Overview
UpCart’s Public API UpCart’s Public API lets you customize your cart, automate workflows, and integrate with third-party apps—whether you're a developer or just getting started. This guide will walk you through the basics and help you get started to using our API.
What You Need to Get Started
Before using UpCart’s API, make sure you have:
Access to UpCart in your Shopify store – Ensure UpCart is installed and active.
A basic understanding of JavaScript – Many customizations work with pre-written scripts, but knowing basic JavaScript helps with advanced edits.
Adding Your First UpCart API Script
To add a script, go to: UpCart Editor → Settings → Custom HTML → Scripts (before load).
Test if scripts are working by adding this example using the API:
<script>
window.upcartOnAddToCart = (id, quantity, item) => {
console.log("You just added " + item.title + " to your cart!");
};
</script>
Save your changes, then test in your store:
Open Dev Tools (
F12orCtrl + Shift + Jon Windows,Cmd + Option + Jon Mac).Add a product to your cart.
Go to the Console tab and look for
"You just added product title to your cart!".
Start Customizing Your Cart
Now that you’re set up, explore our UpCart API Documentation for all available functions and examples:
More Resources:
Explore our API FAQ for troubleshooting and Common Uses for UpCart API for more examples.
Use our pre-written scripts from our Customization Docs to get started quickly.
Shopify’s Cart API Documentation – Learn how Shopify’s cart system handles product quantities, discounts, and line item properties.
Need advanced customizations? Consider hiring a Shopify Expert via the Shopify Partner Directory.