for apps/web I would like to get away from using local storage for persisting avatar emojis / names / isActive and persisting this on a per guest session basis in a database. i want to use drizzle as orm and also for schema migrations. for instances where server components are impractical, I want to use tanstack query to interact with the api and for caching / invalidations and also mutations. i want to use nextauth + jwt for stateless and self contained sessions below I have pasted a generic guide that you can use as a pattern. i want to implement this step by step, testing thoroughly at high resolution checkpoints to ensure that at every step along the path we have a rock solid base. have a deep look at the source and propose a plan. keep in mind that this is a greenfield project with no users. we are aiming for excellent implementation and do not have to worry at all about preserving existign data or backwards compatibility === generic guide for implementing nextauth + jwt for guest session manageement with a clean path for upgrade to full user account === below is a guic guide for impda - **Stateless** on the server (no DB writes just to identify a visitor). - **Self‑contained** in the browser (HttpOnly cookies only — **no localStorage**). - **Easy upgrade** from “guest” → full NextAuth user. It uses **two layers of identity**: 1. a tiny **guest token** (JWT) in an HttpOnly cookie you control; 2. a normal **NextAuth session** (JWT strategy). On upgrade, the guest ID is carried into the NextAuth token so you can merge state. --- ## Why this works - NextAuth’s default **session strategy is `"jwt"`**, stored in a cookie as an **encrypted JWE**; this is stateless and requires no DB lookups. ([Auth.js][1]) - JWT cookies are size‑limited (~4 KB), so we store **only a small guest ID** and timestamps, not carts/settings. (If you need more than a few kilobytes, persist to your backend at upgrade time.) ([NextAuth][2]) - With **lazy initialization**, NextAuth v5 lets you access the request inside your config (e.g., to read the guest cookie during callbacks). ([Auth.js][1]) - Middleware can **create/rotate HttpOnly cookies** at the edge before your app runs. ([Next.js][3]) --- ## The pattern (Next.js App Router + NextAuth v5) ### 0) Install & set secrets ```sh npm i next-auth@beta jose # .env AUTH_SECRET=your-strong-random-secret ``` > Auth.js v5 accepts `AUTH_SECRET` (you can even rotate by passing an array of secrets). ([Auth.js][1]) --- ### 1) A tiny, signed “guest token” cookie Create `lib/guest-token.ts`: ```ts // lib/guest-token.ts import { SignJWT, jwtVerify } from "jose"; const GUEST_COOKIE = "__Host-guest"; // secure + path=/, no Domain export const GUEST_COOKIE_NAME = GUEST_COOKIE; function getKey() { const secret = process.env.AUTH_SECRET!; return new TextEncoder().encode(secret); } export async function createGuestToken( sid: string, maxAgeSec = 60 * 60 * 24 * 30, ) { const now = Math.floor(Date.now() / 1000); return await new SignJWT({ typ: "guest", sid, iat: now }) .setProtectedHeader({ alg: "HS256" }) .setIssuedAt(now) .setExpirationTime(now + maxAgeSec) .sign(getKey()); } export async function verifyGuestToken(token: string) { const { payload } = await jwtVerify(token, getKey()); if (payload.typ !== "guest" || typeof payload.sid !== "string") throw new Error("bad guest token"); return { sid: payload.sid as string, iat: payload.iat as number, exp: payload.exp as number, }; } ``` > We keep this payload tiny (just a stable **sid**) to respect cookie size limits. ([NextAuth][2]) --- ### 2) Middleware: ensure every visitor gets a guest token Create `middleware.ts` (Edge‑compatible): ```ts // middleware.ts import { NextResponse } from "next/server"; import type { NextRequest } from "next/server"; import { createGuestToken, GUEST_COOKIE_NAME } from "./lib/guest-token"; export async function middleware(req: NextRequest) { const res = NextResponse.next(); const existing = req.cookies.get(GUEST_COOKIE_NAME)?.value; if (!existing) { const sid = crypto.randomUUID(); const token = await createGuestToken(sid); res.cookies.set({ name: GUEST_COOKIE_NAME, value: token, httpOnly: true, secure: true, sameSite: "lax", path: "/", // required for "__Host-" prefix }); } return res; } // Run on all HTML/app routes; skip static assets as you prefer. export const config = { matcher: ["/((?!