feat: enhance authentication flow and UI components

- Updated .env.example to include OAuth authentication details and bypass mode for development.
- Integrated AuthProvider in App component to manage authentication state.
- Added AuthCallbackPage for handling OAuth callback.
- Enhanced ExportDropdown and PublicationsTable components to display new publication indicators for authenticated users.
- Updated AppHeader to show authentication status and logout functionality.
- Improved LandingPage to support group search and simulate login in bypass mode.
- Refactored DashboardPage to conditionally handle publication exports based on user authentication status.

frontend/.env.example

@@ -19,3 +19,25 @@ VITE_API_KEY=12ao.9-8a7b-4c&d-9e,f-?89abc
 # Pon "true" SOLO si el backend no está disponible y quieres trabajar
 # con los fixtures de src/services/mocks.js. En producción debe estar a "false".
 VITE_USE_MOCKS=false
+
+# ── Autenticación OAuth ORCID ────────────────────────────────────────────────
+#
+# El flujo real es:
+#   1. Frontend abre popup → GET /api/auth/orcid/authorize
+#   2. Backend redirige a sandbox.orcid.org (o pub.orcid.org en producción)
+#   3. Usuario se autentica en ORCID
+#   4. ORCID redirige a ORCID_REDIRECT_URI (debe apuntar a esta app)
+#   5. /auth/callback extrae el code y llama al backend para obtener el JWT
+#
+# Para que el callback vuelva al frontend, el backend necesita:
+#   ORCID_REDIRECT_URI=http://localhost:5173/auth/callback
+#   (en backend/.env — debe coincidir con el redirect URI del app ORCID sandbox)
+#
+# ── Modo bypass (solo desarrollo sin credenciales OAuth configuradas) ─────────
+# Cuando está a "true", el botón "Iniciar sesión" genera un token simulado
+# a partir del ORCID introducido en el campo de texto, sin abrir popup ni
+# contactar al backend de auth. Útil para probar la UI autenticada
+# (badges "Nuevo", botón "Descargar lo nuevo") sin OAuth real.
+# ADVERTENCIA: el token simulado NO es válido en el backend, por lo que
+# downloaded_by_me siempre será null (sin datos reales de "novedad").
+VITE_AUTH_BYPASS=false

frontend/src/App.jsx

@@ -1,8 +1,11 @@
 import { Navigate, Route, Routes } from "react-router-dom";
 import { Toaster } from "sonner";
 
+import { AuthProvider } from "./contexts/AuthContext";
 import { LandingPage } from "./pages/LandingPage";
 import { DashboardPage } from "./pages/DashboardPage";
+import { GroupResultsPage } from "./pages/GroupResultsPage";
+import { AuthCallbackPage } from "./pages/AuthCallbackPage";
 
 /**
  * App shell. Declares the top-level routes and mounts the global
@@ -11,10 +14,12 @@ import { DashboardPage } from "./pages/DashboardPage";
  */
 export default function App() {
   return (
-    <>
+    <AuthProvider>
       <Routes>
         <Route path="/" element={<LandingPage />} />
         <Route path="/dashboard/:orcid" element={<DashboardPage />} />
+        <Route path="/group" element={<GroupResultsPage />} />
+        <Route path="/auth/callback" element={<AuthCallbackPage />} />
         <Route path="*" element={<Navigate to="/" replace />} />
       </Routes>
 
@@ -25,6 +30,6 @@ export default function App() {
         theme="light"
         toastOptions={{ duration: 4000 }}
       />
-    </>
+    </AuthProvider>
   );
 }

frontend/src/components/dashboard/ExportDropdown.jsx

@@ -4,6 +4,7 @@ import {
   DocumentIcon,
   DownloadIcon,
   PackageIcon,
+  SparkleIcon,
 } from "../ui/Icons";
 import { Spinner } from "../ui/Spinner";
 
@@ -23,17 +24,20 @@ const FORMATS = [
 ];
 
 /**
- * SWORD export dropdown. Delegates the actual download to `onExport(format)`
+ * SWORD export dropdown. Delegatea the actual download to `onExport(format)`.
- * so it can be wired up either to the real API or to a mock layer from the
- * parent page.
  *
- * `exportingFormat` (optional) lets the parent keep the button in a loading
+ * Props:
- * state between clicks (e.g. while waiting for the backend blob).
+ *   - `isAuthenticated`      → cambia el texto del botón principal.
+ *   - `newPublicationsCount` → cuántas publicaciones tiene downloaded_by_me=false.
+ *   - `selectedCount`        → publicaciones seleccionadas manualmente.
+ *   - `exportingFormat`      → formato en curso (pone el botón en loading).
  */
 export function ExportDropdown({
   onExport,
   exportingFormat = null,
   selectedCount = 0,
+  isAuthenticated = false,
+  newPublicationsCount = 0,
 }) {
   const [open, setOpen] = useState(false);
   const rootRef = useRef(null);
@@ -56,19 +60,40 @@ export function ExportDropdown({
     onExport(format);
   }
 
-  const idleLabel = hasSelection
+  // Label logic:
-    ? `Exportar seleccionadas (${selectedCount})`
+  //   manual selection → always "Exportar seleccionadas (N)"
-    : "Exportar todas";
+  //   logged in, no selection → "Descargar lo nuevo (N)" or "Todo descargado"
+  //   not logged in, no selection → "Descargar todo"
+  let idleLabel;
+  let showSparkle = false;
+  if (hasSelection) {
+    idleLabel = `Exportar seleccionadas (${selectedCount})`;
+  } else if (isAuthenticated) {
+    if (newPublicationsCount > 0) {
+      idleLabel = `Descargar lo nuevo (${newPublicationsCount})`;
+      showSparkle = true;
+    } else {
+      idleLabel = "Todo descargado";
+    }
+  } else {
+    idleLabel = "Descargar todo";
+  }
 
   return (
     <div className="relative" ref={rootRef}>
       <button
         type="button"
         onClick={() => setOpen((o) => !o)}
-        disabled={isBusy}
+        disabled={isBusy || (isAuthenticated && !hasSelection && newPublicationsCount === 0)}
         className="inline-flex items-center gap-2 rounded-lg border border-surface-border-strong bg-surface-primary px-[18px] py-2.5 text-sm font-medium text-ink-primary transition-colors enabled:hover:bg-surface-secondary disabled:cursor-not-allowed disabled:opacity-70"
       >
-        {isBusy ? <Spinner size={15} /> : <DownloadIcon />}
+        {isBusy ? (
+          <Spinner size={15} />
+        ) : showSparkle ? (
+          <SparkleIcon size={15} className="text-brand-accent" />
+        ) : (
+          <DownloadIcon />
+        )}
         {isBusy
           ? `Exportando ${exportingFormat.toUpperCase()}...`
           : idleLabel}

frontend/src/components/dashboard/PublicationsTable.jsx

@@ -1,5 +1,5 @@
 import { useEffect, useMemo, useRef, useState } from "react";
-import { AlertIcon, ChevronDownIcon, FilterIcon, SearchIcon } from "../ui/Icons";
+import { AlertIcon, ChevronDownIcon, FilterIcon, SearchIcon, SparkleIcon } from "../ui/Icons";
 import { Spinner } from "../ui/Spinner";
 import { Badge } from "../ui/Badge";
 
