diff --git a/web/src/shell/app-shell.test.tsx b/web/src/shell/app-shell.test.tsx
new file mode 100644
index 0000000..1e58ec9
--- /dev/null
+++ b/web/src/shell/app-shell.test.tsx
@@ -0,0 +1,40 @@
+import { expect, test, beforeEach, afterEach } from "vitest";
+import { screen, waitFor } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { Routes, Route } from "react-router-dom";
+import i18n from "../i18n";
+import { renderApp } from "../test/render";
+import { AppShell } from "./app-shell";
+
+beforeEach(async () => {
+  await i18n.changeLanguage("en");
+});
+
+afterEach(async () => {
+  await i18n.changeLanguage("en");
+});
+
+function tree() {
+  return (
+    <Routes>
+      <Route element={<AppShell />}>
+        <Route path="/objects" element={<div>objects outlet</div>} />
+      </Route>
+      <Route path="/login" element={<div>login page</div>} />
+    </Routes>
+  );
+}
+
+test("shows active and disabled nav and renders the outlet", async () => {
+  renderApp(tree(), { route: "/objects" });
+  expect(await screen.findByText("objects outlet")).toBeInTheDocument();
+  expect(screen.getByRole("link", { name: /objects/i })).toBeInTheDocument();
+  // later milestones are present but disabled
+  expect(screen.getByRole("button", { name: /search/i })).toBeDisabled();
+});
+
+test("language switch toggles to Swedish", async () => {
+  renderApp(tree(), { route: "/objects" });
+  await userEvent.click(await screen.findByRole("button", { name: "SV" }));
+  await waitFor(() => expect(screen.getByText("Föremål")).toBeInTheDocument());
+});
diff --git a/web/src/shell/app-shell.tsx b/web/src/shell/app-shell.tsx
new file mode 100644
index 0000000..2ff6c69
--- /dev/null
+++ b/web/src/shell/app-shell.tsx
@@ -0,0 +1,59 @@
+import { NavLink, Outlet, useNavigate } from "react-router-dom";
+import { useTranslation } from "react-i18next";
+
+import { useLogout } from "../api/queries";
+import { Button } from "@/components/ui/button";
+import { LangSwitch } from "./lang-switch";
+
+const FUTURE = ["vocabularies", "authorities", "fields", "search"] as const;
+
+export function AppShell() {
+  const { t } = useTranslation();
+  const navigate = useNavigate();
+  const logout = useLogout();
+
+  const onSignOut = () =>
+    logout.mutate(undefined, {
+      onSuccess: () => navigate("/login", { replace: true }),
+    });
+
+  return (
+    <div className="flex min-h-screen">
+      <aside className="w-44 shrink-0 border-r bg-neutral-50 p-3">
+        <div className="mb-4 font-semibold">{t("app.name")}</div>
+        <nav className="space-y-1 text-sm">
+          <NavLink
+            to="/objects"
+            className={({ isActive }) =>
+              `block rounded px-2 py-1 ${isActive ? "bg-neutral-200 font-medium" : ""}`
+            }
+          >
+            {t("nav.objects")}
+          </NavLink>
+          {FUTURE.map((key) => (
+            <button
+              key={key}
+              disabled
+              title={t("nav.soon")}
+              className="block w-full cursor-not-allowed rounded px-2 py-1 text-left text-neutral-400"
+            >
+              {t(`nav.${key}`)}
+            </button>
+          ))}
+        </nav>
+      </aside>
+      <div className="flex flex-1 flex-col">
+        <header className="flex items-center gap-4 border-b px-4 py-2">
+          <div className="flex-1" />
+          <LangSwitch />
+          <Button variant="ghost" size="sm" onClick={onSignOut}>
+            {t("auth.signOut")}
+          </Button>
+        </header>
+        <main className="flex-1 overflow-hidden">
+          <Outlet />
+        </main>
+      </div>
+    </div>
+  );
+}
diff --git a/web/src/shell/lang-switch.tsx b/web/src/shell/lang-switch.tsx
new file mode 100644
index 0000000..67b9090
--- /dev/null
+++ b/web/src/shell/lang-switch.tsx
@@ -0,0 +1,21 @@
+import { useLocale } from "../i18n/use-locale";
+
+export function LangSwitch() {
+  const { locale, setLocale } = useLocale();
+  const base = locale.startsWith("sv") ? "sv" : "en";
+
+  return (
+    <div className="flex gap-1 text-xs">
+      {(["sv", "en"] as const).map((lng) => (
+        <button
+          key={lng}
+          onClick={() => setLocale(lng)}
+          aria-pressed={base === lng}
+          className={base === lng ? "font-bold" : "text-neutral-400"}
+        >
+          {lng.toUpperCase()}
+        </button>
+      ))}
+    </div>
+  );
+}