_next|api|.*\\..*).*)"], }; ``` > Reading/setting cookies in Middleware is supported; it runs before your route code. ([Next.js][3]) --- ### 3) NextAuth v5 config: carry guest → session Create `auth.ts` (v5 “lazy init” so you can read the request/cookies): ```ts // auth.ts import NextAuth from "next-auth"; import Credentials from "next-auth/providers/credentials"; // Add your real providers, e.g. GitHub/Google/Email // import GitHub from "next-auth/providers/github"; import { verifyGuestToken, GUEST_COOKIE_NAME } from "@/lib/guest-token"; export type Role = "guest" | "user"; declare module "next-auth" { interface Session { user: { id: string; name?: string | null; email?: string | null; image?: string | null; }; isGuest?: boolean; guestId?: string | null; } } declare module "next-auth/jwt" { interface JWT { role?: Role; guestId?: string | null; // previous guest sid for migrations } } // This provider lets you treat guests as "signed-in" if you want a single code path. // If you prefer to keep guests unauthenticated, you can omit this provider and just use the cookie. const GuestProvider = Credentials({ id: "guest", name: "Guest", credentials: {}, async authorize() { // Create a synthetic user ID. We still rely on the guest cookie as the stable ID. return { id: `guest:${crypto.randomUUID()}`, name: "Guest" } as any; }, }); export const { handlers, auth, signIn, signOut } = NextAuth((req) => ({ session: { strategy: "jwt", maxAge: 60 * 60 * 24 * 30 }, // Include GuestProvider if you want `useSession()` to be "authenticated" for guests too. providers: [GuestProvider /*, GitHub(), Google(), Email() ... */], callbacks: { // 1) When a user signs in (guest or real), shape the token async jwt({ token, user, account, trigger }) { if (trigger === "signIn" && account?.provider === "guest" && user) { token.sub = user.id; token.role = "guest"; // We’ll expose the actual guest sid through the cookie → session below } // On upgrade to a real account, capture the guest sid for migration if (trigger === "signIn" && account && account.provider !== "guest") { const raw = req?.cookies.get(GUEST_COOKIE_NAME)?.value; if (raw) { try { const { sid } = await verifyGuestToken(raw); token.guestId = sid; // carry through to session for merge step } catch {} } token.role = "user"; } return token; }, // 2) What the client gets via useSession()/getSession() async session({ session, token }) { if (session.user && token.sub) session.user.id = token.sub; session.isGuest = token.role === "guest"; // Expose the stable guest sid from the cookie (if present) const raw = req?.cookies.get(GUEST_COOKIE_NAME)?.value; session.guestId = null; if (raw) { try { const { sid } = await verifyGuestToken(raw); session.guestId = sid; } catch {} } return session; }, // 3) Optional: gate admin sections, etc., in middleware via `authorized` authorized({ auth }) { // Example: allow all visitors through; you can add role checks here. return true; }, }, // Cookie + JWT behavior (JWT/JWE cookie by default) // - default JWE encryption; uses AUTH_SECRET // - default cookie maxAge/rotation handled by NextAuth })); ``` **Notes** - NextAuth encrypts the JWT session cookie (JWE) using your `AUTH_SECRET`; JWT is the default session strategy. ([Auth.js][1]) - We **read the guest cookie inside callbacks** thanks to v5 lazy initialization (`NextAuth(req => ({ ... }))`). ([Auth.js][1]) - If you don’t want guests to appear “authenticated” in `useSession()`, **remove the `GuestProvider`**. You’ll still have `session === null` for guests _but_ you can read the `guestId` via a tiny helper (below). --- ### 4) Unified “viewer” helper (server) If you prefer not to include the `GuestProvider`, use this on the server: ```ts // lib/viewer.ts import { auth } from "@/auth"; import { cookies } from "next/headers"; import { verifyGuestToken, GUEST_COOKIE_NAME } from "@/lib/guest-token"; export async function getViewer() { const session = await auth(); // NextAuth session or null if (session) return { kind: "user" as const, session }; const raw = cookies().get(GUEST_COOKIE_NAME)?.value; if (!raw) return { kind: "unknown" as const }; const { sid } = await verifyGuestToken(raw); return { kind: "guest" as const, guestId: sid }; } ``` --- ### 5) The upgrade path When the guest authenticates with any real provider: 1. **JWT callback** (above) copies the `guestId` from the cookie into the token. 