Hey there, we are currently migrating all our ui_extensions to use Polaris web components, Preact and API version 2026-07. The latter two areas didn’t face any major hiccups, but we have a couple extensions that rely on UI components that aren’t currently possible to build using the latest Polaris web components. With regards to migration, I had a few questions:
What happens to extensions if we don’t migrate them? Do they still work as is for merchants?
What if we migrate other ui_extensions but keep the one’s that rely on old UI components as is? Will updates to already migrated extensions be blocked because some other extensions weren’t migrated?
To add more context, here’s what our current extensions rely on which isn’t possible with the move to Polaris web components:
Controllable Popovers: We have an extension that requires a search box + results in a popover (similar to ComboBox) and s-popover cannot achieve the same results as it’s older React-based version. s-popover renders on top of the activator, and we need it at the bottom. It should also be treated like a form, so the user can go from search to selecting an item from the results popover via keyboard navigation. These two aren’t possible with s-popover.
Font size: Earlier, we had the ability to choose the font size of a text component using tokens. In Polaris web components, that’s gone. It now relies on semantics completely. We have an editor that let’s our users customize how the extension looks like on their customer accounts surface and if we switch to using web components, we won’t be able to provide that.
We are willing to wait if there’s a potential release down the line the fixes our issues, but we don’t want that to happen at the cost of blocking updates to our other extensions that were migrated successfully. Out of the two points, the 1st is crucial. The entire feature depends on it. I hope I didn’t break any community rules, this is my first post here.
What happens to extensions if we don’t migrate them? Do they still work as is for merchants?
Extensions that aren’t migrated will continue working for merchants but they cannot be deployed anymore.
What if we migrate other ui_extensions but keep the one’s that rely on old UI components as is? Will updates to already migrated extensions be blocked because some other extensions weren’t migrated?
All UI extensions in an app must be migrated to a supported API version to be able to deploy the app.
Re: your questions about Polaris web components:
Controllable Popovers
Popovers are meant to appear at the top, and aren’t designed to create a combobox. Is the intended behaviour something you can achieve with an alternative component like s-modal? If not, can you help us understand what’s missing from it?
Font size
In Polaris web components, we limit size options by design. However, you can use alternative components to achieve different size text - see Migrate to the Polaris text component
Thank you for the response. Okay, I’ve understood that migration is unavoidable, if we wish to deploy anything after October 1st. We have decided to go ahead with it. As for our concerns with popover and text, here’s how we’re addressing it:
Popover: We can’t use s-modal because we want to show search results below our input box, similar to how ComboBox looked like in Polaris React (on Shopify Admin). Using an s-modal for this would disrupt the flow. Moving our entire search feature inside the modal would also break the flow. We’ve decided to use s-popover for now since there’s no other alternative. We’ll keep the styles consistent (apart from its position). We’re currently figuring out how to make keyboard navigation work properly for our use case.
Font size: We’ve decided to narrow down the font sizes to 3 from our previous 6, and we’ll achieve it via s-heading, s-text and s-text with type="small".