diff --git a/frontend/src/PlaylistEditFailures.dom.test.tsx b/frontend/src/PlaylistEditFailures.dom.test.tsx
index 16dff803..4ea1fc2b 100644
--- a/frontend/src/PlaylistEditFailures.dom.test.tsx
+++ b/frontend/src/PlaylistEditFailures.dom.test.tsx
@@ -22,7 +22,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 });
 vi.mock("./components/ui/confirmContext", () => ({ useConfirm: () => async () => true }));
 const { notify } = vi.hoisted(() => ({
-  notify: vi.fn((_n: { level: string; message: string }) => 0),
+  notify: vi.fn((_n: { level: string; message: NotifText }) => 0),
 }));
 vi.mock("./lib/notifications", async (importOriginal) => ({
   ...(await importOriginal<typeof import("./lib/notifications")>()),
@@ -35,6 +35,7 @@ import PlexPlaylistAdd from "./features/plexCards/PlexPlaylistAdd";
 import TagManager from "./features/channel/TagManager";
 import { api, HttpError, type PlexCard } from "./lib/api";
 import { qk } from "./lib/queryKeys";
+import type { NotifText } from "./lib/notifications";
 
 beforeAll(() => {
   class Stub {
@@ -98,7 +99,7 @@ describe("the Plex playlist page", () => {
       () => fireEvent.contextMenu(screen.getByText("Movie 1").closest("[data-nav-index]")!),
       "plex.playlist.removeFromPlaylist",
     );
-    await waitFor(() => expect(errors()).toEqual(["gone playlist"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("playlist").detailData }]));
     await act(async () => void (await new Promise((r) => setTimeout(r, 20))));
     expect(screen.getByText("Movie 1")).toBeTruthy();
   });
@@ -119,7 +120,7 @@ describe("the Plex playlist page", () => {
     const field = await screen.findByDisplayValue("Films");
     fireEvent.change(field, { target: { value: "Movies" } });
     fireEvent.keyDown(field, { key: "Enter" });
-    await waitFor(() => expect(errors()).toEqual(["gone playlist"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("playlist").detailData }]));
     expect(screen.getByDisplayValue("Movies")).toBeTruthy(); // still open to try again
   });
 
@@ -154,7 +155,7 @@ describe("the add-to-playlist popover", () => {
     );
     fireEvent.click(screen.getByLabelText("playlists.addToPlaylist"));
     fireEvent.click(await screen.findByRole("menuitemcheckbox", { hidden: true }));
-    await waitFor(() => expect(errors()).toEqual(["gone playlist"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("playlist").detailData }]));
     await waitFor(() => expect(lists.mock.calls.length).toBeGreaterThan(1));
   });
 
@@ -282,7 +283,7 @@ describe("the add-to-playlist popover", () => {
     fireEvent.click(await screen.findByText("Gone"));
     // The server's own localized reason wins over the caller's fallback when the detail is
     // STRUCTURED — same as the twin above. What is under test is that anything is said at all.
-    await waitFor(() => expect(errors()).toEqual(["gone playlist"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("playlist").detailData }]));
     await waitFor(() => expect(lists.mock.calls.length).toBeGreaterThan(1));
   });
 });
@@ -300,7 +301,7 @@ describe("the tag manager", () => {
       </QueryClientProvider>,
     );
     fireEvent.click(await screen.findByLabelText("tagManager.delete"));
-    await waitFor(() => expect(errors()).toEqual(["gone tag"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("tag").detailData }]));
     await waitFor(() => expect(tags.mock.calls.length).toBeGreaterThan(1));
   });
 });
diff --git a/frontend/src/WriteFailureReporting.dom.test.tsx b/frontend/src/WriteFailureReporting.dom.test.tsx
index abffcd22..a8aa1779 100644
--- a/frontend/src/WriteFailureReporting.dom.test.tsx
+++ b/frontend/src/WriteFailureReporting.dom.test.tsx
@@ -19,7 +19,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 });
 vi.mock("./components/ui/confirmContext", () => ({ useConfirm: () => async () => true }));
 const { notify } = vi.hoisted(() => ({
-  notify: vi.fn((_n: { level: string; title?: string; message: string }) => 0),
+  notify: vi.fn((_n: { level: string; title?: NotifText; message: NotifText }) => 0),
 }));
 vi.mock("./lib/notifications", async (importOriginal) => ({
   ...(await importOriginal<typeof import("./lib/notifications")>()),
@@ -30,6 +30,7 @@ import PlexCollectionEditor from "./modules/plex/PlexCollectionEditor";
 import UploadDialog from "./modules/files/UploadDialog";
 import DownloadDialog from "./features/downloads/DownloadDialog";
 import { api, HttpError } from "./lib/api";
+import { msg, type NotifText } from "./lib/notifications";
 
 beforeAll(() => {
   class Stub {
@@ -87,7 +88,7 @@ describe("the Plex collection editor", () => {
     );
     mount();
     fireEvent.click(await screen.findByText("Marathon"));
-    await waitFor(() => expect(errors()).toEqual(["plex.collection.editFailed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("plex.collection.editFailed")]));
   });
 
   it("says so when enabling editing is refused", async () => {
@@ -97,7 +98,7 @@ describe("the Plex collection editor", () => {
     );
     mount();
     fireEvent.click(await screen.findByText("plex.collEditor.makeEditable"));
-    await waitFor(() => expect(errors()).toEqual(["plex.collection.editFailed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("plex.collection.editFailed")]));
   });
 
   it("says so when a CONFIRMED delete does not happen", async () => {
@@ -108,7 +109,7 @@ describe("the Plex collection editor", () => {
     );
     mount();
     fireEvent.click(await screen.findByText("plex.collEditor.delete"));
-    await waitFor(() => expect(errors()).toEqual(["plex.collection.deleteFailed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("plex.collection.deleteFailed")]));
   });
 });
 
@@ -144,7 +145,7 @@ describe("the upload dialog", () => {
     mount();
     pick();
     fireEvent.click(screen.getByText("downloads.upload.submit"));
-    await waitFor(() => expect(errors()).toEqual(["downloads.upload.failed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("downloads.upload.failed")]));
   });
 
   it("says nothing when the user cancelled it themselves", async () => {
@@ -172,6 +173,6 @@ describe("the download dialog", () => {
     );
     await screen.findByText("Best");
     fireEvent.click(screen.getByText("downloads.dialog.submit"));
-    await waitFor(() => expect(errors()).toEqual(["errors.writeFailed.enqueueDownload"]));
+    await waitFor(() => expect(errors()).toEqual([msg("errors.writeFailed.enqueueDownload")]));
   });
 });
diff --git a/frontend/src/components/ui/Modal.dom.test.tsx b/frontend/src/components/ui/Modal.dom.test.tsx
index 4169ed69..06abb5e0 100644
--- a/frontend/src/components/ui/Modal.dom.test.tsx
+++ b/frontend/src/components/ui/Modal.dom.test.tsx
@@ -21,7 +21,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 vi.mock("../../lib/history", () => ({ useBackToClose: () => {} }));
 
 import Modal from "./Modal";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 import { pushLayer, removeLayer, useLayer } from "../../lib/layerStack";
 import { createPortal, flushSync } from "react-dom";
 
@@ -121,7 +121,7 @@ describe("Modal focus trap (offsetParent stubbed 'visible')", () => {
         <Body />
       </Modal>,
     );
-    act(() => void notify({ level: "info", message: "Saved" }));
+    act(() => void notify({ level: "info", message: raw("Saved") }));
     try {
       const dismissToast = screen.getByTitle("notifications.dismiss");
       // The panel's last control is no longer the trap's edge: Tab carries on (natively) to the toast.
@@ -234,7 +234,7 @@ describe("Modal focus trap (offsetParent stubbed 'visible')", () => {
         <Body />
       </Modal>,
     );
-    act(() => void notify({ level: "error", message: "Nope" }));
+    act(() => void notify({ level: "error", message: raw("Nope") }));
     const dismissToast = screen.getByTitle("notifications.dismiss");
     dismissToast.focus();
     expect(document.activeElement).toBe(dismissToast); // the scenario is actually being driven
@@ -455,7 +455,7 @@ describe("Modal — toasts raised while it is open", () => {
         <Body />
       </Modal>,
     );
-    act(() => void notify({ level: "error", message: "Couldn't share it." }));
+    act(() => void notify({ level: "error", message: raw("Couldn't share it.") }));
     expect(screen.getByRole("dialog").textContent).toContain("Couldn't share it.");
   });
 });
diff --git a/frontend/src/components/ui/Toaster.dom.test.tsx b/frontend/src/components/ui/Toaster.dom.test.tsx
index 69b50ab6..91b124cd 100644
--- a/frontend/src/components/ui/Toaster.dom.test.tsx
+++ b/frontend/src/components/ui/Toaster.dom.test.tsx
@@ -14,7 +14,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 });
 
 import Toaster from "./Toaster";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 import { dockUnderToasts } from "../../lib/toastDock";
 
 afterEach(() => {
@@ -31,7 +31,7 @@ describe("Toaster — one host shows the toasts", () => {
         <Toaster />
       </div>,
     );
-    act(() => void notify({ level: "error", message: "Couldn't remove the video." }));
+    act(() => void notify({ level: "error", message: raw("Couldn't remove the video.") }));
     expect(screen.getByTestId("app").textContent).toContain("Couldn't remove the video.");
 
     const overlay = render(
@@ -54,7 +54,7 @@ describe("Toaster — one host shows the toasts", () => {
   it("lets a click through where there is no toast and nothing docked, and not where there is", () => {
     const Docked = () => <button>dock</button>;
     const stop = dockUnderToasts(Docked);
-    notify({ level: "info", message: "hello" });
+    notify({ level: "info", message: raw("hello") });
     render(<Toaster />);
     const region = document.querySelector<HTMLElement>("[data-toast-region]")!;
     // The empty part of the region (beside and above a docked control) must not swallow the page's
@@ -75,7 +75,7 @@ describe("Toaster — one host shows the toasts", () => {
         <Toaster overlay />
       </div>,
     );
-    act(() => void notify({ level: "error", message: "boom" }));
+    act(() => void notify({ level: "error", message: raw("boom") }));
     fireEvent.click(screen.getByText("boom"));
     expect(backdrop).not.toHaveBeenCalled();
   });
@@ -86,11 +86,11 @@ describe("Toaster — handing the toasts to another host", () => {
     // The new host gets them as NEW nodes: a screen reader read every one out again, an error
     // assertively, each time a player (or any dialog) opened or closed.
     render(<Toaster />);
-    act(() => void notify({ level: "error", message: "old news" }));
+    act(() => void notify({ level: "error", message: raw("old news") }));
     render(<Toaster overlay />);
     const old = screen.getByText("old news").closest(".toast-card")!;
     expect(old.getAttribute("role")).toBeNull();
-    act(() => void notify({ level: "error", message: "fresh" }));
+    act(() => void notify({ level: "error", message: raw("fresh") }));
     expect(screen.getByText("fresh").closest(".toast-card")!.getAttribute("role")).toBe("alert");
   });
 
@@ -99,8 +99,8 @@ describe("Toaster — handing the toasts to another host", () => {
     // host last showed — re-read on every render, this host's own "first" turned silent the moment
     // "second" arrived (its own screen had become the handover by then).
     render(<Toaster />);
-    act(() => void notify({ level: "error", message: "first" }));
-    act(() => void notify({ level: "error", message: "second" }));
+    act(() => void notify({ level: "error", message: raw("first") }));
+    act(() => void notify({ level: "error", message: raw("second") }));
     const card = (text: string) => screen.getByText(text).closest(".toast-card")!;
     expect(card("first").getAttribute("role")).toBe("alert");
     expect(card("second").getAttribute("role")).toBe("alert");
@@ -111,7 +111,7 @@ describe("Toaster — handing the toasts to another host", () => {
     // inserted announces them anyway. React flushes effects in the SAME task as that render, so the
     // arming has to wait for the next one — a screen reader reads the region's state after the task.
     render(<Toaster />);
-    act(() => void notify({ level: "info", message: "saved" }));
+    act(() => void notify({ level: "info", message: raw("saved") }));
     const overlay = render(<Toaster overlay />);
     const region = overlay.container.querySelector("[aria-live]")!;
     expect(region.textContent).toContain("saved"); // it took the toast over…
@@ -135,7 +135,7 @@ describe("Toaster — handing the toasts to another host", () => {
               <Toaster overlay />
               <button
                 onClick={() => {
-                  notify({ level: "success", message: "upload queued" });
+                  notify({ level: "success", message: raw("upload queued") });
                   setOpen(false);
                 }}
               >
@@ -147,7 +147,7 @@ describe("Toaster — handing the toasts to another host", () => {
       );
     }
     render(<Stage />);
-    act(() => void notify({ level: "error", message: "old news" }));
+    act(() => void notify({ level: "error", message: raw("old news") }));
     fireEvent.click(screen.getByText("upload"));
 
     const card = (text: string) => screen.getByText(text).closest(".toast-card")!;
@@ -168,7 +168,7 @@ describe("Toaster — handing the toasts to another host", () => {
         <Toaster overlay order={2} />
       </div>,
     );
-    act(() => void notify({ level: "error", message: "boom" }));
+    act(() => void notify({ level: "error", message: raw("boom") }));
     expect(screen.getByTestId("dialog").textContent).toContain("boom");
     // The player swaps its host (leaving true fullscreen) while the dialog stays open.
     player.rerender(
@@ -188,7 +188,7 @@ describe("Toaster — handing the toasts to another host", () => {
     const t0 = Date.now();
     const now = vi.spyOn(Date, "now").mockReturnValue(t0);
     render(<Toaster />);
-    act(() => void notify({ level: "info", message: "saved" }));
+    act(() => void notify({ level: "info", message: raw("saved") }));
     now.mockReturnValue(t0 + 4000);
     render(<Toaster overlay />);
     const bar = screen.getByText("saved").closest(".toast-card")!.lastElementChild as HTMLElement;
@@ -199,7 +199,7 @@ describe("Toaster — handing the toasts to another host", () => {
     // At the app's own spot (bottom-4) the stack sat on the Plex transport row and PlayerModal's
     // docked bar, above them at z-overlay, and took their clicks for as long as a toast was up.
     render(<Toaster overlay />);
-    act(() => void notify({ level: "error", message: "boom" }));
+    act(() => void notify({ level: "error", message: raw("boom") }));
     const host = hosts()[0]!.closest("[data-toast-region]")!;
     expect(host.className).toContain("bottom-24");
     expect(host.className).toContain("pointer-events-none");
@@ -218,7 +218,7 @@ describe("Toaster — a toast's actions", () => {
       () =>
         void notify({
           level: "success",
-          message: "Downloaded",
+          message: raw("Downloaded"),
           action: { label: "Copy link", onClick: copy },
           secondaryAction: { label: "Open", onClick: open },
         }),
diff --git a/frontend/src/components/ui/Toaster.language.dom.test.tsx b/frontend/src/components/ui/Toaster.language.dom.test.tsx
new file mode 100644
index 00000000..2bcfd42c
--- /dev/null
+++ b/frontend/src/components/ui/Toaster.language.dom.test.tsx
@@ -0,0 +1,73 @@
+// @vitest-environment jsdom
+//
+// A notice is said in the reader's language when it is shown, not in the one it was raised in. The
+// text used to be translated by the caller and kept so: after a language switch every toast and every
+// row of the notification center stayed in the old language, and so did the history after a reload.
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { act, cleanup, render, screen } from "@testing-library/react";
+import i18n from "../../i18n";
+import Toaster from "./Toaster";
+import { clearAll, msg, notify, raw, sayNotif } from "../../lib/notifications";
+
+beforeEach(async () => {
+  await i18n.changeLanguage("en");
+});
+afterEach(async () => {
+  cleanup();
+  act(() => clearAll());
+  await i18n.changeLanguage("en");
+});
+
+describe("a notice speaks the reader's language of the moment", () => {
+  it("a toast raised in English reads Hungarian after the switch", async () => {
+    render(<Toaster />);
+    act(() => void notify({ level: "success", message: msg("common.copy.done") }));
+    const en = i18n.getFixedT("en")("common.copy.done");
+    const hu = i18n.getFixedT("hu")("common.copy.done");
+    expect(en).not.toBe(hu);
+    expect(screen.getByText(en)).toBeTruthy();
+
+    await act(async () => void (await i18n.changeLanguage("hu")));
+    expect(screen.getByText(hu)).toBeTruthy();
+    expect(screen.queryByText(en)).toBeNull();
+  });
+
+  it("a value inside the text is said again too, and a number is grouped the reader's way", async () => {
+    const text = msg("settings.takeout.read", {
+      name: raw("watch-history.json"),
+      count: 12345,
+      n: { number: 12345 },
+    });
+    const en = sayNotif(text);
+    await i18n.changeLanguage("hu");
+    const hu = sayNotif(text);
+    expect(en).toContain("12,345");
+    expect(hu).not.toContain("12,345");
+    expect(hu).toContain("watch-history.json");
+    expect(hu).not.toBe(en);
+  });
+});
+
+describe("the history kept from before", () => {
+  beforeEach(() => {
+    localStorage.clear();
+    vi.resetModules();
+  });
+
+  it("shows a notice stored as text as it was stored", async () => {
+    localStorage.setItem("siftlode.owner", "5");
+    localStorage.setItem(
+      "siftlode.notifications",
+      JSON.stringify([
+        { id: 1, level: "info", title: "Old title", message: "Old text", ts: 1, read: true },
+      ]),
+    );
+    const notifications = await import("../../lib/notifications");
+    const { claimLocalData } = await import("../../lib/storage");
+    claimLocalData(5);
+    const n = notifications.getNotifications()[0]!;
+    expect(n.message).toEqual(raw("Old text"));
+    expect(n.title).toEqual(raw("Old title"));
+    expect(notifications.sayNotif(n.message)).toBe("Old text");
+  });
+});
diff --git a/frontend/src/components/ui/Toaster.strictmode.dom.test.tsx b/frontend/src/components/ui/Toaster.strictmode.dom.test.tsx
index 699124e1..76d1cc8b 100644
--- a/frontend/src/components/ui/Toaster.strictmode.dom.test.tsx
+++ b/frontend/src/components/ui/Toaster.strictmode.dom.test.tsx
@@ -23,7 +23,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 
 import Toaster from "./Toaster";
 import { useOverlayOrder } from "./overlayOrder";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 
 afterEach(() => {
   cleanup();
@@ -37,7 +37,7 @@ function Harness() {
     <>
       <button
         onClick={() => {
-          notify({ level: "success", message: "Uploaded" });
+          notify({ level: "success", message: raw("Uploaded") });
           setOpen(false); // …in the SAME handler: one batch, one commit
         }}
       >
diff --git a/frontend/src/components/ui/Toaster.tsx b/frontend/src/components/ui/Toaster.tsx
index 0c63810f..c6eeffbe 100644
--- a/frontend/src/components/ui/Toaster.tsx
+++ b/frontend/src/components/ui/Toaster.tsx
@@ -1,7 +1,7 @@
 import { useEffect, useId, useLayoutEffect, useState, useSyncExternalStore } from "react";
 import { useTranslation } from "react-i18next";
 import { X } from "lucide-react";
-import { dismiss, getActiveToasts, subscribe } from "../../lib/notifications";
+import { dismiss, getActiveToasts, sayNotif, subscribe } from "../../lib/notifications";
 import { createStore } from "../../lib/store";
 import { useToastDock } from "../../lib/toastDock";
 import { useOverlayOrder } from "./overlayOrder";
@@ -162,9 +162,11 @@ export default function Toaster({
             >
               <Icon className={`w-5 h-5 shrink-0 mt-0.5 ${color}`} />
               <div className="min-w-0 flex-1">
-                {toast.title && <div className="text-sm font-semibold">{toast.title}</div>}
+                {toast.title && (
+                  <div className="text-sm font-semibold">{sayNotif(toast.title, t)}</div>
+                )}
                 <div className="text-sm wrap-break-word">
-                  {toast.message}
+                  {sayNotif(toast.message, t)}
                   {toast.repeat > 1 && (
                     <span className="ml-1.5 align-middle text-2xs font-semibold text-muted tabular-nums">
                       ×{toast.repeat}
diff --git a/frontend/src/components/ui/copyItems.tsx b/frontend/src/components/ui/copyItems.tsx
index 87ce7819..493a3901 100644
--- a/frontend/src/components/ui/copyItems.tsx
+++ b/frontend/src/components/ui/copyItems.tsx
@@ -2,7 +2,7 @@ import { useTranslation } from "react-i18next";
 import { Copy, Link2 } from "lucide-react";
 
 import { copyText } from "../../lib/clipboard";
-import { notify } from "../../lib/notifications";
+import { msg, type NotifText, notify } from "../../lib/notifications";
 import { type ActionMenuItem } from "./ActionMenu";
 
 // "Copy title" and "Copy link", the two rows every object's menu ends its middle group with
@@ -17,12 +17,12 @@ type Named = "title" | "name";
 
 export function useCopyItems() {
   const { t } = useTranslation();
-  const copy = (text: string, done: string) => {
+  const copy = (text: string, done: NotifText) => {
     void copyText(text).then((ok) =>
       notify(
         ok
           ? { level: "success", message: done }
-          : { level: "error", message: t("common.copy.failed") },
+          : { level: "error", message: msg("common.copy.failed") },
       ),
     );
   };
@@ -43,7 +43,7 @@ export function useCopyItems() {
             label: t(named === "title" ? "common.copy.title" : "common.copy.name"),
             icon: <Copy className="w-4 h-4" />,
             inGesture: true,
-            onSelect: () => copy(text, t("common.copy.done")),
+            onSelect: () => copy(text, msg("common.copy.done")),
           },
         ]
       : []),
@@ -54,7 +54,7 @@ export function useCopyItems() {
             label: linkLabel ?? t("common.copy.link"),
             icon: <Link2 className="w-4 h-4" />,
             inGesture: true,
-            onSelect: () => copy(link, t("common.copy.linkDone")),
+            onSelect: () => copy(link, msg("common.copy.linkDone")),
           },
         ]
       : []),
diff --git a/frontend/src/components/ui/useCopyFeedback.dom.test.ts b/frontend/src/components/ui/useCopyFeedback.dom.test.ts
index 830bb4f9..50ab60e2 100644
--- a/frontend/src/components/ui/useCopyFeedback.dom.test.ts
+++ b/frontend/src/components/ui/useCopyFeedback.dom.test.ts
@@ -11,8 +11,12 @@ vi.mock("react-i18next", async (importOriginal) => ({
   useTranslation: () => ({ i18n: { language: "en" }, t: (key: string) => key }),
 }));
 vi.mock("../../lib/clipboard", () => ({ copyText: h.copyText }));
-vi.mock("../../lib/notifications", () => ({ notify: h.notify }));
+vi.mock("../../lib/notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../../lib/notifications")>()),
+  notify: h.notify,
+}));
 
+import { msg } from "../../lib/notifications";
 import { useCopyFeedback } from "./useCopyFeedback";
 
 afterEach(() => {
@@ -27,7 +31,7 @@ describe("useCopyFeedback", () => {
     await act(() => result.current.copy("sfl_x"));
     expect(h.copyText).toHaveBeenCalledWith("sfl_x");
     expect(result.current.copied).toBe(true);
-    expect(h.notify).toHaveBeenCalledWith({ level: "success", message: "common.copy.done" });
+    expect(h.notify).toHaveBeenCalledWith({ level: "success", message: msg("common.copy.done") });
     act(() => void vi.advanceTimersByTime(2000));
     expect(result.current.copied).toBe(false);
   });
@@ -49,6 +53,6 @@ describe("useCopyFeedback", () => {
     const { result } = renderHook(() => useCopyFeedback());
     await act(() => result.current.copy("sfl_x"));
     expect(result.current.copied).toBe(false);
-    expect(h.notify).toHaveBeenCalledWith({ level: "warning", message: "common.copy.failed" });
+    expect(h.notify).toHaveBeenCalledWith({ level: "warning", message: msg("common.copy.failed") });
   });
 });
diff --git a/frontend/src/components/ui/useCopyFeedback.ts b/frontend/src/components/ui/useCopyFeedback.ts
index 9c12c0a4..2efa2069 100644
--- a/frontend/src/components/ui/useCopyFeedback.ts
+++ b/frontend/src/components/ui/useCopyFeedback.ts
@@ -1,8 +1,7 @@
 import { useEffect, useRef, useState } from "react";
-import { useTranslation } from "react-i18next";
 
 import { copyText } from "../../lib/clipboard";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 
 // How long a Copy button reads "Copied" after it worked.
 const COPIED_MS = 2000;
@@ -15,7 +14,6 @@ const COPIED_MS = 2000;
  *
  *  A feature file, not `ui/`: it speaks the app's notifications (as `copyItems` does). */
 export function useCopyFeedback(): { copied: boolean; copy: (value: string) => Promise<void> } {
-  const { t } = useTranslation();
   const [copied, setCopied] = useState(false);
   // One reset at a time: a copy again within the moment starts it over, not cut short by the last.
   const timer = useRef<number | undefined>(undefined);
@@ -23,12 +21,12 @@ export function useCopyFeedback(): { copied: boolean; copy: (value: string) => P
   const copy = async (value: string) => {
     if (await copyText(value)) {
       setCopied(true);
-      notify({ level: "success", message: t("common.copy.done") });
+      notify({ level: "success", message: msg("common.copy.done") });
       window.clearTimeout(timer.current);
       timer.current = window.setTimeout(() => setCopied(false), COPIED_MS);
       return;
     }
-    notify({ level: "warning", message: t("common.copy.failed") });
+    notify({ level: "warning", message: msg("common.copy.failed") });
   };
   return { copied, copy };
 }
diff --git a/frontend/src/features/channel/TagManager.tsx b/frontend/src/features/channel/TagManager.tsx
index f93309a6..91660987 100644
--- a/frontend/src/features/channel/TagManager.tsx
+++ b/frontend/src/features/channel/TagManager.tsx
@@ -4,7 +4,7 @@ import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { qk } from "../../lib/queryKeys";
 import { Plus, Trash2 } from "lucide-react";
 import { api, type Tag } from "../../lib/api";
-import { notify } from "../../lib/notifications";
+import { msg, type NotifText, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { useScrollFade } from "../../lib/useScrollFade";
 import { Button } from "../../components/ui/Button";
@@ -137,22 +137,22 @@ export default function TagManager({
   });
   // A failure is said and the list refetched — a tag deleted in another tab used to fail in silence
   // (a 404 `not_found/tag` gets no global dialog) and stay listed.
-  const onFailed = (e: unknown, fallback: string) => {
+  const onFailed = (e: unknown, fallback: NotifText) => {
     notifyActionError(e, fallback);
     invalidate();
   };
   const rename = useMutation({
     mutationFn: (v: { id: number; name: string }) => api.updateTag(v.id, { name: v.name }),
     onSuccess: invalidate,
-    onError: (e) => onFailed(e, t("tagManager.renameFailed")),
+    onError: (e) => onFailed(e, msg("tagManager.renameFailed")),
   });
   const del = useMutation({
     mutationFn: (v: { id: number; name: string }) => api.deleteTag(v.id),
     onSuccess: (_d, v) => {
       invalidate();
-      notify({ level: "success", message: t("tagManager.deleted", { name: v.name }) });
+      notify({ level: "success", message: msg("tagManager.deleted", { name: v.name }) });
     },
-    onError: (e) => onFailed(e, t("tagManager.deleteFailed")),
+    onError: (e) => onFailed(e, msg("tagManager.deleteFailed")),
   });
 
   // Picking a channel from a tag's popover: close the dialog, then focus it in the manager.
diff --git a/frontend/src/features/comfort/comfortPin.tsx b/frontend/src/features/comfort/comfortPin.tsx
index 1ecef7ec..cb5b4db7 100644
--- a/frontend/src/features/comfort/comfortPin.tsx
+++ b/frontend/src/features/comfort/comfortPin.tsx
@@ -6,7 +6,7 @@ import { Loader2, Pin, PinOff } from "lucide-react";
 import { plexLang } from "../../i18n";
 import { api, type DiscoverCard, type PinKind } from "../../lib/api";
 import { notifyActionError } from "../../lib/actionErrors";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { type ActionMenuItem } from "../../components/ui/ActionMenu";
 
@@ -139,13 +139,13 @@ export function useComfortPin(open: boolean): ComfortPin {
         await api.addComfortPin(target.kind, target.ref);
         // The shelf lives on another page, so without this the click has no visible consequence at
         // all from the feed — the one place a toast genuinely carries the whole feedback.
-        notify({ level: "success", message: t("home.pin.added", { title }) });
+        notify({ level: "success", message: msg("home.pin.added", { title }) });
       } catch (e) {
-        notifyActionError(e, t("home.pin.addFailed"));
+        notifyActionError(e, msg("home.pin.addFailed"));
       }
       invalidate();
     },
-    [invalidate, t],
+    [invalidate],
   );
 
   const remove = useCallback(
@@ -153,14 +153,14 @@ export function useComfortPin(open: boolean): ComfortPin {
       void (async () => {
         try {
           await api.removeComfortPin(pinId);
-          notify({ level: "success", message: t("home.pin.removed", { title }) });
+          notify({ level: "success", message: msg("home.pin.removed", { title }) });
         } catch (e) {
-          notifyActionError(e, t("home.pin.removeFailed"));
+          notifyActionError(e, msg("home.pin.removeFailed"));
         }
         invalidate();
       })();
     },
-    [invalidate, t],
+    [invalidate],
   );
 
   const toggle = useCallback(
diff --git a/frontend/src/features/diagnostics/DebugRecorder.tsx b/frontend/src/features/diagnostics/DebugRecorder.tsx
index 91e1033f..22f74770 100644
--- a/frontend/src/features/diagnostics/DebugRecorder.tsx
+++ b/frontend/src/features/diagnostics/DebugRecorder.tsx
@@ -18,7 +18,7 @@ import {
 } from "../../lib/debugRecorder";
 import { formatDateTimeSec, formatDuration } from "../../lib/format";
 import { useLayer } from "../../lib/layerStack";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { dockUnderToasts } from "../../lib/toastDock";
 import { useMe } from "../../lib/useMe";
@@ -73,7 +73,7 @@ export default function DebugRecorder() {
     if (!id || !until) return;
     const wait = Math.min(Date.parse(until) - Date.now(), 2 ** 31 - 1);
     const timer = window.setTimeout(() => {
-      notify({ level: "warning", message: t("recorder.pill.expired", { count: minutes ?? 0 }) });
+      notify({ level: "warning", message: msg("recorder.pill.expired", { count: minutes ?? 0 }) });
       openComposer(id);
       void qc.invalidateQueries({ queryKey: qk.me() });
     }, wait);
diff --git a/frontend/src/features/diagnostics/IssueComposer.tsx b/frontend/src/features/diagnostics/IssueComposer.tsx
index ff7a1024..cb635105 100644
--- a/frontend/src/features/diagnostics/IssueComposer.tsx
+++ b/frontend/src/features/diagnostics/IssueComposer.tsx
@@ -6,7 +6,7 @@ import { ExternalLink, FileText, Plus, Server, X } from "lucide-react";
 import { api, type DebugScreenshot, type DebugSession, type ServerLogRow } from "../../lib/api";
 import { closeComposer } from "../../lib/debugRecorder";
 import { formatBytes, formatDateTimeSec, formatUnit } from "../../lib/format";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { useMe } from "../../lib/useMe";
 import {
   draftSteps,
@@ -217,7 +217,7 @@ function ComposerBody({
     meta: { failTitle: "recorder.composer.sendFailed" },
     onSuccess: (r) => {
       qc.setQueryData(qk.debugSession(session.id), r.session);
-      notify({ level: "success", message: t("recorder.composer.sentOk") });
+      notify({ level: "success", message: msg("recorder.composer.sentOk") });
     },
     // A failure half-way still created the issue: show what the server now has.
     onSettled: async () => {
diff --git a/frontend/src/features/diagnostics/useDebugRecording.ts b/frontend/src/features/diagnostics/useDebugRecording.ts
index c0a2b914..79fc095a 100644
--- a/frontend/src/features/diagnostics/useDebugRecording.ts
+++ b/frontend/src/features/diagnostics/useDebugRecording.ts
@@ -1,6 +1,5 @@
 import { useCallback } from "react";
 import { useIsMutating, useMutation, useQueryClient } from "@tanstack/react-query";
-import { useTranslation } from "react-i18next";
 
 import { api, type DebugSession, type DebugSessionLevel } from "../../lib/api";
 import { notifyActionError } from "../../lib/actionErrors";
@@ -14,7 +13,7 @@ import {
 } from "../../lib/debugRecorder";
 import { flushNow, liveSession } from "../../lib/diagnostics";
 import { log } from "../../lib/log";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { updateMeCache, useMe } from "../../lib/useMe";
 
