Shopify & eCommerce
Shopify Functions
Quick definition
Server-side WebAssembly modules that run custom logic at checkout: discounts, shipping rules, payment customizations, and validation.
What it actually means
Shopify Functions execute in Shopify's infrastructure at checkout. They replace the discount apps, custom shipping calculators, and payment customizer apps that previously bloated Plus stores. A well-built Functions setup can collapse several paid apps into native logic, improving checkout speed and reducing monthly app spend.
Related terms
Shopify Plus
Shopify's enterprise plan. Public starting price is $2,300 USD/mo as of 10 November 2026. Adds full checkout customization, unlimited B2B catalogs, expansion stores, and higher API limits versus standard Shopify.
Checkout Extensibility (Shopify)
Shopify Plus's modern checkout customization model using web pixels, UI extensions, and Functions, replacing the deprecated checkout.liquid.