Authentication

NextAuth v5 beta with JWT sessions, split across two files for a reason.

Two config files

src/lib/auth.config.ts is edge-safe. No providers, no Prisma import. It holds the session strategy, the custom pages, the session callback and the authorized callback. This is what src/proxy.ts runs on the edge.

src/lib/auth.ts is Node-only. Providers, the Prisma adapter, and the callbacks that need a database.

Importing Prisma into auth.config.ts breaks the edge runtime. That split is the whole reason there are two files.

Providers

Resend, for magic links. It supplies a custom sendVerificationRequest so the link goes through the app's own mailer and is written to EmailLog like every other message.

Credentials, for email and password. Verifies against passwordHash using scrypt from src/lib/password.ts, and refuses accounts with disabledAt set.

Accounts are never auto-provisioned

The signIn callback calls mayStartSession(), which refuses an address with no existing user. Without it, Auth.js would happily create an account for any address that clicked a magic link.

It retries once on a transient database error, so a single dropped connection during a burst of first sign-ins does not turn into a refusal. (The comment above it in auth.ts still names the old Supabase pooler; the retry is still correct without it.)

Sessions revalidate

The jwt callback re-reads the user row when sessionNeedsRefresh(token.checkedAt) is true, and returns null to invalidate. So a role change, a disable or a delete propagates to live sessions instead of waiting for expiry.

The proxy

src/proxy.ts. Next 16 renamed middleware; the export is proxy.

matcher: ["/admin/:path*", "/write/:path*", "/dashboard/:path*",
          "/account/:path*", "/recruitment/:path*"]

Everything else, including the public site and this documentation, never touches it.

Behind Caddy: AUTH_URL and AUTH_TRUST_HOST

The production image runs Next's standalone server, whose request.url is its bind address, http://0.0.0.0:3000. Auth.js would put that into every sign-in redirect and callbackUrl.

The Dockerfile therefore sets AUTH_URL from NEXT_PUBLIC_APP_URL and AUTH_TRUST_HOST=true. Trusting the forwarded host is safe because Caddy only routes this deployment's own hostnames.

Password recovery

There is no reset token. "Forgot password" switches the form to the magic link tab with callbackUrl=/account, where the user sets a new password. setOwnPassword only demands the current password if one is already set.

Fewer moving parts, and no reset link to leak or expire badly.

Not leaking who has an account

A magic link request lands on /signin/sent whether or not the address exists. underlyingError() distinguishes an infrastructure failure from a real refusal, so a genuine outage reports "try again" instead of silently pretending to have sent mail.

Rate limits

Database-backed, in src/lib/rate-limit.ts, and fail-open: if the limiter itself errors, the request proceeds. Availability is preferred to a hard lockout.

Checks

check-auth-errors.ts, check-auth-page-guards.ts, check-password.ts, check-user-admin.ts.