@@ -22,7 +21,6 @@ import { updateMeCache, useMe } from "../../lib/useMe";
  *  Diagnosztika and the command palette. The session itself is `me.debug_session` — the server's
  *  answer, so a reload, another tab or the cap all show the same thing. */
 export function useDebugRecording() {
-  const { t } = useTranslation();
   const qc = useQueryClient();
   const me = useMe();
   const session = liveSession(me?.debug_session);
@@ -54,7 +52,7 @@ export function useDebugRecording() {
     meta: { failTitle: "recorder.pill.stopFailed" },
     onSuccess: (r) => {
       setSession(null);
-      notify({ level: "success", message: t("recorder.pill.stopped") });
+      notify({ level: "success", message: msg("recorder.pill.stopped") });
       openComposer(r.session.id);
     },
   });
@@ -78,7 +76,7 @@ export function useDebugRecording() {
       );
       // In the evidence too, where the step list is drafted from: which step it belongs to.
       log.info("debug.screenshot", "screenshot taken", { screenshot: r.screenshot.id });
-      notify({ level: "success", message: t("recorder.pill.shotSaved") });
+      notify({ level: "success", message: msg("recorder.pill.shotSaved") });
     },
   });
 
@@ -95,9 +93,9 @@ export function useDebugRecording() {
       const n = nextStep(sessionId);
       const text = label.trim();
       log.info("debug.step", text || `step ${n}`, { n, ...(text ? { label: text } : {}) });
-      notify({ level: "info", message: t("recorder.pill.stepMarked", { n }) });
+      notify({ level: "info", message: msg("recorder.pill.stepMarked", { n }) });
     },
-    [sessionId, t],
+    [sessionId],
   );
 
   /** Capture this tab and attach it. `hide` runs around the capture so the pill is not in the
@@ -111,7 +109,7 @@ export function useDebugRecording() {
       await new Promise((r) => requestAnimationFrame(() => requestAnimationFrame(r)));
       image = await captureTab();
     } catch (err) {
-      notifyActionError(err, t("recorder.pill.shotFailed"));
+      notifyActionError(err, msg("recorder.pill.shotFailed"));
     }
     hide(false);
     if (image) shoot.mutate({ id: session.id, image });
diff --git a/frontend/src/features/downloads/DownloadDialog.tsx b/frontend/src/features/downloads/DownloadDialog.tsx
index c680672d..837c8ed9 100644
--- a/frontend/src/features/downloads/DownloadDialog.tsx
+++ b/frontend/src/features/downloads/DownloadDialog.tsx
@@ -9,7 +9,7 @@ import { invalidateDownloads } from "../../lib/downloads";
 
 // Lazy: the full profile editor only opens from the dialog's "manage presets" affordance.
 const ProfileEditor = lazy(() => import("../../modules/settings/ProfileEditor"));
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { showInTray } from "../../lib/downloadQueue";
 import { profileName } from "../../lib/vocab";
@@ -63,7 +63,7 @@ export default function DownloadDialog({
       setLastProfile(chosen);
       notify({
         level: "success",
-        message: t("downloads.dialog.added"),
+        message: msg("downloads.dialog.added"),
         action: { label: t("downloads.dialog.view"), onClick: () => showInTray(job.id) },
       });
       onClose();
@@ -71,7 +71,7 @@ export default function DownloadDialog({
       // A quota or validation refusal (422/409) is already in the global error dialog, which the
       // reporter skips; a 403/404/429 or a lost connection is not, and used to leave the dialog
       // open with nothing said.
-      notifyActionError(e, t("errors.writeFailed.enqueueDownload"));
+      notifyActionError(e, msg("errors.writeFailed.enqueueDownload"));
       setBusy(false);
     }
   };
diff --git a/frontend/src/features/downloads/DownloadTray.dom.test.tsx b/frontend/src/features/downloads/DownloadTray.dom.test.tsx
index 69096443..2755a017 100644
--- a/frontend/src/features/downloads/DownloadTray.dom.test.tsx
+++ b/frontend/src/features/downloads/DownloadTray.dom.test.tsx
@@ -70,6 +70,7 @@ vi.mock("../../lib/notifications", async (importOriginal) => ({
 }));
 
 import DownloadTray from "./DownloadTray";
+import { msg, type NotifText } from "../../lib/notifications";
 import { noteQueue, resetQueueWatch, showInTray } from "../../lib/downloadQueue";
 import { pushLayer, removeLayer } from "../../lib/layerStack";
 import { qk } from "../../lib/queryKeys";
@@ -199,13 +200,13 @@ describe("DownloadTray", () => {
     poll([job(1, "done")], view);
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(1));
     const notice = h.notify.mock.calls[0]![0] as {
-      title: string;
-      message: string;
+      title: NotifText;
+      message: NotifText;
       action: { label: string; onClick: () => void };
       secondaryAction: { label: string; onClick: () => void };
     };
-    expect(notice.title).toBe("tray.done.title:Clip 1");
-    expect(notice.message).toBe("tray.done.phone");
+    expect(notice.title).toEqual(msg("tray.done.title", { title: "Clip 1" }));
+    expect(notice.message).toEqual(msg("tray.done.phone"));
     expect(notice.action.label).toBe("tray.done.copyLink");
     notice.action.onClick();
     expect(h.share).toHaveBeenCalled();
@@ -225,9 +226,9 @@ describe("DownloadTray", () => {
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(1));
     poll([job(1, "done"), job(2, "done")], view);
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(2));
-    expect(h.notify.mock.calls.map((c) => (c[0] as { title: string }).title)).toEqual([
-      "tray.done.title:Clip 1",
-      "tray.done.title:Clip 2",
+    expect(h.notify.mock.calls.map((c) => (c[0] as { title: NotifText }).title)).toEqual([
+      msg("tray.done.title", { title: "Clip 1" }),
+      msg("tray.done.title", { title: "Clip 2" }),
     ]);
   });
 
@@ -236,7 +237,9 @@ describe("DownloadTray", () => {
     const view = mount();
     poll([job(1, "done", { asset: { media_kind: "file" } as never })], view);
     await waitFor(() =>
-      expect(h.notify).toHaveBeenCalledWith(expect.objectContaining({ message: "tray.done.file" })),
+      expect(h.notify).toHaveBeenCalledWith(
+        expect.objectContaining({ message: msg("tray.done.file") }),
+      ),
     );
   });
 
@@ -257,7 +260,7 @@ describe("DownloadTray", () => {
     poll([job(1, "done", { source_key: "upload" })], view);
     await waitFor(() =>
       expect(h.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ title: "tray.done.uploadedTitle:Clip 1" }),
+        expect.objectContaining({ title: msg("tray.done.uploadedTitle", { title: "Clip 1" }) }),
       ),
     );
   });
diff --git a/frontend/src/features/downloads/DownloadTray.tsx b/frontend/src/features/downloads/DownloadTray.tsx
index c7c80331..c6f30696 100644
--- a/frontend/src/features/downloads/DownloadTray.tsx
+++ b/frontend/src/features/downloads/DownloadTray.tsx
@@ -30,7 +30,7 @@ import {
 } from "../../lib/downloadQueue";
 import { anyBlockingLayer } from "../../lib/layerStack";
 import { focusNavItem, navItemAttrs } from "../../lib/listNav";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { LS } from "../../lib/storage";
 import { useLiveQuery } from "../../lib/useLiveQuery";
@@ -191,10 +191,10 @@ export default function DownloadTray() {
     notify({
       level: "success",
       // An upload the worker had to convert first is done here too — it was never downloaded.
-      title: t(job.source_key === "upload" ? "tray.done.uploadedTitle" : "tray.done.title", {
+      title: msg(job.source_key === "upload" ? "tray.done.uploadedTitle" : "tray.done.title", {
         title,
       }),
-      message: t(job.asset?.media_kind === "file" ? "tray.done.file" : "tray.done.phone"),
+      message: msg(job.asset?.media_kind === "file" ? "tray.done.file" : "tray.done.phone"),
       action: {
         label: t("tray.done.copyLink"),
         onClick: () => void quickShareLink(qc, { kind: "file", id: job.id }, t),
diff --git a/frontend/src/features/downloads/useDownloadActions.tsx b/frontend/src/features/downloads/useDownloadActions.tsx
index 436f3b95..cb896aba 100644
--- a/frontend/src/features/downloads/useDownloadActions.tsx
+++ b/frontend/src/features/downloads/useDownloadActions.tsx
@@ -9,6 +9,7 @@ import { useCopyItems } from "../../components/ui/copyItems";
 import { jobTitle } from "./downloadTitle";
 import { type ActionMenuItem } from "../../components/ui/ActionMenu";
 import { menuGroups } from "../../components/ui/menuGroups";
+import { msg } from "../../lib/notifications";
 
 // A queued download's ONE action list: the row's "…", its right-click, long-press and Shift+F10. The
 // row keeps its primary action (pause / resume / retry) and its state (the error and its details) in
@@ -56,7 +57,7 @@ export function useDownloadActions() {
           ? api.resumeDownload(id)
           : api.cancelDownload(id),
     onSuccess: () => invalidateDownloads(qc),
-    onError: (e, v) => notifyActionError(e, t(`errors.writeFailed.job.${v.op}`)),
+    onError: (e, v) => notifyActionError(e, msg(`errors.writeFailed.job.${v.op}`)),
   });
 
   const confirmThen = async (title: string, body: string, action: string, fn: () => void) => {
diff --git a/frontend/src/features/filters/useSavedViewsStore.ts b/frontend/src/features/filters/useSavedViewsStore.ts
index cc599934..53f47ff8 100644
--- a/frontend/src/features/filters/useSavedViewsStore.ts
+++ b/frontend/src/features/filters/useSavedViewsStore.ts
@@ -8,6 +8,7 @@ import { notifyActionError } from "../../lib/actionErrors";
 import { ownKey } from "../../lib/storage";
 import { useConfirm } from "../../components/ui/confirmContext";
 import type { SavedViewsContext, ViewSource } from "./savedViewsContext";
+import { msg, type NotifText } from "../../lib/notifications";
 
 // Saved "smart views" serve two modules — the feed and Plex — and each owns one store of them in its
 // own folder, built on this hook. The two never switch into each other: a visit to Plex leaves the
@@ -114,7 +115,7 @@ export function useSavedViewsStore(cfg: SavedViewsConfig): SavedViewsContext {
   const isDirty = displayView != null && activeView == null;
 
   const refresh = () => void qc.invalidateQueries({ queryKey: qk.savedViews(source) });
-  async function runViewMutation(fn: () => Promise<unknown>, failMsg: string): Promise<boolean> {
+  async function runViewMutation(fn: () => Promise<unknown>, failMsg: NotifText): Promise<boolean> {
     let ok = true;
     try {
       await fn();
@@ -146,28 +147,28 @@ export function useSavedViewsStore(cfg: SavedViewsConfig): SavedViewsContext {
       if (!clean) return false;
       return runViewMutation(
         () => api.createView(clean, cfg.stripForSave(cfg.filters), source),
-        t("views.actionFailed"),
+        msg("views.actionFailed"),
       );
     },
     rename: async (id, name) => {
       const next = name.trim();
       if (!next) return false;
-      return runViewMutation(() => api.updateView(id, { name: next }), t("views.actionFailed"));
+      return runViewMutation(() => api.updateView(id, { name: next }), msg("views.actionFailed"));
     },
     updateFilters: (id, filters) =>
-      runViewMutation(() => api.updateView(id, { filters }), t("views.actionFailed")),
+      runViewMutation(() => api.updateView(id, { filters }), msg("views.actionFailed")),
     saveCurrent: async (id) => {
       const filters = cfg.stripForSave(cfg.filters);
       const ok = await runViewMutation(
         () => api.updateView(id, { filters }),
-        t("views.actionFailed"),
+        msg("views.actionFailed"),
       );
       return ok ? filters : null;
     },
     toggleDefault: (v) =>
       runViewMutation(
         () => api.updateView(v.id, { is_default: !v.is_default }),
-        t("views.actionFailed"),
+        msg("views.actionFailed"),
       ).then(() => undefined),
     remove: async (v) => {
       const ok = await confirm({
@@ -177,14 +178,14 @@ export function useSavedViewsStore(cfg: SavedViewsConfig): SavedViewsContext {
       });
       if (!ok) return false;
       if (stickyId === v.id) setStickyId(null);
-      return runViewMutation(() => api.deleteView(v.id), t("views.actionFailed"));
+      return runViewMutation(() => api.deleteView(v.id), msg("views.actionFailed"));
     },
     reorder: async (nextIds) => {
       qc.setQueryData<SavedView[]>(
         qk.savedViews(source),
         nextIds.map((id) => views.find((v) => v.id === id)!).filter(Boolean),
       );
-      await runViewMutation(() => api.reorderViews(nextIds), t("views.reorderFailed"));
+      await runViewMutation(() => api.reorderViews(nextIds), msg("views.reorderFailed"));
     },
   };
 }
diff --git a/frontend/src/features/player/ClipPanel.dom.test.tsx b/frontend/src/features/player/ClipPanel.dom.test.tsx
index 5fd20636..650cfcbc 100644
--- a/frontend/src/features/player/ClipPanel.dom.test.tsx
+++ b/frontend/src/features/player/ClipPanel.dom.test.tsx
@@ -30,10 +30,11 @@ vi.mock("../../lib/downloadQueue", () => ({ showInTray: (id: number) => showInTr
 const notifyActionError = vi.fn();
 vi.mock("../../lib/actionErrors", async (importOriginal) => {
   const actual = await importOriginal<typeof import("../../lib/actionErrors")>();
-  return { ...actual, notifyActionError: (e: unknown, t: string) => notifyActionError(e, t) };
+  return { ...actual, notifyActionError: (e: unknown, t: NotifText) => notifyActionError(e, t) };
 });
 
 import ClipPanel, { type ClipCrop, type ClipSource } from "./ClipPanel";
+import { msg, type NotifText } from "../../lib/notifications";
 
 afterEach(() => {
   cleanup();
@@ -188,7 +189,7 @@ describe("ClipPanel", () => {
       display_name: "The bit",
     });
     expect(notify).toHaveBeenCalledWith(
-      expect.objectContaining({ level: "success", message: "clip.queued" }),
+      expect.objectContaining({ level: "success", message: msg("clip.queued") }),
     );
     // Its View opens the tray on the new clip.
     (
@@ -214,7 +215,7 @@ describe("ClipPanel", () => {
     fireEvent.click(screen.getByRole("button", { name: "clip.cut" }));
     await waitFor(() => expect(notifyActionError).toHaveBeenCalledTimes(1));
     expect(notifyActionError.mock.calls[0]![0]).toBe(err);
-    expect(notifyActionError.mock.calls[0]![1]).toBe("clip.failed");
+    expect(notifyActionError.mock.calls[0]![1]).toEqual(msg("clip.failed"));
     expect(onClose).not.toHaveBeenCalled();
     expect((screen.getByRole("button", { name: "clip.cut" }) as HTMLButtonElement).disabled).toBe(
       false,
diff --git a/frontend/src/features/player/ClipPanel.tsx b/frontend/src/features/player/ClipPanel.tsx
index 9e1ee6cd..08690fd6 100644
--- a/frontend/src/features/player/ClipPanel.tsx
+++ b/frontend/src/features/player/ClipPanel.tsx
@@ -5,7 +5,7 @@ import { Crop, Crosshair, Maximize, Minus, Plus, Repeat, Scissors, X } from "luc
 import { api, type ClipRequest } from "../../lib/api";
 import { DISPLAY_NAME_MAX } from "../../lib/api/downloads";
 import { invalidateDownloads } from "../../lib/downloads";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { showInTray } from "../../lib/downloadQueue";
 import { log } from "../../lib/log";
@@ -197,14 +197,14 @@ export default function ClipPanel({
       log.info("clip.queued", "clip queued", { source: src.source, seconds: Math.round(length) });
       notify({
         level: "success",
-        message: t("clip.queued"),
+        message: msg("clip.queued"),
         action: { label: t("clip.view"), onClick: () => showInTray(job.id) },
       });
       onClose();
     } catch (err) {
       // A refusal the server explains (too long, quota) is already in the error dialog; a lost
       // connection or a 404 is not, and must not leave the panel looking as if nothing happened.
-      notifyActionError(err, t("clip.failed"));
+      notifyActionError(err, msg("clip.failed"));
       setBusy(false);
     }
   };
diff --git a/frontend/src/features/player/LinkedPlayer.tsx b/frontend/src/features/player/LinkedPlayer.tsx
index f6f86231..d139fcf2 100644
--- a/frontend/src/features/player/LinkedPlayer.tsx
+++ b/frontend/src/features/player/LinkedPlayer.tsx
@@ -1,5 +1,4 @@
 import { lazy, Suspense, useState } from "react";
-import { useTranslation } from "react-i18next";
 import { useQueryClient } from "@tanstack/react-query";
 import { type Video, type VideoStatus } from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
@@ -7,6 +6,7 @@ import { notifyActionError } from "../../lib/actionErrors";
 import { useStableCallback } from "../../lib/useLatest";
 import { writeVideoState } from "../video/videoWrites";
 import { useOpenLinkedPlayer } from "./useOpenLinkedPlayer";
+import { msg } from "../../lib/notifications";
 
 const PlayerModal = lazy(() => import("./PlayerModal"));
 
@@ -14,7 +14,6 @@ const PlayerModal = lazy(() => import("./PlayerModal"));
  *  channel manager, where the watched-videos dialog played it; any page a link names): the video
  *  alone. Decided at boot, once — `hosted` is whether the page on screen then opens it itself. */
 export function LinkedPlayer({ hosted }: { hosted: boolean }) {
-  const { t } = useTranslation();
   const qc = useQueryClient();
   const [own] = useState(!hosted);
   const [video, setVideo] = useState<Video | null>(null);
@@ -27,7 +26,7 @@ export function LinkedPlayer({ hosted }: { hosted: boolean }) {
     const write = writeVideoState(qc, id, status);
     write
       .then(() => qc.invalidateQueries({ queryKey: qk.feed() }))
-      .catch((e: unknown) => notifyActionError(e, t("errors.writeFailed.videoState")));
+      .catch((e: unknown) => notifyActionError(e, msg("errors.writeFailed.videoState")));
     return write;
   });
   const close = useStableCallback(() => setVideo(null));
diff --git a/frontend/src/features/player/PlayerModal.dom.test.tsx b/frontend/src/features/player/PlayerModal.dom.test.tsx
index f75174d8..2c2bbd90 100644
--- a/frontend/src/features/player/PlayerModal.dom.test.tsx
+++ b/frontend/src/features/player/PlayerModal.dom.test.tsx
@@ -40,7 +40,7 @@ import { closeKeyboardHelp, toggleKeyboardHelp } from "../../lib/keymap";
 import { ConfirmProvider } from "../../components/ui/ConfirmProvider";
 import { useConfirm } from "../../components/ui/confirmContext";
 import { api, type Me, type Video, type VideoStatus } from "../../lib/api";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { writeVideoState } from "../video/videoWrites";
 
@@ -314,7 +314,7 @@ describe("PlayerModal — toasts raised while it is open", () => {
         onState={() => Promise.resolve()}
       />,
     );
-    act(() => void notify({ level: "error", message: "Couldn't remove the video." }));
+    act(() => void notify({ level: "error", message: raw("Couldn't remove the video.") }));
     expect(screen.getByTestId("player-modal").textContent).toContain("Couldn't remove the video.");
   });
 
@@ -336,7 +336,7 @@ describe("PlayerModal — toasts raised while it is open", () => {
     Object.defineProperty(document, "fullscreenElement", { configurable: true, get: () => stage });
     try {
       act(() => void document.dispatchEvent(new Event("fullscreenchange")));
-      act(() => void notify({ level: "error", message: "Connection lost" }));
+      act(() => void notify({ level: "error", message: raw("Connection lost") }));
       await waitFor(() => expect(stage.textContent).toContain("Connection lost"));
     } finally {
       delete (document as { fullscreenElement?: unknown }).fullscreenElement;
diff --git a/frontend/src/features/player/RelatedVideos.tsx b/frontend/src/features/player/RelatedVideos.tsx
index 19873bdf..e412abb2 100644
--- a/frontend/src/features/player/RelatedVideos.tsx
+++ b/frontend/src/features/player/RelatedVideos.tsx
@@ -26,6 +26,7 @@ import VideoCard from "../video/VideoCard";
 import { VideoMenu } from "../video/VideoMenu";
 import { announceVideoState } from "../video/stateNotice";
 import { writeVideoState, writeWatchLater } from "../video/videoWrites";
+import { msg } from "../../lib/notifications";
 
 /** Which list YouTube fills in — on the video's topic or with what trends in Hungary — is a mood,
  *  decided at the list, and the account keeps the last one (the owner's pick). */
@@ -100,7 +101,7 @@ export function RelatedVideos({
         announceVideoState(id, status, v, () => onState(id, "new"));
       })
       .catch((e: unknown) => {
-        notifyActionError(e, t("errors.writeFailed.videoState"));
+        notifyActionError(e, msg("errors.writeFailed.videoState"));
         settle(seq);
       });
   };
@@ -118,7 +119,7 @@ export function RelatedVideos({
       .catch((e: unknown) => {
         notifyActionError(
           e,
-          t(saved ? "errors.writeFailed.watchLaterAdd" : "errors.writeFailed.watchLaterRemove"),
+          msg(saved ? "errors.writeFailed.watchLaterAdd" : "errors.writeFailed.watchLaterRemove"),
         );
         settle(seq);
       });
diff --git a/frontend/src/features/player/useOpenLinkedPlayer.dom.test.tsx b/frontend/src/features/player/useOpenLinkedPlayer.dom.test.tsx
index 1c19b974..ea177b29 100644
--- a/frontend/src/features/player/useOpenLinkedPlayer.dom.test.tsx
+++ b/frontend/src/features/player/useOpenLinkedPlayer.dom.test.tsx
@@ -26,6 +26,7 @@ import { useOpenLinkedPlayer } from "./useOpenLinkedPlayer";
 import { LinkedPlayer } from "./LinkedPlayer";
 import { api, type Video } from "../../lib/api";
 import { notifyActionError } from "../../lib/actionErrors";
+import { msg } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 
 const vid = (id: string) => ({ id, title: id }) as unknown as Video;
@@ -76,7 +77,7 @@ describe("useOpenLinkedPlayer", () => {
     const open = vi.fn();
     renderHook(() => useOpenLinkedPlayer(true, () => undefined, open), { wrapper });
     await waitFor(() =>
-      expect(notifyActionError).toHaveBeenCalledWith(gone, "player.linkedFailed"),
+      expect(notifyActionError).toHaveBeenCalledWith(gone, msg("player.linkedFailed")),
     );
     expect(open).not.toHaveBeenCalled();
     // Said once: the address no longer names it, so a reload or a copied link does not say it again.
diff --git a/frontend/src/features/player/useOpenLinkedPlayer.ts b/frontend/src/features/player/useOpenLinkedPlayer.ts
index 308f0f61..5b776995 100644
--- a/frontend/src/features/player/useOpenLinkedPlayer.ts
+++ b/frontend/src/features/player/useOpenLinkedPlayer.ts
@@ -1,11 +1,11 @@
 import { useEffect, useEffectEvent, useRef, useState } from "react";
-import { useTranslation } from "react-i18next";
 import { useQuery } from "@tanstack/react-query";
 import { api, type Video } from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
 import { linkedPlayer, PLAYER_KEYS } from "../../lib/playerUrlState";
 import { clearParams } from "../../lib/urlState";
 import { notifyActionError } from "../../lib/actionErrors";
+import { msg } from "../../lib/notifications";
 
 /** Opens the player an address names (a reload, a bookmark — lib/playerUrlState) on the page that
  *  hosts it, once: read as the host mounts, opened once its list is in (`ready`). From the list when the
@@ -22,7 +22,6 @@ export function useOpenLinkedPlayer(
   open: (video: Video, inList: boolean) => void,
   scope: string | number | null = null,
 ): void {
-  const { t } = useTranslation();
   const [linked] = useState(() => linkedPlayer()?.watch ?? null);
   const [linkedScope] = useState(scope);
   // Opened, said to be gone or given up, once. A ref for the effect (a StrictMode re-run of it must
@@ -40,7 +39,7 @@ export function useOpenLinkedPlayer(
   });
   const openIt = useEffectEvent(open);
   const failed = useEffectEvent((err: unknown) => {
-    notifyActionError(err, t("player.linkedFailed"));
+    notifyActionError(err, msg("player.linkedFailed"));
     clearParams(...PLAYER_KEYS);
   });
   useEffect(() => {
diff --git a/frontend/src/features/plexCards/PlexCollectionAdd.tsx b/frontend/src/features/plexCards/PlexCollectionAdd.tsx
index f63b90a7..b413ee29 100644
--- a/frontend/src/features/plexCards/PlexCollectionAdd.tsx
+++ b/frontend/src/features/plexCards/PlexCollectionAdd.tsx
@@ -8,6 +8,7 @@ import { PopoverSurface } from "../../components/ui/AnchoredPopover";
 import { useAnchoredPopover } from "../../components/ui/anchoredPopoverHooks";
 import { MembershipMenu } from "../../components/ui/MembershipMenu";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // "Add to collection…" from a movie or show card's menu: a panel beside the card that ticks the title
 // into or out of its library's manual collections, and names a new one — created with this title in
@@ -67,7 +68,7 @@ export default function PlexCollectionAddAt({
       else await api.plexCollectionAddItem(c.id, ratingKey);
       qc.setQueryData<typeof list.data>(forKey, (old) => flipContains(old, c.id));
     } catch (e) {
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     refresh();
     setBusy(false);
@@ -83,7 +84,7 @@ export default function PlexCollectionAddAt({
       made = true;
     } catch (e) {
       made = madeOnPlex(e);
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     refresh();
     setBusy(false);
diff --git a/frontend/src/features/plexCards/PlexPlaylistAdd.tsx b/frontend/src/features/plexCards/PlexPlaylistAdd.tsx
index c7b49d73..27883d47 100644
--- a/frontend/src/features/plexCards/PlexPlaylistAdd.tsx
+++ b/frontend/src/features/plexCards/PlexPlaylistAdd.tsx
@@ -12,6 +12,7 @@ import Modal from "../../components/ui/Modal";
 import { Pressable } from "../../components/ui/Pressable";
 import { Input } from "../../components/ui/Input";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // What we're adding: a single leaf (movie/episode) or a whole group (a season or an entire show, as a
 // set of episode rating_keys). Groups get a tri-state (none / some / all) per playlist.
@@ -80,7 +81,7 @@ export default function PlexPlaylistAdd({
     } catch (e) {
       notifyActionError(
         e,
-        t(allIn ? "plex.playlistAdd.removeFailed" : "plex.playlistAdd.addFailed"),
+        msg(allIn ? "plex.playlistAdd.removeFailed" : "plex.playlistAdd.addFailed"),
       );
     }
     refresh();
@@ -104,7 +105,7 @@ export default function PlexPlaylistAdd({
     } catch (e) {
       // The create may already have landed when the add fails — `refresh()` in `finally` is what
       // makes that half-done state visible instead of leaving a playlist the dialog never lists.
-      notifyActionError(e, t("plex.playlistAdd.createFailed"));
+      notifyActionError(e, msg("plex.playlistAdd.createFailed"));
     }
     refresh();
     setBusy(false);
diff --git a/frontend/src/features/video/AddToPlaylist.tsx b/frontend/src/features/video/AddToPlaylist.tsx
index 3e00298a..02f51af5 100644
--- a/frontend/src/features/video/AddToPlaylist.tsx
+++ b/frontend/src/features/video/AddToPlaylist.tsx
@@ -13,6 +13,7 @@ import { useAnchoredPopover } from "../../components/ui/anchoredPopoverHooks";
 import { IconButton } from "../../components/ui/IconButton";
 import { MembershipMenu } from "../../components/ui/MembershipMenu";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // A small anchored menu for toggling a video's membership in the user's playlists, with inline
 // "new playlist" creation. Its body is the shared MembershipMenu (as the channel tag editor's).
@@ -122,7 +123,7 @@ function MembershipPanel({
         old?.map((p) => (p.id === pl.id ? { ...p, has_video: !p.has_video } : p)),
       );
     } catch (e) {
-      notifyActionError(e, t(pl.has_video ? "playlists.removeFailed" : "playlists.addFailed"));
+      notifyActionError(e, msg(pl.has_video ? "playlists.removeFailed" : "playlists.addFailed"));
     }
     refresh();
     setBusy(false);
@@ -137,7 +138,7 @@ function MembershipPanel({
       await addPlaylistItem(qc, pl, videoId);
       made = true;
     } catch (e) {
-      notifyActionError(e, t("playlists.addFailed"));
+      notifyActionError(e, msg("playlists.addFailed"));
     }
     refresh();
     setBusy(false);
diff --git a/frontend/src/features/video/stateNotice.ts b/frontend/src/features/video/stateNotice.ts
index 458b2a3b..99e6c054 100644
--- a/frontend/src/features/video/stateNotice.ts
+++ b/frontend/src/features/video/stateNotice.ts
@@ -1,5 +1,5 @@
 import i18n from "../../i18n";
-import { notify, resolveVideo } from "../../lib/notifications";
+import { msg, notify, resolveVideo } from "../../lib/notifications";
 import type { Video, VideoStatus } from "../../lib/api";
 
 /** What a notice names the video by; any of it may be unknown to the surface that marked it. */
@@ -24,8 +24,8 @@ export function announceVideoState(
   const hidden = status === "hidden";
   notify({
     message: video?.title
-      ? i18n.t(hidden ? "feed.hiddenNamed" : "feed.markedWatchedNamed", { title: video.title })
-      : i18n.t(hidden ? "feed.hidden" : "feed.markedWatched"),
+      ? msg(hidden ? "feed.hiddenNamed" : "feed.markedWatchedNamed", { title: video.title })
+      : msg(hidden ? "feed.hidden" : "feed.markedWatched"),
     action: { label: i18n.t(hidden ? "feed.undo" : "feed.unwatch"), onClick: undo },
     meta: {
       kind: hidden ? "video-hidden" : "video-watched",
diff --git a/frontend/src/features/wizard/OnboardingWizard.dialog.dom.test.tsx b/frontend/src/features/wizard/OnboardingWizard.dialog.dom.test.tsx
index 8528354e..cb203190 100644
--- a/frontend/src/features/wizard/OnboardingWizard.dialog.dom.test.tsx
+++ b/frontend/src/features/wizard/OnboardingWizard.dialog.dom.test.tsx
@@ -23,7 +23,7 @@ vi.mock("../../lib/onboarding", () => ({ beginGrant: vi.fn(), endOnboarding: vi.
 
 import OnboardingWizard from "./OnboardingWizard";
 import { api, type Me } from "../../lib/api";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 
 const me = { id: 1, email: "a@b", can_read: false, can_write: false } as unknown as Me;
 
