Ability to Listen for URL Changes Within the Checkout Sheet

Description

Add support for a listener or callback (e.g. onUrlChange) that triggers whenever the URL inside the Checkout Sheet changes. This should expose the current URL so developers can track navigation within the embedded checkout flow.

Rationale

Without access to URL changes, developers can't reliably detect key moments in the checkout process—such as order completion or user navigation events. This feature would enable integrations for analytics, custom business logic (e.g. post-checkout handling), and better control over the user experience. Polling or assumptions about checkout timing are unreliable workarounds, making a native event-based approach far more robust.

[kieran-osgood-shopify]

@adithyan-apmkr Thank you for the feature request.

We acknowledge the desire for more information into the checkout process.
After some discussion we don't think the most appropriate way to do this would be via a onURLChange callback, as this may hard code some fragility into the process (schema updates becoming breaking changes.

As such I am going to close this specific issue as not planned, but we will consider any new mechanisms to expose for consumers, I unfortunately cannot commit to any timeframe at this point on that.

If you have any other ideas on specific state you were looking to gather from the URL, please reply as that would be a good starting point for our plans!

Thanks again.