Shopify Scripts Sunset Guide: Migrating to Shopify Functions (2026 Deadline)

TL;DR

Shopify Scripts (Ruby) stop working on June 30, 2026. To migrate, replace your Line Item Scripts with Discount Function API logic (and use Cart Transform for bundles), replace Shipping Scripts with Delivery Customization, and replace Payment Scripts with Payment Customization under Checkout Extensibility.

⚠️ Critical Update: Shopify Scripts Sunset — June 30, 2026

Shopify has officially confirmed that Shopify Scripts will stop working on June 30, 2026. All Ruby scripts must be migrated to Shopify Functions before this deadline.

For years, Shopify Plus merchants relied on Shopify Scripts (Ruby-based) to customize checkout logic—complex discounts, shipping rules, and payment gateway controls.

The era of Ruby scripts is ending. Shopify is replacing them with Shopify Functions, a modern WebAssembly-based architecture offering superior performance and scalability.

Why you can’t wait: While the deadline was extended from 2025 to June 2026, migration requires development resources, testing time, and potential business logic refactoring. Complex stores need 2-4 months for safe migration.

📅 The Deadline: June 30, 2026

Originally scheduled for August 2025, Shopify extended the deprecation to June 30, 2026, providing merchants additional preparation time.

What Happens After June 30, 2026?

Your existing Ruby scripts will completely stop working. The impact includes:

Script Type	Potential Consequences
Line Item Scripts	Custom discounts fail to apply, bundle offers disappear, tiered pricing resets
Shipping Scripts	Free shipping for VIPs becomes paid, regional restrictions lift, expensive shipping options reappear
Payment Scripts	COD restrictions fail for high-risk orders, payment method reordering stops working

Recommended Migration Timeline (Varies by Store)

Good news: many stores can migrate faster than this. The timeline depends on how many scripts you have, how complex the logic is (bundles, VIP shipping rules, payment restrictions, multi-market edge cases), and how much testing you want before rollout.

Phase	Duration	Key Activities
Audit & Planning	2-4 weeks	Document all active scripts, map business logic, identify priorities
Development	4-8 weeks	Build replacement functions, set up testing infrastructure
Testing & QA	2-4 weeks	Parallel testing, edge case validation, performance testing
Deployment	1-2 weeks	Staged rollout, monitoring, rollback planning

Optimistic case: straightforward stores with a small number of scripts can often finish in 2–6 weeks.
Complex case: heavily customized Shopify Plus checkouts can still take 8–16+ weeks, mostly due to QA and edge cases.

Why Migrate? It’s Not Just Mandatory.

Shopify Functions aren’t just a replacement; they are a significant upgrade:

1. Performance: Functions run in under 5ms on Shopify’s global infrastructure using WebAssembly (Wasm).
2. Scalability: They execute effectively during massive traffic spikes (like Black Friday) without the timeout risks of single-threaded Ruby scripts.
3. No Code Required for Changes: Once deployed, your team can configure logic (e.g., change the discount %) directly in the Shopify Admin, removing the need to edit code for day-to-day operations.
4. Checkout Extensibility: Functions work seamlessly with the new Checkout Extensibility, which replaces the checkout.liquid file.

Migration Guide: Mapping Scripts to Functions

The migration involves mapping your “Script types” to the correct “Function APIs”.

1. Line Item Scripts (Discounts & Bundles)

Old Way (Scripts): Iterating through cart items to apply discounts, change prices, or create logic like “Buy 2 T-shirts, get 1 Hat free.”

New Way (Functions):

Discount Function API (replaces deprecated Product/Order/Shipping Discount APIs)

Shopify deprecated the separate Product / Order / Shipping Discount Function APIs and replaced them with the unified Discount Function API, where one function can apply savings across product, order, and shipping discount classes.

• Discount Function API: Unified API for discount logic (product, order, and shipping discount classes).
• Cart Transform API: Essential for bundles. Use this to merge multiple items into a single line item or expand one item into its components.

Example Migration:

Legacy Script: “If cart total > $100, discount the cheapest item by 50%.” New Function: A Rust or JavaScript function using the Discount Function API that calculates the subtotal and targets the lowest-priced line item.

2. Shipping Scripts

Old Way (Scripts): Renaming “Standard Shipping” to “Free VIP Delivery” or hiding expensive shipping options for specific regions.

New Way (Functions):

• Delivery Customization API: Use this to rename, reorder, or hide delivery options based on cart contents or customer tags.

Example Migration:

Legacy Script: “Hide ‘Express Shipping’ if the cart contains a ‘Hazardous’ product.” New Function: A Delivery Customization function that inspects cart items for the ‘Hazardous’ tag and filters out the ‘Express’ handle from the available shipping rates.

3. Payment Scripts

Old Way (Scripts): Hiding “Cash on Delivery” (COD) for orders over $1,000 or specific customer groups.

New Way (Functions):

• Payment Customization API: Allows you to hide or reorder payment methods.

Example Migration:

Legacy Script: “Hide COD if the customer has a history of returns.” New Function: A Payment Customization function that checks the customer’s metafields (e.g., return_risk: high) and outputs a hide operation for the COD gateway.

Essential Extensions for Migration

To replace a complex script.rb file, you won’t write one massive function. Instead, you’ll likely deploy a Shopify App containing multiple extensions:

• Discount Functions: Build discounts with the unified Discount Function API (replaces deprecated Product/Order/Shipping Discount APIs).
• Validation Functions: Replaces Input.cart.errors.add to block checkout (e.g., “Max 5 units per customer”).
• Cart Transform: For all bundling logic.
• Staging & Testing: Unlike Scripts, Functions can be unit-tested locally and version-controlled via Git, ensuring a safer deployment pipeline.

Need Help with the Migration?

Migrating from Shopify Scripts to Functions requires a shift in engineering. You are moving from simple Ruby snippets to a structured application development workflow involving Rust or JavaScript (Javy) and Shopify App deployment.

At Agam Tech, we are Shopify Plus migration experts. We help merchants:

1. Audit existing Ruby scripts and document all business logic.
2. Re-architect solutions using the optimal Function APIs.
3. Deploy & Test the new Functions to ensure zero downtime and accurate checkout behavior.

The June 2026 deadline is closer than it appears. Complex migrations can take months to test and validate.

Contact us today to secure your checkout’s future.