@@ -110,7 +110,7 @@ describe("the onboarding wizard as a dialog", () => {
     document.body.appendChild(outside);
     outside.focus();
     const { unmount } = mount();
-    act(() => void notify({ level: "error", message: "offline" }));
+    act(() => void notify({ level: "error", message: raw("offline") }));
     const dismissToast = screen.getByTitle("notifications.dismiss");
     dismissToast.focus();
     expect(document.activeElement).toBe(dismissToast);
@@ -126,7 +126,7 @@ describe("the onboarding wizard as a dialog", () => {
     // unreachable from the keyboard. `ui/Modal` spans the whole dialog for exactly this reason.
     mount();
     const panel = screen.getByRole("dialog");
-    act(() => void notify({ level: "error", message: "offline" }));
+    act(() => void notify({ level: "error", message: raw("offline") }));
     try {
       const dismissToast = screen.getByTitle("notifications.dismiss");
       expect(panel.contains(dismissToast)).toBe(false);
diff --git a/frontend/src/i18n/backendIds.contract.test.ts b/frontend/src/i18n/backendIds.contract.test.ts
index 9b08e934..c4603e5b 100644
--- a/frontend/src/i18n/backendIds.contract.test.ts
+++ b/frontend/src/i18n/backendIds.contract.test.ts
@@ -89,7 +89,7 @@ const quotaActions = enumValues("quota.py");
 // ruff wraps over several lines still matches.
 const adminCodes = [
   ...(
-    readFileSync(new URL("../lib/api/core.ts", import.meta.url), "utf-8").match(
+    readFileSync(new URL("../lib/api/refusalText.ts", import.meta.url), "utf-8").match(
       /ADMIN_REFUSALS = new Set\(\[([^\]]*)\]/,
     )?.[1] ?? ""
   ).matchAll(/"(\w+)"/g),
diff --git a/frontend/src/lib/actionErrors.test.ts b/frontend/src/lib/actionErrors.test.ts
index a35c366a..6067d4d9 100644
--- a/frontend/src/lib/actionErrors.test.ts
+++ b/frontend/src/lib/actionErrors.test.ts
@@ -4,12 +4,16 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 
 // Spy on the toast sink so we can assert exactly what each error maps to.
-vi.mock("./notifications", () => ({ notify: vi.fn(() => 0) }));
+vi.mock("./notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("./notifications")>()),
+  notify: vi.fn(() => 0),
+}));
 vi.mock("./errorDialog", () => ({ reportError: vi.fn() }));
 
 import { HttpError, api } from "./api";
 import { alreadyReported } from "./api/core";
-import { notify } from "./notifications";
+import { msg, notify, raw, sayNotif } from "./notifications";
+import { localizeDetail } from "./api/refusalText";
 import { reportError } from "./errorDialog";
 import { failureReason, notifyActionError, notifyKnownFailure } from "./actionErrors";
 import i18n from "../i18n";
@@ -32,10 +36,19 @@ describe("a Plex collection name that is already taken", () => {
     );
     const err = await api.plexCreateCollection("1", "Marvel", "m1").catch((e: unknown) => e);
     notifyMock.mockClear();
-    notifyActionError(err, "EDIT_FAILED");
+    notifyActionError(err, raw("EDIT_FAILED"));
     expect(notifyMock.mock.calls).toEqual([
-      [{ level: "error", title: "EDIT_FAILED", message: i18n.t("plex.collection.nameTaken") }],
+      [
+        {
+          level: "error",
+          title: raw("EDIT_FAILED"),
+          message: { detail: { code: "collection", reason: "name_taken" } },
+        },
+      ],
     ]);
+    expect(sayNotif(notifyMock.mock.calls[0]![0].message)).toBe(
+      i18n.t("plex.collection.nameTaken"),
+    );
     expect(reportError).not.toHaveBeenCalled();
   });
 });
@@ -52,26 +65,26 @@ describe("notifyActionError", () => {
     );
     const err = await api.plexSetState("1", "watched").catch((e: unknown) => e);
     notifyMock.mockClear();
-    notifyActionError(err, "FAILED");
+    notifyActionError(err, raw("FAILED"));
     expect(notifyMock).not.toHaveBeenCalled();
   });
 
   it("does toast one the caller was left to handle", () => {
-    notifyActionError(new HttpError(404, "gone"), "FAILED");
+    notifyActionError(new HttpError(404, "gone"), raw("FAILED"));
     expect(notifyMock).toHaveBeenCalled();
   });
 
   it("reports one failure once, however many callers try", () => {
     // What keeps the app-wide mutation reporter quiet for a mutation whose own onError already spoke.
     const err = new HttpError(404, "gone");
-    notifyActionError(err, "FIRST");
-    notifyActionError(err, "SECOND");
+    notifyActionError(err, raw("FIRST"));
+    notifyActionError(err, raw("SECOND"));
     expect(notifyMock).toHaveBeenCalledTimes(1);
     expect(alreadyReported(err)).toBe(true);
   });
 
   it("says nothing about an upload the user cancelled", () => {
-    notifyActionError(new HttpError(0, "aborted"), "FAILED");
+    notifyActionError(new HttpError(0, "aborted"), raw("FAILED"));
     expect(notifyMock).not.toHaveBeenCalled();
   });
 
@@ -79,27 +92,32 @@ describe("notifyActionError", () => {
     // `reportFailure` leaves 403/404/429 to the caller, so for exactly those statuses whatever
     // English a route hand-wrote went straight into the toast — "No user with that email." in an
     // otherwise Hungarian UI, while the caller's translated fallback sat unused.
-    notifyActionError(new HttpError(404, "No user with that email."), "TRANSLATED");
+    notifyActionError(new HttpError(404, "No user with that email."), raw("TRANSLATED"));
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: "TRANSLATED",
-      message: i18n.t("errors.notFound.generic"),
+      title: raw("TRANSLATED"),
+      message: msg("errors.notFound.generic"),
     });
   });
 
-  it("still prefers a STRUCTURED reason, which the request layer has already localized", () => {
-    // `req` runs `{code, reason}` through localizeDetail, so `detail` is in the reader's language
-    // AND more specific than anything a status can say — quota numbers, which row is gone.
+  it("still prefers a STRUCTURED reason, kept as the refusal and said in the reader's language", () => {
+    // The notice keeps `{code, reason}` and says it through localizeDetail when shown: in the
+    // reader's language AND more specific than anything a status can say — quota numbers, which row
+    // is gone.
     const err = new HttpError(404, "Ez a csatorna már nincs a könyvtárban.", {
       code: "not_found",
       reason: "channel",
     });
-    notifyActionError(err, "TRANSLATED FALLBACK");
+    notifyActionError(err, raw("TRANSLATED FALLBACK"));
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: "TRANSLATED FALLBACK",
-      message: "Ez a csatorna már nincs a könyvtárban.",
+      title: raw("TRANSLATED FALLBACK"),
+      message: { detail: { code: "not_found", reason: "channel" } },
     });
+    // Said at display through localizeDetail, in the language of that moment.
+    expect(sayNotif(notifyMock.mock.calls[0]![0].message)).toBe(
+      localizeDetail({ code: "not_found", reason: "channel" }),
+    );
   });
 });
 
@@ -114,17 +132,21 @@ describe("failureReason — why a write failed, when the server did not say", ()
     [0, "errors.reason.unreachable"], // uploadReq's network failure
     [500, "errors.generic"],
   ])("a %s reads %s", (status, key) => {
-    expect(failureReason(new HttpError(status, "hand-written English"))).toBe(i18n.t(key));
+    const reason = failureReason(new HttpError(status, "hand-written English"));
+    expect(reason).toEqual(msg(key));
+    expect(sayNotif(reason)).toBe(i18n.t(key));
   });
 
   it("a request that never reached the server reads as unreachable", () => {
-    expect(failureReason(new TypeError("Failed to fetch"))).toBe(
+    expect(sayNotif(failureReason(new TypeError("Failed to fetch")))).toBe(
       i18n.t("errors.reason.unreachable"),
     );
   });
 
   it("anything else is the app's own fault, not the server's", () => {
-    expect(failureReason(new Error("key import failed"))).toBe(i18n.t("errors.reason.unexpected"));
+    expect(sayNotif(failureReason(new Error("key import failed")))).toBe(
+      i18n.t("errors.reason.unexpected"),
+    );
   });
 
   it("every reason exists in both languages", () => {
@@ -142,9 +164,9 @@ describe("failureReason — why a write failed, when the server did not say", ()
 describe("notifyKnownFailure", () => {
   it("shows the caller's specific sentence and marks the failure reported", () => {
     const err = new HttpError(409, "x", { code: "resend", reason: "email_off" });
-    notifyKnownFailure(err, "EMAIL IS OFF");
-    expect(notifyMock).toHaveBeenCalledWith({ level: "error", message: "EMAIL IS OFF" });
-    notifyActionError(err, "GENERIC");
+    notifyKnownFailure(err, raw("EMAIL IS OFF"));
+    expect(notifyMock).toHaveBeenCalledWith({ level: "error", message: raw("EMAIL IS OFF") });
+    notifyActionError(err, raw("GENERIC"));
     expect(notifyMock).toHaveBeenCalledTimes(1);
   });
 });
diff --git a/frontend/src/lib/actionErrors.ts b/frontend/src/lib/actionErrors.ts
index 9d975767..413a2425 100644
--- a/frontend/src/lib/actionErrors.ts
+++ b/frontend/src/lib/actionErrors.ts
@@ -1,26 +1,24 @@
 // From the core, not the `./api` barrel: these are pure (no request), and a test that mocks the
 // barrel wholesale to stub its requests must not take the error path's own plumbing with it.
 import { alreadyReported, HttpError, isAborted, markReported } from "./api/core";
-import { notify } from "./notifications";
-import i18n from "../i18n";
+import { msg, notify, type NotifText } from "./notifications";
 
 const GATEWAY = new Set([502, 503, 504]);
 
 /**
- * WHY a write failed, in the reader's language — the line under the toast's title.
+ * WHY a write failed — the line under the toast's title, said in the reader's language when shown.
  *
- * The server's own reason wins: `req` has already run the structured detail through
- * `localizeDetail`, and it is the most specific thing there is to say (quota numbers, which row is
+ * The server's own reason wins: the structured detail, which `localizeDetail` says, and it is the most specific thing there is to say (quota numbers, which row is
  * gone). Every refusal the app answers is structured now (backend `app/refusal.py`), and a string
  * detail never reaches `HttpError.detail` (see there) — the hand-written English that once put
  * "No user with that email." into a Hungarian UI has nowhere left to come from. `detailData` still
  * gates it: status-0 errors carry a local sentinel in `detail`, not a reason. Otherwise the status
  * says it.
  */
-export function failureReason(err: unknown): string {
-  const t = i18n.t.bind(i18n);
+export function failureReason(err: unknown): NotifText {
+  const t = msg;
   if (err instanceof HttpError) {
-    if (err.detailData != null && err.detail) return err.detail;
+    if (err.detailData != null && err.detail) return { detail: err.detailData };
     // 0: `uploadReq`'s network failure. 502–504: the gateway could not reach the app. Either way the
     // change did not go through, which the connection notice alone does not say.
     if (err.status === 0 || GATEWAY.has(err.status)) return t("errors.reason.unreachable");
@@ -36,13 +34,13 @@ export function failureReason(err: unknown): string {
 
 /**
  * Surface a failed write as an error toast instead of the click silently doing nothing: the title
- * names WHAT failed (the caller's translated "Couldn't hide the channel"), the line under it says
+ * names WHAT failed (the caller's "Couldn't hide the channel"), the line under it says
  * WHY (`failureReason`). Domain-agnostic — the one way every action failure is reported, including
  * the app-wide mutation reporter in lib/queryClient.
  */
 export function notifyActionError(
   err: unknown,
-  title: string,
+  title: NotifText,
   level: "error" | "warning" = "error",
 ): void {
   // Already on screen (`req` opened the error dialog, the tab is being signed out, or a caller's own
@@ -57,7 +55,7 @@ export function notifyActionError(
  * instance cannot send email", "someone registered on that address") — shown as it is, and marked,
  * so the app-wide mutation reporter does not put a second, generic toast next to it.
  */
-export function notifyKnownFailure(err: unknown, message: string): void {
+export function notifyKnownFailure(err: unknown, message: NotifText): void {
   if (alreadyReported(err)) return;
   notify({ level: "error", message });
   markReported(err);
diff --git a/frontend/src/lib/api/core.test.ts b/frontend/src/lib/api/core.test.ts
index 257050c5..dd0b6292 100644
--- a/frontend/src/lib/api/core.test.ts
+++ b/frontend/src/lib/api/core.test.ts
@@ -14,7 +14,12 @@ const { reportError, notify, remove, getActiveToasts } = vi.hoisted(() => ({
 }));
 
 vi.mock("../errorDialog", () => ({ reportError }));
-vi.mock("../notifications", () => ({ notify, remove, getActiveToasts }));
+vi.mock("../notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../notifications")>()),
+  notify,
+  remove,
+  getActiveToasts,
+}));
 vi.mock("../../i18n", () => ({ default: { t: (k: string) => k, language: "en" } }));
 
 import { setDebugSession } from "../log";
diff --git a/frontend/src/lib/api/core.ts b/frontend/src/lib/api/core.ts
index 42f14450..6caf90d6 100644
--- a/frontend/src/lib/api/core.ts
+++ b/frontend/src/lib/api/core.ts
@@ -2,9 +2,9 @@
 // error, structured-error localization, the connectivity toast, the identity headers,
 // and the keepalive beacon. Domain modules import from here; nothing here imports a domain module,
 // so the runtime graph is a clean barrel → domain → core with no cycles.
-import { getActiveToasts, notify, remove } from "../notifications";
+import { getActiveToasts, msg, notify, remove } from "../notifications";
 import i18n from "../../i18n";
-import { formatBytes, formatDecimal } from "../format";
+import { localizeDetail } from "./refusalText";
 import { reportError } from "../errorDialog";
 import { logRequest, QUIET_HEADER, REQUEST_ID_HEADER, ROUTE_HEADER, send } from "../http";
 import { currentDebugSession, newRequestId } from "../log";
@@ -71,121 +71,6 @@ export const refusalReason = (err: unknown): string | undefined =>
     ? (err.detailData as { reason?: string } | undefined)?.reason
     : undefined;
 
-// Localize a STRUCTURED server error ({ code, reason, ... }) into the user's language. FastAPI
-// usually returns a plain string `detail`, but some routes (e.g. download quota/edit) return a
-// structured object with an i18n reason key + numbers so HU/DE users don't get hardcoded English
-// with a dot-decimal separator. Falls back to a generic message for unknown shapes.
-// The refusal codes of the admin's account and invite actions (routes/admin.py). Their reasons share
-// one namespace, `errors.admin.<reason>`, which i18n/backendIds.contract checks against the backend.
-const ADMIN_REFUSALS = new Set(["activate", "resend", "invite_send"]);
-
-function localizeDetail(d: unknown): string {
-  const t = i18n.t.bind(i18n);
-  // FastAPI request-validation errors: `detail` is an ARRAY of { loc, msg, type }. The UI sends
-  // well-formed requests, so this only fires on genuinely malformed input. The per-field `msg` and
-  // `loc` field names are English, snake_case internal tokens — surface a clean, fully localized
-  // "check your input" message rather than leaking them into a translated sentence.
-  if (Array.isArray(d)) return t("errors.validation");
-  const o = d as
-    | { code?: string; reason?: string; limit?: number; limit_s?: number; min?: number }
-    | null
-    | undefined;
-  if (o?.code === "quota") {
-    if (o.reason === "max_bytes") {
-      const gb = formatDecimal((o.limit || 0) / 1_073_741_824, i18n.language, 1, 0);
-      return t("downloads.errors.quota.max_bytes", { size: gb });
-    }
-    if (o.reason === "max_jobs") return t("downloads.errors.quota.max_jobs", { limit: o.limit });
-    return t("downloads.errors.quota.generic");
-  }
-  if (o?.code === "edit")
-    return t(`downloads.errors.edit.${o.reason}`, t("downloads.errors.edit.generic"));
-  // A clip the server will not cut (downloads/clip): the range, the frame, the source. An unknown
-  // reason reads as the plain failure rather than a key; a cap comes with the refusal (`limit_s`).
-  if (o?.code === "clip")
-    return t(`clip.errors.${o.reason}`, {
-      defaultValue: t("clip.failed"),
-      minutes: o.limit_s == null ? undefined : formatDecimal(o.limit_s / 60, i18n.language, 1, 0),
-    });
-  if (o?.code === "cookies")
-    return t(`downloads.errors.cookies.${o.reason}`, t("downloads.errors.cookies.generic"));
-  // Password sign-in refusals. The card renders the account-shaped ones as a full panel
-  // off `detailData`; this is the one-line form every other consumer (and the card's own fallback)
-  // gets. A reason this build doesn't know falls through to the generic message rather than showing
-  // a raw key, which is what an i18n miss would otherwise put on screen.
-  if (o?.code === "login")
-    return t(`welcome.auth.blocked.${o.reason}.short`, t("welcome.auth.genericError"));
-  // The two email-link confirmations. Their failure is one a user meets by simply clicking an old
-  // link, so it is the last place that may answer in hardcoded English under a bilingual UI.
-  if (o?.code === "verify") return t("welcome.auth.verifyInvalid");
-  if (o?.code === "reset")
-    return o.reason === "weak_password"
-      ? t("welcome.auth.weakPassword", { min: o.limit ?? o.min })
-      : t("welcome.auth.deadLink.short");
-  // Local-upload ingest: the per-file cap carries the limit in bytes; empty is a bare code.
-  if (o?.code === "upload_too_large")
-    return t("downloads.errors.upload.tooLarge", { size: formatBytes(o.limit, i18n.language) });
-  if (o?.code === "upload_empty") return t("downloads.errors.upload.empty");
-  // The EDGE ceiling's refusal (`bodylimit.TOO_LARGE_BODY`), shared by every route and carrying no
-  // number. Not a theoretical case: on a DEFAULT install it is what an over-cap upload gets,
-  // because the ceiling and the route's own cap are the same figure and the edge answers first —
-  // the route's numbered `upload_too_large` above is the answer only once an admin has LOWERED the
-  // knob (see bodylimit.ROUTE_MAX_BODY_BYTES). Without this branch that refusal fell through to
-  // the generic "couldn't carry out that action", the one message no retry can fix.
-  //
-  // A BACKSTOP, not the plan. The middleware answers without draining, so whether the browser gets
-  // to read this at all depends on the client having finished sending: measured readable up to
-  // 200 MiB over loopback, and measured as a bare `onerror` through a dev proxy. That is why the
-  // upload dialog checks the file against `upload_max_bytes` BEFORE sending — this branch is what
-  // happens when that check could not run.
-  //
-  // `errors.tooLarge` stays PAYLOAD-NEUTRAL for that reason. It is also what a JSON form gets
-  // (`debug_sessions` refuses an over-size draft with the same bare code), so wording it as advice
-  // about a file told the issue composer's user to pick a smaller one — of nothing. The
-  // file-specific sentence is `downloads.errors.upload.tooLarge`, one branch up, which has a number.
-  if (o?.code === "too_large") return t("errors.tooLarge");
-  // SEC-12: a download URL the server refuses to fetch. The reasons are deliberately distinct —
-  // "we could not look that host up" is a different thing to tell someone than "we will not fetch
-  // from that address" — so an unknown reason falls back to the generic refusal rather than a key.
-  if (o?.code === "url_blocked")
-    return t(`downloads.errors.urlBlocked.${o.reason}`, t("downloads.errors.urlBlocked.generic"));
-  // The one-step "move to another list". Both reasons mean the same thing to a reader —
-  // the list moved under you — but they are different enough to be worth naming separately, and an
-  // unknown reason falls back to the plain failure rather than printing a key.
-  if (o?.code === "playlist_move")
-    return t(`playlists.moveErrors.${o.reason}`, t("playlists.moveFailed"));
-  // A Plex collection name already taken in that library (the one collection-edit refusal).
-  if (o?.code === "collection")
-    return o.reason === "name_taken"
-      ? t("plex.collection.nameTaken")
-      : t("plex.collection.editFailed");
-  // An action YouTube refused (routes/_common.youtube_refusal): what the reader can do about it —
-  // wait for the budget, reconnect, or retry. An unknown reason reads as the retryable one.
-  if (o?.code === "youtube")
-    return t(`errors.youtube.${o.reason}`, t("errors.youtube.unavailable"));
-  // Every other refusal (backend `app/refusal.py`): one family, the reason naming the sentence and
-  // the rest of the detail its values (`{{min}}`, `{{name}}`, …). A reason this build does not know
-  // reads as the generic failure rather than a key.
-  if (o?.code === "refused")
-    return t(`errors.refused.${o.reason}`, { ...o, defaultValue: t("errors.generic") });
-  // A playlist action the server refused (Watch later can't be deleted, YouTube said no, …).
-  if (o?.code === "playlist") return t(`playlists.errors.${o.reason}`, t("errors.generic"));
-  // An admin action on an account or an invite that the server refused: activating an address that
-  // is no longer approved, a confirmation link or invitation with nothing to go to or no mail to go
-  // by. The toast's title already names the button; this is the WHY, and it used to be the generic
-  // "try again", which no retry could fix.
-  if (ADMIN_REFUSALS.has(o?.code ?? "")) return t(`errors.admin.${o?.reason}`, t("errors.generic"));
-  // Any row that is gone — deleted in another tab or device, or never the caller's (a stranger's
-  // row 404s the same way). `reason` names WHAT is gone; one this build doesn't know says it
-  // generically rather than printing a key.
-  if (o?.code === "not_found")
-    return t(`errors.notFound.${o.reason}`, t("errors.notFound.generic"));
-  // SEC-14: a manual sync trigger on cooldown. Not an error the user caused so much as a pace
-  // limit, and the copy says so.
-  if (o?.code === "sync_cooldown") return t("errors.syncCooldown");
-  return t("errors.generic");
-}
-
 // A single, self-resolving "connection lost" status: while the server is unreachable we
 // show one sticky, transient (non-persisted) notice; the moment any request reaches the
 // server again we remove it. This makes good on its "clears once it's back" copy and keeps
@@ -199,8 +84,8 @@ function markConnectivityLost(): void {
   if (id !== null) remove(id);
   connectivityNotifId = notify({
     level: "error",
-    title: i18n.t("errors.offline.title"),
-    message: i18n.t("errors.offline.body"),
+    title: msg("errors.offline.title"),
+    message: msg("errors.offline.body"),
     transient: true,
   });
 }
diff --git a/frontend/src/lib/api/diagnostics.dom.test.ts b/frontend/src/lib/api/diagnostics.dom.test.ts
index cc145d13..244017a6 100644
--- a/frontend/src/lib/api/diagnostics.dom.test.ts
+++ b/frontend/src/lib/api/diagnostics.dom.test.ts
@@ -7,7 +7,8 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 
 vi.mock("../errorDialog", () => ({ reportError: vi.fn() }));
-vi.mock("../notifications", () => ({
+vi.mock("../notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../notifications")>()),
   notify: vi.fn(() => 1),
   remove: vi.fn(),
   getActiveToasts: vi.fn((): { id: number }[] => []),
diff --git a/frontend/src/lib/api/refusalText.ts b/frontend/src/lib/api/refusalText.ts
new file mode 100644
index 00000000..1a90d127
--- /dev/null
+++ b/frontend/src/lib/api/refusalText.ts
@@ -0,0 +1,120 @@
+// A server refusal ({ code, reason, … }) in the reader's language. Its own module, not the request
+// core's: a notice keeps the refusal it reports and says it again at display, in the language of the
+// moment, and the notice store cannot import the request core that imports it.
+import i18n from "../../i18n";
+import { formatBytes, formatDecimal } from "../format";
+
+// Localize a STRUCTURED server error ({ code, reason, ... }) into the user's language. FastAPI
+// usually returns a plain string `detail`, but some routes (e.g. download quota/edit) return a
+// structured object with an i18n reason key + numbers so HU/DE users don't get hardcoded English
+// with a dot-decimal separator. Falls back to a generic message for unknown shapes.
+// The refusal codes of the admin's account and invite actions (routes/admin.py). Their reasons share
+// one namespace, `errors.admin.<reason>`, which i18n/backendIds.contract checks against the backend.
+const ADMIN_REFUSALS = new Set(["activate", "resend", "invite_send"]);
+
+export function localizeDetail(d: unknown): string {
+  const t = i18n.t.bind(i18n);
+  // FastAPI request-validation errors: `detail` is an ARRAY of { loc, msg, type }. The UI sends
+  // well-formed requests, so this only fires on genuinely malformed input. The per-field `msg` and
+  // `loc` field names are English, snake_case internal tokens — surface a clean, fully localized
+  // "check your input" message rather than leaking them into a translated sentence.
+  if (Array.isArray(d)) return t("errors.validation");
+  const o = d as
+    | { code?: string; reason?: string; limit?: number; limit_s?: number; min?: number }
+    | null
+    | undefined;
+  if (o?.code === "quota") {
+    if (o.reason === "max_bytes") {
+      const gb = formatDecimal((o.limit || 0) / 1_073_741_824, i18n.language, 1, 0);
+      return t("downloads.errors.quota.max_bytes", { size: gb });
+    }
+    if (o.reason === "max_jobs") return t("downloads.errors.quota.max_jobs", { limit: o.limit });
+    return t("downloads.errors.quota.generic");
+  }
+  if (o?.code === "edit")
+    return t(`downloads.errors.edit.${o.reason}`, t("downloads.errors.edit.generic"));
+  // A clip the server will not cut (downloads/clip): the range, the frame, the source. An unknown
+  // reason reads as the plain failure rather than a key; a cap comes with the refusal (`limit_s`).
+  if (o?.code === "clip")
+    return t(`clip.errors.${o.reason}`, {
+      defaultValue: t("clip.failed"),
+      minutes: o.limit_s == null ? undefined : formatDecimal(o.limit_s / 60, i18n.language, 1, 0),
+    });
+  if (o?.code === "cookies")
+    return t(`downloads.errors.cookies.${o.reason}`, t("downloads.errors.cookies.generic"));
+  // Password sign-in refusals. The card renders the account-shaped ones as a full panel
+  // off `detailData`; this is the one-line form every other consumer (and the card's own fallback)
+  // gets. A reason this build doesn't know falls through to the generic message rather than showing
+  // a raw key, which is what an i18n miss would otherwise put on screen.
+  if (o?.code === "login")
+    return t(`welcome.auth.blocked.${o.reason}.short`, t("welcome.auth.genericError"));
+  // The two email-link confirmations. Their failure is one a user meets by simply clicking an old
+  // link, so it is the last place that may answer in hardcoded English under a bilingual UI.
+  if (o?.code === "verify") return t("welcome.auth.verifyInvalid");
+  if (o?.code === "reset")
+    return o.reason === "weak_password"
+      ? t("welcome.auth.weakPassword", { min: o.limit ?? o.min })
+      : t("welcome.auth.deadLink.short");
+  // Local-upload ingest: the per-file cap carries the limit in bytes; empty is a bare code.
+  if (o?.code === "upload_too_large")
+    return t("downloads.errors.upload.tooLarge", { size: formatBytes(o.limit, i18n.language) });
+  if (o?.code === "upload_empty") return t("downloads.errors.upload.empty");
+  // The EDGE ceiling's refusal (`bodylimit.TOO_LARGE_BODY`), shared by every route and carrying no
+  // number. Not a theoretical case: on a DEFAULT install it is what an over-cap upload gets,
+  // because the ceiling and the route's own cap are the same figure and the edge answers first —
+  // the route's numbered `upload_too_large` above is the answer only once an admin has LOWERED the
+  // knob (see bodylimit.ROUTE_MAX_BODY_BYTES). Without this branch that refusal fell through to
+  // the generic "couldn't carry out that action", the one message no retry can fix.
+  //
+  // A BACKSTOP, not the plan. The middleware answers without draining, so whether the browser gets
+  // to read this at all depends on the client having finished sending: measured readable up to
+  // 200 MiB over loopback, and measured as a bare `onerror` through a dev proxy. That is why the
+  // upload dialog checks the file against `upload_max_bytes` BEFORE sending — this branch is what
+  // happens when that check could not run.
+  //
+  // `errors.tooLarge` stays PAYLOAD-NEUTRAL for that reason. It is also what a JSON form gets
+  // (`debug_sessions` refuses an over-size draft with the same bare code), so wording it as advice
+  // about a file told the issue composer's user to pick a smaller one — of nothing. The
+  // file-specific sentence is `downloads.errors.upload.tooLarge`, one branch up, which has a number.
+  if (o?.code === "too_large") return t("errors.tooLarge");
+  // SEC-12: a download URL the server refuses to fetch. The reasons are deliberately distinct —
+  // "we could not look that host up" is a different thing to tell someone than "we will not fetch
+  // from that address" — so an unknown reason falls back to the generic refusal rather than a key.
+  if (o?.code === "url_blocked")
+    return t(`downloads.errors.urlBlocked.${o.reason}`, t("downloads.errors.urlBlocked.generic"));
+  // The one-step "move to another list". Both reasons mean the same thing to a reader —
+  // the list moved under you — but they are different enough to be worth naming separately, and an
+  // unknown reason falls back to the plain failure rather than printing a key.
+  if (o?.code === "playlist_move")
+    return t(`playlists.moveErrors.${o.reason}`, t("playlists.moveFailed"));
+  // A Plex collection name already taken in that library (the one collection-edit refusal).
+  if (o?.code === "collection")
+    return o.reason === "name_taken"
+      ? t("plex.collection.nameTaken")
+      : t("plex.collection.editFailed");
+  // An action YouTube refused (routes/_common.youtube_refusal): what the reader can do about it —
+  // wait for the budget, reconnect, or retry. An unknown reason reads as the retryable one.
+  if (o?.code === "youtube")
+    return t(`errors.youtube.${o.reason}`, t("errors.youtube.unavailable"));
+  // Every other refusal (backend `app/refusal.py`): one family, the reason naming the sentence and
+  // the rest of the detail its values (`{{min}}`, `{{name}}`, …). A reason this build does not know
+  // reads as the generic failure rather than a key.
+  if (o?.code === "refused")
+    return t(`errors.refused.${o.reason}`, { ...o, defaultValue: t("errors.generic") });
+  // A playlist action the server refused (Watch later can't be deleted, YouTube said no, …).
+  if (o?.code === "playlist") return t(`playlists.errors.${o.reason}`, t("errors.generic"));
+  // An admin action on an account or an invite that the server refused: activating an address that
+  // is no longer approved, a confirmation link or invitation with nothing to go to or no mail to go
+  // by. The toast's title already names the button; this is the WHY, and it used to be the generic
+  // "try again", which no retry could fix.
+  if (ADMIN_REFUSALS.has(o?.code ?? "")) return t(`errors.admin.${o?.reason}`, t("errors.generic"));
+  // Any row that is gone — deleted in another tab or device, or never the caller's (a stranger's
+  // row 404s the same way). `reason` names WHAT is gone; one this build doesn't know says it
+  // generically rather than printing a key.
+  if (o?.code === "not_found")
+    return t(`errors.notFound.${o.reason}`, t("errors.notFound.generic"));
+  // SEC-14: a manual sync trigger on cooldown. Not an error the user caused so much as a pace
+  // limit, and the copy says so.
+  if (o?.code === "sync_cooldown") return t("errors.syncCooldown");
+  return t("errors.generic");
+}
diff --git a/frontend/src/lib/channelWriteFailures.dom.test.tsx b/frontend/src/lib/channelWriteFailures.dom.test.tsx
index ec087934..7f705701 100644
--- a/frontend/src/lib/channelWriteFailures.dom.test.tsx
+++ b/frontend/src/lib/channelWriteFailures.dom.test.tsx
@@ -9,13 +9,15 @@ import type { ReactNode } from "react";
 import { act, renderHook, waitFor } from "@testing-library/react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 
-vi.mock("./notifications", () => ({ notify: vi.fn(() => 0) }));
+vi.mock("./notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("./notifications")>()),
+  notify: vi.fn(() => 0),
+}));
 
 import { api, HttpError } from "./api";
-import { notify } from "./notifications";
+import { msg, notify } from "./notifications";
 import { useChannelTagActions } from "./useChannelTagActions";
 import { useChannelPriority } from "./useChannelPriority";
-import i18n from "../i18n";
 
 const notifyMock = vi.mocked(notify);
 beforeEach(() => notifyMock.mockClear());
@@ -37,8 +39,8 @@ describe("useChannelTagActions", () => {
     await waitFor(() => expect(onError).toHaveBeenCalledWith("UC1"));
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: i18n.t("channels.tags.updateFailed"),
-      message: i18n.t("errors.reason.forbidden"),
+      title: msg("channels.tags.updateFailed"),
+      message: msg("errors.reason.forbidden"),
     });
   });
 
@@ -52,8 +54,8 @@ describe("useChannelTagActions", () => {
     await waitFor(() =>
       expect(notifyMock).toHaveBeenCalledWith({
         level: "error",
-        title: i18n.t("channels.tags.createFailed"),
-        message: i18n.t("errors.reason.rateLimited"),
+        title: msg("channels.tags.createFailed"),
+        message: msg("errors.reason.rateLimited"),
       }),
     );
   });
@@ -76,8 +78,8 @@ describe("useChannelPriority", () => {
     await waitFor(() => expect(onError).toHaveBeenCalledWith("UC1"));
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: i18n.t("errors.writeFailed.channelPriority"),
-      message: i18n.t("errors.reason.unreachable"),
+      title: msg("errors.writeFailed.channelPriority"),
+      message: msg("errors.reason.unreachable"),
     });
   });
 });
diff --git a/frontend/src/lib/claimedStores.dom.test.ts b/frontend/src/lib/claimedStores.dom.test.ts
index e0140383..42f915b7 100644
--- a/frontend/src/lib/claimedStores.dom.test.ts
+++ b/frontend/src/lib/claimedStores.dom.test.ts
@@ -5,11 +5,12 @@
 // notification store used to keep its empty, nobody's history, and the tab's first notice replaced the
 // account's stored history with it.
 import { beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import { raw, sayNotif, type NotifText } from "./notifications";
 
 const entry = (id: number, message: string) => ({
   id,
   level: "info",
-  message,
+  message: raw(message),
   ts: 1,
   read: true,
   dismissed: true,
@@ -20,9 +21,9 @@ const entry = (id: number, message: string) => ({
 const storedMessages = () =>
   (
     JSON.parse(localStorage.getItem("siftlode.notifications") ?? "[]") as {
-      message: string;
+      message: NotifText;
     }[]
-  ).map((n) => n.message);
+  ).map((n) => sayNotif(n.message));
 
 // Warm the transform cache once (see verifyEntry.dom.test.tsx): the first cold import costs ~0.8 s
 // alone and outran the 5 s case timeout under a full coverage run. Transformed code outlives
@@ -52,9 +53,9 @@ describe("stores read at import, before the account is known", { timeout: CASE_B
     const notifications = await import("./notifications");
     const { claimLocalData } = await import("./storage");
 
