Checkout session token drops when navigating through custom mobile WebView containers

Hydrogen and Storefront APIs
1

I have run into a frustrating session-handling bug while testing our headless Hydrogen storefront across various localized Android container and emulation setups. We received reports from international customers claiming their carts reset to empty right after initiating the checkout redirect, so I began replicating their environments using the device profiling and container notes documented here to inspect network traffic directly.

During testing, the cart token intermittently disappears as soon as the transition from our custom storefront subdomain over to the Shopify-hosted checkout occurs. It seems tied to how cross-domain storage and SameSite cookie policies are parsed inside these specialized web views, even though standard mobile browsers like Chrome and Safari retain the cart state perfectly.

Has anyone else encountered checkout drop-offs or cookie clearance in non-standard mobile runtimes, and what token-persistence or proxy strategies did you adopt to keep the session alive through the transition?

2

The cart token is already baked into the checkoutUrl the Cart API gives you, so cookies shouldn’t be what loads the cart itself. I’d check whether the WebView has third-party cookies enabled though, Android WebView disables them by default unlike Chrome/Safari (CookieManager.setAcceptThirdPartyCookies), and that can break session/Shop Pay recognition even when the cart line items still show up fine.