NextJS with Auth0: Choose Single Page App or NextJS integration?

I appreciate the question, but this is actually more of an Auth0/Next.js architecture question than a Sanity-specific one. Since you're asking specifically about which Auth0 SDK to use for your Next.js application, you'd get better guidance from the Auth0 community or Next.js forums where they can dive deep into the differences between their SPA SDK and Next.js SDK.

That said, I can briefly point you in the right direction: for Next.js applications, you should use Auth0's Next.js SDK (@auth0/nextjs-auth0) and create a "Regular Web Application" in Auth0's dashboard, not the SPA integration. This is because Next.js has server-side capabilities (API routes, server components, middleware) that the Next.js SDK is designed to leverage.

Where this connects to Sanity: Once you have Auth0 set up in your Next.js app, you might want to integrate it with Sanity in a few ways:

• Securing content access: You can use your Auth0 user data to implement custom authorization logic when querying Sanity content from your Next.js app
• Token-based API access: If you're using API tokens with custom permissions, you might combine Auth0 authentication with Sanity's token-based access control
• Securing Sanity Studio: If you need to add enterprise SSO to your Studio itself, Sanity offers SAML SSO (Enterprise plan) for organization-level access control

For the core Auth0 SDK selection question though, I'd recommend checking Auth0's official Next.js documentation or asking in their community forums for the most detailed guidance specific to their SDKs.