-    notifications.notify({ message: "before the claim" }); // e.g. a failed boot probe
+    notifications.notify({ message: raw("before the claim") }); // e.g. a failed boot probe
     claimLocalData(5);
-    notifications.notify({ message: "after the claim" });
+    notifications.notify({ message: raw("after the claim") });
 
     expect(storedMessages()).toEqual(["older", "before the claim", "after the claim"]);
     expect(notifications.getNotifSettings().durationMs).toBe(0);
@@ -80,7 +81,7 @@ describe("a browser that held another account's state", { timeout: CASE_BUDGET }
     const { claimLocalData } = await import("./storage");
 
     claimLocalData(5);
-    notifications.notify({ message: "as five" });
+    notifications.notify({ message: raw("as five") });
 
     expect(storedMessages()).toEqual(["as five"]);
   });
diff --git a/frontend/src/lib/downloads.test.ts b/frontend/src/lib/downloads.test.ts
index 1e4fe844..8cb6f0dd 100644
--- a/frontend/src/lib/downloads.test.ts
+++ b/frontend/src/lib/downloads.test.ts
@@ -21,17 +21,21 @@ vi.mock("./api", () => ({
   api: { downloadLinks, createDownloadLink, folderLinks, createFolderLink },
 }));
 vi.mock("./clipboard", () => ({ copyText }));
-vi.mock("./notifications", () => ({ notify }));
+vi.mock("./notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("./notifications")>()),
+  notify,
+}));
 
 import { quickShareLink } from "./downloads";
 import { qk } from "./queryKeys";
+import { msg, type NotifText } from "./notifications";
 
 const t = (k: string) => k;
 const origin = window.location.origin;
 
 type ToastArg = {
   level: string;
-  message: string;
+  message: NotifText;
   action?: { label: string; onClick: () => void };
 };
 const firstToast = () => notify.mock.calls[0]![0] as ToastArg;
@@ -63,7 +67,7 @@ describe("quickShareLink", () => {
     expect(copyText).toHaveBeenCalledWith(`${origin}/watch/tok7`);
     const arg = firstToast();
     expect(arg.level).toBe("success");
-    expect(arg.message).toBe("downloads.share.linkCopied");
+    expect(arg.message).toEqual(msg("downloads.share.linkCopied"));
     expect(arg.action!.label).toBe("downloads.share.openNewTab");
     arg.action!.onClick();
     expect(openSpy).toHaveBeenCalledWith(`${origin}/watch/tok7`, "_blank", "noopener,noreferrer");
@@ -134,7 +138,7 @@ describe("quickShareLink", () => {
     expect(url).toBe(`${origin}/watch/x`); // the link is never a dead end
     const arg = firstToast();
     expect(arg.level).toBe("warning");
-    expect(arg.message).toBe("downloads.share.copyFailed");
+    expect(arg.message).toEqual(msg("downloads.share.copyFailed"));
     expect(arg.action!.label).toBe("downloads.share.openNewTab");
   });
 
@@ -148,7 +152,7 @@ describe("quickShareLink", () => {
     expect(copyText).not.toHaveBeenCalled();
     // Titled with what failed, and carrying why (notifyActionError), not a bare message.
     expect(notify).toHaveBeenCalledWith(
-      expect.objectContaining({ level: "error", title: "downloads.share.linkFailed" }),
+      expect.objectContaining({ level: "error", title: msg("downloads.share.linkFailed") }),
     );
   });
 });
diff --git a/frontend/src/lib/downloads.ts b/frontend/src/lib/downloads.ts
index 14615ad0..104ea690 100644
--- a/frontend/src/lib/downloads.ts
+++ b/frontend/src/lib/downloads.ts
@@ -2,7 +2,7 @@ import type { QueryClient } from "@tanstack/react-query";
 import { qk } from "./queryKeys";
 import { api, type NewShareLink } from "./api";
 import { copyText } from "./clipboard";
-import { notify } from "./notifications";
+import { msg, notify } from "./notifications";
 import { notifyActionError } from "./actionErrors";
 
 // The download queue, the per-card download index, the library (its listings and folder counts) and
@@ -65,7 +65,7 @@ export async function quickShareLink(
     }
     if (!path) throw new Error("the new link came back without its address");
   } catch (e) {
-    notifyActionError(e, t("downloads.share.linkFailed"));
+    notifyActionError(e, msg("downloads.share.linkFailed"));
     return null;
   }
   const url = window.location.origin + path;
@@ -75,8 +75,8 @@ export async function quickShareLink(
   };
   notify(
     (await copyText(url))
-      ? { level: "success", message: t("downloads.share.linkCopied"), action }
-      : { level: "warning", message: t("downloads.share.copyFailed"), action },
+      ? { level: "success", message: msg("downloads.share.linkCopied"), action }
+      : { level: "warning", message: msg("downloads.share.copyFailed"), action },
   );
   return url;
 }
diff --git a/frontend/src/lib/notifications.actionTtl.dom.test.ts b/frontend/src/lib/notifications.actionTtl.dom.test.ts
index 4c1106bb..3456a9e8 100644
--- a/frontend/src/lib/notifications.actionTtl.dom.test.ts
+++ b/frontend/src/lib/notifications.actionTtl.dom.test.ts
@@ -10,6 +10,7 @@ import {
   configureNotifications,
   getActiveToasts,
   notify,
+  raw,
 } from "./notifications";
 
 beforeEach(() => vi.useFakeTimers());
@@ -25,8 +26,8 @@ const shown = (id: number) => getActiveToasts().some((n) => n.id === id);
 describe("an action toast's lifetime", () => {
   it("stays for the floor when the reader's toasts last 3 s", () => {
     configureNotifications({ durationMs: 3000 });
-    const plain = notify({ message: "plain" });
-    const withUndo = notify({ message: "removed", action: undo });
+    const plain = notify({ message: raw("plain") });
+    const withUndo = notify({ message: raw("removed"), action: undo });
     vi.advanceTimersByTime(3001);
     expect(shown(plain)).toBe(false);
     expect(shown(withUndo)).toBe(true);
@@ -36,7 +37,7 @@ describe("an action toast's lifetime", () => {
 
   it("keeps a longer setting", () => {
     configureNotifications({ durationMs: 12000 });
-    const id = notify({ message: "removed", action: undo });
+    const id = notify({ message: raw("removed"), action: undo });
     vi.advanceTimersByTime(ACTION_TTL_MIN + 1);
     expect(shown(id)).toBe(true);
     vi.advanceTimersByTime(12000 - ACTION_TTL_MIN);
@@ -45,7 +46,7 @@ describe("an action toast's lifetime", () => {
 
   it("never dismisses when the reader chose never", () => {
     configureNotifications({ durationMs: 0 });
-    const id = notify({ message: "removed", action: undo });
+    const id = notify({ message: raw("removed"), action: undo });
     vi.advanceTimersByTime(60000);
     expect(shown(id)).toBe(true);
   });
diff --git a/frontend/src/lib/notifications.ts b/frontend/src/lib/notifications.ts
index eb216449..65634342 100644
--- a/frontend/src/lib/notifications.ts
+++ b/frontend/src/lib/notifications.ts
@@ -2,9 +2,56 @@
 // the Notification Center shows (info events, actions awaiting interaction, and app
 // errors). History is persisted to localStorage so it survives reloads; action
 // callbacks are live-only and dropped on reload.
+import type { TFunction } from "i18next";
+import i18n from "../i18n";
+import { localizeDetail } from "./api/refusalText";
+import { formatBytes, formatNumber } from "./format";
 import { LS, onLocalDataClaimed, readAccount, readAccountMerged, writeAccount } from "./storage";
 import { log, type Level } from "./log";
 
+// What a notice SAYS, kept as what to say rather than the said text: a key and its values, said in
+// the reader's language each time it is shown. The text a caller translated at raise time was kept
+// in the history, so a language switch left every notice in the language it was raised in. `raw` is
+// text that has no translation (a video's title, a name); `detail` is a server refusal, localized at
+// display like the key. `notify` takes nothing else, so a pre-translated string does not type-check.
+// A value is formatted when shown too: `{ number }` / `{ bytes }` group digits the reader's way.
+export type NotifValue = string | number | NotifText | { number: number } | { bytes: number };
+export type NotifText =
+  | { key: string; values?: Readonly<Record<string, NotifValue>> }
+  | { raw: string }
+  | { detail: unknown };
+
+/** The notice text for `t(key, values)`, said when it is shown. */
+export const msg = (key: string, values?: Record<string, NotifValue>): NotifText =>
+  values ? { key, values } : { key };
+/** Text with no translation of its own (a title, a name), shown as it is. */
+export const raw = (text: string): NotifText => ({ raw: text });
+
+/** A notice text in the language `t` speaks — the reader's, from a component's `useTranslation`. */
+export function sayNotif(text: NotifText, t: TFunction = i18n.t.bind(i18n)): string {
+  if ("raw" in text) return text.raw;
+  if ("detail" in text) return localizeDetail(text.detail);
+  if (!text.values) return t(text.key);
+  const values = Object.fromEntries(
+    Object.entries(text.values).map(([k, v]) => [k, sayValue(v, t)]),
+  );
+  return t(text.key, values);
+}
+
+function sayValue(v: NotifValue, t: TFunction): string | number {
+  if (typeof v !== "object") return v;
+  if ("number" in v) return formatNumber(v.number, i18n.language);
+  if ("bytes" in v) return formatBytes(v.bytes, i18n.language);
+  return sayNotif(v, t);
+}
+
+const sameText = (a: NotifText | undefined, b: NotifText | undefined): boolean =>
+  JSON.stringify(a ?? null) === JSON.stringify(b ?? null);
+
+// A notice the history kept from before it said keys: its text, in the language it was raised in.
+const asText = (v: unknown): NotifText | undefined =>
+  typeof v === "string" ? raw(v) : (v as NotifText | undefined);
+
 // A notification's level in the client log: what the user was TOLD is part of the story a log tells.
 const LOG_LEVEL: Record<NotifLevel, Level> = {
   info: "INFO",
@@ -56,8 +103,8 @@ export type NotifMeta =
 export interface Notification {
   id: number;
   level: NotifLevel;
-  title?: string;
-  message: string;
+  title?: NotifText;
+  message: NotifText;
   action?: NotifAction;
   // A second, lesser action beside it (a done download's "Open" after its "Copy link").
   secondaryAction?: NotifAction;
@@ -79,9 +126,9 @@ export interface Notification {
 }
 
 export interface NotifyInput {
-  message: string;
+  message: NotifText;
   level?: NotifLevel;
-  title?: string;
+  title?: NotifText;
   action?: NotifAction;
   secondaryAction?: NotifAction;
   meta?: NotifMeta;
@@ -175,17 +222,19 @@ let cachedUnread = 0;
 
 function load(): Notification[] {
   try {
-    const raw = readAccount<unknown>(HISTORY_KEY, []);
-    if (!Array.isArray(raw)) return [];
+    const stored = readAccount<unknown>(HISTORY_KEY, []);
+    if (!Array.isArray(stored)) return [];
     // Restored entries are history only. Mark them dismissed so they don't
     // resurrect as active toasts on reload — their auto-dismiss timers aren't
     // re-armed across a reload, so otherwise they'd stick forever. Also drop the
     // live `action` callback, which can't survive serialization.
-    return raw.map(
+    return stored.map(
       (n) =>
         ({
           repeat: 1,
           ...(n as object),
+          title: asText((n as { title?: unknown }).title),
+          message: asText((n as { message?: unknown }).message) ?? raw(""),
           action: undefined,
           secondaryAction: undefined,
           dismissed: true,
@@ -261,9 +310,12 @@ const COALESCE_WINDOW_MS = 5000;
 export function notify(input: NotifyInput): number {
   const requiresInteraction = input.requiresInteraction ?? false;
   const level = input.level ?? "info";
-  log.at(LOG_LEVEL[level], "ui.notify", input.message, {
+  // In English, whatever the reader's language (a server refusal aside: it says itself in the
+  // reader's), so one log reads the same for every reader.
+  const en = i18n.getFixedT("en");
+  log.at(LOG_LEVEL[level], "ui.notify", sayNotif(input.message, en), {
     level,
-    ...(input.title ? { title: input.title } : {}),
+    ...(input.title ? { title: sayNotif(input.title, en) } : {}),
     ...(input.meta ? { kind: input.meta.kind } : {}),
   });
   const now = Date.now();
@@ -294,8 +346,8 @@ export function notify(input: NotifyInput): number {
         !n.action &&
         now - n.ts <= COALESCE_WINDOW_MS &&
         n.level === level &&
-        (n.title ?? "") === (input.title ?? "") &&
-        n.message === input.message,
+        sameText(n.title, input.title) &&
+        sameText(n.message, input.message),
     );
     if (prior) {
       // Re-surface the existing toast (undismiss + unread) and re-arm its auto-dismiss timer.
diff --git a/frontend/src/lib/playlistName.ts b/frontend/src/lib/playlistName.ts
index 962ebfdc..0185dadc 100644
--- a/frontend/src/lib/playlistName.ts
+++ b/frontend/src/lib/playlistName.ts
@@ -1,7 +1,13 @@
 import type { TFunction } from "i18next";
+import { msg, raw, type NotifText } from "./notifications";
 
 /** Watch later is a built-in playlist whose stored `name` is not translatable — show the localized
  * label instead. Was hand-inlined in Playlists, PlaylistsRail and AddToPlaylist; one copy now. */
 export function playlistName(p: { kind: string; name: string }, t: TFunction): string {
   return p.kind === "watch_later" ? t("playlists.watchLater") : p.name;
 }
+
+/** The same name in a notice, said in the reader's language when it is shown. */
+export function playlistNameText(p: { kind: string; name: string }): NotifText {
+  return p.kind === "watch_later" ? msg("playlists.watchLater") : raw(p.name);
+}
diff --git a/frontend/src/lib/plexWatch.ts b/frontend/src/lib/plexWatch.ts
index a7511e6c..ec04cf29 100644
--- a/frontend/src/lib/plexWatch.ts
+++ b/frontend/src/lib/plexWatch.ts
@@ -1,6 +1,6 @@
-import type { TFunction } from "i18next";
 import { api, type PlexCard } from "./api";
 import { notifyActionError } from "./actionErrors";
+import { msg } from "./notifications";
 
 // Persist a watch-state toggle from any Plex surface: flip via the caller's `optimistic` cache
 // updater, call the API, surface a failure (the click used to look dead on 403/404/429), then
@@ -12,7 +12,6 @@ import { notifyActionError } from "./actionErrors";
 // (react-query keeps the same `data`), or a cache whose refetch lands later than the click's answer.
 export async function toggleWatchState(
   card: PlexCard,
-  t: TFunction,
   handlers: { optimistic: (next: string) => void; resync: () => void; revert?: () => void },
 ) {
   const next = card.status === "watched" ? "new" : "watched";
@@ -21,7 +20,7 @@ export async function toggleWatchState(
     await api.plexSetState(card.id, next);
   } catch (e) {
     handlers.revert?.();
-    notifyActionError(e, t("plex.watchedFailed"));
+    notifyActionError(e, msg("plex.watchedFailed"));
   }
   handlers.resync();
 }
diff --git a/frontend/src/lib/queryClient.dom.test.ts b/frontend/src/lib/queryClient.dom.test.ts
index e38ceced..1e35774e 100644
--- a/frontend/src/lib/queryClient.dom.test.ts
+++ b/frontend/src/lib/queryClient.dom.test.ts
@@ -5,16 +5,18 @@
 // silence on a 403/404/429 or a lost connection — 34 of them.
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
-vi.mock("./notifications", () => ({ notify: vi.fn(() => 0) }));
+vi.mock("./notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("./notifications")>()),
+  notify: vi.fn(() => 0),
+}));
 vi.mock("./errorDialog", () => ({ reportError: vi.fn() }));
 
 import { MutationObserver, type MutationObserverOptions } from "@tanstack/react-query";
 import { createQueryClient } from "./queryClient";
 import { HttpError, req } from "./api/core";
-import { notify } from "./notifications";
+import { msg, notify, raw } from "./notifications";
 import { reportError } from "./errorDialog";
 import { notifyActionError } from "./actionErrors";
-import i18n from "../i18n";
 
 const notifyMock = vi.mocked(notify);
 beforeEach(() => {
@@ -39,7 +41,7 @@ describe("a failed mutation", () => {
       meta: { failTitle: TITLE },
     });
     expect(notifyMock.mock.calls).toEqual([
-      [{ level: "error", title: i18n.t(TITLE), message: i18n.t("errors.notFound.generic") }],
+      [{ level: "error", title: msg(TITLE), message: msg("errors.notFound.generic") }],
     ]);
   });
 
@@ -47,8 +49,8 @@ describe("a failed mutation", () => {
     await fail({ mutationFn: () => Promise.reject(new HttpError(429, "slow down")) });
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: i18n.t("errors.title"),
-      message: i18n.t("errors.reason.rateLimited"),
+      title: msg("errors.title"),
+      message: msg("errors.reason.rateLimited"),
     });
   });
 
@@ -58,7 +60,7 @@ describe("a failed mutation", () => {
       meta: { failTitle: TITLE },
     });
     expect(notifyMock).toHaveBeenCalledWith(
-      expect.objectContaining({ message: i18n.t("errors.reason.unreachable") }),
+      expect.objectContaining({ message: msg("errors.reason.unreachable") }),
     );
   });
 
@@ -66,9 +68,9 @@ describe("a failed mutation", () => {
     await fail({
       mutationFn: () => Promise.reject(new HttpError(404, "gone")),
       meta: { failTitle: TITLE },
-      onError: (e) => notifyActionError(e, "OWN TITLE"),
+      onError: (e) => notifyActionError(e, raw("OWN TITLE")),
     });
-    expect(notifyMock.mock.calls.map(([n]) => n.title)).toEqual(["OWN TITLE"]);
+    expect(notifyMock.mock.calls.map(([n]) => n.title)).toEqual([raw("OWN TITLE")]);
   });
 
   it("is still reported when the mutation's onError only rolls back", async () => {
@@ -79,7 +81,7 @@ describe("a failed mutation", () => {
       onError: rollback,
     });
     expect(rollback).toHaveBeenCalled();
-    expect(notifyMock.mock.calls.map(([n]) => n.title)).toEqual([i18n.t(TITLE)]);
+    expect(notifyMock.mock.calls.map(([n]) => n.title)).toEqual([msg(TITLE)]);
   });
 
   it("gets no toast when the page shows the failure itself", async () => {
diff --git a/frontend/src/lib/queryClient.ts b/frontend/src/lib/queryClient.ts
index 56722ac2..ed23f846 100644
--- a/frontend/src/lib/queryClient.ts
+++ b/frontend/src/lib/queryClient.ts
@@ -1,7 +1,7 @@
 import { MutationCache, QueryCache, QueryClient } from "@tanstack/react-query";
-import i18n from "../i18n";
 import { notifyActionError } from "./actionErrors";
 import { log } from "./log";
+import { msg } from "./notifications";
 
 /** A failed query or mutation, for the client log. Only the key's HEAD (the resource, `"videos"`):
  *  the rest of a key is filter state, which the base level does not keep. The status is what
@@ -42,7 +42,7 @@ type FailMeta = { failTitle?: string; errorShownInline?: boolean } | undefined;
  */
 function reportMutationFailure(err: unknown, meta: FailMeta): void {
   if (meta?.errorShownInline) return;
-  setTimeout(() => notifyActionError(err, i18n.t(meta?.failTitle ?? "errors.title")), 0);
+  setTimeout(() => notifyActionError(err, msg(meta?.failTitle ?? "errors.title")), 0);
 }
 
 export function createQueryClient(): QueryClient {
diff --git a/frontend/src/lib/useAccountSwitchNotice.dom.test.ts b/frontend/src/lib/useAccountSwitchNotice.dom.test.ts
index ea83cdb5..c22fbe2c 100644
--- a/frontend/src/lib/useAccountSwitchNotice.dom.test.ts
+++ b/frontend/src/lib/useAccountSwitchNotice.dom.test.ts
@@ -28,6 +28,7 @@ vi.mock("./entryUrl", async (importOriginal) => {
   return { ...actual, accountSwitchNotice: () => notice() };
 });
 const { useAccountSwitchNotice } = await import("./useAccountSwitchNotice");
+const { msg } = await import("./notifications");
 
 afterEach(() => {
   notifyMock.mockClear();
@@ -53,7 +54,7 @@ describe("the shell's word on a switch of account", () => {
     expect(notifyMock).toHaveBeenCalledTimes(1);
     expect(notifyMock).toHaveBeenCalledWith({
       level: "info",
-      message: 'header.account.switchRequested {"email":"b@example.com"}',
+      message: msg("header.account.switchRequested", { email: "b@example.com" }),
     });
   });
 
diff --git a/frontend/src/lib/useAccountSwitchNotice.ts b/frontend/src/lib/useAccountSwitchNotice.ts
index 77e72de2..30e79138 100644
--- a/frontend/src/lib/useAccountSwitchNotice.ts
+++ b/frontend/src/lib/useAccountSwitchNotice.ts
@@ -1,7 +1,7 @@
 import { useEffect, useRef } from "react";
 import { useTranslation } from "react-i18next";
 import { accountSwitchNotice } from "./entryUrl";
-import { notify } from "./notifications";
+import { msg, notify } from "./notifications";
 
 /** Say, once per load, what the entry URL tells the account signed in here about a switch of
  * account (`accountSwitchNotice`): a sign-in as someone else the server refused, or a tab that
@@ -14,6 +14,6 @@ export function useAccountSwitchNotice(signedIn: boolean): void {
     if (!signedIn || said.current) return;
     said.current = true;
     const notice = accountSwitchNotice();
-    if (notice) notify({ level: notice.level, message: t(notice.key, notice.values) });
+    if (notice) notify({ level: notice.level, message: msg(notice.key, notice.values) });
   }, [signedIn, t]);
 }
diff --git a/frontend/src/lib/useChannelPriority.ts b/frontend/src/lib/useChannelPriority.ts
index 42b4e66c..4087e9a8 100644
--- a/frontend/src/lib/useChannelPriority.ts
+++ b/frontend/src/lib/useChannelPriority.ts
@@ -1,8 +1,8 @@
 import { useCallback, useEffect, useRef } from "react";
 import { api } from "./api";
 import { notifyActionError } from "./actionErrors";
-import i18n from "../i18n";
 import { useLatest } from "./useLatest";
+import { msg } from "./notifications";
 
 /** The shared feed-priority flow used by both the channel manager and the channel detail page:
  *  an optimistic bump/set with a debounced server flush (~400ms after the last notch) so a
@@ -40,7 +40,7 @@ export function useChannelPriority(opts: {
         .catch((err: unknown) => {
           // Said here, once, for both callers: their `onError` only refetches, so a refused priority
           // used to just snap back — often after the stepper had already been let go.
-          notifyActionError(err, i18n.t("errors.writeFailed.channelPriority"));
+          notifyActionError(err, msg("errors.writeFailed.channelPriority"));
           optsRef.current.onError(channelId);
         });
     },
diff --git a/frontend/src/lib/useChannelTagActions.ts b/frontend/src/lib/useChannelTagActions.ts
index 11388a43..a85e152c 100644
--- a/frontend/src/lib/useChannelTagActions.ts
+++ b/frontend/src/lib/useChannelTagActions.ts
@@ -1,8 +1,8 @@
 import { useQueryClient } from "@tanstack/react-query";
-import { useTranslation } from "react-i18next";
 import { api } from "./api";
 import { qk } from "./queryKeys";
 import { notifyActionError } from "./actionErrors";
+import { msg } from "./notifications";
 
 /** The shared channel-tag mutation flow used by both the channel manager and the channel detail
  *  page: optimistic attach/detach + a create-then-attach shortcut, with the cache-shape-specific
@@ -21,7 +21,6 @@ export function useChannelTagActions(opts: {
   onError: (channelId: string) => void;
 }) {
   const qc = useQueryClient();
-  const { t } = useTranslation();
 
   const toggleTag = (channelId: string, tagId: number, hasTag: boolean) => {
     opts.optimisticToggle(channelId, tagId, !hasTag);
@@ -31,7 +30,7 @@ export function useChannelTagActions(opts: {
     call
       .then(() => opts.onSuccess?.(channelId))
       .catch((err: unknown) => {
-        notifyActionError(err, t("channels.tags.updateFailed"));
+        notifyActionError(err, msg("channels.tags.updateFailed"));
         opts.onError(channelId);
       });
   };
@@ -45,7 +44,7 @@ export function useChannelTagActions(opts: {
         qc.invalidateQueries({ queryKey: qk.tags() });
         toggleTag(channelId, tag.id, false);
       })
-      .catch((err: unknown) => notifyActionError(err, t("channels.tags.createFailed")));
+      .catch((err: unknown) => notifyActionError(err, msg("channels.tags.createFailed")));
   };
 
   return { toggleTag, createAndAttachTag };
diff --git a/frontend/src/lib/usePref.saveFailure.dom.test.ts b/frontend/src/lib/usePref.saveFailure.dom.test.ts
index 2ef8e931..a12e21c4 100644
--- a/frontend/src/lib/usePref.saveFailure.dom.test.ts
+++ b/frontend/src/lib/usePref.saveFailure.dom.test.ts
@@ -17,7 +17,7 @@ vi.mock("./api", () => ({ api: { savePrefs, me: vi.fn() } }));
 vi.mock("./actionErrors", () => ({ notifyActionError }));
 
 import { usePref, useSavePref } from "./usePref";
-import i18n from "../i18n";
+import { msg } from "./notifications";
 
 afterEach(() => {
   savePrefs.mockReset();
@@ -34,7 +34,7 @@ describe("a refused preference save", () => {
     const { result } = renderHook(() => usePref<boolean>("hintsOn", true), { wrapper });
     act(() => result.current[1](false));
     await waitFor(() =>
-      expect(notifyActionError).toHaveBeenCalledWith(refusal, i18n.t("errors.writeFailed.prefs")),
+      expect(notifyActionError).toHaveBeenCalledWith(refusal, msg("errors.writeFailed.prefs")),
     );
     expect(result.current[0]).toBe(false); // the local value stays; the toast says it did not save
   });
@@ -45,7 +45,7 @@ describe("a refused preference save", () => {
     const { result } = renderHook(() => useSavePref(), { wrapper });
     act(() => result.current({ stripSources: { c1: false } }));
     await waitFor(() =>
-      expect(notifyActionError).toHaveBeenCalledWith(refusal, i18n.t("errors.writeFailed.prefs")),
+      expect(notifyActionError).toHaveBeenCalledWith(refusal, msg("errors.writeFailed.prefs")),
     );
   });
 });
diff --git a/frontend/src/lib/usePref.ts b/frontend/src/lib/usePref.ts
index 5afc5941..4a8172da 100644
--- a/frontend/src/lib/usePref.ts
+++ b/frontend/src/lib/usePref.ts
@@ -6,13 +6,13 @@ import type { Me } from "./api/account";
 import { getAccountRaw, writeAccount } from "./storage";
 import { notifyActionError } from "./actionErrors";
 import { updateMeCache } from "./useMe";
-import i18n from "../i18n";
+import { msg } from "./notifications";
 
 // The local state + cache already show the new value, so a refused save is otherwise invisible until
 // the next load quietly puts the old one back. `req` reports none of 403/404/429 and only the
 // connection notice for a lost connection — say it.
 const reportPrefSaveFailure = (err: unknown) =>
-  notifyActionError(err, i18n.t("errors.writeFailed.prefs"));
+  notifyActionError(err, msg("errors.writeFailed.prefs"));
 
 // The ONE per-account + server preference hook. A preference (unlike an ephemeral filter) persists to
 // the account on the server (PUT /api/me/preferences, which MERGES the partial payload) and follows the
diff --git a/frontend/src/lib/useRail.ts b/frontend/src/lib/useRail.ts
index 58299e7a..cfe953ad 100644
--- a/frontend/src/lib/useRail.ts
+++ b/frontend/src/lib/useRail.ts
@@ -1,6 +1,5 @@
 import { useState } from "react";
 import { useQueryClient } from "@tanstack/react-query";
-import { useTranslation } from "react-i18next";
 import { api, type Me } from "./api";
 import { qk } from "./queryKeys";
 import { notifyActionError } from "./actionErrors";
@@ -15,6 +14,7 @@ import {
   type PanelId,
   type PanelLayout,
 } from "./panelLayout";
+import { msg } from "./notifications";
 
 // A side rail's own state: its group cards' layout and whether it is collapsed. Each rail reads it
 // here rather than being handed it, so the shell only places the rail.
@@ -24,7 +24,6 @@ import {
 // it. The server keeps the copy that follows the account, this browser a local one for an account
 // whose server copy has none.
 export function usePanelLayout(panel: PanelId): [PanelLayout, (next: PanelLayout) => void] {
-  const { t } = useTranslation();
   const qc = useQueryClient();
   const [layout, setState] = useState(() =>
     seedLayout(panel, qc.getQueryData<Me | null>(qk.me())?.preferences),
@@ -38,7 +37,7 @@ export function usePanelLayout(panel: PanelId): [PanelLayout, (next: PanelLayout
     }));
     api
       .savePrefs({ [PREF_KEY[panel]]: next })
-      .catch((e: unknown) => notifyActionError(e, t("errors.writeFailed.prefs")));
+      .catch((e: unknown) => notifyActionError(e, msg("errors.writeFailed.prefs")));
   };
   return [layout, setLayout];
 }
diff --git a/frontend/src/lib/youtubeErrors.ts b/frontend/src/lib/youtubeErrors.ts
index df369f98..02007230 100644
--- a/frontend/src/lib/youtubeErrors.ts
+++ b/frontend/src/lib/youtubeErrors.ts
@@ -1,16 +1,16 @@
 import { HttpError } from "./api";
 import { markReported } from "./api/core";
-import { notify } from "./notifications";
+import { msg, notify, type NotifText } from "./notifications";
 import { notifyActionError } from "./actionErrors";
 import i18n from "../i18n";
 
 // A YouTube-gated action (subscribe, sync, backfill, unsubscribe) that 403s means the user hasn't
 // granted the write scope — surface a "Connect" affordance instead of a vague failure. Pass
 // `onConnect` to offer the connect-wizard button (callers that have no wizard handle, e.g. the
-// channel page, just get the message). `fallbackMessage` is the already-translated non-403 error.
+// channel page, just get the message). `fallbackMessage` is what a non-403 error says.
 export function notifyYouTubeActionError(
   err: unknown,
-  fallbackMessage: string,
+  fallbackMessage: NotifText,
   onConnect?: () => void,
 ): void {
   const httpErr = err instanceof HttpError ? err : null;
@@ -18,7 +18,7 @@ export function notifyYouTubeActionError(
     // A 403 on a YouTube write action means the write scope isn't granted — offer to connect.
     notify({
       level: "error",
-      message: i18n.t("channels.notify.needYouTube"),
+      message: msg("channels.notify.needYouTube"),
       action: onConnect
         ? { label: i18n.t("channels.notify.connect"), onClick: onConnect }
         : undefined,
diff --git a/frontend/src/modules/activity/ActivityAudit.tsx b/frontend/src/modules/activity/ActivityAudit.tsx
index 942687a2..6a124d77 100644
--- a/frontend/src/modules/activity/ActivityAudit.tsx
+++ b/frontend/src/modules/activity/ActivityAudit.tsx
@@ -8,7 +8,7 @@ import { notifyActionError } from "../../lib/actionErrors";
 import { sinceOf } from "../../lib/activityUrlState";
 import { auditActionLabel, auditText } from "../../lib/auditText";
 import { formatDateTimeSec } from "../../lib/format";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { useHistoryList } from "../../lib/useHistoryList";
 import type { Shared } from "./ActivityRuns";
@@ -70,9 +70,9 @@ export default function ActivityAudit({
     onSuccess: (r) => {
       void qc.invalidateQueries({ queryKey: qk.adminAudit() });
       void qc.invalidateQueries({ queryKey: qk.adminAuditFacets() });
-      notify({ level: "success", message: t("audit.cleared", { count: r.cleared }) });
+      notify({ level: "success", message: msg("audit.cleared", { count: r.cleared }) });
     },
-    onError: (e) => notifyActionError(e, t("audit.clearFailed")),
+    onError: (e) => notifyActionError(e, msg("audit.clearFailed")),
   });
   const onClear = async () => {
     if (
diff --git a/frontend/src/modules/activity/AdminLogs.tsx b/frontend/src/modules/activity/AdminLogs.tsx
index 17ffe65e..0fe6654a 100644
--- a/frontend/src/modules/activity/AdminLogs.tsx
+++ b/frontend/src/modules/activity/AdminLogs.tsx
@@ -15,7 +15,7 @@ import { nextPageOnClick } from "../../lib/nextPage";
 import { LEVEL_GROUPS, type LevelGroup } from "../../lib/log";
 import { sinceOf } from "../../lib/activityUrlState";
 import { logsParamsToState, logsParamUpdates, type LogsUrlState } from "../../lib/logsUrlState";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { useUrlMirror } from "../../lib/useUrlMirror";
 import { HistoryFrame } from "./HistoryList";
@@ -187,8 +187,8 @@ export default function AdminLogs({
     const ok = await copyText(text);
     notify(
       ok
-        ? { level: "success", message: t("adminLogs.copied", { count: rows.length }) }
-        : { level: "error", message: t("adminLogs.copyFailed") },
+        ? { level: "success", message: msg("adminLogs.copied", { count: rows.length }) }
+        : { level: "error", message: msg("adminLogs.copyFailed") },
     );
   };
 
diff --git a/frontend/src/modules/channels/ChannelDiscovery.tsx b/frontend/src/modules/channels/ChannelDiscovery.tsx
index a8fdb44c..4b01c686 100644
--- a/frontend/src/modules/channels/ChannelDiscovery.tsx
+++ b/frontend/src/modules/channels/ChannelDiscovery.tsx
@@ -11,7 +11,7 @@ import { hydrateSort, sortRows, type SortState } from "../../lib/columnSort";
 import { usePref } from "../../lib/usePref";
 import { useCardPager } from "../../lib/useCardPager";
 import { subsColumn } from "./channelColumns";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import Tooltip from "../../components/ui/Tooltip";
 import ChannelLink from "./ChannelLink";
@@ -70,13 +70,13 @@ export default function ChannelDiscovery({
       // callbacks are gone (see ChannelSubscribedMeta).
       notify({
         level: "success",
-        title: t("channels.discovery.subscribedTitle"),
-        message: t("channels.discovery.subscribedBody", { name }),
+        title: msg("channels.discovery.subscribedTitle"),
+        message: msg("channels.discovery.subscribedBody", { name }),
         meta: { kind: "channel-subscribed", channelId: c.id, channelName: name },
       });
     },
     onError: (err: unknown) =>
-      notifyYouTubeActionError(err, t("channels.discovery.subscribeFailed"), onOpenWizard),
+      notifyYouTubeActionError(err, msg("channels.discovery.subscribeFailed"), onOpenWizard),
   });
 
