diff --git a/src/actions/auth-actions.ts b/src/actions/auth-actions.ts
index 1aed79a..6c1d6dc 100644
--- a/src/actions/auth-actions.ts
+++ b/src/actions/auth-actions.ts
@@ -2,20 +2,40 @@
 
 import "server-only";
 import { signIn, signOut } from "@/lib/auth";
+import { redirect } from "next/navigation";
 
 /**
  * Kick off the Google OAuth flow. Auth.js will redirect to Google's
  * consent screen and then back to /api/auth/callback/google, which sets
  * the session cookie and redirects to /admin.
- *
- * The historical Supabase-backed email/password sign-in action was
- * removed in the cleanup pass. Admin accounts are provisioned by an
- * existing platform admin via /admin/users.
  */
 export async function signInWithGoogle(): Promise<void> {
   await signIn("google", { redirectTo: "/admin" });
 }
 
+/**
+ * Sign in with email + password. The `credentials` provider is enabled
+ * in dev (see `isDevLoginEnabled()` in `src/auth.config.ts`); in
+ * production it is omitted entirely and this action returns an
+ * `AuthError` (Auth.js surfaces `?error=Configuration` on /login).
+ *
+ * On a failed credential check Auth.js redirects back to
+ * /login?error=CredentialsSignin, which the LoginClient renders as
+ * "Invalid email or password."
+ */
+export async function signInWithCredentials(formData: FormData): Promise<void> {
+  const email = String(formData.get("email") ?? "").trim().toLowerCase();
+  const password = String(formData.get("password") ?? "");
+  if (!email || !password) {
+    redirect("/login?error=MissingCredentials");
+  }
+  await signIn("credentials", {
+    email,
+    password,
+    redirectTo: "/admin",
+  });
+}
+
 /**
  * Sign out and clear the Auth.js session cookie.
  */
diff --git a/src/auth.config.ts b/src/auth.config.ts
new file mode 100644
index 0000000..5dc54fe
--- /dev/null
+++ b/src/auth.config.ts
@@ -0,0 +1,108 @@
+import type { NextAuthConfig, DefaultSession } from "next-auth";
+import Google from "next-auth/providers/google";
+
+/**
+ * Edge-safe Auth.js v5 configuration.
+ *
+ * This file is imported by `src/middleware.ts`, which runs in the Edge
+ * runtime. It must NOT import:
+ *   - `pg` / `@auth/pg-adapter` (Node-only)
+ *   - `next-auth/providers/credentials` (uses Node `crypto` internally)
+ *   - The Drizzle client
+ *   - Anything else that touches the database or Node-only APIs
+ *
+ * Provider definitions, callbacks, and pages all live here. The full
+ * server-side handler in `src/lib/auth.ts` extends this with the
+ * Credentials provider (Node-only) for email + password sign-in.
+ *
+ * Both instances share the same session cookie, so the middleware can
+ * read JWTs minted by the server-side handler.
+ */
+
+declare module "next-auth" {
+  interface Session {
+    user: {
+      id: string;
+    } & DefaultSession["user"];
+  }
+}
+
+const hasGoogleCreds = !!(
+  process.env.AUTH_GOOGLE_ID && process.env.AUTH_GOOGLE_SECRET
+);
+
+const googleProvider = hasGoogleCreds
+  ? [
+      Google({
+        clientId: process.env.AUTH_GOOGLE_ID,
+        clientSecret: process.env.AUTH_GOOGLE_SECRET,
+      }),
+    ]
+  : [];
+
+export const authConfig = {
+  trustHost: true,
+  pages: { signIn: "/login" },
+  session: { strategy: "jwt" as const },
+  providers: googleProvider,
+  callbacks: {
+    /**
+     * Gate /admin, /wholesale, and /protected-example. Anything on those
+     * paths and not signed in is redirected to /login (the default
+     * pages.signIn). Public storefronts and the homepage pass through.
+     *
+     * The actual role-based gating still happens in `getAdminUser()` —
+     * this callback only ensures the user is *signed in*.
+     */
+    authorized({ auth, request: { nextUrl } }) {
+      const isLoggedIn = !!auth?.user;
+      const isOnAdmin = nextUrl.pathname.startsWith("/admin");
+      const isOnWholesale = nextUrl.pathname.startsWith("/wholesale");
+      const isOnProtectedExample = nextUrl.pathname.startsWith(
+        "/protected-example"
+      );
+      if (isOnAdmin || isOnWholesale || isOnProtectedExample) {
+        return isLoggedIn;
+      }
+      return true;
+    },
+
+    /**
+     * Forward the user id into the JWT on initial sign-in. With
+     * `session.strategy: "jwt"` this is the field downstream code reads
+     * via `session.user.id`.
+     */
+    async jwt({ token, user }) {
+      if (user) {
+        if (user.id) token.id = user.id;
+        if (user.email) token.email = user.email;
+      }
+      return token;
+    },
+
+    async session({ session, token }) {
+      if (session.user) {
+        session.user.id =
+          (typeof token.id === "string" && token.id) ||
+          (typeof token.sub === "string" && token.sub) ||
+          "";
+      }
+      return session;
+    },
+  },
+} satisfies NextAuthConfig;
+
+/**
+ * Is the dev Credentials provider enabled?
+ *   - Disabled in production (NODE_ENV === "production")
+ *   - Can be force-disabled by setting `ALLOW_DEV_LOGIN=false`
+ *
+ * Surfaced so `src/lib/auth.ts` can decide whether to include the
+ * Credentials provider in its providers list.
+ */
+export function isDevLoginEnabled(): boolean {
+  return (
+    process.env.NODE_ENV !== "production" &&
+    process.env.ALLOW_DEV_LOGIN !== "false"
+  );
+}
diff --git a/src/lib/auth.ts b/src/lib/auth.ts
index 25dcc33..6949463 100644
--- a/src/lib/auth.ts
+++ b/src/lib/auth.ts
@@ -1,84 +1,89 @@
 import "server-only";
 
