************************  
*** Subscription Upgrades ***  
*****************************/  
'upcart-subscription-upgrade-section',  
'upcart-subscription-upgrade-button',  
'upcart-subscription-upgrade-dropdown',  
  
/***************************  
*** Express Pay Buttons ***  
***************************/  
'upcart-express-pay-buttons-container',  
'upcart-express-pay-buttons-row',  
'upcart-express-pay-button',  
'upcart-express-pay-button-shop-pay',  
'upcart-express-pay-button-google-pay',  
'upcart-express-pay-button-paypal',  
'upcart-express-pay-button-apple-pay',  
'upcart-express-pay-button-amazon-pay',  
'upcart-express-pay-button-meta-pay',  
  
/********************  
*** Trust Badges ***  
********************/  
'upcart-trust-badge',  
'upcart-trust-badge-image',  
  
/********************  
*** Integrations ***  
********************/  
'upcart-integration-zapiet-pickup',  
  
/*****************  
*** Skeletons ***  
*****************/  
'upcart-skeleton',  
'upcart-product-item-skeleton',  
'upcart-product-image-skeleton',  
'upcart-product-title-skeleton',  
'upcart-item-option-skeleton',  
'upcart-product-quantity-skeleton',  
'upcart-product-price-container-skeleton',  
'upcart-announcement-skeleton',  
'upcart-rewards-skeleton',  
'upcart-rewards-message-skeleton',  
'upcart-rewards-bar-skeleton',  
'upcart-upsells-module-skeleton',  
'upcart-upsells-title-skeleton',  
'upcart-upsell-item-image-skeleton',  
'upcart-upsell-item-title-skeleton',  
'upcart-upsell-item-price-skeleton',  
'upcart-upsells-button-skeleton',  
'upcart-trust-badge-skeleton',  
'upcart-trust-badge-image-skeleton',  
'upcart-checkout-button-container-skeleton',  
'upcart-checkout-button-skeleton',  
'upcart-addons-skeleton',  
'upcart-addons-image-wrapper-skeleton',  
'upcart-addons-skeleton-text-container',  
'upcart-discount-code-module-skeleton',  
'upcart-discount-code-input-skeleton',  
'upcart-discount-code-button-skeleton',  
'upcart-express-pay-buttons-container-skeleton',  
'upcart-express-pay-button-skeleton'

V2.0 classes (new system)

V2.0 introduces a structured naming system with internal and public class prefixes.

Internal classnames

These are reserved for internal use and may change without notice. If you override these classes, future compatibility is not guaranteed.

/* Internal classes - for Upcart's internal styling */   
.upcart-internal-header  
.upcart-internal-header__close-button  
.upcart-internal-cart-items  
.upcart-internal-rewards  
...

Public classnames

🚨 Public classnames available list

/*******************  
***** Skeleton *****  
*******************/  
'upcart-public-skeleton'  
  
/*******************  
****** Header ******  
*******************/  
'upcart-public-header'  
'upcart-public-header__close-button'  
'upcart-public-header__close-button-icon'  
  
/*******************  
*** Announcement ***  
*******************/  
'upcart-public-announcement'  
  
/*******************  
** Recommendation **  
****** Upsell ******  
*******************/  
'upcart-public-component-upsell-tile'  
'upcart-public-component-upsell-tile__image-container'  
'upcart-public-component-upsell-tile__image'  
'upcart-public-component-upsell-tile__info'  
'upcart-public-component-upsell-tile__title-link'  
'upcart-public-component-upsell-tile__title'  
'upcart-public-component-upsell-tile__rating-row'  
'upcart-public-component-upsell-tile__stars'  
'upcart-public-component-upsell-tile__star--partial'  
'upcart-public-component-upsell-tile__reviews'  
'upcart-public-component-upsell-tile__price-row'  
'upcart-public-component-upsell-tile__price-compare-at'  
'upcart-public-component-upsell-tile__price'  
'upcart-public-component-upsell-tile__variant-row'  
'upcart-public-component__button'  
'upcart-public-component-loader'  
'upcart-public-upsell__skeleton'  
'upcart-public-upsell__skeleton-title'  
'upcart-public-upsell__skeleton-image'  
'upcart-public-upsell__skeleton-product-title'  
'upcart-public-upsell__skeleton-product-price'  
  
/*******************  
****** Notes *******  
*******************/  
'upcart-public-notes'  
'upcart-public-component-collapse__dropdown-container'  
'upcart-public-component-collapse__expand-icon'  
'upcart-public-notes__text-container'  
'upcart-public-notes__textarea'  
  