   // Subscribing changes the user's real YouTube account and spends a little quota — confirm
diff --git a/frontend/src/modules/channels/Channels.tsx b/frontend/src/modules/channels/Channels.tsx
index 9358d4aa..a1f92739 100644
--- a/frontend/src/modules/channels/Channels.tsx
+++ b/frontend/src/modules/channels/Channels.tsx
@@ -18,7 +18,7 @@ import { Sparkles } from "lucide-react";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { LS, ownKey } from "../../lib/storage";
 import { buildChannelColumns, applySyncFilter, tagFilterChips } from "./channelColumns";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { Badge } from "../../components/ui/Badge";
 import { Button } from "../../components/ui/Button";
 import Tooltip from "../../components/ui/Tooltip";
@@ -168,9 +168,9 @@ export default function Channels() {
     (tagId: number, name: string) => {
       setFeedFilters({ ...feedFilters, tags: [tagId], channelIds: [] });
       setPage("feed");
-      notify({ level: "info", message: t("channels.notify.filteredByTag", { name }) });
+      notify({ level: "info", message: msg("channels.notify.filteredByTag", { name }) });
     },
-    [setFeedFilters, feedFilters, setPage, t],
+    [setFeedFilters, feedFilters, setPage],
   );
 
   const channelsQuery = useQuery({ queryKey: qk.channels(), queryFn: api.channels });
@@ -294,10 +294,10 @@ export default function Channels() {
       invalidate();
       notify({
         level: "success",
-        message: t("channels.notify.synced", { count: r.subscriptions ?? 0 }),
+        message: msg("channels.notify.synced", { count: r.subscriptions ?? 0 }),
       });
     },
-    onError: (e) => notifyYouTubeActionError(e, t("channels.notify.syncFailed"), onOpenWizard),
+    onError: (e) => notifyYouTubeActionError(e, msg("channels.notify.syncFailed"), onOpenWizard),
   });
   const deepAll = useMutation({
     mutationFn: () => api.deepAll(true),
@@ -306,11 +306,11 @@ export default function Channels() {
       qc.invalidateQueries({ queryKey: qk.myStatus() });
       notify({
         level: "success",
-        message: t("channels.notify.fullHistoryRequested", { count: r.updated ?? 0 }),
+        message: msg("channels.notify.fullHistoryRequested", { count: r.updated ?? 0 }),
       });
     },
     onError: (e) =>
-      notifyYouTubeActionError(e, t("channels.notify.fullHistoryFailed"), onOpenWizard),
+      notifyYouTubeActionError(e, msg("channels.notify.fullHistoryFailed"), onOpenWizard),
   });
 
   // The tag-chip row is a controlled view over the Tags COLUMN filter (`filters.tags`, a string[] of
diff --git a/frontend/src/modules/channels/SyncStatus.tsx b/frontend/src/modules/channels/SyncStatus.tsx
index 810b011d..5bd2fdb0 100644
--- a/frontend/src/modules/channels/SyncStatus.tsx
+++ b/frontend/src/modules/channels/SyncStatus.tsx
@@ -12,6 +12,7 @@ import { Button } from "../../components/ui/Button";
 import { IconButton } from "../../components/ui/IconButton";
 import { Pressable } from "../../components/ui/Pressable";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // Per-user status (not the global catalog): shows the number of videos available to *this*
 // user, how many of *their* channels are still being fetched, and how many lack full
@@ -64,7 +65,7 @@ export default function SyncStatus({
     onError: (e) =>
       notifyActionError(
         e,
-        t(data?.paused ? "errors.writeFailed.syncResume" : "errors.writeFailed.syncPause"),
+        msg(data?.paused ? "errors.writeFailed.syncResume" : "errors.writeFailed.syncPause"),
       ),
   });
 
diff --git a/frontend/src/modules/channels/WatchedVideosDialog.tsx b/frontend/src/modules/channels/WatchedVideosDialog.tsx
index ed578056..6ee4b37d 100644
--- a/frontend/src/modules/channels/WatchedVideosDialog.tsx
+++ b/frontend/src/modules/channels/WatchedVideosDialog.tsx
@@ -16,6 +16,7 @@ import { Pressable } from "../../components/ui/Pressable";
 import RemoteImage from "../../components/ui/RemoteImage";
 import Tooltip from "../../components/ui/Tooltip";
 import type { WatchedChannelActions } from "./useWatchedChannelActions";
+import { msg } from "../../lib/notifications";
 
 const PlayerModal = lazy(() => import("../../features/player/PlayerModal"));
 
@@ -67,7 +68,7 @@ export default function WatchedVideosDialog({
         );
         void qc.invalidateQueries({ queryKey: qk.feed() });
       })
-      .catch((e: unknown) => notifyActionError(e, t("errors.writeFailed.videoState")));
+      .catch((e: unknown) => notifyActionError(e, msg("errors.writeFailed.videoState")));
     return write;
   });
   const closePlayer = useStableCallback(() => setPlaying(null));
diff --git a/frontend/src/modules/channels/useChannelActions.dom.test.tsx b/frontend/src/modules/channels/useChannelActions.dom.test.tsx
index 879b167e..4e980c00 100644
--- a/frontend/src/modules/channels/useChannelActions.dom.test.tsx
+++ b/frontend/src/modules/channels/useChannelActions.dom.test.tsx
@@ -33,6 +33,7 @@ vi.mock("../../lib/useMe", () => ({ useMe: () => ({ role: h.role, can_write: h.c
 import { useChannelActions } from "./useChannelActions";
 import { api, type ManagedChannel, type Tag } from "../../lib/api";
 import type { ActionMenuItem } from "../../components/ui/ActionMenu";
+import { msg, type NotifText } from "../../lib/notifications";
 
 afterEach(() => {
   cleanup();
@@ -195,10 +196,10 @@ describe("useChannelActions — hide and unsubscribe", () => {
     expect(h.confirm).not.toHaveBeenCalled();
     expect(upd).toHaveBeenCalledWith("UC1", { hidden: true });
     const toast = h.notify.mock.calls[0]![0] as {
-      message: string;
+      message: NotifText;
       action: { onClick: () => void };
     };
-    expect(toast.message).toBe("channels.notify.hidden");
+    expect(toast.message).toEqual(msg("channels.notify.hidden", { name: "Chan" }));
     act(() => toast.action.onClick());
     await waitFor(() => expect(upd).toHaveBeenCalledWith("UC1", { hidden: false }));
   });
diff --git a/frontend/src/modules/channels/useChannelActions.tsx b/frontend/src/modules/channels/useChannelActions.tsx
index 8bc2fad7..d29ab2fc 100644
--- a/frontend/src/modules/channels/useChannelActions.tsx
+++ b/frontend/src/modules/channels/useChannelActions.tsx
@@ -7,7 +7,7 @@ import { api, type ManagedChannel, type Tag } from "../../lib/api";
 import { priorityChoices } from "../../lib/channelOrder";
 import { compareText } from "../../lib/collate";
 import { channelYouTubeUrl } from "../../lib/format";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { useMe } from "../../lib/useMe";
 import { useConfirm } from "../../components/ui/confirmContext";
@@ -70,7 +70,7 @@ export function useChannelActions({
       refresh();
       notify({
         level: "success",
-        message: t("channels.notify.hidden", { name: nameOf(c) }),
+        message: msg("channels.notify.hidden", { name: nameOf(c) }),
         action: {
           label: t("common.undo"),
           onClick: () => patch.mutate({ id: c.id, body: { hidden: false } }),
@@ -82,19 +82,22 @@ export function useChannelActions({
     mutationFn: (c: ManagedChannel) => api.unsubscribeChannel(c.id),
     onSuccess: (_d, c) => {
       invalidateSubscription(qc, c.id);
-      notify({ level: "success", message: t("channels.notify.unsubscribed", { name: nameOf(c) }) });
+      notify({
+        level: "success",
+        message: msg("channels.notify.unsubscribed", { name: nameOf(c) }),
+      });
     },
     onError: (e) =>
-      notifyYouTubeActionError(e, t("channels.notify.unsubscribeFailed"), onOpenWizard),
+      notifyYouTubeActionError(e, msg("channels.notify.unsubscribeFailed"), onOpenWizard),
   });
   const resetBackfill = useMutation({
     mutationFn: (c: ManagedChannel) => api.resetChannelBackfill(c.id),
     onSuccess: (_d, c) => {
       qc.invalidateQueries({ queryKey: qk.channels() });
       qc.invalidateQueries({ queryKey: qk.myStatus() });
-      notify({ level: "success", message: t("channels.notify.resetDone", { name: nameOf(c) }) });
+      notify({ level: "success", message: msg("channels.notify.resetDone", { name: nameOf(c) }) });
     },
-    onError: (e) => notifyYouTubeActionError(e, t("channels.notify.resetFailed"), onOpenWizard),
+    onError: (e) => notifyYouTubeActionError(e, msg("channels.notify.resetFailed"), onOpenWizard),
   });
 
   async function onUnsubscribe(c: ManagedChannel) {
diff --git a/frontend/src/modules/channels/useWatchedChannelActions.ts b/frontend/src/modules/channels/useWatchedChannelActions.ts
index 8b30bd7e..467396bf 100644
--- a/frontend/src/modules/channels/useWatchedChannelActions.ts
+++ b/frontend/src/modules/channels/useWatchedChannelActions.ts
@@ -3,7 +3,7 @@ import { useMutation, useQueryClient } from "@tanstack/react-query";
 import { qk } from "../../lib/queryKeys";
 import { invalidateSubscription } from "../../lib/subscriptionCache";
 import { api, type WatchedChannel } from "../../lib/api";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { useConfirm } from "../../components/ui/confirmContext";
 
@@ -21,13 +21,13 @@ export function useWatchedChannelActions(onOpenWizard: () => void) {
       invalidateSubscription(qc, c.id);
       notify({
         level: "success",
-        title: t("channels.discovery.subscribedTitle"),
-        message: t("channels.discovery.subscribedBody", { name: nameOf(c) }),
+        title: msg("channels.discovery.subscribedTitle"),
+        message: msg("channels.discovery.subscribedBody", { name: nameOf(c) }),
         meta: { kind: "channel-subscribed", channelId: c.id, channelName: nameOf(c) },
       });
     },
     onError: (err: unknown) =>
-      notifyYouTubeActionError(err, t("channels.discovery.subscribeFailed"), onOpenWizard),
+      notifyYouTubeActionError(err, msg("channels.discovery.subscribeFailed"), onOpenWizard),
   });
   const restore = useMutation({
     mutationFn: (c: WatchedChannel) => api.restoreWatchedChannel(c.id),
@@ -43,7 +43,7 @@ export function useWatchedChannelActions(onOpenWizard: () => void) {
       void qc.invalidateQueries({ queryKey: qk.watchedChannels() });
       notify({
         level: "success",
-        message: t("channels.watched.dismissed", { name: nameOf(c) }),
+        message: msg("channels.watched.dismissed", { name: nameOf(c) }),
         action: { label: t("common.undo"), onClick: () => restore.mutate(c) },
       });
     },
diff --git a/frontend/src/modules/config/ConfigPanel.tsx b/frontend/src/modules/config/ConfigPanel.tsx
index f183596b..ac9f577d 100644
--- a/frontend/src/modules/config/ConfigPanel.tsx
+++ b/frontend/src/modules/config/ConfigPanel.tsx
@@ -4,7 +4,7 @@ import { useTranslation } from "react-i18next";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { Plug, RotateCcw, Send } from "lucide-react";
 import { api, type ConfigItem, type PlexTestResult } from "../../lib/api";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import Tooltip from "../../components/ui/Tooltip";
 import InlineNotice from "../../components/ui/InlineNotice";
 import { useMe } from "../../lib/useMe";
@@ -130,7 +130,7 @@ export default function ConfigPanel() {
       setTimeout(() => setSaveState((s) => (s === "saved" ? "idle" : s)), 2500);
     } catch (e) {
       setSaveState("error");
-      notifyActionError(e, t("config.saveFailed"));
+      notifyActionError(e, msg("config.saveFailed"));
     }
   }
 
@@ -142,8 +142,8 @@ export default function ConfigPanel() {
 
   const testEmail = useMutation({
     mutationFn: () => api.testEmail(),
-    onSuccess: (r) => notify({ level: "success", message: t("config.testSent", { to: r.to }) }),
-    onError: (e) => notifyActionError(e, t("config.testFailed")),
+    onSuccess: (r) => notify({ level: "success", message: msg("config.testSent", { to: r.to }) }),
+    onError: (e) => notifyActionError(e, msg("config.testFailed")),
   });
 
   // Plex "Test connection": verifies the server URL + token and returns the library sections,
@@ -154,19 +154,19 @@ export default function ConfigPanel() {
     mutationFn: () => api.testPlex(),
     onSuccess: (r) => {
       setPlexResult(r);
-      notify({ level: "success", message: t("config.plexTestOk", { name: r.server_name }) });
+      notify({ level: "success", message: msg("config.plexTestOk", { name: r.server_name }) });
     },
     onError: (e) => {
       setPlexResult(null);
-      notifyActionError(e, t("config.plexTestFailed"));
+      notifyActionError(e, msg("config.plexTestFailed"));
     },
   });
   // Bug reports' "Test connection": the repository answers, takes issues, is private.
   const testIssues = useMutation({
     mutationFn: () => api.testIssues(),
     onSuccess: (r) =>
-      notify({ level: "success", message: t("config.issuesTestOk", { repo: r.repo }) }),
-    onError: (e) => notifyActionError(e, t("config.issuesTestFailed")),
+      notify({ level: "success", message: msg("config.issuesTestOk", { repo: r.repo }) }),
+    onError: (e) => notifyActionError(e, msg("config.issuesTestFailed")),
   });
 
   const plexLibs = (draft["plex_libraries"] ?? "")
diff --git a/frontend/src/modules/feed/ChannelPage.tsx b/frontend/src/modules/feed/ChannelPage.tsx
index ce18418d..a9282d0a 100644
--- a/frontend/src/modules/feed/ChannelPage.tsx
+++ b/frontend/src/modules/feed/ChannelPage.tsx
@@ -42,7 +42,7 @@ import {
 } from "../../lib/channelPageUrlState";
 import { LS } from "../../lib/storage";
 import { useConfirm } from "../../components/ui/confirmContext";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { notifyActionError } from "../../lib/actionErrors";
 import {
@@ -152,11 +152,11 @@ export default function ChannelPage({
           })
           // Both the automatic first-visit explore and "load more" used to fail in silence: an empty
           // channel page that looked like a channel with no videos.
-          .catch((err: unknown) => notifyActionError(err, t("errors.writeFailed.exploreChannel")))
+          .catch((err: unknown) => notifyActionError(err, msg("errors.writeFailed.exploreChannel")))
           .finally(() => setExploring(false))
       );
     },
-    [channelId, qc, t],
+    [channelId, qc],
   );
 
   // First visit of an un-subscribed channel → ingest its recent uploads. Skipped when videos are
@@ -201,16 +201,16 @@ export default function ChannelPage({
     mutationFn: () => api.subscribeChannel(channelId),
     onSuccess: () => {
       invalidateSubscription(qc, channelId);
-      notify({ level: "info", message: t("channel.subscribed", { name: ch?.title ?? "" }) });
+      notify({ level: "info", message: msg("channel.subscribed", { name: ch?.title ?? "" }) });
     },
     // A 403 (missing write scope) otherwise fails silently on the channel page (no wizard handle
     // here, so no Connect button — but the user at least sees why it didn't work).
-    onError: (err) => notifyYouTubeActionError(err, t("channels.discovery.subscribeFailed")),
+    onError: (err) => notifyYouTubeActionError(err, msg("channels.discovery.subscribeFailed")),
   });
   const unsubscribe = useMutation({
     mutationFn: () => api.unsubscribeChannel(channelId),
     onSuccess: () => invalidateSubscription(qc, channelId),
-    onError: (err) => notifyYouTubeActionError(err, t("channels.notify.unsubscribeFailed")),
+    onError: (err) => notifyYouTubeActionError(err, msg("channels.notify.unsubscribeFailed")),
   });
   // "Get full history": the catalog only holds the recent-backfill/RSS subset of a channel's
   // uploads (video_count is YouTube's raw total), so flipping deep_requested queues the full
@@ -222,9 +222,9 @@ export default function ChannelPage({
       qc.invalidateQueries({ queryKey: qk.feed() });
       qc.invalidateQueries({ queryKey: qk.channels() });
       qc.invalidateQueries({ queryKey: qk.myStatus() });
-      notify({ level: "info", message: t("channel.fullHistoryQueued") });
+      notify({ level: "info", message: msg("channel.fullHistoryQueued") });
     },
-    onError: (err) => notifyYouTubeActionError(err, t("channel.fullHistoryFailed")),
+    onError: (err) => notifyYouTubeActionError(err, msg("channel.fullHistoryFailed")),
   });
 
   // Feed priority, editable here with the same stepper + debounced-flush the manager uses (shared
diff --git a/frontend/src/modules/feed/Feed.tsx b/frontend/src/modules/feed/Feed.tsx
index 36143f8d..82a282c9 100644
--- a/frontend/src/modules/feed/Feed.tsx
+++ b/frontend/src/modules/feed/Feed.tsx
@@ -31,7 +31,6 @@ import {
   type Video,
   type VideoStatus,
 } from "../../lib/api";
-import i18n from "../../i18n";
 import { notifyActionError } from "../../lib/actionErrors";
 import { announceVideoState, type NoticeVideo } from "../../features/video/stateNotice";
 import {
@@ -39,7 +38,7 @@ import {
   writeVideoState,
   writeWatchLater,
 } from "../../features/video/videoWrites";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { useMe } from "../../lib/useMe";
 import { YT_COUNTS } from "../../lib/ytSearchUrlState";
 import { useNavigation, useNavigationActions } from "../../features/navigation/navigationContext";
@@ -419,7 +418,7 @@ export default function Feed({
           // Server rejected the change — drop the optimistic override so the card
           // reverts to the real (unchanged) state instead of staying phantom-hidden, and say so:
           // a card that silently snaps back reads as a misclick.
-          notifyActionError(e, i18n.t("errors.writeFailed.videoState"));
+          notifyActionError(e, msg("errors.writeFailed.videoState"));
           setOverrides((o) => withoutWrite(o, id, seq));
         });
       return write;
@@ -447,7 +446,7 @@ export default function Feed({
           qc.invalidateQueries({ queryKey: qk.feed(), refetchType: "none" });
         })
         .catch((e: unknown) => {
-          notifyActionError(e, i18n.t("errors.writeFailed.videoReset"));
+          notifyActionError(e, msg("errors.writeFailed.videoReset"));
           setOverrides((o) => withoutWrite(o, id, seq));
           if (resets.current.get(id) !== seq) return;
           resets.current.delete(id);
@@ -471,9 +470,7 @@ export default function Feed({
         .catch((e: unknown) => {
           notifyActionError(
             e,
-            i18n.t(
-              saved ? "errors.writeFailed.watchLaterAdd" : "errors.writeFailed.watchLaterRemove",
-            ),
+            msg(saved ? "errors.writeFailed.watchLaterAdd" : "errors.writeFailed.watchLaterRemove"),
           );
           setSavedOverrides((o) => withoutWrite(o, id, seq));
         });
@@ -619,11 +616,9 @@ export default function Feed({
                   const ids = ytItems.map((v) => v.id);
                   api
                     .clearSearch(ids)
-                    .then((r) =>
-                      notify({ message: i18n.t("feed.yt.cleared", { count: r.removed }) }),
-                    )
+                    .then((r) => notify({ message: msg("feed.yt.cleared", { count: r.removed }) }))
                     .catch((e: unknown) =>
-                      notifyActionError(e, i18n.t("errors.writeFailed.clearSearch")),
+                      notifyActionError(e, msg("errors.writeFailed.clearSearch")),
                     );
                   setFilters({ ...filters, librarySource: "organic", sort: FEED_DEFAULT_SORT });
                   onExitYtSearch();
diff --git a/frontend/src/modules/files/Files.menu.dom.test.tsx b/frontend/src/modules/files/Files.menu.dom.test.tsx
index 676f8d02..72ae6dea 100644
--- a/frontend/src/modules/files/Files.menu.dom.test.tsx
+++ b/frontend/src/modules/files/Files.menu.dom.test.tsx
@@ -116,6 +116,7 @@ vi.mock("../../components/ui/PageShell", async (importOriginal) => ({
 }));
 
 import Files from "./Files";
+import { msg } from "../../lib/notifications";
 import { FILES_LIST_CAP, type QueueJob } from "../../lib/api";
 import { noteQueue, resetQueueWatch, useFinished } from "../../lib/downloadQueue";
 
@@ -589,10 +590,13 @@ describe("Files · a library past the list's cap", { timeout: 30_000 }, () => {
     await waitFor(() =>
       expect(mocks.notify).toHaveBeenCalledWith({
         level: "info",
-        message: "files.arrival.notListed",
+        message: msg("files.arrival.notListed"),
       }),
     );
-    expect(mocks.notify).not.toHaveBeenCalledWith({ level: "info", message: "files.arrival.gone" });
+    expect(mocks.notify).not.toHaveBeenCalledWith({
+      level: "info",
+      message: msg("files.arrival.gone"),
+    });
   });
 
   it("an arrival's cleared search is asked of the server at once, not after the typing pause", () => {
@@ -805,7 +809,7 @@ describe("Files · a file the address names", () => {
     mount();
     await waitFor(() =>
       expect(mocks.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "warning", message: "files.linkedGone" }),
+        expect.objectContaining({ level: "warning", message: msg("files.linkedGone") }),
       ),
     );
     expect(screen.queryByRole("dialog")).toBeNull();
@@ -822,11 +826,11 @@ describe("Files · a file the address names", () => {
     mount();
     await waitFor(() =>
       expect(mocks.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "info", message: "files.linkedNotListed" }),
+        expect.objectContaining({ level: "info", message: msg("files.linkedNotListed") }),
       ),
     );
     expect(mocks.notify).not.toHaveBeenCalledWith(
-      expect.objectContaining({ message: "files.linkedGone" }),
+      expect.objectContaining({ message: msg("files.linkedGone") }),
     );
     expect(here().get("fview")).toBe("9999");
   }, 30_000); // a full page of FILES_LIST_CAP rows
@@ -839,11 +843,11 @@ describe("Files · a file the address names", () => {
     mount();
     await waitFor(() =>
       expect(mocks.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "info", message: "files.linkedNotListed" }),
+        expect.objectContaining({ level: "info", message: msg("files.linkedNotListed") }),
       ),
     );
     expect(mocks.notify).not.toHaveBeenCalledWith(
-      expect.objectContaining({ message: "files.linkedGone" }),
+      expect.objectContaining({ message: msg("files.linkedGone") }),
     );
     expect(here().get("fview")).toBe("9999");
   }, 30_000); // a full page of FILES_LIST_CAP rows
@@ -1344,7 +1348,10 @@ describe("Files · when what it needs is missing", () => {
     mocks.folders = [YT];
     mount(ALL_FILES, vi.fn(), "", { focus: { id: 9, token: 1 } });
     await waitFor(() =>
-      expect(mocks.notify).toHaveBeenCalledWith({ level: "info", message: "files.arrival.gone" }),
+      expect(mocks.notify).toHaveBeenCalledWith({
+        level: "info",
+        message: msg("files.arrival.gone"),
+      }),
     );
   });
 });
diff --git a/frontend/src/modules/files/Files.tsx b/frontend/src/modules/files/Files.tsx
index 7399601e..4fd1310e 100644
--- a/frontend/src/modules/files/Files.tsx
+++ b/frontend/src/modules/files/Files.tsx
@@ -19,7 +19,7 @@ import {
 import { libraryRowActions, sharedRowActions } from "../../lib/downloadActions";
 import { formatBytes, formatDateTime, relativeTime } from "../../lib/format";
 import { focusNavItem } from "../../lib/listNav";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { LS, ownKey } from "../../lib/storage";
 import { useCardPager } from "../../lib/useCardPager";
@@ -296,9 +296,9 @@ export default function Files() {
   const openLinked = useEffectEvent((file: LibraryFile | undefined) => {
     // Looked for in the list it was shown in: a cut one cannot tell (the newest files, or the first by
     // its sort or search), as the arrival decides it.
-    if (!file && cut) notify({ level: "info", message: t("files.linkedNotListed") });
+    if (!file && cut) notify({ level: "info", message: msg("files.linkedNotListed") });
     else if (!file) {
-      notify({ level: "warning", message: t("files.linkedGone") });
+      notify({ level: "warning", message: msg("files.linkedGone") });
       clearParams(FILES_VIEW_KEY, FILES_PLAY_KEY);
     } else if (linkedFile?.open === "play") play(file);
     else setViewing(file.id);
@@ -387,7 +387,10 @@ export default function Files() {
       consumeFocus(null);
       // Said, not swallowed. A list the cap cut cannot tell a deleted file from one beyond its end;
       // a whole list can: an old notice's file may have expired or been deleted since.
-      notify({ level: "info", message: t(cut ? "files.arrival.notListed" : "files.arrival.gone") });
+      notify({
+        level: "info",
+        message: msg(cut ? "files.arrival.notListed" : "files.arrival.gone"),
+      });
     }
   }, [here, missing, lookEverywhere, cut, viewKey, setView, consumeFocus, t]);
   const arrival = arrived && arrived.view === viewKey ? arrived : null;
@@ -434,7 +437,7 @@ export default function Files() {
       const dropped = e.dataTransfer.files;
       const first = dropped.item(0);
       if (first) setUpload({ file: first });
-      if (dropped.length > 1) notify({ level: "info", message: t("files.drop.oneAtATime") });
+      if (dropped.length > 1) notify({ level: "info", message: msg("files.drop.oneAtATime") });
     }
     setDragging(dragDepth.current > 0);
   });
diff --git a/frontend/src/modules/files/ShareDialog.tsx b/frontend/src/modules/files/ShareDialog.tsx
index 7b6335fd..55359e98 100644
--- a/frontend/src/modules/files/ShareDialog.tsx
+++ b/frontend/src/modules/files/ShareDialog.tsx
@@ -5,7 +5,7 @@ import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { Check, Copy, Link2, Lock, Trash2, UserPlus, Eye } from "lucide-react";
 import Modal from "../../components/ui/Modal";
 import { useConfirm } from "../../components/ui/confirmContext";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { formatDate } from "../../lib/format";
 import { api, type DownloadJob, type ShareLink, type ShareRecipient } from "../../lib/api";
@@ -40,9 +40,9 @@ function UserShare({ job }: { job: DownloadJob }) {
   const share = useMutation({
     mutationFn: (email: string) => api.shareDownload(job.id, email),
     onSuccess: (r) => {
-      notify({ level: "success", message: t("downloads.share.done", { email: r.shared_with }) });
+      notify({ level: "success", message: msg("downloads.share.done", { email: r.shared_with }) });
     },
-    onError: (e) => notifyActionError(e, t("downloads.share.failed")),
+    onError: (e) => notifyActionError(e, msg("downloads.share.failed")),
   });
 
   return (
diff --git a/frontend/src/modules/files/UploadDialog.dom.test.tsx b/frontend/src/modules/files/UploadDialog.dom.test.tsx
index abff6ffa..671d0f2c 100644
--- a/frontend/src/modules/files/UploadDialog.dom.test.tsx
+++ b/frontend/src/modules/files/UploadDialog.dom.test.tsx
@@ -45,6 +45,7 @@ vi.mock("../../lib/downloadQueue", () => ({
 
 import UploadDialog from "./UploadDialog";
 import { FilesActionsContext } from "./filesContext";
+import { msg, type NotifText } from "../../lib/notifications";
 
 const wrap = (
   onClose = vi.fn(),
@@ -101,7 +102,9 @@ describe("UploadDialog", () => {
     expect(passedFile).toBe(f);
     expect((opts as { displayName?: string }).displayName).toBe("My notes");
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(1));
-    expect(h.notify.mock.calls[0]![0]).toMatchObject({ message: "downloads.upload.added" });
+    expect((h.notify.mock.calls[0]![0] as { message: NotifText }).message).toEqual(
+      msg("downloads.upload.added"),
+    );
     await waitFor(() => expect(onClose).toHaveBeenCalled());
   });
 
@@ -115,9 +118,9 @@ describe("UploadDialog", () => {
     });
     fireEvent.click(screen.getByText("downloads.upload.submit"));
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(1));
-    expect(h.notify.mock.calls[0]![0]).toMatchObject({
-      message: "downloads.upload.addedConverting",
-    });
+    expect((h.notify.mock.calls[0]![0] as { message: NotifText }).message).toEqual(
+      msg("downloads.upload.addedConverting"),
+    );
     // Its finish is still to come, and the tray's to announce.
     expect(h.uploadEnded).toHaveBeenCalledWith(null);
   });
diff --git a/frontend/src/modules/files/UploadDialog.tsx b/frontend/src/modules/files/UploadDialog.tsx
index 6c19ff5e..7ecabfec 100644
--- a/frontend/src/modules/files/UploadDialog.tsx
+++ b/frontend/src/modules/files/UploadDialog.tsx
@@ -9,7 +9,7 @@ import { qk } from "../../lib/queryKeys";
 import { isAborted } from "../../lib/api/core";
 import { notifyActionError } from "../../lib/actionErrors";
 import { invalidateDownloads } from "../../lib/downloads";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { showInTray, uploadEnded, uploadStarted } from "../../lib/downloadQueue";
 import type { DownloadJob } from "../../lib/api";
 import { useFilesActions } from "./filesContext";
@@ -105,7 +105,7 @@ export default function UploadDialog({
       invalidateDownloads(qc);
       notify({
         level: "success",
-        message: t(uploadedKey(job.status)),
+        message: msg(uploadedKey(job.status)),
         action: {
           label: t("downloads.dialog.view"),
           onClick: () => openUploaded(job),
@@ -120,7 +120,7 @@ export default function UploadDialog({
       // named and no job in the list. The comment here claimed the global error modal had it; it
       // had not since the shared `reportFailure` landed.
       uploadEnded(null);
-      if (!isAborted(e)) notifyActionError(e, t("downloads.upload.failed"));
+      if (!isAborted(e)) notifyActionError(e, msg("downloads.upload.failed"));
       // Re-arm the form so the user can retry or pick again.
       setPct(null);
       abortRef.current = null;
diff --git a/frontend/src/modules/files/VideoEditor.partial.dom.test.tsx b/frontend/src/modules/files/VideoEditor.partial.dom.test.tsx
index e694fd7c..d6b0f9ff 100644
--- a/frontend/src/modules/files/VideoEditor.partial.dom.test.tsx
+++ b/frontend/src/modules/files/VideoEditor.partial.dom.test.tsx
@@ -22,6 +22,7 @@ vi.mock("../../lib/notifications", async (importOriginal) => ({
 import VideoEditor from "./VideoEditor";
 import { api, HttpError, type DownloadJob } from "../../lib/api";
 import { markReported } from "../../lib/api/core";
+import { msg } from "../../lib/notifications";
 
 beforeAll(() => {
   class Stub {
@@ -88,7 +89,10 @@ describe("VideoEditor — a split export that fails part-way", () => {
     await act(async () => refuse(refused));
     await waitFor(() =>
       expect(notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "error", title: "editor.partlyCreated" }),
+        expect.objectContaining({
+          level: "error",
+          title: msg("editor.partlyCreated", { done: 1, total: 2 }),
+        }),
       ),
     );
     expect(enqueue.mock.calls[0]![0].display_name).toBe("Talk (1/2)");
diff --git a/frontend/src/modules/files/VideoEditor.tsx b/frontend/src/modules/files/VideoEditor.tsx
index b42441c2..0063e9ca 100644
--- a/frontend/src/modules/files/VideoEditor.tsx
+++ b/frontend/src/modules/files/VideoEditor.tsx
@@ -6,7 +6,7 @@ import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { Crop, Eye, EyeOff, Pause, Play, Scissors, SplitSquareHorizontal, X } from "lucide-react";
 import clsx from "clsx";
 import Modal, { ModalFooter } from "../../components/ui/Modal";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { api, type DownloadJob, type EditSpec } from "../../lib/api";
 import { cropToSourcePx, type Frac } from "../../lib/cropGeometry";
 import { CropFrame } from "../../components/ui/CropFrame";
@@ -288,7 +288,7 @@ export default function VideoEditor({ job, onClose }: { job: DownloadJob; onClos
           // what the dialog does not tell.
           notify({
             level: "error",
-            title: t("editor.partlyCreated", { done: done.length, total: N }),
+            title: msg("editor.partlyCreated", { done: done.length, total: N }),
             message: failureReason(e),
           });
           markReported(e);
@@ -300,10 +300,10 @@ export default function VideoEditor({ job, onClose }: { job: DownloadJob; onClos
     onSuccess: ({ files }) => {
       // The whole library moves with it: an edit the user already made is done at once, and lists.
       invalidateDownloads(qc);
-      notify({ level: "success", message: t("editor.created", { count: files }) });
+      notify({ level: "success", message: msg("editor.created", { count: files }) });
       onClose();
     },
-    onError: (e) => notifyActionError(e, t("editor.failed")),
+    onError: (e) => notifyActionError(e, msg("editor.failed")),
     onSettled: () => {
       creating.current = false;
     },
diff --git a/frontend/src/modules/files/useFileActions.tsx b/frontend/src/modules/files/useFileActions.tsx
index ca16009d..775c3365 100644
--- a/frontend/src/modules/files/useFileActions.tsx
+++ b/frontend/src/modules/files/useFileActions.tsx
@@ -28,6 +28,7 @@ import { jobTitle } from "../../features/downloads/downloadTitle";
 import { folderLabel } from "../../features/folders/fileFolders";
 import { type ActionMenuItem } from "../../components/ui/ActionMenu";
 import { menuGroups } from "../../components/ui/menuGroups";
+import { msg } from "../../lib/notifications";
 
