Hosting via Vercel not working because of AUTH0_BASE_URL.

Description

Hi, I would like to reopen https://github.com/auth0/nextjs-auth0/issues/383, as https://github.com/auth0/nextjs-auth0/pull/404 did not fix the problem, as you can see in the last comments of https://github.com/auth0/nextjs-auth0/issues/383.

The documentation at https://github.com/auth0/nextjs-auth0/blob/main/examples/README.md#assigning-the-auth0_base_url seems wrong to me, as the env key in config and the webpack DefinePlugin don’t work for files in node_module, which are not touched by webpack.

Moreover, on a Vercel side, the VERCEL_URL reference the “by commit domain”, and not the “by PR domain”, so we can’t use auth0 with the standard PR domain.

We have to figure out another way to do this.

Any thoughts about this?

Thanks.

Environment

• Version of this library used: v1.4.0
• Version of the platform or framework used, if applicable: Next 10.2.3 with Vercel

[tusbar]

I can confirm that committing a .env.production with the following works.

# .env.production
AUTH0_BASE_URL=${VERCEL_URL}

Also, specifying AUTH0_BASE_URL for your production domain in the Vercel environment config (through GUI or CLI) will properly override what’s defined in the .env.production file.

[adamjmcgrath]

Managed to have a work-around for this issue by overriding Vercel’s Build Command AUTH0_BASE_URL=“$VERCEL_URL” yarn build

@sioquim - I’ve been testing this and assiging AUTH0_BASE_URL for the build command (AUTH0_BASE_URL="$VERCEL_URL" npm build) doesn’t work because it only provides the AUTH0_BASE_URL during the Build Step not during Serverless Function execution when it’s required by the SDK. Am I missing something?