@@ -83,6 +83,7 @@ export function PublicationsTable({
   onRetry,
   selectedIds = EMPTY_SELECTION,
   onSelectedIdsChange,
+  isAuthenticated = false,
 }) {
   const [filter, setFilter] = useState("");
   const [sortKey, setSortKey] = useState("publication_year");
@@ -447,7 +448,18 @@ export function PublicationsTable({
                         />
                       </td>
                       <td className="max-w-[280px] px-4 py-3.5 text-[13px] font-medium leading-relaxed text-ink-primary">
-                        {pub.title}
+                        <span className="flex flex-wrap items-start gap-1.5">
+                          {isAuthenticated && pub.downloaded_by_me === false && (
+                            <span
+                              title="No descargada aún por ti"
+                              className="mt-0.5 inline-flex shrink-0 items-center gap-0.5 rounded-full bg-brand-accent/10 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide text-brand-accent"
+                            >
+                              <SparkleIcon size={9} />
+                              Nuevo
+                            </span>
+                          )}
+                          {pub.title}
+                        </span>
                       </td>
                       <td className="whitespace-nowrap px-4 py-3.5 text-[13px] text-ink-secondary">
                         {pub.journal || "—"}

frontend/src/components/layout/AppHeader.jsx

@@ -1,15 +1,29 @@
-import { Link } from "react-router-dom";
+import { Link, useNavigate } from "react-router-dom";
-import { ArrowLeftIcon, LayersIcon } from "../ui/Icons";
+import { toast } from "sonner";
+import { ArrowLeftIcon, LayersIcon, LogoutIcon, UserCheckIcon } from "../ui/Icons";
+import { useAuth } from "../../contexts/AuthContext";
 
 /**
  * Institutional navy header used across all views.
  *
  * Variants:
- *   - `landing`  → logo + full product name (centered brand title).
+ *   - `landing`   → logo + full product name.
- *   - `dashboard`→ back button to `/` + discrete product label on the right.
+ *   - `dashboard` → back button to `/` + auth indicator + logout (if logged in).
+ *   - `group`     → back button to `/` + group label + auth indicator.
  */
 export function AppHeader({ variant = "landing" }) {
-  if (variant === "dashboard") {
+  const { isAuthenticated, logout } = useAuth();
+  const navigate = useNavigate();
+
+  function handleLogout() {
+    logout();
+    toast.success("Sesión cerrada", {
+      description: "Has cerrado sesión correctamente.",
+    });
+    navigate("/");
+  }
+
+  if (variant === "dashboard" || variant === "group") {
     return (
       <header className="flex h-14 items-center gap-4 bg-brand-primary px-7 text-white">
         <Link
@@ -20,8 +34,24 @@ export function AppHeader({ variant = "landing" }) {
           Inicio
         </Link>
         <div className="flex-1" />
+        {isAuthenticated && (
+          <div className="flex items-center gap-3">
+            <span className="inline-flex items-center gap-1.5 rounded-full bg-white/10 px-2.5 py-1 text-[12px] text-white/80">
+              <UserCheckIcon size={13} />
+              Sesión activa
+            </span>
+            <button
+              type="button"
+              onClick={handleLogout}
+              className="inline-flex items-center gap-1.5 rounded-md bg-white/10 px-2.5 py-1.5 text-[13px] transition-colors hover:bg-white/20"
+            >
+              <LogoutIcon />
+              Cerrar sesión
+            </button>
+          </div>
+        )}
         <span className="text-[13px] text-white/60">
-          Sistema ORCID · SWORD
+          {variant === "group" ? "Búsqueda grupal · ORCID" : "Sistema ORCID · SWORD"}
         </span>
       </header>
     );
@@ -35,6 +65,22 @@ export function AppHeader({ variant = "landing" }) {
       <span className="text-sm font-medium tracking-wide text-white">
         Sistema de Integración ORCID · SWORD
       </span>
+      {isAuthenticated && (
+        <div className="ml-auto flex items-center gap-2">
+          <span className="inline-flex items-center gap-1.5 rounded-full bg-white/10 px-2.5 py-1 text-[12px] text-white/80">
+            <UserCheckIcon size={13} />
+            Sesión activa
+          </span>
+          <button
+            type="button"
+            onClick={handleLogout}
+            className="inline-flex items-center gap-1.5 rounded-md bg-white/10 px-2.5 py-1.5 text-[13px] transition-colors hover:bg-white/20"
+          >
+            <LogoutIcon />
+            Cerrar sesión
+          </button>
+        </div>
+      )}
     </header>
   );
 }

frontend/src/components/ui/Icons.jsx

@@ -120,3 +120,39 @@ export function PackageIcon({ size = 18, className = "" }) {
     </svg>
   );
 }
+
+export function LogoutIcon({ size = 15, className = "" }) {
+  return (
+    <svg {...base} width={size} height={size} strokeWidth={2} className={className}>
+      <path d="M9 21H5a2 2 0 01-2-2V5a2 2 0 012-2h4M16 17l5-5-5-5M21 12H9" />
+    </svg>
+  );
+}
+
+export function UsersIcon({ size = 16, className = "" }) {
+  return (
+    <svg {...base} width={size} height={size} strokeWidth={1.8} className={className}>
+      <path d="M17 21v-2a4 4 0 00-4-4H5a4 4 0 00-4 4v2" />
+      <circle cx="9" cy="7" r="4" />
+      <path d="M23 21v-2a4 4 0 00-3-3.87M16 3.13a4 4 0 010 7.75" />
+    </svg>
+  );
+}
+
+export function SparkleIcon({ size = 12, className = "" }) {
+  return (
+    <svg {...base} width={size} height={size} strokeWidth={2} className={className}>
+      <path d="M12 2l2.4 7.4H22l-6.2 4.5 2.4 7.4L12 17l-6.2 4.3 2.4-7.4L2 9.4h7.6z" />
+    </svg>
+  );
+}
+
+export function UserCheckIcon({ size = 15, className = "" }) {
+  return (
+    <svg {...base} width={size} height={size} strokeWidth={1.8} className={className}>
+      <path d="M16 21v-2a4 4 0 00-4-4H6a4 4 0 00-4 4v2" />
+      <circle cx="9" cy="7" r="4" />
+      <polyline points="16 11 18 13 22 9" />
+    </svg>
+  );
+}

frontend/src/contexts/AuthContext.jsx

@@ -0,0 +1,81 @@
+import {
+  createContext,
+  useCallback,
+  useContext,
+  useEffect,
+  useMemo,
+  useState,
+} from "react";
+
+const STORAGE_KEY = "orcid_auth_token";
+
+// Message type sent by AuthCallbackPage (runs in the OAuth popup)
+// to notify the parent window that authentication succeeded.
+export const AUTH_MESSAGE_TYPE = "ORCID_AUTH_TOKEN";
+export const AUTH_ERROR_TYPE = "ORCID_AUTH_ERROR";
+
+const AuthContext = createContext(null);
+
+/**
+ * Provides JWT-based authentication state throughout the app.
+ *
+ * Authentication flow (OAuth 3-legged):
+ *   1. User clicks "Iniciar sesión" → frontend opens popup at
+ *      GET /api/auth/orcid/authorize.
+ *   2. Backend redirects to ORCID (sandbox or production).
+ *   3. User authenticates at orcid.org.
+ *   4. ORCID redirects to ORCID_REDIRECT_URI (= frontend /auth/callback).
+ *   5. AuthCallbackPage exchanges the `code` for a JWT via the backend.
+ *   6. Popup sends postMessage({ type: "ORCID_AUTH_TOKEN", token }) to
+ *      opener and closes itself.
+ *   7. This provider's message listener stores the token and updates state.
+ *
+ * For development / sandbox bypass (VITE_AUTH_BYPASS=true), the token is
+ * stored directly via storeToken() without going through ORCID.
+ */
+export function AuthProvider({ children }) {
+  const [token, setToken] = useState(() => localStorage.getItem(STORAGE_KEY));
+
+  // Listen for messages from the OAuth popup window.
+  useEffect(() => {
+    function handleMessage(event) {
+      // Only accept messages from the same origin (the React app itself,
+      // running in the popup after the OAuth redirect lands there).
+      if (event.origin !== window.location.origin) return;
+
+      if (event.data?.type === AUTH_MESSAGE_TYPE && event.data?.token) {
+        localStorage.setItem(STORAGE_KEY, event.data.token);
+        setToken(event.data.token);
+      }
+    }
+    window.addEventListener("message", handleMessage);
+    return () => window.removeEventListener("message", handleMessage);
+  }, []);
+
+  /**
+   * Stores a JWT directly (used by AuthCallbackPage and bypass mode).
+   * Does NOT trigger any network request.
+   */
+  const storeToken = useCallback((accessToken) => {
+    localStorage.setItem(STORAGE_KEY, accessToken);
+    setToken(accessToken);
+  }, []);
+
+  const logout = useCallback(() => {
+    localStorage.removeItem(STORAGE_KEY);
+    setToken(null);
+  }, []);
+
+  const value = useMemo(
+    () => ({ token, isAuthenticated: Boolean(token), storeToken, logout }),
+    [token, storeToken, logout],
+  );
+
+  return <AuthContext.Provider value={value}>{children}</AuthContext.Provider>;
+}
+
+export function useAuth() {
+  const ctx = useContext(AuthContext);
+  if (!ctx) throw new Error("useAuth must be used inside <AuthProvider>");
+  return ctx;
+}

