Sync customer privacy consents to checkout

[patrick-schneider-latori]

We are having a real hard time to get the cookie consent synchronization correctly done between our Hydrogen storefront and the Shopify checkout. The main problem here is that the domains are differently, which means that any cookie stored on the Hydrogen storefront won't be recognized by the checkout url.

We tried now different things to get it running, e.g. based on https://shopify.dev/docs/api/consent-tracking we found out that the endpoint /set_tracking_consent.json receives a POST, we then used a proxy (example can be seen here https://shopify.dev/docs/custom-storefronts/oxygen/migrate/incremental) but forwarding the request results in an error and that specific cookies are missing for the endpoint to be valid.

Using an iframe and embedding the original Shopify store to trigger Javascript to set the cookies are also not possible due to CSP frame-ancestors 'none'.

I know this question is very specific to EU shop merchants, but how do you handle this circumstance?

Thanks for any suggestion here.