2. Handle the actual merge in an **event** or the first request after sign‑in: ```ts // in auth.ts (inside NextAuth config) events: { async signIn(msg) { // For credentials providers, msg.user is the raw user. // For OAuth/email, you'll have an adapter user in msg.user (if using an adapter) // If you're JWT-only, you can read the guest cookie again here. // Example (pseudocode): // const guestId = ...read from cookie or msg... // await mergeGuestDataIntoUser(guestId, msg.user.id) }, }, ``` Events are the right hook for one‑time merge/audit work. ([Auth.js][1]) **What to merge?** - Browser‑only state (e.g., a cart in another cookie/IndexedDB) → POST it to your API immediately after login, keyed by `session.guestId`. - Server‑side, tie any anonymous trail you kept (e.g., telemetry keyed by `guestId`) to the new `userId`. --- ## Client usage examples - **Guest‑aware UI** (works both with and without `GuestProvider`): ```tsx "use client"; import { useSession } from "next-auth/react"; export function UserBadge() { const { data } = useSession(); if (data?.isGuest) return <>Browsing as guest • id {data.guestId?.slice(0, 8)}…; if (data?.user?.id) return <>Signed in • {data.user.name ?? data.user.id}; return <>Loading…; } ``` --- ## Security & pitfalls - **Keep the guest token tiny.** Cookies have practical limits; NextAuth does cookie chunking, but you still pay in bandwidth; don’t stuff carts/preferences into JWTs. ([NextAuth][2]) - Use the `__Host-` prefix + `Secure` + `HttpOnly` + `SameSite=Lax` to harden your cookie (as shown). - **Don’t rely on cookie names** for NextAuth’s own session; use the framework helpers (`auth()`, `getSession()`, `getToken()`), since cookie names can differ across versions/configs. NextAuth stores the session token in its **Session Token cookie** (JWE) and lets you customize names if needed. ([NextAuth][4]) - **Role‑guard your APIs**: treat `session.isGuest`/`token.role === "guest"` as read‑only access. --- ## Variants you can choose **A) “Guest as real session”** (single code path) - Keep `GuestProvider` in `providers`. On first visit, call `await signIn("guest", { redirect: false })` client‑side to mint the NextAuth cookie (still no localStorage). - Everything reads from `useSession()`; check `session.isGuest`. - Upgrade with any provider; the `jwt` callback carries `guestId` across. **B) “Guest as separate cookie” (leaner)** - Omit `GuestProvider`. - Use `getViewer()` server‑side (or a small `/api/viewer` endpoint) to get either `{ kind: "guest", guestId }` or a full session. - Upgrade flow is the same; NextAuth’s callbacks can still read the guest cookie at sign‑in time. Both variants remain **stateless** and **browser‑contained** (HttpOnly cookies only). NextAuth’s JWT cookies are **encrypted by default** and rotated/extended by its helpers. ([Auth.js][1]) --- ## What you get - Stable **guest identity** from first pixel paint (middleware sets the cookie). - A clean, **reliable upgrade path**: guest → user without losing context. - No localStorage; everything is **HttpOnly** cookies + NextAuth JWT. If you want, tell me whether you’d prefer Variant A or B for your app (and which auth providers you’ll use). I can tailor the config and add a tiny client hook for fetching `viewer` on the client without exposing tokens. [1]: https://authjs.dev/reference/nextjs "Auth.js | Nextjs" [2]: https://next-auth.js.org/faq "Frequently Asked Questions | NextAuth.js" [3]: https://nextjs.org/docs/app/guides/authentication?utm_source=chatgpt.com "Guides: Authentication" [4]: https://next-auth.js.org/configuration/options?utm_source=chatgpt.com "Options | NextAuth.js"