 /**
- * Auth.js (NextAuth v5) configuration.
+ * Auth.js (NextAuth v5) — server-side configuration.
+ *
+ * This file is Node-only. It is imported by:
+ *   - `src/app/api/auth/[...nextauth]/route.ts` (the OAuth + credentials handlers)
+ *   - Server actions that call `signIn` / `signOut`
+ *   - `src/lib/admin-permissions.ts` (reads `auth()` for the current user)
+ *
+ * The middleware imports a separate, edge-safe instance built from
+ * `src/auth.config.ts`. Both instances share the same JWT cookie, so the
+ * middleware can read sessions minted here.
  *
  * Providers:
- *   - Google OAuth — only active when AUTH_GOOGLE_ID + AUTH_GOOGLE_SECRET
- *     are set.
+ *   - Google OAuth — active when AUTH_GOOGLE_ID + AUTH_GOOGLE_SECRET are set.
+ *   - Email + password (Credentials) — active in dev only; backed by the
+ *     `users.password_hash` column. In production, set ALLOW_DEV_LOGIN=false
+ *     (the default) and the provider is omitted entirely.
  *
- * Supabase is no longer used for auth (or anything else) on this platform.
- * The historical Supabase-backed Credentials provider was removed in the
- * cleanup pass. New admin users are provisioned manually by an existing
- * platform admin via /admin/users (the action creates an `admin_users`
- * row linked to the Google `sub` after the user signs in for the first
- * time).
- *
- * Session strategy: JWT. No database adapter — admin user lookup is
- * delegated to `getAdminUser()` in `src/lib/admin-permissions.ts`.
- *
- * Required env vars (production):
- *   - AUTH_SECRET          — JWT signing secret
- *   - AUTH_URL             — base URL (auto-detected on Vercel)
- *   - AUTH_GOOGLE_ID       — Google OAuth client id
- *   - AUTH_GOOGLE_SECRET   — Google OAuth client secret
- *
- * Backward compatibility: the `dev_session` cookie was the source of
- * truth for the demo flow but has been removed — `getAdminUser()` and
- * the middleware now use only the Auth.js session. The legacy
- * `rc_auth_uid` cookie was retired earlier — see the
- * final report for the cleanup notes.
+ * For local dev, run `npm run db:seed` to create the seeded admin user
+ * (`admin@route-commerce.local` / `admin`). The `authorize` function
+ * looks up the user by email, verifies the password against the stored
+ * hash, and returns the real user record. No `dev_session` cookie
+ * bypass; this is real Auth.js sign-in.
  */
 
-import NextAuth, { type DefaultSession } from "next-auth";
-import Google from "next-auth/providers/google";
+import NextAuth from "next-auth";
+import Credentials from "next-auth/providers/credentials";
+import { eq } from "drizzle-orm";
+import { authConfig, isDevLoginEnabled } from "@/auth.config";
+import { withDb } from "@/db/client";
+import { users } from "@/db/schema";
+import { verifyPassword } from "@/lib/passwords";
 