frontend/src/pages/AuthCallbackPage.jsx

@@ -0,0 +1,154 @@
+import { useEffect, useState } from "react";
+import { useNavigate, useSearchParams } from "react-router-dom";
+
+import { Spinner } from "../components/ui/Spinner";
+import { AlertIcon, CheckIcon } from "../components/ui/Icons";
+import { exchangeOrcidCode } from "../services/api";
+import { useAuth } from "../contexts/AuthContext";
+import { AUTH_MESSAGE_TYPE, AUTH_ERROR_TYPE } from "../contexts/AuthContext";
+
+/**
+ * OAuth callback page — mounted at /auth/callback.
+ *
+ * ORCID redirects here after the user authenticates. We extract the
+ * authorization `code`, exchange it for a JWT via the backend, store
+ * the token and — if running inside a popup — notify the opener and
+ * close the window. Otherwise we navigate back to the landing page.
+ *
+ * For this page to be reached, the backend's ORCID_REDIRECT_URI env var
+ * must be set to <frontend-origin>/auth/callback, e.g.:
+ *   ORCID_REDIRECT_URI=http://localhost:5173/auth/callback
+ */
+export function AuthCallbackPage() {
+  const [searchParams] = useSearchParams();
+  const navigate = useNavigate();
+  const { storeToken } = useAuth();
+
+  const [status, setStatus] = useState("loading"); // loading | success | error
+  const [errorMsg, setErrorMsg] = useState("");
+
+  useEffect(() => {
+    const code = searchParams.get("code");
+    const oauthError = searchParams.get("error");
+    const errorDescription = searchParams.get("error_description");
+
+    // User denied access at ORCID
+    if (oauthError) {
+      const msg =
+        errorDescription ??
+        (oauthError === "access_denied"
+          ? "Acceso denegado en ORCID."
+          : `Error OAuth: ${oauthError}`);
+      setStatus("error");
+      setErrorMsg(msg);
+      notifyAndClose({ type: AUTH_ERROR_TYPE, error: msg });
+      return;
+    }
+
+    if (!code) {
+      const msg = "No se recibió el código de autorización de ORCID.";
+      setStatus("error");
+      setErrorMsg(msg);
+      notifyAndClose({ type: AUTH_ERROR_TYPE, error: msg });
+      return;
+    }
+
+    exchangeOrcidCode(code)
+      .then(({ access_token }) => {
+        storeToken(access_token);
+        setStatus("success");
+        notifyAndClose({ type: AUTH_MESSAGE_TYPE, token: access_token });
+      })
+      .catch((err) => {
+        const msg = err?.message ?? "No se pudo completar el inicio de sesión.";
+        setStatus("error");
+        setErrorMsg(msg);
+        notifyAndClose({ type: AUTH_ERROR_TYPE, error: msg });
+      });
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  // After a short delay, redirect to home if we're NOT in a popup
+  // (fallback for browsers that block window.open).
+  useEffect(() => {
+    if (status === "success" || status === "error") {
+      const isPopup = Boolean(window.opener);
+      if (!isPopup) {
+        const timer = setTimeout(() => navigate("/"), 2000);
+        return () => clearTimeout(timer);
+      }
+    }
+  }, [status, navigate]);
+
+  return (
+    <div className="flex min-h-screen flex-col items-center justify-center gap-5 bg-surface-tertiary p-8 text-center">
+      {status === "loading" && (
+        <>
+          <Spinner size={32} />
+          <div>
+            <p className="text-base font-medium text-ink-primary">
+              Completando inicio de sesión...
+            </p>
+            <p className="mt-1 text-sm text-ink-secondary">
+              Verificando credenciales con ORCID.
+            </p>
+          </div>
+        </>
+      )}
+
+      {status === "success" && (
+        <>
+          <div className="flex h-14 w-14 items-center justify-center rounded-full bg-green-100 text-green-600">
+            <CheckIcon size={28} />
+          </div>
+          <div>
+            <p className="text-base font-medium text-ink-primary">
+              ¡Sesión iniciada correctamente!
+            </p>
+            <p className="mt-1 text-sm text-ink-secondary">
+              Cerrando ventana...
+            </p>
+          </div>
+        </>
+      )}
+
+      {status === "error" && (
+        <>
+          <div className="flex h-14 w-14 items-center justify-center rounded-full bg-red-100 text-red-500">
+            <AlertIcon size={28} />
+          </div>
+          <div>
+            <p className="text-base font-medium text-ink-primary">
+              Error al iniciar sesión
+            </p>
+            <p className="mt-1 text-sm text-ink-secondary">{errorMsg}</p>
+            <p className="mt-2 text-xs text-ink-tertiary">
+              Cerrando ventana...
+            </p>
+          </div>
+        </>
+      )}
+    </div>
+  );
+}
+
+/* ─────────────────────────── Helpers ───────────────────────────── */
+
+/**
+ * If running in a popup, posts a message to the opener and closes the
+ * window. If not in a popup (e.g. browser blocked it), the message is
+ * irrelevant — the useEffect above handles the redirect to "/".
+ */
+function notifyAndClose(message) {
+  if (window.opener && !window.opener.closed) {
+    try {
+      window.opener.postMessage(message, window.location.origin);
+    } catch {
+      /* opener may have navigated away */
+    }
+    // Small delay so the user sees the success/error state before close.
+    setTimeout(() => window.close(), 1200);
+  }
+}
+
+export default AuthCallbackPage;

frontend/src/pages/DashboardPage.jsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useRef, useState } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { useLocation, useParams, Navigate } from "react-router-dom";
 import { toast } from "sonner";
 
@@ -14,24 +14,27 @@ import {
   syncResearcher,
 } from "../services/api";
 import { isValidOrcid } from "../utils/orcid";
+import { useAuth } from "../contexts/AuthContext";
 
 const SUCCESS_FLASH_MS = 3000;
 
 /**
  * Researcher detail page. Owns:
- *   - Carga inicial vía `searchResearcher` (todo en uno: researcher +
+ *   - Carga inicial vía `searchResearcher`. Si llegamos desde la landing
- *     publications + resumen de cambios). Si llegamos desde la landing
  *     usamos el bundle ya cargado en `location.state` para evitar
  *     duplicar la petición.
  *   - Re-sync manual (POST + actualización de estado in-place + toast).
- *   - Exportación SWORD/ZIP (selectiva si hay selección, masiva si no).
+ *   - Exportación SWORD/ZIP:
+ *       · Si hay selección manual → exporta esos IDs.
+ *       · Si el usuario está autenticado y sin selección → exporta solo
+ *         los IDs con downloaded_by_me=false ("lo nuevo").
+ *       · Si no está autenticado y sin selección → exporta todo.
  */
 export function DashboardPage() {
   const { orcid } = useParams();
   const location = useLocation();
-  // El bundle del Landing solo lo consumimos UNA vez: la primera vez
+  const { isAuthenticated } = useAuth();
-  // que se monta el componente. Si el usuario refresca, navega o vuelve
+
-  // atrás, queremos que se vuelva a pedir al backend.
   const initialBundleRef = useRef(location.state?.bundle ?? null);
 
   const initialBundle = initialBundleRef.current;
@@ -47,11 +50,17 @@ export function DashboardPage() {
 
   const [selectedIds, setSelectedIds] = useState(() => new Set());
 
