Persistent PGRST106 Error with Supabase Adapter despite all configurations

[akoldevs]

Hello,

I'm building a Next.js 15 (App Router) project and am facing a persistent PGRST106 error when using the EmailProvider with the @next-auth/supabase-adapter. I have followed all documentation and debugging steps but am completely stuck.

The Error:
When I try to sign in with email, the server crashes with a 500 error. The terminal log shows:

[next-auth][error][adapter_error_getUserByEmail]
https://next-auth.js.org/errors#adapter_error_getuserbyemail
The schema must be one of the following: public, graphql_public
{ code: 'PGRST106' }

What I Have Already Done:

My environment variables (NEXT_PUBLIC_SUPABASE_URL, SUPABASE_SERVICE_ROLE_KEY, AUTH_SECRET, NEXTAUTH_URL) are all set correctly in both .env.local and on Vercel.

I have synced my AUTH_SECRET with the JWT Secret in the Supabase dashboard.

I have successfully run the official SQL schema script to create the users, accounts, sessions, and verification_tokens tables in my public schema.

My public schema is correctly listed in the "Exposed schemas" section of the Supabase API settings.

I have confirmed that a direct database connection from a test API route works perfectly. A simple createClient with the service_role key can successfully select() from the public.users table. This proves my keys and basic connection are correct.

Key Files:

Here is my src/app/api/auth/[...nextauth]/route.ts:

import NextAuth from 'next-auth'
import { SupabaseAdapter } from '@next-auth/supabase-adapter'
import EmailProvider from 'next-auth/providers/email'

const handler = NextAuth({
  providers: [
    EmailProvider({}),
  ],
  adapter: SupabaseAdapter({
    url: process.env.NEXT_PUBLIC_SUPABASE_URL!,
    secret: process.env.SUPABASE_SERVICE_ROLE_KEY!,
  }),
  secret: process.env.AUTH_SECRET,
  session: {
    strategy: 'jwt',
  },
})

export { handler as GET, handler as POST }

Here are my dependencies from package.json:
"dependencies": { "@next-auth/supabase-adapter": "^0.2.1", "@supabase/ssr": "^0.4.0", "@supabase/supabase-js": "^2.44.3", "next": "15.3.3", "next-auth": "^5.0.0-beta.19", "react": "^19.0.0-rc-f994737d14-20240522", "react-dom": "^19.0.0-rc-f994737d14-20240522" }

My Question:
Given that a direct connection with the service key works, why would the adapter specifically fail with a PGRST106 schema error? Is this a known issue with these library versions or a subtle Supabase policy I might be missing?

Thank you for any help you can provide.