 // The Files rows' ONE menu, and the actions the rows show as icons (the same ones, so a row's every
 // action is reachable by right click — DESIGN.md "Library list columns"). My own files and the ones
@@ -79,7 +80,7 @@ export function useFileActions({
   const update = useMutation({
     mutationFn: ({ id, patch }: { id: number; patch: Patch }) => api.updateFile(id, patch),
     onSuccess: () => invalidateDownloads(qc),
-    onError: (e, v) => notifyActionError(e, t(patchFail(v.patch))),
+    onError: (e, v) => notifyActionError(e, msg(patchFail(v.patch))),
   });
   const remove = useMutation({
     mutationFn: (id: number) => api.deleteFile(id),
diff --git a/frontend/src/modules/files/useFolderActions.tsx b/frontend/src/modules/files/useFolderActions.tsx
index 33833de9..a2c28d09 100644
--- a/frontend/src/modules/files/useFolderActions.tsx
+++ b/frontend/src/modules/files/useFolderActions.tsx
@@ -9,6 +9,7 @@ import { useConfirm } from "../../components/ui/confirmContext";
 import { folderLabel } from "../../features/folders/fileFolders";
 import { type ActionMenuItem } from "../../components/ui/ActionMenu";
 import { menuGroups } from "../../components/ui/menuGroups";
+import { msg } from "../../lib/notifications";
 
 // A library folder's ONE menu — the rail entry's right click and the Files page's "…" beside an open
 // folder's name. An own folder is shared by link (its link opens whatever is in it), renamed (inline,
@@ -43,7 +44,7 @@ export function useFolderActions({ onRename }: { onRename: (folder: FileFolder)
   const update = useMutation({
     mutationFn: ({ id, patch }: { id: number; patch: FolderPatch }) => api.updateFolder(id, patch),
     onSuccess: () => invalidateDownloads(qc),
-    onError: (e, v) => notifyActionError(e, t(patchFail(v.patch))),
+    onError: (e, v) => notifyActionError(e, msg(patchFail(v.patch))),
   });
   const remove = useMutation({
     mutationFn: (id: number) => api.deleteFolder(id),
diff --git a/frontend/src/modules/home/Home.tsx b/frontend/src/modules/home/Home.tsx
index 42bfb30c..926a749e 100644
--- a/frontend/src/modules/home/Home.tsx
+++ b/frontend/src/modules/home/Home.tsx
@@ -81,6 +81,7 @@ import RemoteImage from "../../components/ui/RemoteImage";
 import { useOpenLinkedPlayer } from "../../features/player/useOpenLinkedPlayer";
 import { budgetFrom, budgetParams, DEFAULT_BUDGET } from "../../lib/homeUrlState";
 import { useUrlMirror } from "../../lib/useUrlMirror";
+import { msg } from "../../lib/notifications";
 
 // The Home surface — "Mit nézzek most?".
 //
@@ -868,10 +869,10 @@ export default function Home() {
         // click raises a bare fetch TypeError, so there is no server reason to prefer over it. It
         // would describe a state the user can see is untrue, over a fully populated page whose
         // invalidations never even ran (they sit inside `.then`).
-        .catch((e: unknown) => notifyActionError(e, t("home.actionFailed")));
+        .catch((e: unknown) => notifyActionError(e, msg("home.actionFailed")));
       return write;
     },
-    [qc, t],
+    [qc],
   );
 
   const onToggleSave = useCallback(
@@ -887,9 +888,9 @@ export default function Home() {
           qc.invalidateQueries({ queryKey: qk.discover() });
         })
         // The write key, for the same reason as `onState` above.
-        .catch((e: unknown) => notifyActionError(e, t("home.actionFailed")));
+        .catch((e: unknown) => notifyActionError(e, msg("home.actionFailed")));
     },
-    [qc, t],
+    [qc],
   );
 
   // One click plays. A shelf tile resolves through its `next` (a show → the episode that would
@@ -940,11 +941,11 @@ export default function Home() {
   // re-asks the server rather than trying to predict a cross-rail consequence.
   const onToggleWatched = useCallback(
     (card: PlexCard) =>
-      void toggleWatchState(card, t, {
+      void toggleWatchState(card, {
         optimistic: () => {},
         resync: () => qc.invalidateQueries({ queryKey: qk.discover() }),
       }),
-    [qc, t],
+    [qc],
   );
 
   // Shelf reorder, from the comfort rail's menu. Optimistic on THIS budget's cached payload so the
@@ -986,7 +987,7 @@ export default function Home() {
         .reorderComfortPins(ids)
         .catch((e: unknown) => {
           qc.setQueryData<DiscoverPayload>(key, (old) => (old ? { ...old, comfort: cards } : old));
-          notifyActionError(e, t("home.shelf.moveFailed"));
+          notifyActionError(e, msg("home.shelf.moveFailed"));
         })
         .finally(() => {
           shelfSavingRef.current = false;
@@ -1000,7 +1001,7 @@ export default function Home() {
           void qc.invalidateQueries({ queryKey: qk.discover() });
         });
     },
-    [budget, lang, qc, t],
+    [budget, lang, qc],
   );
 
   const reroll = useCallback(
diff --git a/frontend/src/modules/notifications/NotificationsPanel.menu.dom.test.tsx b/frontend/src/modules/notifications/NotificationsPanel.menu.dom.test.tsx
index d42adf50..3579b89b 100644
--- a/frontend/src/modules/notifications/NotificationsPanel.menu.dom.test.tsx
+++ b/frontend/src/modules/notifications/NotificationsPanel.menu.dom.test.tsx
@@ -9,7 +9,7 @@ import { afterEach, describe, expect, it, onTestFinished, vi } from "vitest";
 import { act, cleanup, fireEvent, render, screen, waitFor, within } from "@testing-library/react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { api, type AppNotification } from "../../lib/api";
-import type { Notification as ClientNotif } from "../../lib/notifications";
+import { raw, type Notification as ClientNotif } from "../../lib/notifications";
 
 const h = vi.hoisted(() => ({
   server: [] as unknown[],
@@ -116,7 +116,7 @@ const client = (id: number, extra: Partial<ClientNotif> = {}) =>
   ({
     id,
     level: "success",
-    message: `Activity ${id}`,
+    message: raw(`Activity ${id}`),
     requiresInteraction: false,
     ts: Date.now(),
     read: true,
diff --git a/frontend/src/modules/notifications/NotificationsPanel.order.dom.test.tsx b/frontend/src/modules/notifications/NotificationsPanel.order.dom.test.tsx
index 3099056f..8375b070 100644
--- a/frontend/src/modules/notifications/NotificationsPanel.order.dom.test.tsx
+++ b/frontend/src/modules/notifications/NotificationsPanel.order.dom.test.tsx
@@ -50,6 +50,7 @@ vi.mock("../../components/ui/PageShell", async (importOriginal) => ({
 
 import NotificationsPanel from "./NotificationsPanel";
 import { focusNavItem, restoreNavPosition } from "../../lib/listNav";
+import { raw } from "../../lib/notifications";
 
 // The server list goes through the real live query, so an optimistic patch of its cache is seen.
 beforeEach(() => {
@@ -80,7 +81,7 @@ const client = (id: number, ageMs: number, extra: Partial<ClientNotif> = {}) =>
   ({
     id,
     level: "success",
-    message: `Activity ${id}.`,
+    message: raw(`Activity ${id}.`),
     requiresInteraction: false,
     ts: Date.now() - ageMs,
     read: true,
@@ -122,8 +123,8 @@ describe("NotificationsPanel · order", () => {
     h.client = [
       client(9, 5 * 60 * 1000, {
         level: "warning",
-        title: "common.accessRequestsTitle",
-        message: "1 pending",
+        title: raw("common.accessRequestsTitle"),
+        message: raw("1 pending"),
         meta: { kind: "access-requests" },
       }),
       client(8, 2 * D),
@@ -366,8 +367,8 @@ describe("NotificationsPanel · order", () => {
     h.client = [
       client(9, 5 * 60 * 1000, {
         level: "warning",
-        title: "common.accessRequestsTitle",
-        message: "1 pending",
+        title: raw("common.accessRequestsTitle"),
+        message: raw("1 pending"),
         meta: { kind: "access-requests" },
       }),
     ];
@@ -465,7 +466,9 @@ describe("NotificationsPanel · order", () => {
     // A screen reader hears the name while the keyboard is on the row, and Back finds the row it
     // left by it: "Download ready" alone was every download's name.
     h.server = [server(1, 1 * H, true), server(2, 2 * H, true)];
-    h.client = [client(3, 3 * H, { title: "Something broke", message: "Unexpected error." })];
+    h.client = [
+      client(3, 3 * H, { title: raw("Something broke"), message: raw("Unexpected error.") }),
+    ];
     mount();
     await loaded();
     expect(
diff --git a/frontend/src/modules/notifications/NotificationsPanel.tsx b/frontend/src/modules/notifications/NotificationsPanel.tsx
index 79c747de..5e0bce79 100644
--- a/frontend/src/modules/notifications/NotificationsPanel.tsx
+++ b/frontend/src/modules/notifications/NotificationsPanel.tsx
@@ -29,16 +29,18 @@ import { useLiveQuery } from "../../lib/useLiveQuery";
 import { focusAccessRequestsTab } from "../../lib/adminUsersTab";
 import { focusSettingsTab } from "../../lib/settingsTab";
 import {
+  type ChannelSubscribedMeta,
   clearAll as clearClient,
   dismiss as dismissClient,
   getNotifications,
   getUnreadCount,
   markAllRead as markAllClientRead,
+  msg,
+  type Notification as ClientNotif,
   remove as removeClient,
   resolveVideo,
+  sayNotif,
   subscribe,
-  type Notification as ClientNotif,
-  type ChannelSubscribedMeta,
   type VideoHiddenMeta,
   type VideoWatchedMeta,
 } from "../../lib/notifications";
@@ -250,7 +252,7 @@ export default function NotificationsPanel() {
         // Quietly resolve the now-stale notice (no confirmation toast — the change is visible).
         resolveVideo(meta.videoId);
       })
-      .catch((e) => notifyActionError(e, t("inbox.revertFailed")));
+      .catch((e) => notifyActionError(e, msg("inbox.revertFailed")));
   }
 
   // --- The rows' ONE menu -------------------------------------------------------------
@@ -707,10 +709,12 @@ function serverRowText(
  *  Trimmed as Back saves it (`lib/listNav`), or a title ending in a space never matches its row. */
 const rowName = (title: string, body: string | null | undefined): string =>
   (body ? `${title}: ${body}` : title).trim();
-const clientRowName = (n: ClientNotif): string =>
-  n.title ? rowName(n.title, n.message) : rowName(n.message, null);
+const clientRowName = (n: ClientNotif, t: TFunction): string =>
+  n.title
+    ? rowName(sayNotif(n.title, t), sayNotif(n.message, t))
+    : rowName(sayNotif(n.message, t), null);
 const entryName = (e: InboxEntry, t: TFunction, lang: string): string => {
-  if (e.src === "client") return clientRowName(e.n);
+  if (e.src === "client") return clientRowName(e.n, t);
   const { title, body } = serverRowText(e.n, t, lang);
   return rowName(title, body);
 };
@@ -854,15 +858,15 @@ function ClientActivityRow({
   const access = n.meta?.kind === "access-requests" ? n.meta : null;
   return (
     <div
-      {...navItemAttrs(navIndex, clientRowName(n))}
+      {...navItemAttrs(navIndex, clientRowName(n, t))}
       {...rowProps}
       className={`${SURFACE.card} group p-3.5 flex items-start gap-3 ${needsAction ? "ring-1 ring-accent/30" : ""}`}
     >
       <Icon className={`w-4 h-4 shrink-0 mt-0.5 ${color}`} />
       <div className="min-w-0 flex-1">
-        {n.title && <div className="text-sm font-semibold">{n.title}</div>}
+        {n.title && <div className="text-sm font-semibold">{sayNotif(n.title, t)}</div>}
         <div className="text-sm wrap-break-word">
-          {n.message}
+          {sayNotif(n.message, t)}
           {n.repeat > 1 && (
             <span className="ml-1.5 align-middle text-2xs font-semibold text-muted tabular-nums">
               ×{n.repeat}
diff --git a/frontend/src/modules/playlists/Playlists.dom.test.tsx b/frontend/src/modules/playlists/Playlists.dom.test.tsx
index d6950002..ed57bb99 100644
--- a/frontend/src/modules/playlists/Playlists.dom.test.tsx
+++ b/frontend/src/modules/playlists/Playlists.dom.test.tsx
@@ -94,6 +94,7 @@ import { PageMenuSlot, type PageMenuOpener } from "../../components/ui/pageMenuS
 import { api, HttpError, type Video } from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
 import { patchCachedProgress } from "../../lib/progressCache";
+import { msg, type NotifText } from "../../lib/notifications";
 
 beforeAll(() => {
   class Stub {
@@ -644,7 +645,7 @@ describe("Playlists — a change the server refused is taken back on screen", ()
     await act(async () => void (await new Promise((r) => setTimeout(r, 20))));
     expect(rowsOnScreen()).toEqual(["Video V", "Video W"]);
     expect(h.notify).toHaveBeenCalledWith(
-      expect.objectContaining({ level: "error", title: "playlists.removeFailed" }),
+      expect.objectContaining({ level: "error", title: msg("playlists.removeFailed") }),
     );
   });
 });
@@ -662,8 +663,8 @@ describe("Playlists — removing a row, and undoing it", () => {
   // removal may notify too.
   const lastToast = () =>
     h.notify.mock.calls
-      .map((c) => c[0] as { message: string; action?: { label: string; onClick: () => void } })
-      .filter((n) => n.message?.startsWith("playlists.removedToast"))
+      .map((c) => c[0] as { message: NotifText; action?: { label: string; onClick: () => void } })
+      .filter((n) => "key" in n.message && n.message.key === "playlists.removedToast")
       .pop()!;
   // The list's keys are live once its effect has registered it (`data-nav-list`), a passive effect that
   // can run AFTER the rows are on screen: a key pressed on a slow machine in between did nothing (CI flake).
@@ -686,7 +687,9 @@ describe("Playlists — removing a row, and undoing it", () => {
     expect(rowsOnScreen()).toEqual(["Video A", "Video C"]);
     // No confirm: the toast's Undo is the safety net.
     expect(h.confirm).not.toHaveBeenCalled();
-    await waitFor(() => expect(lastToast().message).toBe("playlists.removedToast:Video B"));
+    await waitFor(() =>
+      expect(lastToast().message).toEqual(msg("playlists.removedToast", { title: "Video B" })),
+    );
     expect(lastToast().action?.label).toBe("common.undo");
     act(() => lastToast().action!.onClick());
     // Index 1 of the STORED order: where it was, not the end of the list.
@@ -733,7 +736,7 @@ describe("Playlists — removing a row, and undoing it", () => {
     act(() => lastToast().action!.onClick());
     await waitFor(() =>
       expect(h.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "error", title: "playlists.undoRemoveFailed" }),
+        expect.objectContaining({ level: "error", title: msg("playlists.undoRemoveFailed") }),
       ),
     );
   });
diff --git a/frontend/src/modules/playlists/Playlists.tsx b/frontend/src/modules/playlists/Playlists.tsx
index 3ac7cf0b..6e89bf4e 100644
--- a/frontend/src/modules/playlists/Playlists.tsx
+++ b/frontend/src/modules/playlists/Playlists.tsx
@@ -34,10 +34,10 @@ import {
   type Video,
   type VideoStatus,
 } from "../../lib/api";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
-import { playlistName } from "../../lib/playlistName";
+import { playlistName, playlistNameText } from "../../lib/playlistName";
 import { reinsertAt } from "../../lib/reinsert";
 import { useUndoable } from "../../lib/useUndoable";
 import { cycleSort, type SortState } from "../../lib/columnSort";
@@ -231,7 +231,7 @@ function PlaylistDetail() {
           // Was a bare .then(): a failed reorder left the UI showing an order the server had
           // rejected, and produced an unhandled rejection. Say so, and put back the order the server
           // still has — or the rejected one becomes the base for the next drag.
-          notifyYouTubeActionError(e, t("playlists.reorderFailed"));
+          notifyYouTubeActionError(e, msg("playlists.reorderFailed"));
           restoreFromCache(listId);
           qc.invalidateQueries({ queryKey: qk.playlist(listId) });
         });
@@ -535,7 +535,7 @@ function PlaylistDetail() {
       // Said here, as moveItemTo does, or a removal fails in silence (inside the full-screen player
       // there is not even a row snapping back to show it) — unless `req` already put it in its error
       // dialog, which `notifyActionError` checks.
-      notifyActionError(e, t("playlists.removeFailed"));
+      notifyActionError(e, msg("playlists.removeFailed"));
       // …and the row goes back NOW, not when the resync lands: a removal that failed because the
       // server was unreachable has a resync that fails too, and the list kept showing the row as
       // removed while it was still in the playlist.
@@ -545,7 +545,7 @@ function PlaylistDetail() {
     }
     notify({
       level: "success",
-      message: t("playlists.removedToast", { title: video.title }),
+      message: msg("playlists.removedToast", { title: video.title ?? "" }),
       action: {
         label: t("common.undo"),
         // ONE request that puts it back at its index (the server renumbers around it): an append
@@ -567,7 +567,7 @@ function PlaylistDetail() {
               if (back.keys.length)
                 return addPlaylistItem(qc, listRef(listId), video.id, back.positions[0]);
             })
-            .catch((e: unknown) => notifyActionError(e, t("playlists.undoRemoveFailed")))
+            .catch((e: unknown) => notifyActionError(e, msg("playlists.undoRemoveFailed")))
             .finally(() => {
               refreshAll(listId);
               qc.invalidateQueries({ queryKey: qk.playlistMembership(video.id) });
@@ -619,6 +619,8 @@ function PlaylistDetail() {
     const next = items.filter((v) => v.id !== video.id);
     order.rebase((list) => list.filter((v) => v.id !== video.id));
     lastSetRef.current = `${selectedId}:${idsKey(next)}`;
+    // Outside the `try`: a `??` inside it makes the React Compiler skip the component.
+    const title = video.title ?? "";
     try {
       // ONE request. The two-call version (add there, remove here) leaves the video in BOTH lists
       // whenever the second call fails — see the endpoint's docstring.
@@ -628,7 +630,7 @@ function PlaylistDetail() {
       setLastMoveTargetId(target.id);
       notify({
         level: "success",
-        message: t("playlists.movedToast", { title: video.title, name: plName(target) }),
+        message: msg("playlists.movedToast", { title, name: playlistNameText(target) }),
       });
     } catch (e) {
       // NOT a silent revert. `req` deliberately leaves 401/403/404 to the caller as control flow, and
@@ -637,7 +639,7 @@ function PlaylistDetail() {
       // explanation and the shipped moveErrors strings were unreachable.
       // A fault `req` already put in its error dialog is not toasted again — `notifyActionError`
       // checks (a review found it reported twice).
-      notifyActionError(e, t("playlists.moveFailed"));
+      notifyActionError(e, msg("playlists.moveFailed"));
       restoreFromCache(selectedId); // the row is still in this list
     }
     // BOTH sides changed, and so did this video's membership. `qk.playlist(selectedId)` is an exact
@@ -677,7 +679,7 @@ function PlaylistDetail() {
         qc.invalidateQueries({ queryKey: qk.feed() });
       })
       // No catch used to mean an unhandled rejection and nothing said.
-      .catch((e: unknown) => notifyActionError(e, t("errors.writeFailed.videoState")));
+      .catch((e: unknown) => notifyActionError(e, msg("errors.writeFailed.videoState")));
     return write;
   }
 
diff --git a/frontend/src/modules/playlists/PlaylistsRail.tsx b/frontend/src/modules/playlists/PlaylistsRail.tsx
index e4474984..1849ebbd 100644
--- a/frontend/src/modules/playlists/PlaylistsRail.tsx
+++ b/frontend/src/modules/playlists/PlaylistsRail.tsx
@@ -7,7 +7,7 @@ import { YouTubeIcon } from "../../lib/brandIcons";
 import { api, type Playlist } from "../../lib/api";
 import { compareText } from "../../lib/collate";
 import { formatRuntime } from "../../lib/format";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { LS } from "../../lib/storage";
 import { usePref } from "../../lib/usePref";
@@ -155,9 +155,9 @@ export default function PlaylistsRail() {
       const r = await api.syncYoutubePlaylists();
       qc.invalidateQueries({ queryKey: qk.playlists() });
       qc.invalidateQueries({ queryKey: qk.playlist() });
-      notify({ level: "success", message: t("playlists.syncedToast", { count: r.synced }) });
+      notify({ level: "success", message: msg("playlists.syncedToast", { count: r.synced }) });
     } catch (e) {
-      notifyYouTubeActionError(e, t("playlists.syncFailed"));
+      notifyYouTubeActionError(e, msg("playlists.syncFailed"));
     }
     setSyncing(false);
   }
diff --git a/frontend/src/modules/playlists/usePlaylistActions.dom.test.tsx b/frontend/src/modules/playlists/usePlaylistActions.dom.test.tsx
index ce75c3f2..a3d29b76 100644
--- a/frontend/src/modules/playlists/usePlaylistActions.dom.test.tsx
+++ b/frontend/src/modules/playlists/usePlaylistActions.dom.test.tsx
@@ -31,6 +31,7 @@ vi.mock("../../lib/useMe", () => ({ useMe: () => ({ can_write: h.canWrite }) }))
 
 import { usePlaylistActions } from "./usePlaylistActions";
 import { HttpError, api } from "../../lib/api";
+import { msg, sayNotif, type NotifText } from "../../lib/notifications";
 
 type Menuable = Parameters<ReturnType<typeof usePlaylistActions>["items"]>[0];
 
@@ -73,21 +74,21 @@ describe("usePlaylistActions — deleting a list", () => {
     const { result } = mount();
     await act(() => result.current.remove(linked));
     expect(h.notify).toHaveBeenCalledWith(
-      expect.objectContaining({ title: "playlists.deleteYtFailed" }),
-    );
-    expect(h.notify).not.toHaveBeenCalledWith(
-      expect.objectContaining({ message: "Unknown playlist" }),
+      expect.objectContaining({ title: msg("playlists.deleteYtFailed") }),
     );
+    expect(
+      h.notify.mock.calls.map(([n]) => sayNotif((n as { message: NotifText }).message)),
+    ).not.toContain("Unknown playlist");
   });
 
-  it("prefers a STRUCTURED reason, which the request layer has already localized", async () => {
+  it("prefers a STRUCTURED reason, kept as the refusal to say in the reader's language", async () => {
     vi.spyOn(api, "deletePlaylist").mockRejectedValue(
       new HttpError(404, "Ez a lista már nem létezik.", { code: "not_found", reason: "playlist" }),
     );
     const { result } = mount();
     await act(() => result.current.remove(linked));
     expect(h.notify).toHaveBeenCalledWith(
-      expect.objectContaining({ message: "Ez a lista már nem létezik." }),
+      expect.objectContaining({ message: { detail: { code: "not_found", reason: "playlist" } } }),
     );
   });
 });
diff --git a/frontend/src/modules/playlists/usePlaylistActions.tsx b/frontend/src/modules/playlists/usePlaylistActions.tsx
index 38c95858..060e3229 100644
--- a/frontend/src/modules/playlists/usePlaylistActions.tsx
+++ b/frontend/src/modules/playlists/usePlaylistActions.tsx
@@ -4,10 +4,10 @@ import { ExternalLink, Pencil, RotateCcw, Trash2, Upload } from "lucide-react";
 import { YouTubeIcon } from "../../lib/brandIcons";
 import { qk } from "../../lib/queryKeys";
 import { api, type Playlist } from "../../lib/api";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
-import { playlistName } from "../../lib/playlistName";
+import { playlistName, playlistNameText } from "../../lib/playlistName";
 import { useChoice, useConfirm } from "../../components/ui/confirmContext";
 import { usePlaylists, usePlaylistsActions } from "./playlistsContext";
 import { useMe } from "../../lib/useMe";
@@ -72,7 +72,7 @@ export function usePlaylistActions() {
     try {
       await api.renamePlaylist(id, next);
     } catch (e) {
-      notifyYouTubeActionError(e, t("playlists.renameFailed"));
+      notifyYouTubeActionError(e, msg("playlists.renameFailed"));
     }
     refresh(id);
   }
@@ -112,7 +112,7 @@ export function usePlaylistActions() {
       // `req` already put it in its error dialog: not twice (notifyActionError checks).
       notifyActionError(
         err,
-        onYoutube ? t("playlists.deleteYtFailed") : t("playlists.deleteFailed"),
+        msg(onYoutube ? "playlists.deleteYtFailed" : "playlists.deleteFailed"),
         "warning",
       );
     }
@@ -136,29 +136,28 @@ export function usePlaylistActions() {
       refresh(pl.id);
       notify({
         level: "success",
-        message: t("playlists.revertDone", { name: playlistName(pl, t) }),
+        message: msg("playlists.revertDone", { name: playlistNameText(pl) }),
       });
     } catch (e) {
-      notifyYouTubeActionError(e, t("playlists.revertFailed"));
+      notifyYouTubeActionError(e, msg("playlists.revertFailed"));
     }
     mark("reverting", pl.id, false);
   }
 
   async function push(pl: Menuable) {
     if (syncing(pl.id)) return;
-    const name = playlistName(pl, t);
     mark("pushing", pl.id, true);
     try {
-      await pushSteps(pl, name);
+      await pushSteps(pl);
     } catch (e) {
-      notifyYouTubeActionError(e, t("playlists.pushFailed"));
+      notifyYouTubeActionError(e, msg("playlists.pushFailed"));
     }
     mark("pushing", pl.id, false);
   }
 
   /** push()'s steps, apart so its "pushing" mark clears on every way out without a try/finally
    *  (the React Compiler cannot lower one yet, and skips the whole hook). */
-  async function pushSteps(pl: Menuable, name: string) {
+  async function pushSteps(pl: Menuable) {
     const plan = await api.playlistPushPlan(pl.id);
     const nothingToDo =
       plan.action === "update" &&
@@ -169,13 +168,16 @@ export function usePlaylistActions() {
       !plan.to_reorder &&
       !plan.rename;
     if (nothingToDo) {
-      notify({ level: "info", message: t("playlists.pushUpToDate", { name }) });
+      notify({
+        level: "info",
+        message: msg("playlists.pushUpToDate", { name: playlistNameText(pl) }),
+      });
       return;
     }
     if (!plan.affordable) {
       notify({
         level: "warning",
-        message: t("playlists.pushNoQuota", {
+        message: msg("playlists.pushNoQuota", {
           left: plan.remaining_today,
           units: plan.units_estimate,
         }),
@@ -224,10 +226,13 @@ export function usePlaylistActions() {
     if (r.failures.length) {
       notify({
         level: "warning",
-        message: t("playlists.pushPartial", { count: r.failures.length }),
+        message: msg("playlists.pushPartial", { count: r.failures.length }),
       });
     } else {
-      notify({ level: "success", message: t("playlists.pushDone", { name }) });
+      notify({
+        level: "success",
+        message: msg("playlists.pushDone", { name: playlistNameText(pl) }),
+      });
     }
   }
 
diff --git a/frontend/src/modules/plex/PlexBrowse.tsx b/frontend/src/modules/plex/PlexBrowse.tsx
index d08dfbe5..dd820682 100644
--- a/frontend/src/modules/plex/PlexBrowse.tsx
+++ b/frontend/src/modules/plex/PlexBrowse.tsx
@@ -393,7 +393,7 @@ function PlexBrowseView({ sub }: { sub: ReturnType<typeof useHistorySubview<Sub>
     );
   }
   const toggleWatched = (card: PlexCard) =>
-    toggleWatchState(card, t, {
+    toggleWatchState(card, {
       optimistic: (next) => optimisticStatus(card.id, next),
       resync: () => qc.invalidateQueries({ queryKey: qk.plexLibrary() }),
     });
diff --git a/frontend/src/modules/plex/PlexCollectionEditor.tsx b/frontend/src/modules/plex/PlexCollectionEditor.tsx
index 5aae15e9..a2c0074c 100644
--- a/frontend/src/modules/plex/PlexCollectionEditor.tsx
+++ b/frontend/src/modules/plex/PlexCollectionEditor.tsx
@@ -13,6 +13,7 @@ import { useConfirm } from "../../components/ui/confirmContext";
 import { Pressable } from "../../components/ui/Pressable";
 import { Input } from "../../components/ui/Input";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // Admin-only "manage this movie's collections" dialog. Lists the library's EDITABLE
 // collections with an in/out toggle (add/remove the movie, written back to Plex), plus a field to
@@ -85,7 +86,7 @@ export default function PlexCollectionEditor({
       // 403/404 are left to the caller by `req` (see reportFailure), so without this the tick
       // simply never appeared and the user clicked again — a collection deleted on the Plex server
       // or flipped read-only failed in silence.
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     setBusy(null);
   }
@@ -97,7 +98,7 @@ export default function PlexCollectionEditor({
       await api.plexSetCollectionEditable(id, true);
       refresh();
     } catch (e) {
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     setBusy(null);
   }
@@ -114,7 +115,7 @@ export default function PlexCollectionEditor({
     } catch (e) {
       // The backend rejects a duplicate name with 409 (Plex conflates same names), structured — so
       // it reads in the reader's language (see localizeDetail).
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     setBusy(null);
   }
@@ -134,7 +135,7 @@ export default function PlexCollectionEditor({
     } catch (e) {
       // The worst of the three to lose: the user has just confirmed a destructive dialog, and the
       // row stayed where it was with nothing said.
-      notifyActionError(e, t("plex.collection.deleteFailed"));
+      notifyActionError(e, msg("plex.collection.deleteFailed"));
     }
     setBusy(null);
   }
diff --git a/frontend/src/modules/plex/PlexCollectionView.dom.test.tsx b/frontend/src/modules/plex/PlexCollectionView.dom.test.tsx
index 9b6f2892..5446ab97 100644
--- a/frontend/src/modules/plex/PlexCollectionView.dom.test.tsx
+++ b/frontend/src/modules/plex/PlexCollectionView.dom.test.tsx
@@ -44,6 +44,7 @@ vi.mock("../../lib/notifications", async (importOriginal) => ({
 }));
 
 import PlexCollectionView from "./PlexCollectionView";
+import { msg } from "../../lib/notifications";
 import {
   api,
   HttpError,
@@ -135,7 +136,7 @@ describe("PlexCollectionView — Play-all", () => {
     fireEvent.click(await screen.findByText("plex.collection.playAll"));
     await waitFor(() =>
       expect(h.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "info", message: "plex.collection.playEmpty" }),
+        expect.objectContaining({ level: "info", message: msg("plex.collection.playEmpty") }),
       ),
     );
     expect(onPlay).not.toHaveBeenCalled();
diff --git a/frontend/src/modules/plex/PlexCollectionView.tsx b/frontend/src/modules/plex/PlexCollectionView.tsx
index 0fe9c233..291fc1cd 100644
--- a/frontend/src/modules/plex/PlexCollectionView.tsx
+++ b/frontend/src/modules/plex/PlexCollectionView.tsx
@@ -8,7 +8,7 @@ import { plexLang } from "../../i18n";
 import { api, isIntrinsicReadOnly, type PlexCard, type PlexCollectionDetail } from "../../lib/api";
 import { formatRuntime } from "../../lib/format";
 import { notifyActionError } from "../../lib/actionErrors";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { showEpisodeKeys } from "../../lib/plexQueue";
 import { healPlexSort, plexSortOptions } from "../../lib/plexSort";
 import { usePref } from "../../lib/usePref";
@@ -154,9 +154,9 @@ export default function PlexCollectionView({
       // canPlay gates on "has a show member", but a show can expand to zero episodes (unmatched /
       // empty). An enabled Play-all that silently no-ops is a dishonest state, so say so plainly.
       if (queue.length > 0) onPlay(queue[0]!, queue);
-      else notify({ level: "info", message: t("plex.collection.playEmpty") });
+      else notify({ level: "info", message: msg("plex.collection.playEmpty") });
     } catch (e) {
-      notifyActionError(e, t("plex.collection.playFailed"));
+      notifyActionError(e, msg("plex.collection.playFailed"));
     }
     setQueueBusy(false);
   }
@@ -168,7 +168,7 @@ export default function PlexCollectionView({
   const readOnly = !d?.can_edit && !canEnableEdit; // external / smart auto-list
 
   const toggleWatched = (card: PlexCard) =>
-    toggleWatchState(card, t, {
+    toggleWatchState(card, {
       optimistic: (next) => {
         qc.setQueryData<PlexCollectionDetail>(detailKey, (old) =>
           old
@@ -211,7 +211,7 @@ export default function PlexCollectionView({
       setRenaming(false);
     } catch (e) {
       // The backend enforces per-library name uniqueness — a taken name comes back localized.
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     setBusy(false);
   }
@@ -226,7 +226,7 @@ export default function PlexCollectionView({
       invalidate();
       onBack();
     } catch (e) {
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
       setBusy(false);
     }
   }
@@ -240,7 +240,7 @@ export default function PlexCollectionView({
       await api.plexCollectionRemoveItem(collectionId, card.id);
       invalidate();
     } catch (e) {
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     setBusy(false);
   }
@@ -251,7 +251,7 @@ export default function PlexCollectionView({
       await api.plexSetCollectionEditable(collectionId, true);
       invalidate();
     } catch (e) {
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     setBusy(false);
   }
@@ -495,7 +495,7 @@ function AddItemPanel({
       setAdded((s) => new Set(s).add(card.id));
       onAdded();
     } catch (e) {
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
   }
 
diff --git a/frontend/src/modules/plex/PlexDiscover.tsx b/frontend/src/modules/plex/PlexDiscover.tsx
index ecbab1d4..19a8d3d1 100644
--- a/frontend/src/modules/plex/PlexDiscover.tsx
+++ b/frontend/src/modules/plex/PlexDiscover.tsx
@@ -172,7 +172,7 @@ export default function PlexDiscover({
           : old,
     );
   const toggleWatched = (card: PlexCard) =>
-    toggleWatchState(card, t, {
+    toggleWatchState(card, {
       optimistic: (next) => {
         const flip = (cards: PlexCard[]) =>
           cards.map((c) => (c.id === card.id ? { ...c, status: next } : c));
diff --git a/frontend/src/modules/plex/PlexInfo.tsx b/frontend/src/modules/plex/PlexInfo.tsx
index 70f7c5da..ad2f46e1 100644
--- a/frontend/src/modules/plex/PlexInfo.tsx
+++ b/frontend/src/modules/plex/PlexInfo.tsx
@@ -36,6 +36,7 @@ import { usePlexCardActions } from "../../features/plexCards/usePlexCardActions"
 import { toggleWatchState } from "../../lib/plexWatch";
 import { vocab } from "../../lib/vocab";
 import RemoteImage from "../../components/ui/RemoteImage";
+import { msg } from "../../lib/notifications";
 