-  /**
+  // IDs de publicaciones que el usuario no ha descargado todavía
-   * Carga (o recarga) el bundle completo del investigador. Centralizamos
+  const newPublicationIds = useMemo(
-   * la lógica aquí para que tanto el `useEffect` inicial como el botón
+    () =>
-   * "Reintentar" del estado de error compartan código.
+      isAuthenticated
-   */
+        ? publications
+            .filter((p) => p.downloaded_by_me === false)
+            .map((p) => p.id)
+        : [],
+    [publications, isAuthenticated],
+  );
+
   const loadBundle = useCallback(
     async (signal) => {
       setPubsLoading(true);
@@ -61,8 +70,6 @@ export function DashboardPage() {
         if (signal?.aborted) return;
         setResearcher(bundle.researcher);
         setPublications(bundle.publications);
-        // La selección sobrevive recargas: nos quedamos con los IDs que
-        // siguen existiendo tras el sync, descartamos los que no.
         setSelectedIds((prev) => {
           if (prev.size === 0) return prev;
           const alive = new Set(bundle.publications.map((p) => p.id));
@@ -85,9 +92,6 @@ export function DashboardPage() {
 
   useEffect(() => {
     if (!isValidOrcid(orcid)) return;
-    // Si venimos del Landing con el bundle precargado, evitamos la
-    // segunda petición y consumimos el ref para que un refresh sí pegue
-    // al backend.
     if (initialBundleRef.current) {
       initialBundleRef.current = null;
       return;
@@ -135,15 +139,32 @@ export function DashboardPage() {
   async function handleExport(format) {
     setExportingFormat(format);
     try {
-      const ids = Array.from(selectedIds);
+      let ids;
+      if (selectedIds.size > 0) {
+        // Manual selection takes priority
+        ids = Array.from(selectedIds);
+      } else if (isAuthenticated) {
+        // Authenticated → only download publications not yet downloaded by me
+        ids = newPublicationIds;
+        if (ids.length === 0) {
+          toast.info("No hay publicaciones nuevas", {
+            description: "Ya has descargado todas las publicaciones de este investigador.",
+          });
+          setExportingFormat(null);
+          return;
+        }
+      } else {
+        // Anonymous → download everything
+        ids = undefined;
+      }
+
       const { blob } = await downloadExport(orcid, format, {
-        publicationIds: ids.length > 0 ? ids : undefined,
+        publicationIds: ids,
       });
       if (blob) {
         const objectUrl = URL.createObjectURL(blob);
         const anchor = document.createElement("a");
         anchor.href = objectUrl;
-        // Usamos extensiones reales: el endpoint SWORD devuelve XML.
         const extension = format === "xml" ? "xml" : format;
         anchor.download = `sword-${orcid}.${extension}`;
         document.body.appendChild(anchor);
@@ -151,10 +172,15 @@ export function DashboardPage() {
         anchor.remove();
         URL.revokeObjectURL(objectUrl);
       }
-      const scope =
+
-        ids.length > 0
+      let scope;
-          ? `${ids.length} publicación${ids.length === 1 ? "" : "es"} seleccionada${ids.length === 1 ? "" : "s"}`
+      if (selectedIds.size > 0) {
-          : "todo el investigador";
+        scope = `${selectedIds.size} publicación${selectedIds.size === 1 ? "" : "es"} seleccionada${selectedIds.size === 1 ? "" : "s"}`;
+      } else if (isAuthenticated) {
+        scope = `${newPublicationIds.length} publicación${newPublicationIds.length === 1 ? "" : "es"} nueva${newPublicationIds.length === 1 ? "" : "s"}`;
+      } else {
+        scope = "todo el investigador";
+      }
       toast.success(`Exportación ${format.toUpperCase()} completada`, {
         description: scope,
       });
@@ -182,6 +208,8 @@ export function DashboardPage() {
                   onExport={handleExport}
                   exportingFormat={exportingFormat}
                   selectedCount={selectedIds.size}
+                  isAuthenticated={isAuthenticated}
+                  newPublicationsCount={newPublicationIds.length}
                 />
               </>
             }
@@ -199,6 +227,7 @@ export function DashboardPage() {
           onRetry={() => loadBundle()}
           selectedIds={selectedIds}
           onSelectedIdsChange={setSelectedIds}
+          isAuthenticated={isAuthenticated}
         />
 