/*******************  
** Discount Code ***  
*******************/  
'upcart-public-discount-code'  
'upcart-public-discount-code__form'  
'upcart-public-discount-code__input-wrapper'  
'upcart-public-discount-code__input'  
'upcart-public-discount-code__suffix'  
'upcart-public-discount-code__error'  
'upcart-public-discount-code__button'  
'upcart-public-component__button'  
'upcart-public-skeleton'  
'upcart-public-discount-code__skeleton'  
'upcart-public-discount-code__skeleton-input'  
'upcart-public-discount-code__skeleton-button'  
  
/*******************  
** Trust Badges ****  
*******************/  
'upcart-public-trust-badges'  
'upcart-public-trust-badges__image'  
  
/*******************  
** Tiered Rewards **  
*******************/  
'upcart-public-rewards'  
'upcart-public-rewards__message'  
'upcart-public-rewards__bar'  
'upcart-public-component-segmented-progress-bar'  
'upcart-public-component-segmented-progress-bar__segments-container'  
'upcart-public-component-segmented-progress-bar__segment'  
'upcart-public-component-segmented-progress-bar__segment-fill'  
'upcart-public-component-segmented-progress-bar__milestone'  
'upcart-public-component-segmented-progress-bar__milestone--bottom'  
'upcart-public-component-segmented-progress-bar__milestone--top'  
'upcart-public-component-segmented-progress-bar__milestone--middle'  
'upcart-public-component-segmented-progress-bar__milestone-icon'  
'upcart-public-component-segmented-progress-bar__milestone-label'  
'upcart-public-component-segmented-progress-bar__milestone-label--align-right'  
'upcart-public-component-segmented-progress-bar__milestone-label--align-center'  
'upcart-public-rewards__skeleton',  
'upcart-public-rewards__skeleton-message',  
'upcart-public-rewards__skeleton-bar',  
  
/*******************  
**** Cart Items ****  
*******************/  
'upcart-public-component-product-tile'  
'upcart-public-component-product-tile__content'  
'upcart-public-component-product-tile__image-wrapper'  
'upcart-public-component-product-tile__image'  
'upcart-public-component-product-tile__info'  
'upcart-public-component-product-tile__header'  
'upcart-public-component-product-tile__product-title'  
'upcart-public-component-product-tile__title-link'  
'upcart-public-component-product-tile__remove-button'  
'upcart-public-component-loader'  
'upcart-public-component-product-tile__variant'  
'upcart-public-component-product-tile__properties'  
'upcart-public-component-product-tile__bundle'  
'upcart-public-component-product-tile__product-pricing'  
'upcart-public-component-product-tile__price-compare-at'  
'upcart-public-component-product-tile__price'  
'upcart-public-component-product-tile__savings'  
'upcart-public-component-product-tile__controls'  
'upcart-public-component-product-tile__quantity-selector'  
'upcart-public-component-product-tile__quantity-minus'  
'upcart-public-component-product-tile__quantity-plus'  
'upcart-public-component-product-tile__discount-codes'  
'upcart-public-component-tag'  
'upcart-public-component-tag__icon'  
'upcart-public-component-tag__text'  
'upcart-public-component-product-tile__subscription-upgrade'  
'upcart-public-component__button'  
'upcart-public-component-product-tile__select-wrapper'  
'upcart-public-component-product-tile__select'  
'upcart-public-product-properties__subscription'  
'upcart-public-product-properties__item'  
'upcart-public-product-properties__link'  
'upcart-public-cart-items__key-value-pair'  
'upcart-public-bundle-properties'  
'upcart-public-bundle-properties__variant-title'  
'upcart-public-component-collapse__dropdown-container'  
'upcart-public-bundle-properties__header'  
'upcart-public-component-collapse__expand-icon'  
'upcart-public-notes__text-container'  
'upcart-public-bundle-properties__item-components'  
'upcart-public-bundle-properties__item-component-row'  
'upcart-public-bundle-properties__image-wrapper'  
'upcart-public-bundle-properties__content'  
'upcart-public-bundle-properties__product-title'  
'upcart-public-upsell__skeleton'  
'upcart-public-upsell__skeleton-title'  
'upcart-public-upsell__skeleton-image'  
'upcart-public-upsell__skeleton-product-title'  
'upcart-public-upsell__skeleton-product-price'  
  
/*******************  
***** Add-ons ******  
*******************/  
'upcart-public-addons'  
'upcart-public-addons__image-wrapper'  
'upcart-public-addons__content-wrapper'  
'upcart-public-addons__content-title-wrapper'  
'upcart-public-addons__content-title'  
'upcart-public-addons__content-price'  
'upcart-public-addons__compare-at-price'  
'upcart-public-addons__price'  
'upcart-public-addons__content-description'  
'upcart-public-addons__toggle-wrapper'  
'upcart-public-addons__toggle'  
'upcart-public-addons__toggle-switch'  
'upcart-public-addons__toggle-slider'  
'upcart-public-skeleton'  
'upcart-public-addons__skeleton'  
'upcart-public-addons__skeleton-image'  
'upcart-public-addons__skeleton-text'  
  