 // The rich "media info" surface for a Plex item — poster/art, IMDb score + link, content rating,
 // genres, director, cast (with photos), summary. Reused in TWO places: a full-page view opened from
@@ -254,7 +255,7 @@ export default function PlexInfo({
     try {
       await api.plexSetState(detail.id, status);
     } catch (e) {
-      notifyActionError(e, t("plex.watchedFailed"));
+      notifyActionError(e, msg("plex.watchedFailed"));
     }
     qc.invalidateQueries({ queryKey: qk.plexItem(detail.id) });
     qc.invalidateQueries({ queryKey: qk.plexLibrary() });
@@ -267,7 +268,7 @@ export default function PlexInfo({
   // is; the resync corrects it to the truth either way.
   const colMenu = useContextMenu<PlexCard>();
   const toggleColWatched = (card: PlexCard) =>
-    toggleWatchState(card, t, {
+    toggleWatchState(card, {
       optimistic: (next) =>
         qc.setQueriesData<PlexItemDetail>({ queryKey: qk.plexItem(detail.id) }, (old) =>
           old
diff --git a/frontend/src/modules/plex/PlexPlayer.session.dom.test.tsx b/frontend/src/modules/plex/PlexPlayer.session.dom.test.tsx
index e8680d20..25b6d497 100644
--- a/frontend/src/modules/plex/PlexPlayer.session.dom.test.tsx
+++ b/frontend/src/modules/plex/PlexPlayer.session.dom.test.tsx
@@ -20,7 +20,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 import PlexPlayer from "./PlexPlayer";
 import { api, HttpError, type PlexItemDetail } from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
-import { notify } from "../../lib/notifications";
+import { notify, raw } from "../../lib/notifications";
 import { claimLocalData } from "../../lib/storage";
 
 type Media = HTMLMediaElement & { _t?: number };
@@ -285,7 +285,7 @@ it("shows a toast raised while it is open inside itself, not under its scrim", a
   mount({ details: { A: item("A") }, sessions: { A: () => new Promise(() => {}) } });
   await screen.findByText("Title A");
   act(() => {
-    notify({ level: "error", message: "Couldn't mark it watched." });
+    notify({ level: "error", message: raw("Couldn't mark it watched.") });
   });
   const toast = await screen.findByText("Couldn't mark it watched.");
   let host: Element | null = video();
diff --git a/frontend/src/modules/plex/PlexPlayer.tsx b/frontend/src/modules/plex/PlexPlayer.tsx
index 3e4619d7..becc6443 100644
--- a/frontend/src/modules/plex/PlexPlayer.tsx
+++ b/frontend/src/modules/plex/PlexPlayer.tsx
@@ -103,6 +103,7 @@ import { closeThenAct, useAnchoredPopover } from "../../components/ui/anchoredPo
 import { Slider } from "../../components/ui/NativeControls";
 import { formatUnit } from "../../lib/format";
 import { trackLabel } from "../../lib/vocab";
+import { msg } from "../../lib/notifications";
 
 // The rich info overlay (poster/cast/ratings) reuses the same component as the card's info page.
 const PlexInfo = lazy(() => import("./PlexInfo"));
@@ -716,8 +717,8 @@ export default function PlexPlayer({
   });
 
   const reportWatchedError = useCallback(
-    (e: unknown) => notifyActionError(e, t("plex.watchedFailed")),
-    [t],
+    (e: unknown) => notifyActionError(e, msg("plex.watchedFailed")),
+    [],
   );
 
   const go = useCallback(
diff --git a/frontend/src/modules/plex/PlexPlaylistView.menu.dom.test.tsx b/frontend/src/modules/plex/PlexPlaylistView.menu.dom.test.tsx
index 5341dd5c..2aa52235 100644
--- a/frontend/src/modules/plex/PlexPlaylistView.menu.dom.test.tsx
+++ b/frontend/src/modules/plex/PlexPlaylistView.menu.dom.test.tsx
@@ -29,6 +29,7 @@ vi.mock("../../components/ui/confirmContext", () => ({ useConfirm: () => h.confi
 import PlexPlaylistView from "./PlexPlaylistView";
 import { api, type PlexCard } from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
+import { msg, type NotifText } from "../../lib/notifications";
 
 beforeAll(() => {
   class Stub {
@@ -98,8 +99,8 @@ const moreOf = (text: string) =>
   rowOf(text).querySelector<HTMLElement>('button[aria-label="plex.playlist.rowMenu"]')!;
 const toast = () =>
   h.notify.mock.calls
-    .map((c) => c[0] as { message: string; action?: { label: string; onClick: () => void } })
-    .filter((n) => n.message?.startsWith("plex.playlist.removedToast"))
+    .map((c) => c[0] as { message: NotifText; action?: { label: string; onClick: () => void } })
+    .filter((n) => "key" in n.message && n.message.key === "plex.playlist.removedToast")
     .pop();
 // The list's keys are live once its effect has registered it (`data-nav-list`), a passive effect that
 // can run AFTER the rows are on screen: a key pressed on a slow machine in between did nothing (CI flake).
@@ -181,7 +182,9 @@ describe("PlexPlaylistView · a row's menu", () => {
     await pick(() => fireEvent.contextMenu(rowOf("Movie 2")), "plex.playlist.removeFromPlaylist");
     await waitFor(() => expect(api.plexPlaylistRemoveItem).toHaveBeenCalledWith(5, "2"));
     expect(h.confirm).not.toHaveBeenCalled();
-    await waitFor(() => expect(toast()?.message).toBe("plex.playlist.removedToast:Movie 2"));
+    await waitFor(() =>
+      expect(toast()?.message).toEqual(msg("plex.playlist.removedToast", { title: "Movie 2" })),
+    );
     act(() => toast()!.action!.onClick());
     await waitFor(() => expect(add).toHaveBeenCalledWith(5, ["2"], [1]));
   });
@@ -208,7 +211,9 @@ describe("PlexPlaylistView · a row's menu", () => {
     const bulk = vi.spyOn(api, "plexPlaylistRemoveBulk").mockResolvedValue({} as never);
     await pick(() => fireEvent.click(moreOf("The Show")), "plex.playlist.removeShow");
     await waitFor(() => expect(bulk).toHaveBeenCalledWith(5, ["e1", "e2"]));
-    await waitFor(() => expect(toast()?.message).toBe("plex.playlist.removedToast:The Show"));
+    await waitFor(() =>
+      expect(toast()?.message).toEqual(msg("plex.playlist.removedToast", { title: "The Show" })),
+    );
   });
 
   it("removes one season from its label's menu", async () => {
@@ -349,7 +354,7 @@ describe("PlexPlaylistView · a failed watched toggle", () => {
     await pick(() => fireEvent.contextMenu(rowOf("Movie 2")), "plex.markWatched");
     await waitFor(() =>
       expect(h.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "error", title: "plex.watchedFailed" }),
+        expect.objectContaining({ level: "error", title: msg("plex.watchedFailed") }),
       ),
     );
     await act(async () => {});
diff --git a/frontend/src/modules/plex/PlexPlaylistView.tsx b/frontend/src/modules/plex/PlexPlaylistView.tsx
index def9d9b2..68d1d350 100644
--- a/frontend/src/modules/plex/PlexPlaylistView.tsx
+++ b/frontend/src/modules/plex/PlexPlaylistView.tsx
@@ -58,6 +58,7 @@ import { MEDIA_BADGE } from "../../components/ui/mediaCardStyles";
 import { seasonTitle } from "../../lib/plexDetail";
 import { cardImage } from "../../lib/plexImage";
 import RemoteImage from "../../components/ui/RemoteImage";
+import { msg } from "../../lib/notifications";
 
 // A playlist's items, grouped for readability: movies stay standalone, while a run of episodes from the
 // same show collapses into a season/show group so a whole series doesn't sprawl into an endless flat
@@ -459,7 +460,7 @@ export default function PlexPlaylistView({
     try {
       await api.plexRenamePlaylist(playlistId, title);
     } catch (e) {
-      notifyActionError(e, t("plex.playlist.renameFailed")); // the field stays open to try again
+      notifyActionError(e, msg("plex.playlist.renameFailed")); // the field stays open to try again
       return;
     }
     setRenaming(false);
@@ -479,7 +480,7 @@ export default function PlexPlaylistView({
       // Gone already (deleted on another device): what was asked for is true — leave the dead page.
       // Anything else is a real failure, and the page stays.
       if (!(e instanceof HttpError && e.status === 404)) {
-        notifyActionError(e, t("plex.playlist.deleteFailed"));
+        notifyActionError(e, msg("plex.playlist.deleteFailed"));
         return;
       }
     }
@@ -569,7 +570,7 @@ export default function PlexPlaylistView({
       onRestart: (c) => onPlay(c.id, order, true),
       onInfo: onInfoCard,
       onToggleWatched: (c) =>
-        void toggleWatchState(c, t, {
+        void toggleWatchState(c, {
           optimistic: (next) => setStatus(c.id, next),
           // The flip is on the view's LOCAL copy: a failed write's resync refetches an identical
           // list, react-query keeps the same `data`, and the copy is never re-seeded from it.
diff --git a/frontend/src/modules/plex/PlexSidebar.tsx b/frontend/src/modules/plex/PlexSidebar.tsx
index f6890a23..80ead6cd 100644
--- a/frontend/src/modules/plex/PlexSidebar.tsx
+++ b/frontend/src/modules/plex/PlexSidebar.tsx
@@ -22,6 +22,7 @@ import { usePlex, usePlexActions } from "./plexContext";
 import { DismissibleChip } from "../../components/ui/Chip";
 import { Input } from "../../components/ui/Input";
 import { useRail } from "../../lib/useRail";
+import { msg } from "../../lib/notifications";
 
 // The Plex module's left filter column — now the shared floating SidePanel with its filter groups
 // as reorderable "islands" (same system as the feed rail). Movie libraries get the full metadata
@@ -350,7 +351,7 @@ export function PlaylistPicker() {
       onOpenPlaylist(pl.id);
     } catch (e) {
       // Called without an await from the picker, so a refusal was an unhandled rejection.
-      notifyActionError(e, t("plex.playlistAdd.createFailed"));
+      notifyActionError(e, msg("plex.playlistAdd.createFailed"));
     }
   }
 
diff --git a/frontend/src/modules/plex/plexBrowseLists.tsx b/frontend/src/modules/plex/plexBrowseLists.tsx
index 16c91c1a..b54865d5 100644
--- a/frontend/src/modules/plex/plexBrowseLists.tsx
+++ b/frontend/src/modules/plex/plexBrowseLists.tsx
@@ -16,6 +16,7 @@ import { Button } from "../../components/ui/Button";
 import { IconButton } from "../../components/ui/IconButton";
 import { Input } from "../../components/ui/Input";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // A collection tile's sub-line: item count · total runtime (each dropped when unknown, e.g. show-only
 // collections have no movie runtime).
@@ -103,7 +104,7 @@ function NewCollectionPanel({
     } catch (e) {
       // The backend is authoritative on per-library name uniqueness — a taken name comes back
       // structured, and so localized (see localizeDetail).
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
       setBusy(false);
     }
   }
diff --git a/frontend/src/modules/plex/plexViews.tsx b/frontend/src/modules/plex/plexViews.tsx
index ea84d7ec..2ee74481 100644
--- a/frontend/src/modules/plex/plexViews.tsx
+++ b/frontend/src/modules/plex/plexViews.tsx
@@ -69,6 +69,7 @@ import { PageHeading } from "../../components/ui/Headings";
 import { vocab } from "../../lib/vocab";
 import { formatDate, formatDecimal } from "../../lib/format";
 import RemoteImage from "../../components/ui/RemoteImage";
+import { msg } from "../../lib/notifications";
 
 // The Plex sub-router's view branches, split out of PlexBrowse. Each is invoked by PlexBrowse with
 // shell callbacks as props (onBack/onPlay/onFilter/…) — no view reaches back into the shell's state,
@@ -209,7 +210,7 @@ export function PlexPersonView({
   // (both the movies and shows arrays — an id matches only one), then persist + resync via the shared
   // helper; also invalidate the library so its grid agrees.
   const toggle = (card: PlexCard) =>
-    toggleWatchState(card, t, {
+    toggleWatchState(card, {
       optimistic: (next) =>
         qc.setQueryData<PlexPersonDetail>(personKey, (old) =>
           old
@@ -500,7 +501,7 @@ export function PlexShowView({
     try {
       await api.plexShowState(showId, w);
     } catch (e) {
-      notifyActionError(e, t("plex.watchedFailed"));
+      notifyActionError(e, msg("plex.watchedFailed"));
     }
     setBusy(false);
     qc.invalidateQueries({ queryKey: qk.plexShow(showId) });
@@ -510,7 +511,7 @@ export function PlexShowView({
     try {
       await api.plexSeasonState(seasonRk, w);
     } catch (e) {
-      notifyActionError(e, t("plex.watchedFailed"));
+      notifyActionError(e, msg("plex.watchedFailed"));
     }
     qc.invalidateQueries({ queryKey: qk.plexShow(showId) });
     qc.invalidateQueries({ queryKey: qk.plexLibrary() });
@@ -836,7 +837,7 @@ export function PlexSeasonView({
     try {
       await api.plexSeasonState(seasonId, w);
     } catch (e) {
-      notifyActionError(e, t("plex.watchedFailed"));
+      notifyActionError(e, msg("plex.watchedFailed"));
     }
     setBusy(false);
     qc.invalidateQueries({ queryKey: qk.plexShow(showId) });
@@ -847,7 +848,7 @@ export function PlexSeasonView({
     try {
       await api.plexSetState(ep.id, next);
     } catch (e) {
-      notifyActionError(e, t("plex.watchedFailed"));
+      notifyActionError(e, msg("plex.watchedFailed"));
     }
     qc.invalidateQueries({ queryKey: qk.plexShow(showId) });
     qc.invalidateQueries({ queryKey: qk.plexLibrary() });
diff --git a/frontend/src/modules/plex/usePlayShow.dom.test.tsx b/frontend/src/modules/plex/usePlayShow.dom.test.tsx
index 9eec49d3..0eb2e312 100644
--- a/frontend/src/modules/plex/usePlayShow.dom.test.tsx
+++ b/frontend/src/modules/plex/usePlayShow.dom.test.tsx
@@ -17,6 +17,7 @@ vi.mock("react-i18next", async (importOriginal) => ({
 import { api, type PlexCard } from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
 import { usePlayShow } from "./usePlayShow";
+import { msg } from "../../lib/notifications";
 
 afterEach(() => {
   vi.restoreAllMocks();
@@ -106,7 +107,7 @@ describe("usePlayShow", () => {
     vi.spyOn(api, "plexShowNext").mockRejectedValue(new Error("down"));
     const { play, openShow, playShow } = mount();
     await act(() => playShow(show, false));
-    expect(notified).toHaveBeenCalledWith(expect.any(Error), "plex.playShowFailed");
+    expect(notified).toHaveBeenCalledWith(expect.any(Error), msg("plex.playShowFailed"));
     expect(play).not.toHaveBeenCalled();
     expect(openShow).not.toHaveBeenCalled();
   });
diff --git a/frontend/src/modules/plex/usePlayShow.ts b/frontend/src/modules/plex/usePlayShow.ts
index 8efadd59..3903a9e9 100644
--- a/frontend/src/modules/plex/usePlayShow.ts
+++ b/frontend/src/modules/plex/usePlayShow.ts
@@ -6,6 +6,7 @@ import { qk } from "../../lib/queryKeys";
 import { notifyActionError } from "../../lib/actionErrors";
 import { plexLang } from "../../i18n";
 import { useLatest } from "../../lib/useLatest";
+import { msg } from "../../lib/notifications";
 
 /** A show's card plays like any card: the episode in progress, else the first unwatched, else the
  *  first (`/show/{id}/next`). Asked fresh on the click, since the card's preview may hold an answer
@@ -25,7 +26,7 @@ export function usePlayShow(
   const asked = useRef(0);
   // Unmounted, nothing of it may navigate any more.
   useEffect(() => () => void ++asked.current, []);
-  const { t, i18n } = useTranslation();
+  const { i18n } = useTranslation();
   const lang = plexLang(i18n.language);
   // `undefined` when the question failed (said in the toast).
   const next = (id: string) =>
@@ -37,7 +38,7 @@ export function usePlayShow(
       })
       .then(
         (r) => r.next,
-        (e: unknown) => void notifyActionError(e, t("plex.playShowFailed")),
+        (e: unknown) => void notifyActionError(e, msg("plex.playShowFailed")),
       );
   return async (show: PlexCard, fromStart: boolean) => {
     const ask = ++asked.current;
diff --git a/frontend/src/modules/plex/usePlexPlaylistEdits.dom.test.tsx b/frontend/src/modules/plex/usePlexPlaylistEdits.dom.test.tsx
index ebdd3b24..f3edf9a0 100644
--- a/frontend/src/modules/plex/usePlexPlaylistEdits.dom.test.tsx
+++ b/frontend/src/modules/plex/usePlexPlaylistEdits.dom.test.tsx
@@ -15,7 +15,8 @@ vi.mock("react-i18next", async (importOriginal) => ({
 }));
 const { notify } = vi.hoisted(() => ({
   notify: vi.fn(
-    (_n: { level: string; message: string; action?: { label: string; onClick: () => void } }) => 0,
+    (_n: { level: string; message: NotifText; action?: { label: string; onClick: () => void } }) =>
+      0,
   ),
 }));
 vi.mock("../../lib/notifications", async (importOriginal) => ({
@@ -26,6 +27,7 @@ vi.mock("../../lib/notifications", async (importOriginal) => ({
 import { usePlexPlaylistEdits } from "./usePlexPlaylistEdits";
 import { api, type PlexCard } from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
+import { msg, type NotifText } from "../../lib/notifications";
 
 afterEach(() => {
   cleanup();
@@ -39,7 +41,7 @@ const ids = (items: PlexCard[]) => items.map((i) => i.id);
 const errors = () =>
   notify.mock.calls
     .filter(([n]) => n.level === "error")
-    .map(([n]) => (n as { title?: string }).title);
+    .map(([n]) => (n as { title?: NotifText }).title);
 
 function setup(items: PlexCard[]) {
   const qc = new QueryClient({ defaultOptions: { queries: { retry: false } } });
@@ -61,7 +63,7 @@ describe("usePlexPlaylistEdits · the reorder", () => {
 
     act(() => hook.result.current.commit([movie("3"), movie("1"), movie("2")]));
     expect(ids(hook.result.current.items)).toEqual(["3", "1", "2"]); // optimistic
-    await waitFor(() => expect(errors()).toEqual(["plex.playlist.reorderFailed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("plex.playlist.reorderFailed")]));
     expect(ids(hook.result.current.items)).toEqual(["1", "2", "3"]);
   });
 
@@ -112,7 +114,7 @@ describe("usePlexPlaylistEdits · the reorder", () => {
     await waitFor(() => expect(ids(hook.result.current.items)).toEqual(["1", "3"]));
     await act(async () => fail(new Error("offline")));
 
-    await waitFor(() => expect(errors()).toEqual(["plex.playlist.reorderFailed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("plex.playlist.reorderFailed")]));
     expect(ids(hook.result.current.items)).toEqual(["1", "3"]);
   });
 });
@@ -124,7 +126,7 @@ describe("usePlexPlaylistEdits · the removal", () => {
     vi.spyOn(api, "plexPlaylistRemoveItem").mockRejectedValue(new Error("offline"));
 
     await act(() => hook.result.current.onRemove(["2"], "Movie 2"));
-    expect(errors()).toEqual(["plex.playlist.removeFailed"]);
+    expect(errors()).toEqual([msg("plex.playlist.removeFailed")]);
     expect(ids(hook.result.current.items)).toEqual(["1", "2"]);
     expect(hook.result.current.busy).toBe(false);
     // A failed removal offers no Undo: there is nothing to put back.
@@ -144,7 +146,7 @@ describe("usePlexPlaylistEdits · the removal", () => {
     // A season whose episodes do not sit together: rows 2 and 4.
     await act(() => hook.result.current.onRemove(["4", "2"], "Show · Season 1"));
     const toast = notify.mock.calls.map(([n]) => n).find((n) => n.action)!;
-    expect(toast.message).toBe("plex.playlist.removedToast");
+    expect(toast.message).toEqual(msg("plex.playlist.removedToast", { title: "Show · Season 1" }));
     expect(toast.action!.label).toBe("common.undo");
     act(() => toast.action!.onClick());
     await waitFor(() => expect(add).toHaveBeenCalledTimes(1));
@@ -180,6 +182,6 @@ describe("usePlexPlaylistEdits · the removal", () => {
     await act(() => hook.result.current.onRemove(["1"], "Movie 1"));
     const toast = notify.mock.calls.map(([n]) => n).find((n) => n.action)!;
     act(() => toast.action!.onClick());
-    await waitFor(() => expect(errors()).toEqual(["plex.playlist.undoRemoveFailed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("plex.playlist.undoRemoveFailed")]));
   });
 });
diff --git a/frontend/src/modules/plex/usePlexPlaylistEdits.ts b/frontend/src/modules/plex/usePlexPlaylistEdits.ts
index a80d3209..d09971b7 100644
--- a/frontend/src/modules/plex/usePlexPlaylistEdits.ts
+++ b/frontend/src/modules/plex/usePlexPlaylistEdits.ts
@@ -5,7 +5,7 @@ import { useQuery, useQueryClient } from "@tanstack/react-query";
 import { plexLang } from "../../i18n";
 import { api, type PlexCard } from "../../lib/api";
 import { notifyActionError } from "../../lib/actionErrors";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { reinsertAt } from "../../lib/reinsert";
 
@@ -79,7 +79,7 @@ export function usePlexPlaylistEdits(playlistId: number) {
         qc.invalidateQueries({ queryKey: qk.plexPlaylists() });
       })
       .catch((e: unknown) => {
-        notifyActionError(e, t("plex.playlist.reorderFailed"));
+        notifyActionError(e, msg("plex.playlist.reorderFailed"));
         putBack();
       });
   }
@@ -102,7 +102,7 @@ export function usePlexPlaylistEdits(playlistId: number) {
       else await api.plexPlaylistRemoveBulk(playlistId, keys);
       invalidate();
     } catch (e) {
-      notifyActionError(e, t("plex.playlist.removeFailed"));
+      notifyActionError(e, msg("plex.playlist.removeFailed"));
       putBack();
       removed = false;
     }
@@ -110,7 +110,7 @@ export function usePlexPlaylistEdits(playlistId: number) {
     if (!removed) return;
     notify({
       level: "success",
-      message: t("plex.playlist.removedToast", { title }),
+      message: msg("plex.playlist.removedToast", { title }),
       action: {
         label: t("common.undo"),
         onClick: () =>
@@ -129,7 +129,7 @@ export function usePlexPlaylistEdits(playlistId: number) {
               if (back.keys.length)
                 return api.plexPlaylistAddBulk(playlistId, back.keys, back.positions);
             })
-            .catch((e: unknown) => notifyActionError(e, t("plex.playlist.undoRemoveFailed")))
+            .catch((e: unknown) => notifyActionError(e, msg("plex.playlist.undoRemoveFailed")))
             .finally(invalidate),
       },
     });
diff --git a/frontend/src/modules/scheduler/Scheduler.tsx b/frontend/src/modules/scheduler/Scheduler.tsx
index f3f708d5..8a5355d1 100644
--- a/frontend/src/modules/scheduler/Scheduler.tsx
+++ b/frontend/src/modules/scheduler/Scheduler.tsx
@@ -31,7 +31,7 @@ import { Button } from "../../components/ui/Button";
 import { LoadingState, StateMessage } from "../../components/ui/QueryState";
 import { useConfirm } from "../../components/ui/confirmContext";
 import { formatDateTime, formatNumber, formatUnit, relativeTime } from "../../lib/format";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import Tooltip from "../../components/ui/Tooltip";
 import { notifyActionError } from "../../lib/actionErrors";
 import { IconButton } from "../../components/ui/IconButton";
@@ -550,14 +550,14 @@ export default function Scheduler() {
   const pauseResume = useMutation({
     mutationFn: (paused: boolean) => (paused ? api.resumeSync() : api.pauseSync()),
     onSuccess: () => qc.invalidateQueries({ queryKey: qk.scheduler() }),
-    onError: (e) => notifyActionError(e, t("scheduler.toggleFailed")),
+    onError: (e) => notifyActionError(e, msg("scheduler.toggleFailed")),
   });
 
   const intervalMut = useMutation({
     mutationFn: (v: { jobId: string; minutes: number }) =>
       api.updateSchedulerJob(v.jobId, v.minutes),
     onSuccess: () => qc.invalidateQueries({ queryKey: qk.scheduler() }),
-    onError: (e) => notifyActionError(e, t("scheduler.intervalFailed")),
+    onError: (e) => notifyActionError(e, msg("scheduler.intervalFailed")),
   });
 
   // Manual "run now" triggers. The wrapper runs in a background thread server-side; the
@@ -568,7 +568,9 @@ export default function Scheduler() {
     onSuccess: (_d, jobId) => {
       notify({
         level: "success",
-        message: t("scheduler.triggered", { job: t(`scheduler.jobs.${jobId}`, jobId) }),
+        message: msg("scheduler.triggered", {
+          job: msg(`scheduler.jobs.${jobId}`, { defaultValue: jobId }),
+        }),
       });
       qc.invalidateQueries({ queryKey: qk.scheduler() });
     },
@@ -579,7 +581,7 @@ export default function Scheduler() {
     onSuccess: (res) => {
       notify({
         level: "success",
-        message: t("scheduler.triggeredAll", { count: res.started.length }),
+        message: msg("scheduler.triggeredAll", { count: res.started.length }),
       });
       qc.invalidateQueries({ queryKey: qk.scheduler() });
     },
@@ -595,7 +597,7 @@ export default function Scheduler() {
     onSuccess: (res) => {
       const removed =
         (res.search_videos_deleted ?? 0) + (res.videos_deleted ?? 0) + (res.channels_deleted ?? 0);
-      notify({ level: "success", message: t("scheduler.purgedDiscovery", { count: removed }) });
+      notify({ level: "success", message: msg("scheduler.purgedDiscovery", { count: removed }) });
       qc.invalidateQueries({ queryKey: qk.scheduler() });
     },
   });
diff --git a/frontend/src/modules/settings/MyLogViewer.tsx b/frontend/src/modules/settings/MyLogViewer.tsx
index b906c9c7..e600af0d 100644
--- a/frontend/src/modules/settings/MyLogViewer.tsx
+++ b/frontend/src/modules/settings/MyLogViewer.tsx
@@ -12,7 +12,7 @@ import {
   type LevelGroup as Filter,
   type LogEvent,
 } from "../../lib/log";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import LogLine from "../../features/diagnostics/LogLine";
 import NavGrid from "../../components/ui/NavGrid";
 import { Button } from "../../components/ui/Button";
@@ -115,8 +115,8 @@ export default function MyLogViewer() {
     const ok = await copyText(text);
     notify(
       ok
-        ? { level: "success", message: t("settings.myLog.copied", { count: shown.length }) }
-        : { level: "error", message: t("settings.myLog.copyFailed") },
+        ? { level: "success", message: msg("settings.myLog.copied", { count: shown.length }) }
+        : { level: "error", message: msg("settings.myLog.copyFailed") },
     );
   };
 
diff --git a/frontend/src/modules/settings/SettingsPanel.tsx b/frontend/src/modules/settings/SettingsPanel.tsx
index dc14ec49..59254aa4 100644
--- a/frontend/src/modules/settings/SettingsPanel.tsx
+++ b/frontend/src/modules/settings/SettingsPanel.tsx
@@ -29,7 +29,7 @@ import { LS, useTabPersistedState } from "../../lib/storage";
 import { SETTINGS_TAB_KEY, settingsTabParams } from "../../lib/settingsTab";
 import { useUrlMirror } from "../../lib/useUrlMirror";
 import Avatar from "../../components/ui/Avatar";
-import { notify, type NotifSettings } from "../../lib/notifications";
+import { msg, type NotifSettings, notify } from "../../lib/notifications";
 import Tooltip from "../../components/ui/Tooltip";
 import { Section, SwitchRow } from "../../components/ui/form";
 import { Badge } from "../../components/ui/Badge";
@@ -297,8 +297,8 @@ function Notifications({ prefs }: { prefs: PrefsController }) {
         onClick={() =>
           notify({
             level: "info",
-            title: t("settings.notifications.testTitle"),
-            message: t("settings.notifications.testMessage"),
+            title: msg("settings.notifications.testTitle"),
+            message: msg("settings.notifications.testMessage"),
             sound: true,
           })
         }
@@ -379,9 +379,9 @@ export function SignInMethods({ me }: { me: Me }) {
       // Every API token went with the other sessions: the Tokens tab asks again when it next opens,
       // rather than trusting its cached list for another half minute.
       void qc.invalidateQueries({ queryKey: qk.apiTokens() });
-      notify({ level: "success", message: t("settings.account.sessions.done") });
+      notify({ level: "success", message: msg("settings.account.sessions.done") });
     } catch (e) {
-      notifyActionError(e, t("settings.account.sessions.failed"));
+      notifyActionError(e, msg("settings.account.sessions.failed"));
     }
     setSessBusy(false);
   };
@@ -402,7 +402,7 @@ export function SignInMethods({ me }: { me: Me }) {
       await qc.invalidateQueries({ queryKey: qk.me() });
       notify({
         level: "success",
-        message: t("settings.account.password.saved", { email: me.email }),
+        message: msg("settings.account.password.saved", { email: me.email }),
       });
     } catch (e) {
       setErr(
@@ -540,7 +540,7 @@ function PlexWatchSync() {
     if (imp) {
       notify({
         level: "success",
-        message: t("settings.plexSync.imported", {
+        message: msg("settings.plexSync.imported", {
           watched: imp.watched,
           in_progress: imp.in_progress,
         }),
@@ -640,7 +640,7 @@ export function DownloadAuth() {
       qc.setQueryData(qk.downloadCredentials(), res);
       setOpenHost(null);
       setDraft("");
-      notify({ level: "success", message: t("settings.downloadAuth.saved") });
+      notify({ level: "success", message: msg("settings.downloadAuth.saved") });
     },
     // Validation errors (empty / not-a-cookies.txt) surface via the global error modal, which
     // localizes the structured { code: "cookies" } detail (see lib/api core localizeDetail); the
@@ -652,7 +652,7 @@ export function DownloadAuth() {
     meta: { failTitle: "errors.writeFailed.downloadCookiesRemove" },
     onSuccess: (res) => {
       qc.setQueryData(qk.downloadCredentials(), res);
-      notify({ level: "success", message: t("settings.downloadAuth.removed") });
+      notify({ level: "success", message: msg("settings.downloadAuth.removed") });
     },
   });
 
