Better AuthBA
Better Auth•11mo ago
.jsonp

Correct way to determine the baseURL?

Hey there 👋

What is the recommended way in Next.js to determine the baseURL on the client?

The docs tell us to create an environment variable BETTER_AUTH_URL. However, I don't see where the docs recommends that we use this env variable. On the client, the example used only shows an explicitly defined string. In Next.js, I have used the following:
import { createAuthClient } from "better-auth/react"
export const authClient = createAuthClient({
    baseURL: NEXT_PUBLIC_BETTER_AUTH_BASE_URL
    // or...  NEXT_PUBLIC_APP_DOMAIN
})


However, I am inclined to follow a method usually used in tRPC. On the client, we typically do something like this to determine the URL:
function getBaseUrl() {
  if (typeof window !== "undefined") return window.location.origin;
  if (process.env.VERCEL_URL) return `https://${process.env.VERCEL_URL}`;
  return `http://localhost:${process.env.PORT ?? 3000}`;
}


So, should we really just be using a function like getBaseUrl() on the client to determine the auth location? Also, is BETTER_AUTH_URL used somewhere internally that I'm not seeing?
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