/*******************  
*** Cart summary ***  
*******************/  
'upcart-public-cart-summary'  
'upcart-public-cart-summary__discount-codes'  
'upcart-public-cart-summary__discount-label'  
'upcart-public-cart-summary__slide-codes'  
'upcart-public-cart-summary__total-discount'

These are part of the public styling API (upcart-public-) and are safe to override for custom designs.

.upcart-public-header  
.upcart-public-header__close-button  
.upcart-public-rewards  
...

✅ DO’s

Use only upcart-public- class names for styling.

/* ✅ Correct usage */  
.upcart-public-header {     
  font-size: 18px;  
  font-weight: bold;   
}

❌ DON’T’s

Avoid override internal classnames

/* ❌ Avoid this */  
.upcart-internal-header {     
  font-size: 18px;  
  font-weight: bold;   
}

Avoid targeting specific nodes with deep or custom selectors.

/* ❌ Avoid this */  
.upcart-public-upsell div a {     
  font-size: 18px;  
  font-weight: bold;   
}

Data attribute system

V2.0 introduces a structured data attribute system for improved targeting and advanced customization.

<!-- V2 data attributes for targeting -->   
<div data-upcart-chunk="header-title-content" />     
<div data-internal-properties="hasNonDefaultTitleAlignment=true" />       
<div data-placement="topOfFooter" />

These attributes make it easier to create flexible, data-driven templates while maintaining code clarity.

Template variable changes

V2 modules use a new template variable syntax with double curly braces {{ }}.

Announcement Module

V1.0: `{TIMER}`
V2.0: `{{timer}}`

Tiered Rewards Module

V1.0: `{AMOUNT}` → V2: `{{amount}}`
V1.0: `{COUNT}` → V2: `{{count}}`

Migration process

1. Backup Current Configuration

Before making any changes, back up your existing custom CSS and HTML files.

2. Test in Sandbox Mode

Set up your updated cart using sandbox mode to safely test new modules before going live.

Advanced customization with V2.0

Custom templates

V2.0 modules support fully custom templates for merchants who want complete control over layout and structure. To enable custom templates:

Go to Settings > Cart settings, expand Advanced Settings, and tick Access custom templates. The checkbox is inside that collapsed section, not on the Cart settings tab itself.
Enable the feature toggle.
Reference Upcart’s developer documentation for syntax and examples.

Note: Upcart’s support team cannot assist with developing, debugging, or troubleshooting custom templates.

Best Practices

Always test updates in sandbox mode first.
Migrate and update customizations incrementally.
Use public classes for styling instead of internal ones.
Keep backups of all previous versions before updating live settings.

Future Considerations

V2 modules will continue to receive new features, optimizations, and updates.
V1 modules are now in maintenance mode with limited support and no new features.
Merchants are encouraged to migrate to V2 as soon as possible for full compatibility.

Getting Started

Cart Modules

Cart Settings

Sticky Cart Button

Multicart

Customizations

Analytics

Integrations & Compatibility

Billing & Account

Troubleshooting

Overview

Breaking changes - CSS classname changes

V1 Classes (Deprecated)

V2.0 classes (new system)

Internal classnames

Public classnames

✅ DO’s

❌ DON’T’s

Data attribute system

Template variable changes

Announcement Module

Tiered Rewards Module

Migration process

1. Backup Current Configuration

2. Test in Sandbox Mode

Advanced customization with V2.0

Custom templates

Best Practices

Future Considerations

​Overview

​Breaking changes - CSS classname changes

​V1 Classes (Deprecated)

​V2.0 classes (new system)

​Internal classnames

​Public classnames

​

​✅ DO’s

​❌ DON’T’s

​Data attribute system

​Template variable changes

​Announcement Module

​Tiered Rewards Module

​Migration process

​1. Backup Current Configuration

​2. Test in Sandbox Mode

​Advanced customization with V2.0

​Custom templates

​Best Practices

​Future Considerations

​

​

Overview

Breaking changes - CSS classname changes

V1 Classes (Deprecated)

V2.0 classes (new system)

Internal classnames

Public classnames

✅ DO’s

❌ DON’T’s

Data attribute system

Template variable changes

Announcement Module

Tiered Rewards Module

Migration process

1. Backup Current Configuration

2. Test in Sandbox Mode

Advanced customization with V2.0

Custom templates

Best Practices

Future Considerations