         <footer className="mt-4 flex flex-wrap items-center justify-between gap-2 px-1">

frontend/src/pages/GroupResultsPage.jsx

@@ -0,0 +1,496 @@
+import { useEffect, useMemo, useRef, useState } from "react";
+import { useLocation, useNavigate, Link } from "react-router-dom";
+import { toast } from "sonner";
+
+import { AppHeader } from "../components/layout/AppHeader";
+import { Spinner } from "../components/ui/Spinner";
+import { OrcidLogo } from "../components/ui/OrcidLogo";
+import {
+  AlertIcon,
+  ArrowLeftIcon,
+  DownloadIcon,
+  SparkleIcon,
+  UsersIcon,
+} from "../components/ui/Icons";
+import { downloadExport, searchResearchersBulk } from "../services/api";
+import { useAuth } from "../contexts/AuthContext";
+
+/**
+ * Group results view: shows one summary card per researcher, plus a global
+ * "download all new" (or "download everything") action in the header.
+ *
+ * Receives `{ orcidIds: string[] }` via `location.state` (set by LandingPage).
+ * If no state is present the user is redirected back to `/`.
+ */
+export function GroupResultsPage() {
+  const location = useLocation();
+  const navigate = useNavigate();
+  const { isAuthenticated } = useAuth();
+
+  const orcidIds = location.state?.orcidIds;
+
+  const [results, setResults] = useState([]);
+  const [errors, setErrors] = useState([]);
+  const [loading, setLoading] = useState(true);
+  const [globalExporting, setGlobalExporting] = useState(null); // format | null
+
+  // Track per-researcher export state (format | null)
+  const [cardExporting, setCardExporting] = useState({});
+
+  const abortRef = useRef(null);
+
+  useEffect(() => {
+    if (!orcidIds || orcidIds.length === 0) {
+      navigate("/", { replace: true });
+      return;
+    }
+
+    const ctrl = new AbortController();
+    abortRef.current = ctrl;
+
+    (async () => {
+      setLoading(true);
+      try {
+        const data = await searchResearchersBulk(orcidIds, {
+          signal: ctrl.signal,
+        });
+        if (ctrl.signal.aborted) return;
+        setResults(data.results ?? []);
+        setErrors(data.errors ?? []);
+
+        const failCount = (data.errors ?? []).length;
+        const okCount = (data.results ?? []).length;
+        if (failCount > 0) {
+          toast.warning(
+            `${okCount} investigador${okCount !== 1 ? "es" : ""} cargado${okCount !== 1 ? "s" : ""}, ${failCount} con error`,
+            {
+              description: "Comprueba los ORCID iDs que fallaron abajo.",
+            },
+          );
+        }
+      } catch (err) {
+        if (ctrl.signal.aborted) return;
+        toast.error("Error al buscar investigadores", {
+          description: err?.message ?? "Inténtalo de nuevo.",
+        });
+        setResults([]);
+        setErrors([]);
+      } finally {
+        if (!ctrl.signal.aborted) setLoading(false);
+      }
+    })();
+
+    return () => ctrl.abort();
+  }, [orcidIds, navigate]);
+
+  // All new publication IDs across all loaded researchers
+  const allNewIds = useMemo(() => {
+    if (!isAuthenticated) return [];
+    return results.flatMap((r) =>
+      (r.publications ?? [])
+        .filter((p) => p.downloaded_by_me === false)
+        .map((p) => p.id),
+    );
+  }, [results, isAuthenticated]);
+
+  const allIds = useMemo(
+    () => results.flatMap((r) => (r.publications ?? []).map((p) => p.id)),
+    [results],
+  );
+
+  async function handleGlobalExport(format) {
+    const ids = isAuthenticated ? allNewIds : allIds;
+    if (ids.length === 0) {
+      toast.info(
+        isAuthenticated
+          ? "No hay publicaciones nuevas"
+          : "No hay publicaciones para exportar",
+        { description: "No se encontraron publicaciones en los investigadores cargados." },
+      );
+      return;
+    }
+    setGlobalExporting(format);
+    try {
+      // For bulk export we send all IDs together, passing a placeholder orcid
+      // since the endpoint is POST /export/{format}/publications (no orcid needed)
+      const { blob } = await downloadExport(null, format, {
+        publicationIds: ids,
+      });
+      if (blob) {
+        const objectUrl = URL.createObjectURL(blob);
+        const anchor = document.createElement("a");
+        anchor.href = objectUrl;
+        anchor.download = `sword-group.${format === "xml" ? "xml" : format}`;
+        document.body.appendChild(anchor);
+        anchor.click();
+        anchor.remove();
+        URL.revokeObjectURL(objectUrl);
+      }
+      toast.success(`Exportación ${format.toUpperCase()} completada`, {
+        description: `${ids.length} publicaciones exportadas.`,
+      });
+    } catch (err) {
+      toast.error(`Error al exportar ${format.toUpperCase()}`, {
+        description: err?.message ?? "No se pudo generar el fichero.",
+      });
+    } finally {
+      setGlobalExporting(null);
+    }
+  }
+
+  async function handleCardExport(orcidId, format, newIds, totalIds) {
+    const ids = isAuthenticated ? newIds : totalIds;
+    if (ids.length === 0) {
+      toast.info("No hay publicaciones para exportar");
+      return;
+    }
+    setCardExporting((prev) => ({ ...prev, [orcidId]: format }));
+    try {
+      const { blob } = await downloadExport(orcidId, format, {
+        publicationIds: ids,
+      });
+      if (blob) {
+        const objectUrl = URL.createObjectURL(blob);
+        const anchor = document.createElement("a");
+        anchor.href = objectUrl;
+        anchor.download = `sword-${orcidId}.${format === "xml" ? "xml" : format}`;
+        document.body.appendChild(anchor);
+        anchor.click();
+        anchor.remove();
+        URL.revokeObjectURL(objectUrl);
+      }
+      toast.success(`Exportación ${format.toUpperCase()} completada`, {
+        description: `${ids.length} publicaciones de ${orcidId}.`,
+      });
+    } catch (err) {
+      toast.error(`Error al exportar ${format.toUpperCase()}`, {
+        description: err?.message ?? "No se pudo generar el fichero.",
+      });
+    } finally {
+      setCardExporting((prev) => {
+        const next = { ...prev };
+        delete next[orcidId];
+        return next;
+      });
+    }
+  }
+
+  const globalLabel = isAuthenticated
+    ? allNewIds.length > 0
+      ? `Descargar lo nuevo de todos (${allNewIds.length})`
+      : "Todo descargado"
+    : `Descargar todo (${allIds.length})`;
+
+  const globalDisabled =
+    Boolean(globalExporting) ||
+    (isAuthenticated ? allNewIds.length === 0 : allIds.length === 0);
+
+  return (
+    <div className="flex min-h-screen flex-col bg-surface-tertiary">
+      <AppHeader variant="group" />
+
+      <div className="mx-auto w-full max-w-[1100px] px-5 py-7">
+        {/* Page header */}
+        <div className="mb-6 flex flex-wrap items-center justify-between gap-4">
+          <div className="flex items-center gap-3">
+            <div className="flex h-10 w-10 shrink-0 items-center justify-center rounded-xl bg-brand-primary text-white">
+              <UsersIcon size={20} />
+            </div>
+            <div>
+              <h1 className="text-xl font-semibold text-ink-primary">
+                Búsqueda grupal
+              </h1>
+              {!loading && (
+                <p className="text-xs text-ink-tertiary">
+                  {results.length} investigador{results.length !== 1 ? "es" : ""} encontrado{results.length !== 1 ? "s" : ""}
+                  {errors.length > 0 && (
+                    <span className="ml-1 text-ink-danger">
+                      · {errors.length} con error
+                    </span>
+                  )}
+                </p>
+              )}
+            </div>
+          </div>
+
+          {/* Global export buttons */}
+          {!loading && results.length > 0 && (
+            <div className="flex gap-2">
+              {["xml", "zip"].map((fmt) => (
+                <button
+                  key={fmt}
+                  type="button"
+                  onClick={() => handleGlobalExport(fmt)}
+                  disabled={globalDisabled}
+                  className="inline-flex items-center gap-2 rounded-lg border border-surface-border-strong bg-surface-primary px-4 py-2 text-sm font-medium text-ink-primary transition-colors enabled:hover:bg-surface-secondary disabled:cursor-not-allowed disabled:opacity-60"
+                >
+                  {globalExporting === fmt ? (
+                    <Spinner size={14} />
+                  ) : isAuthenticated && allNewIds.length > 0 ? (
+                    <SparkleIcon size={13} className="text-brand-accent" />
+                  ) : (
+                    <DownloadIcon size={14} />
+                  )}
+                  {globalExporting === fmt
+                    ? `Exportando ${fmt.toUpperCase()}...`
+                    : `${fmt.toUpperCase()} · ${globalLabel}`}
+                </button>
+              ))}
+            </div>
+          )}
+        </div>
+
+        {/* Loading state */}
