Checkout Upsell, Conditional Pricing & Shipping — Checkout UI Extension
Rule-based checkout upsells, dynamic per-customer pricing, and conditional shipping charges — built on Shopify Checkout UI Extensions and Shopify Functions for Plus merchants
The project
A custom Shopify Plus app that lifts checkout conversion and AOV through three coordinated layers: rule-based upsell blocks inside the new Shopify Checkout, dynamic per-customer pricing (B2B tier pricing, loyalty discounts, segment-based overrides), and conditional shipping logic (free shipping thresholds, region/weight surcharges, restricted-product fees). Built on Shopify Checkout UI Extensions for the storefront layer and the new Shopify Functions API (Discount, Cart Transform, Delivery Customization) for the logic layer — fully native, fully extensible, and replaces the deprecated Shopify Checkout.liquid + Shopify Scripts pattern.
Build something similarWhat it does, in detail
Every feature designed around real merchant workflows — built for scale, performance, and zero theme-edit overhead.
Rule-based upsell blocks inside Shopify Checkout
Native Checkout UI Extension blocks (post-information, post-shipping, post-payment) that surface targeted upsells, cross-sells, and bundles based on cart contents, customer segment, cart value, or geo. No checkout redirect, no slowdown, no third-party iframe.
Dynamic per-customer pricing engine
Apply different prices to different customers in real time using the Product Discount Function: B2B wholesale tiers, loyalty member discounts, VIP-segment pricing, country-based pricing, or scheduled promo prices. Stacks intelligently with native Shopify discount codes.
Conditional shipping logic
Use the Delivery Customization Function to hide, rename, reorder, or surcharge shipping methods based on cart criteria: free shipping over $X, regional restrictions, weight-based surcharges, hazmat/oversize fees, or VIP free-express on loyalty members.
Built on Shopify Functions + Checkout Extensions
Wasm modules running on Shopify's edge with sub-50ms execution. Native to the new commerce platform — works on the new extensible Checkout, not checkout.liquid. Replaces deprecated Shopify Scripts and the legacy Additional Checkout Scripts pattern.
Merchant rule builder + admin reporting
Visual rule editor with conditions and actions — no SQL, no code. Per-rule analytics show take-rate, revenue lift, and AOV impact. A/B test variants of any rule directly from the admin. Schedule rules for BFCM, holiday weekends, or VIP-only windows.
Plus-grade compliance and observability
Audit logging on every pricing/shipping rule change, role-based admin access for large teams, and OpenTelemetry-compatible function-execution tracing for Plus merchants who need observability into every cart transformation.
Next project · Custom App
Free Shipping Threshold App — Built on Shopify Functions
Free-shipping threshold rules powered by the new Shopify Functions API — migrated from the deprecated Shopify Scripts (Cart & Shipping Scripts)
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