-declare module "next-auth" {
-  interface Session {
-    user: {
-      id: string;
-    } & DefaultSession["user"];
-  }
+function buildCredentialsProvider() {
+  return Credentials({
+    id: "credentials",
+    name: "Email + password",
+    credentials: {
+      email: { label: "Email", type: "email" },
+      password: { label: "Password", type: "password" },
+    },
+    /**
+     * Returns the user on success, or `null` on any failure. Auth.js
+     * never throws from `authorize` — a throw is treated as a 500.
+     */
+    async authorize(creds) {
+      if (!isDevLoginEnabled()) return null;
+      const email = String(creds?.email ?? "").trim().toLowerCase();
+      const password = String(creds?.password ?? "");
+      if (!email || !password) return null;
+
+      try {
+        // The `users` table is global (not tenant-scoped), so we use
+        // `withDb` rather than `withTenant` — no GUC to set.
+        const u = await withDb(async (db) => {
+          const rows = await db
+            .select()
+            .from(users)
+            .where(eq(users.email, email))
+            .limit(1);
+          return rows[0] ?? null;
+        });
+        if (!u || !u.passwordHash) return null;
+        if (!verifyPassword(password, u.passwordHash)) return null;
+        return {
+          id: u.id,
+          name: u.name ?? undefined,
+          email: u.email,
+        };
+      } catch (err) {
+        // eslint-disable-next-line no-console
+        console.error("[auth] credentials authorize failed:", err);
+        return null;
+      }
+    },
+  });
 }
 
-const hasGoogleCreds = !!(
-  process.env.AUTH_GOOGLE_ID && process.env.AUTH_GOOGLE_SECRET
-);
-
-const googleProvider = hasGoogleCreds
-  ? [
-      Google({
-        clientId: process.env.AUTH_GOOGLE_ID,
-        clientSecret: process.env.AUTH_GOOGLE_SECRET,
-      }),
-    ]
-  : [];
+const providers = [
+  ...authConfig.providers,
+  ...(isDevLoginEnabled() ? [buildCredentialsProvider()] : []),
+];
 
 export const { handlers, auth, signIn, signOut } = NextAuth({
-  trustHost: true,
-  providers: googleProvider,
-  session: { strategy: "jwt" },
-  pages: {
-    signIn: "/login",
-  },
-  callbacks: {
-    async jwt({ token, user }) {
-      if (user) {
-        // `user.id` is the provider's stable subject — for Google sign-ins
-        // this is the opaque `sub` claim.
-        if (user.id) token.id = user.id;
-        if (user.email) token.email = user.email;
-      }
-      return token;
-    },
-    async session({ session, token }) {
-      if (session.user) {
-        session.user.id =
-          (typeof token.id === "string" && token.id) ||
-          (typeof token.sub === "string" && token.sub) ||
-          "";
-      }
-      return session;
-    },
-  },
+  ...authConfig,
+  providers,
 });
diff --git a/src/middleware.ts b/src/middleware.ts
index c7d1228..29c018b 100644
--- a/src/middleware.ts
+++ b/src/middleware.ts
@@ -1,23 +1,26 @@
 // NextAuth v5 middleware
 //
-// Runs on every non-static request. Responsibilities:
-//   1. Allow Auth.js v5 to read/write its own session cookie
-//   2. Protect /admin/* and /wholesale/* — redirect to /login if not authenticated
+// Runs on every non-static request in the Edge runtime. It uses a
+// lightweight NextAuth instance built from the edge-safe `authConfig` —
+// NOT the full `src/lib/auth.ts` (which uses `pg` and is Node-only).
+//
+// Responsibilities:
+//   1. Allow Auth.js to read/write its own session cookie
+//   2. Protect /admin/*, /wholesale/*, /protected-example — redirect to
+//      /login if not authenticated
 //   3. Redirect away from /login when the user already has a session
 //   4. Add a handful of baseline security headers
 //
 // The legacy `dev_session` cookie bypass has been removed. The only way
-// into the admin is through real Auth.js (Google in production; for
-// local dev, configure `AUTH_GOOGLE_ID` / `AUTH_GOOGLE_SECRET`).
-//
-// Backward compatibility: the legacy `rc_auth_uid` / `rc_uid` cookies
-// are intentionally no longer read here — `getAdminUser()` in
-// src/lib/admin-permissions.ts is the single source of truth and reads
-// the Auth.js session instead.
+// into the admin is through real Auth.js — Google in production, or the
+// seeded Credentials provider in dev (see `src/lib/auth.ts`).
 
-import { auth } from "@/lib/auth";
+import NextAuth from "next-auth";
+import { authConfig } from "@/auth.config";
 import { NextResponse } from "next/server";
 
+const { auth } = NextAuth(authConfig);
+
 export default auth((req) => {
   const { pathname } = req.nextUrl;