+        {loading && (
+          <div className="flex flex-col items-center justify-center gap-4 py-24 text-ink-tertiary">
+            <Spinner size={28} />
+            <p className="text-sm">
+              Sincronizando {orcidIds?.length ?? "?"} investigadores con ORCID...
+            </p>
+            <p className="text-xs text-ink-tertiary/60">
+              Esto puede tardar unos segundos si hay muchos perfiles nuevos.
+            </p>
+          </div>
+        )}
+
+        {/* Results grid */}
+        {!loading && results.length > 0 && (
+          <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
+            {results.map((bundle) => (
+              <ResearcherResultCard
+                key={bundle.researcher?.orcid_id}
+                bundle={bundle}
+                isAuthenticated={isAuthenticated}
+                exporting={cardExporting[bundle.researcher?.orcid_id] ?? null}
+                onExport={(fmt, newIds, totalIds) =>
+                  handleCardExport(
+                    bundle.researcher?.orcid_id,
+                    fmt,
+                    newIds,
+                    totalIds,
+                  )
+                }
+              />
+            ))}
+          </div>
+        )}
+
+        {/* Errors */}
+        {!loading && errors.length > 0 && (
+          <div className="mt-6">
+            <h2 className="mb-3 text-sm font-medium text-ink-secondary">
+              ORCID iDs que no pudieron cargarse
+            </h2>
+            <div className="space-y-2">
+              {errors.map((e) => (
+                <div
+                  key={e.orcid_id}
+                  className="flex items-start gap-3 rounded-xl border border-red-200 bg-red-50 px-4 py-3"
+                >
+                  <AlertIcon size={16} className="mt-0.5 shrink-0 text-red-500" />
+                  <div>
+                    <p className="font-mono text-[13px] font-medium text-red-700">
+                      {e.orcid_id}
+                    </p>
+                    <p className="text-xs text-red-500">
+                      {e.detail ?? "No se pudo obtener información de este ORCID."}
+                    </p>
+                  </div>
+                </div>
+              ))}
+            </div>
+          </div>
+        )}
+
+        {/* Empty state */}
+        {!loading && results.length === 0 && errors.length === 0 && (
+          <div className="flex flex-col items-center justify-center gap-3 py-24 text-center text-ink-tertiary">
+            <UsersIcon size={32} className="opacity-30" />
+            <p className="text-sm">No se encontraron resultados.</p>
+            <Link
+              to="/"
+              className="mt-1 inline-flex items-center gap-1.5 rounded-md bg-brand-primary px-3 py-1.5 text-xs font-medium text-white hover:bg-brand-primary-hover"
+            >
+              <ArrowLeftIcon />
+              Volver al inicio
+            </Link>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}
+
+/* ─────────────────────────── Researcher card ─────────────────────────── */
+
+function ResearcherResultCard({ bundle, isAuthenticated, exporting, onExport }) {
+  const researcher = bundle.researcher ?? {};
+  const publications = bundle.publications ?? [];
+  const totalRecords = bundle.totalRecords ?? publications.length;
+
+  const newIds = isAuthenticated
+    ? publications.filter((p) => p.downloaded_by_me === false).map((p) => p.id)
+    : [];
+
+  const allPubIds = publications.map((p) => p.id);
+
+  const newCount = newIds.length;
+  const hasNew = isAuthenticated && newCount > 0;
+
+  const initials = getInitials(researcher.name);
+
+  return (
+    <div className="flex flex-col rounded-2xl border border-surface-border/60 bg-surface-primary p-5 shadow-sm">
+      {/* Researcher identity */}
+      <div className="mb-4 flex items-start gap-3">
+        <div className="flex h-11 w-11 shrink-0 items-center justify-center rounded-full bg-brand-primary text-base font-semibold text-white">
+          {initials}
+        </div>
+        <div className="min-w-0 flex-1">
+          <p className="truncate font-semibold text-ink-primary">
+            {researcher.name || "Sin nombre"}
+          </p>
+          <div className="mt-0.5 flex items-center gap-1">
+            <OrcidLogo />
+            <span className="truncate font-mono text-[12px] text-ink-secondary">
+              {researcher.orcid_id}
+            </span>
+          </div>
+          {researcher.affiliation && (
+            <p className="mt-0.5 truncate text-[12px] text-ink-tertiary">
+              {researcher.affiliation}
+            </p>
+          )}
+        </div>
+      </div>
+
+      {/* Stats row */}
+      <div className="mb-4 flex items-center gap-3 rounded-lg bg-surface-secondary px-3 py-2">
+        <div className="flex-1 text-center">
+          <p className="text-lg font-bold text-ink-primary">{totalRecords}</p>
+          <p className="text-[11px] text-ink-tertiary">publicaciones</p>
+        </div>
+        {isAuthenticated && (
+          <>
+            <div className="h-8 w-px bg-surface-border" />
+            <div className="flex-1 text-center">
+              <p className={`text-lg font-bold ${hasNew ? "text-brand-accent" : "text-ink-tertiary"}`}>
+                {newCount}
+              </p>
+              <p className="text-[11px] text-ink-tertiary">nuevas</p>
+            </div>
+          </>
+        )}
+      </div>
+
+      {/* Actions */}
+      <div className="mt-auto flex flex-wrap gap-2">
+        <Link
+          to={`/dashboard/${researcher.orcid_id}`}
+          state={{ bundle }}
+          className="flex-1 rounded-lg border border-surface-border-strong bg-surface-secondary px-3 py-2 text-center text-[13px] font-medium text-ink-primary transition-colors hover:bg-surface-primary"
+        >
+          Ver detalle
+        </Link>
+        <ExportFormatMenu
+          onExport={(fmt) => onExport(fmt, newIds, allPubIds)}
+          exporting={exporting}
+          isAuthenticated={isAuthenticated}
+          hasNew={hasNew}
+          newCount={newCount}
+          totalCount={totalRecords}
+        />
+      </div>
+    </div>
+  );
+}
+
+/* ─────────────────────── Inline export format picker ─────────────────── */
+
+function ExportFormatMenu({
+  onExport,
+  exporting,
+  isAuthenticated,
+  hasNew,
+  newCount,
+  totalCount,
+}) {
+  const [open, setOpen] = useState(false);
+  const ref = useRef(null);
+
+  useEffect(() => {
+    function handleClick(e) {
+      if (ref.current && !ref.current.contains(e.target)) setOpen(false);
+    }
+    document.addEventListener("mousedown", handleClick);
+    return () => document.removeEventListener("mousedown", handleClick);
+  }, []);
+
+  const isBusy = Boolean(exporting);
+  const disabled =
+    isBusy || (isAuthenticated && !hasNew && totalCount > 0 && newCount === 0);
+
+  let label;
+  if (isBusy) {
+    label = `Exportando ${exporting.toUpperCase()}...`;
+  } else if (isAuthenticated) {
+    label = hasNew ? `Nuevo (${newCount})` : "Descargado";
+  } else {
+    label = `Todo (${totalCount})`;
+  }
+
+  return (
+    <div className="relative" ref={ref}>
+      <button
+        type="button"
+        onClick={() => setOpen((o) => !o)}
+        disabled={disabled}
+        className="inline-flex items-center gap-1.5 rounded-lg border border-surface-border-strong bg-surface-primary px-3 py-2 text-[13px] font-medium text-ink-primary transition-colors enabled:hover:bg-surface-secondary disabled:cursor-not-allowed disabled:opacity-60"
+      >
+        {isBusy ? (
+          <Spinner size={13} />
+        ) : hasNew ? (
+          <SparkleIcon size={11} className="text-brand-accent" />
+        ) : (
+          <DownloadIcon size={13} />
+        )}
+        {label}
+      </button>
+
+      {open && (
+        <div className="absolute right-0 top-[calc(100%+4px)] z-50 min-w-[160px] overflow-hidden rounded-xl border border-surface-border-strong bg-surface-primary shadow-lg">
+          {["xml", "zip"].map((fmt, idx) => (
+            <button
+              key={fmt}
+              type="button"
+              onClick={() => {
+                setOpen(false);
+                onExport(fmt);
+              }}
+              className={`flex w-full items-center gap-2 px-3 py-2.5 text-left text-[13px] font-medium text-ink-primary transition-colors hover:bg-surface-secondary ${
+                idx === 0 ? "border-b border-surface-border/60" : ""
+              }`}
+            >
+              <DownloadIcon size={13} />
+              {fmt.toUpperCase()}
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}
+
+/* ─────────────────────────── Helpers ─────────────────────────────────── */
+
+function getInitials(name) {
+  if (!name) return "?";
+  return name
+    .split(/\s+/)
+    .filter(Boolean)
+    .slice(0, 2)
+    .map((w) => w[0].toUpperCase())
+    .join("");
+}
+
+export default GroupResultsPage;

