Use Checkout UI Extension and subscribe users to email marketing

Retired Boards Appdev Extensions

Topic summary

A developer built a Checkout UI Extension that adds a custom checkbox on the Information page to collect email marketing consent from non-logged-in users. The challenge is subscribing these users to Shopify email marketing without backend infrastructure.

Key Issues:

  • The buyerIdentity API doesn’t provide access to the customer object for non-logged-in users
  • Adding read and write customer scopes to the app doesn’t enable the subscription functionality
  • The email is available with the order via the API, but direct subscription seems blocked

Current Status:

  • The developer found a related thread but remains uncertain if subscribing users is possible without adding a backend to the app
  • Seeking confirmation on whether they’re missing something or if backend integration is required
  • Legal requirements necessitate specific checkbox language, making custom implementation necessary
Summarized with AI on November 8. AI used: claude-sonnet-4-5-20250929.
1

Hello,

We built a Checkout UI Extension that creates a checkbox on the Information page on a site and when checked, we would like to be able to also subscribe the user associated with the order, who consents and is not logged in. (It is required that the checkbox has particular language for legal reasons) I understand this to be significant as we cannot access the customer object using the buyerIdentity API. However, the email associated with the order is available to the API.

Am i missing something? Is this possible? We found this thread, but can’t seem to subscribe users using our app to Shopify email marketing. Adding the read and write customer scopes to the app doesn’t seem to allow this to function. Is there a way to do this without adding a backend to the app?