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Subbly.js SDK
    InstallConfigureKeep it up to dateBuild a checkoutHandle errorsRun a funnel
SubblyCart.js widget
    InstallConfigureKeep it up to dateWire it into your pageDrive it from your codeStyle it
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SubblyCart.js widget

Install the widget

Write the config object first, then load the script. The widget reads window.subblyConfig the moment it runs, so the order matters.

Embed the widget
<!-- 1. Configure --> <script> window.subblyConfig = { apiKey: 'YOUR_STOREFRONT_API_KEY' } </script> <!-- 2. Load --> <script type="module" src="https://assets.subbly.co/cart/cart-widget.js"></script>

Your Storefront API key is in the Subbly admin, under Settings, Developers.

The script tag carries no data- attributes; everything goes through the config object. cart-widget.js is a small loader that imports the real bundle and its stylesheet, so do not cache it. The files it pulls from assets/ carry a hash in the name and can be cached for a long time.

Wait for the widget

The script loads asynchronously. The widget fires two events on window. Neither carries data.

EventMeaning
subbly-cart-loadedThe code is downloaded and window.SubblyCart, the class, is set. There is no instance yet.
subbly-cart-initializedThe widget is up and window.subblyCart, the instance, is set. Wait for this one.

There is no ready callback and no command queue. Guard against the event having already fired:

Run code once the widget is ready
const onReady = (fn) => { if (window.subblyCart) { fn(window.subblyCart) return } window.addEventListener('subbly-cart-initialized', () => fn(window.subblyCart) ) } onReady((cart) => { cart.open() })

The other pages in this section use this onReady helper.

The widget also emits its own CART_READY event, but it fires inside initialize(), before the instance is handed out, so no handler of yours can see it. Read the cart from subblyCart.cart once subbly-cart-initialized has fired instead.

Next steps

  • Configure — the keys of window.subblyConfig.
  • Wire it into your page — buy links, your own cart button and the container.
Last modified on September 15, 2026
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Javascript