frontend/src/pages/LandingPage.jsx

@@ -1,31 +1,54 @@
-import { useState } from "react";
+import { useEffect, useRef, useState } from "react";
 import { useNavigate } from "react-router-dom";
 import { toast } from "sonner";
 
 import { AppHeader } from "../components/layout/AppHeader";
-import { DocumentIcon } from "../components/ui/Icons";
+import { DocumentIcon, UsersIcon } from "../components/ui/Icons";
 import { OrcidLogo } from "../components/ui/OrcidLogo";
 import { Spinner } from "../components/ui/Spinner";
 import { formatOrcidInput, isValidOrcid } from "../utils/orcid";
-import { searchResearcher } from "../services/api";
+import { getOrcidAuthorizeUrl, searchResearcher } from "../services/api";
+import { useAuth } from "../contexts/AuthContext";
+import { AUTH_MESSAGE_TYPE, AUTH_ERROR_TYPE } from "../contexts/AuthContext";
+
+// When VITE_AUTH_BYPASS=true, skip the real OAuth popup and simulate login
+// with the ORCID entered in the text field. Use only in development.
+const AUTH_BYPASS = import.meta.env.VITE_AUTH_BYPASS === "true";
 
 /**
- * Entry view: OAuth button + manual ORCID iD entry.
+ * Entry view: login con ORCID iD + búsqueda individual anónima +
+ * buscador grupal para múltiples investigadores.
  *
- * El endpoint de búsqueda grupal `POST /api/researchers/search` (usado
+ * Flujo de login:
- * para 1 solo ORCID) es "todo en uno":
+ *   - Modo normal:   abre popup OAuth → sandbox.orcid.org → /auth/callback
- * valida el formato + dígito de control en el servidor, lo crea en BD si
+ *                    → JWT → cierra popup → estado actualizado aquí.
- * no existe, sincroniza con ORCID y devuelve `researcher + publications`.
+ *   - VITE_AUTH_BYPASS=true (solo dev): genera un token simulado con el
- * Por eso aquí basta con una sola llamada y, una vez que tenemos el
+ *     ORCID del campo de texto, sin tocar el backend de auth.
- * bundle, navegamos al dashboard pasándoselo por `state` para evitar
- * la doble petición.
  */
 export function LandingPage() {
   const navigate = useNavigate();
+  const { isAuthenticated, storeToken } = useAuth();
+
   const [orcidInput, setOrcidInput] = useState("");
   const [error, setError] = useState("");
   const [validating, setValidating] = useState(false);
-  const [oauthLoading, setOauthLoading] = useState(false);
+  const [loginLoading, setLoginLoading] = useState(false);
+
+  // Group search state
+  const [groupInput, setGroupInput] = useState("");
+  const [groupError, setGroupError] = useState("");
+  const [groupLoading, setGroupLoading] = useState(false);
+
+  // Cleanup refs for popup polling interval
+  const popupRef = useRef(null);
+  const popupTimerRef = useRef(null);
+
+  // Clean up popup polling on unmount
+  useEffect(() => {
+    return () => {
+      if (popupTimerRef.current) clearInterval(popupTimerRef.current);
+    };
+  }, []);
 
   function handleOrcidChange(event) {
     setOrcidInput(formatOrcidInput(event.target.value));
@@ -44,7 +67,7 @@ export function LandingPage() {
       const bundle = await searchResearcher(orcidInput);
       navigate(`/dashboard/${orcidInput}`, { state: { bundle } });
     } catch (err) {
-      toast.error("No se pudo validar el ORCID iD", {
+      toast.error("No se pudo buscar el ORCID iD", {
         description: err?.message ?? "Inténtalo de nuevo en unos segundos.",
       });
     } finally {
@@ -52,19 +75,105 @@ export function LandingPage() {
     }
   }
 
-  async function handleOrcidLogin() {
+  function handleOrcidLogin() {
-    setOauthLoading(true);
+    // ── Modo bypass (solo desarrollo / sandbox sin credenciales OAuth) ──
-    try {
+    if (AUTH_BYPASS) {
-      // Real implementation will redirect to ORCID OAuth (handled by backend).
+      if (!isValidOrcid(orcidInput)) {
-      // For now we emulate the flow locally with a known sample ORCID.
+        setError(
-      await new Promise((r) => setTimeout(r, 800));
+          "Introduce un ORCID iD válido para simular el login (modo bypass).",
-      navigate(`/dashboard/0000-0002-1234-5678`);
+        );
-    } catch (err) {
+        return;
-      toast.error("No se pudo iniciar sesión con ORCID", {
+      }
-        description: err?.message ?? "Inténtalo de nuevo.",
+      // Genera un token simulado (no válido en el backend) solo para
+      // probar la UI en estado autenticado.
+      storeToken(`bypass_token_${orcidInput}`);
+      toast.success("Login simulado (modo bypass)", {
+        description: `Sesión activa para ${orcidInput}. El backend no reconocerá este token.`,
       });
+      return;
+    }
+
+    // ── Flujo OAuth real (popup) ──
+    setLoginLoading(true);
+
+    const authorizeUrl = getOrcidAuthorizeUrl();
+    const popup = window.open(
+      authorizeUrl,
+      "orcid_oauth",
+      "width=600,height=700,scrollbars=yes,resizable=yes",
+    );
+
+    if (!popup || popup.closed) {
+      // El navegador bloqueó el popup → hacemos redirect completo
+      setLoginLoading(false);
+      window.location.href = authorizeUrl;
+      return;
+    }
+
+    popupRef.current = popup;
+
+    // Escuchamos el postMessage que AuthCallbackPage envía al completar
+    function handleMessage(event) {
+      if (event.origin !== window.location.origin) return;
+
+      if (event.data?.type === AUTH_MESSAGE_TYPE) {
+        cleanup();
+        setLoginLoading(false);
+        toast.success("Sesión iniciada con ORCID", {
+          description: "Ya puedes ver qué publicaciones son nuevas para ti.",
+        });
+      } else if (event.data?.type === AUTH_ERROR_TYPE) {
+        cleanup();
+        setLoginLoading(false);
+        toast.error("No se pudo iniciar sesión", {
+          description: event.data.error ?? "Inténtalo de nuevo.",
+        });
+      }
+    }
+
+    window.addEventListener("message", handleMessage);
+
+    // Detectamos si el usuario cierra el popup manualmente antes de autenticar
+    popupTimerRef.current = setInterval(() => {
+      if (popup.closed) {
+        cleanup();
+        setLoginLoading(false);
+      }
+    }, 500);
+
+    function cleanup() {
+      window.removeEventListener("message", handleMessage);
+      if (popupTimerRef.current) {
+        clearInterval(popupTimerRef.current);
+        popupTimerRef.current = null;
+      }
+    }
+  }
+
+  function parseGroupOrcids(raw) {
+    return raw
+      .split(/[\s,\n]+/)
+      .map((s) => s.trim())
+      .filter(Boolean);
+  }
+
+  async function handleGroupSearch() {
+    const ids = parseGroupOrcids(groupInput);
+    if (ids.length === 0) {
+      setGroupError("Introduce al menos un ORCID iD.");
+      return;
+    }
+    const invalid = ids.filter((id) => !isValidOrcid(id));
+    if (invalid.length > 0) {
+      setGroupError(`ORCID iDs con formato incorrecto: ${invalid.join(", ")}`);
+      return;
+    }
+    setGroupError("");
+    setGroupLoading(true);
+    try {
+      navigate("/group", { state: { orcidIds: ids } });
     } finally {
-      setOauthLoading(false);
+      setGroupLoading(false);
     }
   }
 
@@ -72,6 +181,13 @@ export function LandingPage() {
     if (event.key === "Enter") handleValidate();
   }
 
+  function handleGroupKeyDown(event) {
+    if (event.key === "Enter" && !event.shiftKey) {
+      event.preventDefault();
+      handleGroupSearch();
+    }
+  }
+
   return (
     <div className="flex min-h-screen flex-col bg-surface-tertiary">
       <AppHeader variant="landing" />
@@ -94,22 +210,41 @@ export function LandingPage() {
 
