authjs-skills

Auth.js v5 authentication in Next.js requires creating an auth.ts config file at your project root with the auth() export, configuring providers like Google OAuth or Credentials, setting the AUTH_SECRET environment variable, and integrating API routes and middleware. This streamlines session management across server, middleware, and client contexts in App Router projects.

Yes. Auth.js v5 supports Google OAuth as a built-in provider for Next.js. You configure it in your auth.ts file with Google credentials from your OAuth application, then Auth.js handles the sign-in flow, token exchange, and session creation automatically.

Auth.js v5 introduces a unified auth() export that works across server, middleware, and client contexts in App Router, replacing separate APIs in v4. Migration to v5 preserves security practices while simplifying integration patterns and reducing configuration overhead for modern Next.js projects.

Database adapters are optional in Auth.js v5. You can start with credentials or OAuth providers without a database for basic authentication. Database adapters become necessary only when you need persistent user data, session storage beyond defaults, or advanced features like account linking.

Auth.js v5 manages sessions through environment variables like AUTH_SECRET for encryption and provides middleware integration for edge-runtime readiness. Configure your providers, set secure environment variables, and use the middleware to protect routes while Auth.js handles token validation and session lifecycle.

Yes. Auth.js v5 includes a Credentials provider for username/password authentication alongside OAuth. You configure it in auth.ts with custom validation logic, and it integrates with the same session and middleware patterns as Google OAuth or other providers.