Overview
Here are answers to some of the most common questions about using UpCart's API.
Where to Add UpCart API Scripts?
You can add scripts in UpCart’s Custom HTML settings or directly in your Shopify theme code. The best option depends on your customization needs.
How Do I Use UpCart’s Custom HTML?
Navigate to UpCart → Settings → Custom HTML
Use API scripts to modify cart behavior, like opening timing or upsell displays
Adjust elements outside UpCart, such as hiding product page buttons
💡 Example: Hide the sticky cart button when the cart is empty
<script>
window.upcartOnCartLoaded = (cart) => {
document.querySelector("#upCartStickyButton").style.display = cart.item_count === 0 ? "none" : "block";
console.log("Sticky Cart is hiding!");
};
</script>
Do I Need to Be a Developer to Use UpCart’s API?
No! UpCart’s API is easy to use, even without coding skills. Many features are built-in, and our customization docs include pre-written scripts you can copy into UpCart’s Custom HTML settings—no coding required!
If you’d like to write custom scripts, basic JavaScript knowledge helps. If you're new to JavaScript, don’t worry! These beginner-friendly resources—W3Schools and MDN Web Docs—can help you get started.
Can UpCart’s API integrate with Other Third-Party Apps?
Yes! UpCart’s API works with apps for translations, analytics, upsells, and more. Some integrate automatically, while others may need a small script.
For example, if you're using TripleWhale for tracking, you'll need to add the following script to ensure it records cart activity correctly:
<script>
window.upcartOnAddToCart = (id, quantity, item) => {
window.TriplePixel('AddToCart', {item: id, q: quantity});
}
</script>
Since each app is different, consult your app’s support team to see if extra code is needed. UpCart doesn’t offer script support for third-party apps, but your app provider may have an integration guide.
How Do I Test If My API Changes Are Working?
After adding a script to UpCart’s Custom HTML settings, follow these steps to ensure it works:
Refresh your store and add an item to the cart.
Clear your cache and try again to see the latest changes.
Add a test message: Insert
console.log("The script works!");before</script>to check if your script runs.
Check your browser console:
Open Dev Tools (
F12orCtrl + Shift + Jon Windows,Cmd + Option + Jon Mac).Go to the Console tab and look for "The script works!"
If you see the message, your script is running! If not, the script may not be executing correctly.
Test different actions (e.g., removing an item) to ensure expected behavior.
Troubleshoot issues by checking for typos or console errors and adjusting the code as needed.
What Should I Do If an API Script Isn’t Working?
If your API script isn’t working, try these troubleshooting steps:
Check for typos – Even small errors can break a script. Look for missing characters or incorrect syntax.
Verify script placement – Make sure the script is in the correct section under UpCart → Settings → Custom HTML. UpCart has nine script section — Review these sections here.
Check the browser console – Follow the steps above to look for errors.
Test a different script – Try another pre-written UpCart API script to see if the issue is with your code.
Still stuck? – If you're modifying your Shopify theme or integrating third-party apps, a Shopify Expert from the Shopify Partner Directory can help.
These steps should help you identify and resolve most script issues!
How Do I Undo Changes If I Add a Script That Breaks Something?
If you add a script that doesn’t work as expected, you can easily remove or disable it:
Go to UpCart’s Custom HTML settings where the script was added.
Remove the script or temporarily disable it by adding
//at the start of each line (this turns it into a comment, preventing it from running).
Save changes & refresh your store to check if the issue is resolved.
If the issue persists, try clearing your cache or reverting recent theme changes—this often resolves hidden conflicts.
🚧 Looking for Advanced Customizations?
Need store-wide customizations or third-party app integrations? You may need a developer to add UpCart’s API to your Shopify theme.
Consider hiring a Shopify Expert through the Shopify Partner Directory and share our API documentation with them for assistance