           {/* Main card */}
           <div className="rounded-2xl border border-surface-border/60 bg-surface-primary p-8">
-            <button
+            {isAuthenticated ? (
-              type="button"
+              <div className="flex items-center justify-between rounded-xl border border-green-200 bg-green-50 px-4 py-2.5 text-sm text-green-800">
-              onClick={handleOrcidLogin}
+                <span className="font-medium">Sesión activa</span>
-              disabled={oauthLoading}
+                <span className="text-xs text-green-600">
-              className="flex w-full items-center justify-center gap-2.5 rounded-xl bg-orcid-green px-5 py-3 text-[15px] font-semibold tracking-wide text-orcid-green-dark transition-opacity enabled:hover:opacity-95 disabled:cursor-not-allowed disabled:opacity-75"
+                  Verás publicaciones nuevas marcadas en el dashboard
-            >
+                </span>
-              {oauthLoading ? <Spinner size={17} /> : <OrcidLogo />}
+              </div>
-              {oauthLoading
+            ) : (
-                ? "Redirigiendo a ORCID..."
+              <>
-                : "Iniciar sesión con ORCID"}
+                <button
-            </button>
+                  type="button"
+                  onClick={handleOrcidLogin}
+                  disabled={loginLoading}
+                  className="flex w-full items-center justify-center gap-2.5 rounded-xl bg-orcid-green px-5 py-3 text-[15px] font-semibold tracking-wide text-orcid-green-dark transition-opacity enabled:hover:opacity-95 disabled:cursor-not-allowed disabled:opacity-75"
+                >
+                  {loginLoading ? <Spinner size={17} /> : <OrcidLogo />}
+                  {loginLoading
+                    ? "Abriendo ventana de ORCID..."
+                    : AUTH_BYPASS
+                    ? "Simular login (bypass)"
+                    : "Iniciar sesión con ORCID"}
+                </button>
+                {AUTH_BYPASS && (
+                  <p className="mt-2 rounded-lg bg-amber-50 px-3 py-1.5 text-center text-xs text-amber-700">
+                    Modo bypass activo — introduce un ORCID abajo y pulsa el botón.
+                    No se valida contra el backend.
+                  </p>
+                )}
+              </>
+            )}
 
             <div className="my-6 flex items-center gap-3">
               <div className="h-px flex-1 bg-surface-border" />
               <span className="text-xs tracking-widest text-ink-tertiary">
-                O INTRODUCE TU ORCID iD
+                {isAuthenticated ? "TU ORCID iD" : "O INTRODUCE TU ORCID iD"}
               </span>
               <div className="h-px flex-1 bg-surface-border" />
             </div>
@@ -141,7 +276,7 @@ export function LandingPage() {
                 <button
                   type="button"
                   onClick={handleValidate}
-                  disabled={validating || !orcidInput}
+                  disabled={validating || loginLoading || !orcidInput}
                   className={`inline-flex items-center gap-2 whitespace-nowrap rounded-lg px-5 py-2.5 text-sm font-medium transition-colors ${
                     orcidInput
                       ? "bg-brand-primary text-white enabled:hover:bg-brand-primary-hover"
@@ -158,12 +293,61 @@ export function LandingPage() {
                 </p>
               )}
               <p className="mt-2 text-xs text-ink-tertiary">
-                Formato: 16 dígitos separados con guiones (ej.
+                {isAuthenticated
-                0000-0002-1234-5678)
+                  ? "Busca un investigador o usa «Cerrar sesión» arriba."
+                  : AUTH_BYPASS
+                  ? "Introduce tu ORCID y pulsa «Simular login» para probar la UI autenticada."
+                  : "Pulsa «Iniciar sesión» para autenticarte, o «Buscar» de forma anónima."}
               </p>
             </div>
           </div>
 
+          {/* Group search card */}
+          <div className="mt-4 rounded-2xl border border-surface-border/60 bg-surface-primary p-6">
+            <div className="mb-3 flex items-center gap-2">
+              <UsersIcon size={17} className="text-brand-accent" />
+              <h2 className="text-[14px] font-semibold text-ink-primary">
+                Búsqueda grupal de investigadores
+              </h2>
+            </div>
+            <p className="mb-3 text-xs leading-relaxed text-ink-secondary">
+              Pega varios ORCID iDs separados por comas, espacios o saltos de
+              línea para buscar y comparar varios investigadores a la vez.
+            </p>
+            <textarea
+              rows={3}
+              placeholder={"0000-0002-1825-0097\n0000-0001-5000-0007, 0000-0003-4321-9876"}
+              value={groupInput}
+              onChange={(e) => {
+                setGroupInput(e.target.value);
+                if (groupError) setGroupError("");
+              }}
+              onKeyDown={handleGroupKeyDown}
+              className={`w-full resize-none rounded-lg border px-3.5 py-2.5 font-mono text-[13px] text-ink-primary outline-none transition-colors ${
+                groupError
+                  ? "border-border-danger"
+                  : "border-surface-border-strong focus:border-brand-accent"
+              }`}
+            />
+            {groupError && (
+              <p className="mt-1 text-xs text-ink-danger">{groupError}</p>
+            )}
+            <button
+              type="button"
+              onClick={handleGroupSearch}
+              disabled={groupLoading || !groupInput.trim()}
+              className={`mt-3 inline-flex w-full items-center justify-center gap-2 rounded-lg px-5 py-2.5 text-sm font-medium transition-colors ${
+                groupInput.trim()
+                  ? "bg-brand-primary text-white enabled:hover:bg-brand-primary-hover"
+                  : "bg-surface-secondary text-ink-tertiary"
+              } disabled:cursor-not-allowed`}
+            >
+              {groupLoading && <Spinner size={14} />}
+              <UsersIcon size={14} />
+              {groupLoading ? "Preparando..." : "Buscar investigadores"}
+            </button>
+          </div>
+
           {/* Info chips */}
           <div className="mt-6 flex flex-wrap justify-center gap-4">
             {["ORCID OAuth 2.0", "SWORD v2", "DSpace · EPrints"].map((label) => (

frontend/src/services/api.js

@@ -50,8 +50,8 @@ export class ApiError extends Error {
 
 /**
  * Construye la cabecera base que llevan TODAS las peticiones (incluidas
- * las descargas de blob). Si la API key está sin definir lo avisamos en
+ * las descargas de blob). Incluye X-API-Key siempre y, si existe un JWT
- * consola para no fallar silenciosamente con un 401 críptico.
+ * en localStorage, también Authorization: Bearer <token>.
  */
 function buildAuthHeaders(extra = {}) {
   if (!API_KEY && import.meta.env.DEV) {
@@ -59,9 +59,11 @@ function buildAuthHeaders(extra = {}) {
       "[api] VITE_API_KEY no está definida; las peticiones serán rechazadas por el backend.",
     );
   }
+  const token = localStorage.getItem("orcid_auth_token");
   return {
     Accept: "application/json",
     ...(API_KEY ? { "X-API-Key": API_KEY } : {}),
+    ...(token ? { Authorization: `Bearer ${token}` } : {}),
     ...extra,
   };
 }
@@ -143,6 +145,8 @@ function normalizePublication(p) {
     hash_fingerprint: p.hash_fingerprint ?? null,
     last_modified: p.last_modified ?? null,
     status: p.status ?? null,
+    // null when request was made without a JWT (user not logged in)
+    downloaded_by_me: p.downloaded_by_me ?? null,
   };
 }
 
@@ -176,6 +180,38 @@ function normalizeResearcherBundle(raw) {
   };
 }
 
+/* ───────────────────────────── Auth ─────────────────────────────── */
+
+/**
+ * URL a la que debe redirigirse (o abrirse en popup) para iniciar el
+ * flujo OAuth 3-legged de ORCID.
+ *
+ * Secuencia completa:
+ *   1. Frontend abre/redirige a GET /api/auth/orcid/authorize
+ *   2. Backend construye la URL de ORCID y redirige al navegador.
+ *   3. El usuario se autentica en orcid.org (o sandbox.orcid.org).
+ *   4. ORCID redirige a ORCID_REDIRECT_URI (debe apuntar a la página
+ *      /auth/callback del frontend).
+ *   5. El frontend extrae el `code` y llama a exchangeOrcidCode(code).
+ *   6. El backend intercambia el code → access_token y lo devuelve.
+ */
+export function getOrcidAuthorizeUrl() {
+  return `${BASE_URL}/auth/orcid/authorize`;
+}
+
+/**
+ * GET /auth/orcid/callback?code=<code>
+ *
+ * Intercambia el authorization code (recibido de ORCID tras el OAuth)
+ * por un JWT propio del backend. Devuelve `{ access_token, token_type }`.
+ */
+export async function exchangeOrcidCode(code, { signal } = {}) {
+  return request(
+    `/auth/orcid/callback?${new URLSearchParams({ code }).toString()}`,
+    { signal },
+  );
+}
+
 /* ───────────────────────────── Endpoints ─────────────────────────────── */
 
 /**