deckhearth/.cursor/rules/auth-and-permissions.mdc

---
description: Auth model + permission model for Deck Hearth (JWT + collection roles)
globs: pages/api/**/*.js,lib/*.js,components/*.js,pages/*.js
---

# Auth + permissions

There are three parallel client-side auth implementations and one server-side helper. New code should use the canonical set listed below; don't proliferate variants.

## Canonical surface (use these)

| Concern | Module |
| --- | --- |
| Server: extract user from request | `lib/permission-middleware.js::getUserFromRequest` |
| Server: gate a collection route | `lib/permission-middleware.js::withCollectionPermission` |
| Server: log collection mutation | `lib/permission-middleware.js::logCollectionActivity` |
| Server: JWT secret + canonical TTL | `lib/auth-secret.js` (`JWT_SECRET`, `JWT_TOKEN_TTL`) — single source of truth, fail-loud on unset env |
| Server: token / password primitives | `pages/api/auth-utils.js` (`generateToken`, `verifyToken`, `hashPassword`, `verifyPassword`) — reads secret + TTL from `lib/auth-secret.js` |
| Server: rate-limit auth endpoints | `lib/rate-limit.js::checkAuthRateLimit` (5 attempts / 15 min sliding window via `@upstash/ratelimit`) |
| Client: hook | `lib/use-auth.js::useAuth` |
| Client: route protection | `components/ProtectedRoute.js` |
| Client: admin route protection | `components/AdminProtected.js` |

## Legacy (deleted by `single-auth-provider`)

`lib/auth-context.js` and `lib/admin-auth.js` were the two parallel client-side
auth surfaces that lived alongside `lib/use-auth.js`. They were deleted by the
`single-auth-provider` convoy (P1). Do **not** reintroduce a `<AuthProvider>`
or `<AdminProvider>` wrapper in `pages/_app.js` — `useAuth()` from
`lib/use-auth.js` is hook-only (reads token from `localStorage` and hits
`/api/auth/verify` on mount) and does not require a context provider. The
`useIsAdmin` semantic is now `const { user } = useAuth(); const isAdmin = user?.role === 'admin'`.

## Token model

- JWT in localStorage under the key `auth_token`.
- Signed with `JWT_SECRET` (HS256), **24-hour expiry** (canonical `JWT_TOKEN_TTL = '24h'` from `lib/auth-secret.js`), payload `{ userId, email, role }`.
- Sent on every authenticated fetch as `Authorization: Bearer <token>`.
- Verified server-side with `jsonwebtoken.verify(token, JWT_SECRET)` (or `verifyToken` from `pages/api/auth-utils.js`).

**`JWT_SECRET` MUST be set in the deploy environment.** `lib/auth-secret.js` is the only place either `JWT_SECRET` or `JWT_TOKEN_TTL` is defined; the module **throws at import time** if `process.env.JWT_SECRET` is unset, which fails the request loudly rather than silently signing with a literal fallback. (The legacy `'your-secret-key-change-in-production'` fallback was duplicated across 7 files pre-`fix-auth-bypass`; that whole pattern is gone — do not reintroduce it.)

## Roles

Two role surfaces are in play:

1. **User role** — `users.role` column, values `'user'` or `'admin'`. Admin gates `/admin/*` pages and admin-only API endpoints.
2. **Collection role** — `collection_permissions.role` (`viewer` / `editor` / `owner`) + `collections.is_public` (anonymous viewer access). Resolved by `checkCollectionPermission` in priority order: owner → public-viewer → explicit row.

When introducing a new permission tier, update both `checkRolePermission`'s hierarchy AND every gate that reads `is_public`.

## Authentication state on the client

`useAuth()` returns `{ user, loading, logout, refreshAuth }`. `user === null` means logged out; `loading === true` means token verification in flight. Always render against `loading === false` before deciding to redirect. The login / register flows do **not** go through `useAuth` — `pages/login.js` and `pages/signup.js` `fetch` `/api/auth/{login,register}` directly and write the returned token to `localStorage`; `useAuth()` will pick it up on next mount via its `useEffect` → `/api/auth/verify` roundtrip (or call `refreshAuth()` to re-verify in place).

## Server-side authorization patterns

`getUserFromRequest` returns `{ userId, email, role }` for a valid Bearer token, or `null` for any other case (missing header, malformed token, wrong signature, expired token, unknown user id). **`null` means 401** — always early-return before doing anything that depends on the user:

```js
const user = await getUserFromRequest(req);
if (!user) return res.status(401).json({ error: 'Authentication required' });
```

There is **no synthetic-admin fallback** for missing tokens. The old dev-mode behavior of returning user 1 as admin is gone (resolved by `fix-auth-bypass` Brief 2, commit `258e479`). Do not reintroduce it under any framing — `test/lib/permission-middleware.test.js` has a negative regression test that will fail if the synthetic-admin shape comes back.

From there:

- **Owner-only** (delete, settings): inside the handler, `if (user.userId !== resource.user_id) return res.status(403)`.
- **Editor-or-owner**: use `withCollectionPermission('editor')`.
- **Public read**: use `withCollectionPermission('viewer')` — handles `is_public` and explicit-permission case.
- **Admin-only**: check `user.role === 'admin'` directly; consider extracting `withAdmin()` if a third call site appears.