Sign in / social using social media in scope of theme extension app?

Topic summary

Seeking to enable customer login within a Shopify theme app block or embedded block. Traditional email/password via an app proxy to a backend seems feasible.

Unsure whether a social login flow (OAuth/OIDC) can work: redirecting users to an external identity provider and then returning them to the extension after successful authentication.

Key terms: Theme app block/embedded block—components rendered in the storefront theme; App proxy—Shopify mechanism to route storefront requests to an external app server; Identity provider—service (e.g., social media) that authenticates users via OAuth/OpenID Connect.

No decisions or implementation guidance provided yet. No attachments or code referenced.

Status: Open question seeking confirmation and best-practice approach for redirects and returning context to the extension after authentication.

Summarized with AI on January 15. AI used: gpt-5.

I am looking at giving possibility for Shopify customers to login in my web app in scope of theme app block extension or theme app embedded block extension. I imagine it will doable using regular credentials (email, password) sign up / sign in as it just involves send http request through app proxy to my back-end however I am not sure if it’s possible to do a redirect to social media identity provider for sign / sign up and and get user back to extension after successful authentication. Can