@@ -837,7 +837,7 @@ function Account({ me, onOpenWizard }: { me: Me; onOpenWizard: () => void }) {
     } catch (e) {
       // A refusal with a reason (the last admin, a 409) is already in the global error dialog, which
       // the reporter skips; anything else used to end the confirmed delete with nothing said.
-      notifyActionError(e, t("errors.writeFailed.deleteAccount"));
+      notifyActionError(e, msg("errors.writeFailed.deleteAccount"));
     }
   };
   return (
diff --git a/frontend/src/modules/settings/TakeoutImport.dom.test.tsx b/frontend/src/modules/settings/TakeoutImport.dom.test.tsx
index 88701b94..61ffc4cc 100644
--- a/frontend/src/modules/settings/TakeoutImport.dom.test.tsx
+++ b/frontend/src/modules/settings/TakeoutImport.dom.test.tsx
@@ -10,14 +10,16 @@ import { act, cleanup, fireEvent, render, screen, waitFor } from "@testing-libra
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { api, HttpError, type TakeoutStatus, type TakeoutUpload } from "../../lib/api";
 
-const mocks = vi.hoisted(() => ({ notify: vi.fn(), notifyActionError: vi.fn() }));
+const mocks = vi.hoisted(() => ({
+  notify: vi.fn(),
+  notifyActionError: vi.fn(),
+  // The values ride along, so an assertion can see what each said.
+  t: (key: string, o?: Record<string, unknown>) =>
+    o && Object.keys(o).length ? `${key}(${Object.values(o).join(",")})` : key,
+}));
 vi.mock("react-i18next", async (importOriginal) => ({
   ...(await importOriginal<typeof import("react-i18next")>()),
-  useTranslation: () => ({
-    i18n: { language: "en" },
-    t: (key: string, o?: Record<string, unknown>) =>
-      o && Object.keys(o).length ? `${key}(${Object.values(o).join(",")})` : key,
-  }),
+  useTranslation: () => ({ i18n: { language: "en" }, t: mocks.t }),
 }));
 vi.mock("../../lib/notifications", async (importOriginal) => ({
   ...(await importOriginal<typeof import("../../lib/notifications")>()),
@@ -29,7 +31,9 @@ vi.mock("../../lib/format", async (importOriginal) => ({
   formatDateTime: (iso: string) => `at ${iso}`,
 }));
 
+import type { TFunction } from "i18next";
 import TakeoutImport from "./TakeoutImport";
+import { msg, sayNotif, type NotifText } from "../../lib/notifications";
 
 afterEach(() => {
   cleanup();
@@ -184,13 +188,16 @@ describe("YouTube history import · the upload", () => {
 
     await waitFor(() => expect(line()).toContain("settings.takeout.count.watched(7,7)"));
     expect(sent).toEqual(["watch-history.json", "bad.html", "Watch later-videos.csv"]);
-    expect(mocks.notify.mock.calls.map(([n]) => (n as { message: string }).message)).toEqual([
+    // What each notice says, said by the same `t` the page speaks.
+    const said = (n: unknown) =>
+      sayNotif((n as { message: NotifText }).message, mocks.t as TFunction);
+    expect(mocks.notify.mock.calls.map(([n]) => said(n))).toEqual([
       "settings.takeout.read(watch-history.json,9034,9,034)",
       "settings.takeout.read(Watch later-videos.csv,56,56)",
     ]);
     expect(mocks.notifyActionError).toHaveBeenCalledWith(
       refused,
-      "errors.writeFailed.takeoutUpload",
+      msg("errors.writeFailed.takeoutUpload"),
     );
   });
 
@@ -274,8 +281,14 @@ describe("YouTube history import · while it runs", () => {
     expect(send).not.toHaveBeenCalled();
     expect(mocks.notify).toHaveBeenCalledWith({
       level: "error",
-      message: "settings.takeout.tooLarge(watch-history.json,10 B)",
+      message: msg("settings.takeout.tooLarge", {
+        name: "watch-history.json",
+        limit: { bytes: 10 },
+      }),
     });
+    expect(sayNotif(mocks.notify.mock.calls[0]![0].message, mocks.t as TFunction)).toBe(
+      "settings.takeout.tooLarge(watch-history.json,10 B)",
+    );
     // Nothing was taken: the zone stays open for the right file, and so after a refusal.
     await waitFor(() => expect(zone()).toBeTruthy());
     send.mockRejectedValue(new HttpError(422, "refused"));
diff --git a/frontend/src/modules/settings/TakeoutImport.tsx b/frontend/src/modules/settings/TakeoutImport.tsx
index 9bab8821..e2cf53ac 100644
--- a/frontend/src/modules/settings/TakeoutImport.tsx
+++ b/frontend/src/modules/settings/TakeoutImport.tsx
@@ -9,9 +9,9 @@ import { StateMessage } from "../../components/ui/QueryState";
 import { api, type TakeoutStatus, type TakeoutUpload } from "../../lib/api";
 import type { TAKEOUT_OUTCOMES } from "../../lib/api/feed";
 import { qk } from "../../lib/queryKeys";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
-import { formatBytes, formatDateTime, formatNumber } from "../../lib/format";
+import { formatDateTime, formatNumber } from "../../lib/format";
 import { importBusy, invalidateImported, watchTakeout } from "./takeoutWatch";
 
 // Settings › Account: the user's Google Takeout export, imported. What they watched on YouTube and
@@ -129,7 +129,7 @@ export default function TakeoutImport() {
       // Refused here, not after minutes of upload, and with the limit named.
       notify({
         level: "error",
-        message: t("settings.takeout.tooLarge", { name: file.name, limit: formatBytes(max, lang) }),
+        message: msg("settings.takeout.tooLarge", { name: file.name, limit: { bytes: max } }),
       });
       return false;
     }
@@ -139,15 +139,15 @@ export default function TakeoutImport() {
       res = await api.takeoutUpload(file);
     } catch (e) {
       // A refusal names its reason (not a Takeout file, nothing in it); the next file still goes.
-      notifyActionError(e, t("errors.writeFailed.takeoutUpload"));
+      notifyActionError(e, msg("errors.writeFailed.takeoutUpload"));
     }
     if (res === null) return false;
     notify({
       level: "success",
-      message: t("settings.takeout.read", {
+      message: msg("settings.takeout.read", {
         name: file.name,
         count: res.videos,
-        n: formatNumber(res.videos, lang),
+        n: { number: res.videos },
       }),
     });
     return true;
diff --git a/frontend/src/modules/stats/Stats.tsx b/frontend/src/modules/stats/Stats.tsx
index 17cdd932..8f742aa3 100644
--- a/frontend/src/modules/stats/Stats.tsx
+++ b/frontend/src/modules/stats/Stats.tsx
@@ -4,7 +4,7 @@ import { qk } from "../../lib/queryKeys";
 import { History, RefreshCw } from "lucide-react";
 import { api } from "../../lib/api";
 import { formatEta, formatNumber, quotaActionLabel } from "../../lib/format";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { useWizard } from "../../features/wizard/wizardContext";
 import Tooltip from "../../components/ui/Tooltip";
@@ -43,7 +43,7 @@ function Overview() {
       qc.invalidateQueries({ queryKey: qk.channels() });
       notify({
         level: "success",
-        message: t("stats.sync.synced", { count: r.subscriptions ?? 0 }),
+        message: msg("stats.sync.synced", { count: r.subscriptions ?? 0 }),
       });
     },
     // The same helper and the same wizard handle as the Channels page: it translates the 403 into
@@ -51,7 +51,7 @@ function Overview() {
     // English detail under a Hungarian UI — and delegates everything else to notifyActionError so
     // the server's own reason wins, which is what makes the SEC-14 cooldown read as a pace limit
     // rather than "Sync failed".
-    onError: (e) => notifyYouTubeActionError(e, t("stats.sync.syncFailed"), openWizard),
+    onError: (e) => notifyYouTubeActionError(e, msg("stats.sync.syncFailed"), openWizard),
   });
   const deepAll = useMutation({
     mutationFn: () => api.deepAll(true),
@@ -60,10 +60,10 @@ function Overview() {
       qc.invalidateQueries({ queryKey: qk.channels() });
       notify({
         level: "success",
-        message: t("stats.sync.fullHistoryRequested", { count: r.updated ?? 0 }),
+        message: msg("stats.sync.fullHistoryRequested", { count: r.updated ?? 0 }),
       });
     },
-    onError: (e) => notifyActionError(e, t("stats.sync.fullHistoryFailed")),
+    onError: (e) => notifyActionError(e, msg("stats.sync.fullHistoryFailed")),
   });
 
   return (
diff --git a/frontend/src/modules/users/AccountPanel.tsx b/frontend/src/modules/users/AccountPanel.tsx
index 4fe459e7..63725276 100644
--- a/frontend/src/modules/users/AccountPanel.tsx
+++ b/frontend/src/modules/users/AccountPanel.tsx
@@ -7,7 +7,7 @@ import { LoadingState, StateMessage } from "../../components/ui/QueryState";
 import { api } from "../../lib/api";
 import { displayName } from "../../lib/api/account";
 import { qk } from "../../lib/queryKeys";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { formatDateTime } from "../../lib/format";
 import { invalidateUserAccess } from "../../lib/adminUsers";
@@ -73,19 +73,19 @@ export default function AccountPanel({
   const issue = useMutation({
     mutationFn: () => api.createSetPasswordLink(user.id),
     onSuccess: (r) => setLink({ url: r.url, expires_at: r.expires_at }),
-    onError: (err) => notifyActionError(err, t("users.account.linkFailed")),
+    onError: (err) => notifyActionError(err, msg("users.account.linkFailed")),
   });
 
   const resend = useMutation({
     mutationFn: () => api.resendUserVerification(user.id),
-    onSuccess: () => notify({ level: "success", message: t("users.account.resendSent") }),
-    onError: (err) => notifyActionError(err, t("users.pendingAccess.resendFailed")),
+    onSuccess: () => notify({ level: "success", message: msg("users.account.resendSent") }),
+    onError: (err) => notifyActionError(err, msg("users.pendingAccess.resendFailed")),
   });
 
   const activate = useMutation({
     mutationFn: () => api.activateUser(user.id),
     onSuccess: () => invalidateUserAccess(qc, user.id),
-    onError: (err) => notifyActionError(err, t("users.pendingAccess.activateFailed")),
+    onError: (err) => notifyActionError(err, msg("users.pendingAccess.activateFailed")),
   });
 
   // Via the shared helper, whose synchronous `execCommand` path is what makes copying work on a
diff --git a/frontend/src/modules/users/AdminUsers.dom.test.tsx b/frontend/src/modules/users/AdminUsers.dom.test.tsx
index b1506036..4fbb808f 100644
--- a/frontend/src/modules/users/AdminUsers.dom.test.tsx
+++ b/frontend/src/modules/users/AdminUsers.dom.test.tsx
@@ -26,7 +26,7 @@ vi.mock("../../lib/useMe", () => ({
 }));
 vi.mock("../../components/ui/confirmContext", () => ({ useConfirm: () => async () => true }));
 const { notify } = vi.hoisted(() => ({
-  notify: vi.fn((_n: { level: string; message: string }) => 0),
+  notify: vi.fn((_n: { level: string; title?: NotifText; message: NotifText }) => 0),
 }));
 vi.mock("../../lib/notifications", async (importOriginal) => ({
   ...(await importOriginal<typeof import("../../lib/notifications")>()),
@@ -39,6 +39,7 @@ import { PageToolbarSlot } from "../../components/ui/pageToolbarSlot";
 import { api, type AdminUserRow } from "../../lib/api";
 import { relativeTime } from "../../lib/format";
 import i18n from "../../i18n";
+import { msg, sayNotif, type NotifText } from "../../lib/notifications";
 
 const row = {
   id: 2,
@@ -175,10 +176,12 @@ describe("a user action that fails", () => {
     await waitFor(() =>
       expect(notify).toHaveBeenCalledWith({
         level: "error",
-        title: "users.roles.failed", // what failed…
-        message: i18n.t("errors.notFound.user"), // …and why: the request layer localizes a structured detail
+        title: msg("users.roles.failed"), // what failed…
+        message: { detail: { code: "not_found", reason: "user" } }, // …and why: the server's refusal
       }),
     );
+    // …said in the reader's language when it is shown.
+    expect(sayNotif(notify.mock.lastCall![0].message)).toBe(i18n.t("errors.notFound.user"));
     await waitFor(() => expect(users).toHaveBeenCalledTimes(2));
   });
 
diff --git a/frontend/src/modules/users/AdminUsers.tsx b/frontend/src/modules/users/AdminUsers.tsx
index 8c5a39e5..ec6f627a 100644
--- a/frontend/src/modules/users/AdminUsers.tsx
+++ b/frontend/src/modules/users/AdminUsers.tsx
@@ -24,7 +24,7 @@ import {
   type PendingAccessRow,
 } from "../../lib/api";
 import { displayName } from "../../lib/api/account";
-import { notify } from "../../lib/notifications";
+import { msg, type NotifText, notify } from "../../lib/notifications";
 import { formatDateTime, relativeTime } from "../../lib/format";
 import { invalidateUserAccess } from "../../lib/adminUsers";
 import { ADMIN_USERS_TAB_KEY, USERS_TAB_URL_KEY, usersTabParams } from "../../lib/adminUsersTab";
@@ -134,7 +134,7 @@ function UsersRoles({ me }: { me: Me }) {
   // A failed user action: said once (notifyActionError skips what `req` already put in its dialog),
   // and the list refetched — a user deleted in another tab would otherwise stay listed, every click
   // on the row doing nothing.
-  const onGoneOrFailed = (e: unknown, fallback: string) => {
+  const onGoneOrFailed = (e: unknown, fallback: NotifText) => {
     notifyActionError(e, fallback);
     qc.invalidateQueries({ queryKey: qk.adminUsers() });
   };
@@ -144,12 +144,12 @@ function UsersRoles({ me }: { me: Me }) {
     onMutate: (vars) => startPending(vars.id),
     onSuccess: (_d, vars) => {
       qc.invalidateQueries({ queryKey: qk.adminUsers() });
-      notify({ level: "success", message: t("users.roles.updated", { email: vars.email }) });
+      notify({ level: "success", message: msg("users.roles.updated", { email: vars.email }) });
     },
     onSettled: (_d, _e, vars) => endPending(vars.id),
     // Guards (last admin / self) surface via the global error dialog with the server's detail; what
     // it does not show (a user deleted meanwhile, a 404) is said here — see onGoneOrFailed.
-    onError: (e) => onGoneOrFailed(e, t("users.roles.failed")),
+    onError: (e) => onGoneOrFailed(e, msg("users.roles.failed")),
   });
 
   const suspend = useMutation({
@@ -160,24 +160,24 @@ function UsersRoles({ me }: { me: Me }) {
       qc.invalidateQueries({ queryKey: qk.adminUsers() });
       notify({
         level: "success",
-        message: t(vars.suspended ? "users.suspend.done" : "users.suspend.undone", {
+        message: msg(vars.suspended ? "users.suspend.done" : "users.suspend.undone", {
           email: vars.email,
         }),
       });
     },
     onSettled: (_d, _e, vars) => endPending(vars.id),
     // Guards (self / last admin) surface via the global error dialog; the rest, as above.
-    onError: (e) => onGoneOrFailed(e, t("users.suspend.failed")),
+    onError: (e) => onGoneOrFailed(e, msg("users.suspend.failed")),
   });
   const del = useMutation({
     mutationFn: ({ id }: { id: number; email: string }) => api.adminDeleteUser(id),
     onMutate: (vars) => startPending(vars.id),
     onSuccess: (_d, vars) => {
       qc.invalidateQueries({ queryKey: qk.adminUsers() });
-      notify({ level: "success", message: t("users.delete.done", { email: vars.email }) });
+      notify({ level: "success", message: msg("users.delete.done", { email: vars.email }) });
     },
     onSettled: (_d, _e, vars) => endPending(vars.id),
-    onError: (e) => onGoneOrFailed(e, t("users.delete.failed")),
+    onError: (e) => onGoneOrFailed(e, msg("users.delete.failed")),
   });
 
   const onToggle = async (u: AdminUserRow) => {
@@ -367,20 +367,23 @@ function PendingAccess() {
     mutationFn: (u: PendingAccessRow) => api.activateUser(u.id),
     onSuccess: (_r, u) => {
       refresh();
-      notify({ level: "success", message: t("users.pendingAccess.activated", { email: u.email }) });
+      notify({
+        level: "success",
+        message: msg("users.pendingAccess.activated", { email: u.email }),
+      });
     },
-    onError: (err) => notifyActionError(err, t("users.pendingAccess.activateFailed")),
+    onError: (err) => notifyActionError(err, msg("users.pendingAccess.activateFailed")),
   });
 
   const resend = useMutation({
     mutationFn: (u: PendingAccessRow) => api.resendUserVerification(u.id),
     onSuccess: (_r, u) => {
       refresh();
-      notify({ level: "success", message: t("users.pendingAccess.resent", { email: u.email }) });
+      notify({ level: "success", message: msg("users.pendingAccess.resent", { email: u.email }) });
     },
     // The public resend is deliberately silent; this one is not, and the server's reason says WHY
     // (no working SMTP, a refused send) — a success toast for a mail never sent would be the lie.
-    onError: (err) => notifyActionError(err, t("users.pendingAccess.resendFailed")),
+    onError: (err) => notifyActionError(err, msg("users.pendingAccess.resendFailed")),
   });
 
   const list = rows.data ?? [];
@@ -543,17 +546,20 @@ function AdminInvites() {
     mutationFn: ({ id }: { id: number; email: string }) => api.approveInvite(id),
     onSuccess: (_d, vars) => {
       refresh();
-      notify({ level: "success", message: t("settings.invites.approved", { email: vars.email }) });
+      notify({
+        level: "success",
+        message: msg("settings.invites.approved", { email: vars.email }),
+      });
     },
-    onError: (e) => notifyActionError(e, t("settings.invites.approveFailed")),
+    onError: (e) => notifyActionError(e, msg("settings.invites.approveFailed")),
   });
   const deny = useMutation({
     mutationFn: (id: number) => api.denyInvite(id),
     onSuccess: (_d, _id) => {
       refresh();
-      notify({ level: "success", message: t("settings.invites.denied") });
+      notify({ level: "success", message: msg("settings.invites.denied") });
     },
-    onError: (e) => notifyActionError(e, t("settings.invites.denyFailed")),
+    onError: (e) => notifyActionError(e, msg("settings.invites.denyFailed")),
   });
   const onDeny = async (i: { id: number; email: string }) => {
     const ok = await confirm({
@@ -571,15 +577,15 @@ function AdminInvites() {
       // Removing the row is not always a revoke: is_allowed falls back to the env allow-lists, so
       // for an address on those the person keeps access. Saying "removed" alone would mislead.
       if (d.still_allowed_by_env)
-        notify({ level: "warning", message: t("settings.invites.deletedStillAllowed") });
-      else notify({ level: "success", message: t("settings.invites.deleted") });
+        notify({ level: "warning", message: msg("settings.invites.deletedStillAllowed") });
+      else notify({ level: "success", message: msg("settings.invites.deleted") });
     },
     onError: (e) => {
       // A 409 means the list was stale — someone registered on that address since it loaded. Say
       // what to do instead of a generic failure, and refetch so the row re-renders as read-only.
       const conflict = e instanceof HttpError && e.status === 409;
-      if (conflict) notifyKnownFailure(e, t("settings.invites.deleteHasAccount"));
-      else notifyActionError(e, t("settings.invites.deleteFailed"));
+      if (conflict) notifyKnownFailure(e, msg("settings.invites.deleteHasAccount"));
+      else notifyActionError(e, msg("settings.invites.deleteFailed"));
       if (conflict) refresh();
     },
   });
@@ -607,9 +613,12 @@ function AdminInvites() {
     mutationFn: (v: { inv: Invite; lang: LangCode }) => api.sendInvitation(v.inv.id, v.lang),
     onSuccess: (_r, v) => {
       refresh();
-      notify({ level: "success", message: t("settings.invites.invited", { email: v.inv.email }) });
+      notify({
+        level: "success",
+        message: msg("settings.invites.invited", { email: v.inv.email }),
+      });
     },
-    onError: (err) => notifyActionError(err, t("settings.invites.inviteFailed")),
+    onError: (err) => notifyActionError(err, msg("settings.invites.inviteFailed")),
   });
   // The one recipient the app has no language signal about: the admin typed this address in, so
   // nobody ever told us how to write to its owner. The dialog is where that gets decided — and it
@@ -648,9 +657,9 @@ function AdminInvites() {
     onSuccess: (_d, email) => {
       setNewEmail("");
       refresh();
-      notify({ level: "success", message: t("settings.invites.addedToWhitelist", { email }) });
+      notify({ level: "success", message: msg("settings.invites.addedToWhitelist", { email }) });
     },
-    onError: (e) => notifyActionError(e, t("settings.invites.addFailed")),
+    onError: (e) => notifyActionError(e, msg("settings.invites.addFailed")),
   });
 
   const list = invites.data ?? [];
diff --git a/frontend/src/modules/users/accountPanel.dom.test.tsx b/frontend/src/modules/users/accountPanel.dom.test.tsx
index d1307d02..f10cf45b 100644
--- a/frontend/src/modules/users/accountPanel.dom.test.tsx
+++ b/frontend/src/modules/users/accountPanel.dom.test.tsx
@@ -13,6 +13,7 @@
 import { describe, it, expect, afterEach, beforeEach, vi } from "vitest";
 import { render, screen, cleanup, waitFor, fireEvent } from "@testing-library/react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import type { NotifText } from "../../lib/notifications";
 
 vi.mock("react-i18next", async (importOriginal) => {
   const actual = await importOriginal<typeof import("react-i18next")>();
@@ -51,6 +52,8 @@ vi.mock("../../lib/api", async (importOriginal) => {
 });
 
 const { HttpError } = await import("../../lib/api");
+const { msg, sayNotif } = await import("../../lib/notifications");
+const i18n = (await import("../../i18n")).default;
 const AccountPanel = (await import("./AccountPanel")).default;
 
 const user = {
@@ -90,7 +93,7 @@ afterEach(cleanup);
 // it), else the specific sentence (the no-mail case).
 const errorMessages = () =>
   notifyMock.mock.calls
-    .map(([a]) => a as { level?: string; title?: string; message?: string })
+    .map(([a]) => a as { level?: string; title?: NotifText; message?: NotifText })
     .filter((a) => a.level === "error")
     .map((a) => a.title ?? a.message);
 
@@ -100,13 +103,13 @@ describe("the account panel reports a refused recovery action", () => {
 
     await clickAction("users.account.setPassword");
 
-    await waitFor(() => expect(errorMessages()).toContain("users.account.linkFailed"));
+    await waitFor(() => expect(errorMessages()).toContainEqual(msg("users.account.linkFailed")));
     // …and no link block was rendered, so the toast is the only thing that happened.
     expect(screen.queryByText("users.account.copy")).toBeNull();
   });
 
   it("names the no-mail case, so a no-SMTP instance does not read as a bug", async () => {
-    // `req` has already localized the refusal into `detail` (lib/api/core); the toast carries it.
+    // The toast carries the refusal itself, said in the reader's language when it is shown.
     apiMock.resendUserVerification.mockRejectedValue(
       new HttpError(409, "errors.admin.email_off", { code: "resend", reason: "email_off" }),
     );
@@ -116,11 +119,14 @@ describe("the account panel reports a refused recovery action", () => {
     await waitFor(() =>
       expect(notifyMock).toHaveBeenCalledWith(
         expect.objectContaining({
-          title: "users.pendingAccess.resendFailed",
-          message: "errors.admin.email_off",
+          title: msg("users.pendingAccess.resendFailed"),
+          message: { detail: { code: "resend", reason: "email_off" } },
         }),
       ),
     );
+    // …which says the no-mail sentence, not a generic failure.
+    const [shown] = notifyMock.mock.lastCall as [{ message: NotifText }];
+    expect(sayNotif(shown.message)).toBe(i18n.t("errors.admin.email_off"));
   });
 
   it("reports a genuine send failure as a failure, not as a sent mail", async () => {
@@ -130,11 +136,13 @@ describe("the account panel reports a refused recovery action", () => {
 
     await clickAction("users.account.resend");
 
-    await waitFor(() => expect(errorMessages()).toContain("users.pendingAccess.resendFailed"));
-    // The success toast must NOT also fire — that is the exact lie the backend guards against.
-    expect(notifyMock.mock.calls.map(([a]) => (a as { message?: string }).message)).not.toContain(
-      "users.account.resendSent",
+    await waitFor(() =>
+      expect(errorMessages()).toContainEqual(msg("users.pendingAccess.resendFailed")),
     );
+    // The success toast must NOT also fire — that is the exact lie the backend guards against.
+    expect(
+      notifyMock.mock.calls.map(([a]) => (a as { message?: NotifText }).message),
+    ).not.toContainEqual(msg("users.account.resendSent"));
   });
 
   it("reports a refused activation", async () => {
@@ -144,6 +152,8 @@ describe("the account panel reports a refused recovery action", () => {
 
     await clickAction("users.account.activate");
 
-    await waitFor(() => expect(errorMessages()).toContain("users.pendingAccess.activateFailed"));
+    await waitFor(() =>
+      expect(errorMessages()).toContainEqual(msg("users.pendingAccess.activateFailed")),
+    );
   });
 });
diff --git a/frontend/src/modules/users/adminInvites.dom.test.tsx b/frontend/src/modules/users/adminInvites.dom.test.tsx
index abc7f8a5..83d18e6a 100644
--- a/frontend/src/modules/users/adminInvites.dom.test.tsx
+++ b/frontend/src/modules/users/adminInvites.dom.test.tsx
@@ -81,6 +81,8 @@ vi.mock("../../lib/api", async (importOriginal) => {
 
 import { HttpError } from "../../lib/api";
 import AdminUsers from "./AdminUsers";
+import { msg, sayNotif, type NotifText } from "../../lib/notifications";
+import i18n from "../../i18n";
 
 const invite = (over: Partial<Record<string, unknown>> = {}) => ({
   id: 1,
@@ -207,7 +209,7 @@ describe("Access requests — the delete affordance", () => {
     await waitFor(() =>
       expect(notifyMock).toHaveBeenCalledWith({
         level: "warning",
-        message: "settings.invites.deletedStillAllowed",
+        message: msg("settings.invites.deletedStillAllowed"),
       }),
     );
   });
@@ -223,7 +225,7 @@ describe("Access requests — the delete affordance", () => {
     await waitFor(() =>
       expect(notifyMock).toHaveBeenCalledWith({
         level: "error",
-        message: "settings.invites.deleteHasAccount",
+        message: msg("settings.invites.deleteHasAccount"),
       }),
     );
   });
@@ -261,7 +263,9 @@ describe("inviting someone the admin whitelisted", () => {
     // Falls back to the admin's own UI language: nobody ever told us anything about this mailbox.
     await waitFor(() => expect(inviteMock).toHaveBeenCalledWith(1, "en"));
     expect(notifyMock).toHaveBeenCalledWith(
-      expect.objectContaining({ message: "settings.invites.invited:asker@example.com" }),
+      expect.objectContaining({
+        message: msg("settings.invites.invited", { email: "asker@example.com" }),
+      }),
     );
   });
 
@@ -356,14 +360,16 @@ describe("inviting someone the admin whitelisted", () => {
     fireEvent.click(screen.getByLabelText("settings.invites.inviteLabel:asker@example.com"));
 
     // A button the admin pressed must not answer with a success toast for a mail nobody received.
-    // `req` has already localized the refusal into `detail` (lib/api/core); the toast carries it.
+    // The toast carries the refusal itself, said in the reader's language when it is shown.
     await waitFor(() =>
       expect(notifyMock).toHaveBeenCalledWith(
         expect.objectContaining({
-          title: "settings.invites.inviteFailed",
-          message: "errors.admin.email_off",
+          title: msg("settings.invites.inviteFailed"),
+          message: { detail: { code: "invite_send", reason: "email_off" } },
         }),
       ),
     );
+    const [shown] = notifyMock.mock.lastCall as [{ message: NotifText }];
+    expect(sayNotif(shown.message)).toBe(i18n.t("errors.admin.email_off"));
   });
 });
diff --git a/frontend/src/modules/users/adminPendingAccess.dom.test.tsx b/frontend/src/modules/users/adminPendingAccess.dom.test.tsx
index a733adfc..c0f259b3 100644
--- a/frontend/src/modules/users/adminPendingAccess.dom.test.tsx
+++ b/frontend/src/modules/users/adminPendingAccess.dom.test.tsx
@@ -69,6 +69,8 @@ vi.mock("../../lib/api", async (importOriginal) => {
 });
 
 import AdminUsers from "./AdminUsers";
+import { msg, sayNotif, type NotifText } from "../../lib/notifications";
+import i18n from "../../i18n";
 
 /** A row as /api/admin/pending-access serves it. */
 const row = (over: Record<string, unknown> = {}) => ({
@@ -113,7 +115,9 @@ describe("the stuck sign-ups section", () => {
 
     await waitFor(() => expect(activateMock).toHaveBeenCalledWith(7));
     expect(notifyMock).toHaveBeenCalledWith(
-      expect.objectContaining({ message: "users.pendingAccess.activated:later@example.com" }),
+      expect.objectContaining({
+        message: msg("users.pendingAccess.activated", { email: "later@example.com" }),
+      }),
     );
   });
 
@@ -165,16 +169,18 @@ describe("the stuck sign-ups section", () => {
     fireEvent.click(await screen.findByLabelText("users.pendingAccess.resend"));
 
     // Mail is fail-soft everywhere else, which is what left the 0.78.5 sign-ups with nothing to fall
-    // back on. A button the admin pressed must not answer with a success toast. `req` has already
-    // localized the refusal into `detail` (lib/api/core); the toast carries it.
+    // back on. A button the admin pressed must not answer with a success toast. The toast carries the
+    // refusal itself, said in the reader's language when it is shown.
     await waitFor(() =>
       expect(notifyMock).toHaveBeenCalledWith(
         expect.objectContaining({
-          title: "users.pendingAccess.resendFailed",
-          message: "errors.admin.email_off",
+          title: msg("users.pendingAccess.resendFailed"),
+          message: { detail: { code: "resend", reason: "email_off" } },
         }),
       ),
     );
+    const [shown] = notifyMock.mock.lastCall as [{ message: NotifText }];
+    expect(sayNotif(shown.message)).toBe(i18n.t("errors.admin.email_off"));
   });
 
   it("renders nothing at all when nobody is stuck", async () => {
diff --git a/frontend/src/shell/App.tsx b/frontend/src/shell/App.tsx
index 5f0810c3..4a3e1dde 100644
--- a/frontend/src/shell/App.tsx
+++ b/frontend/src/shell/App.tsx
@@ -37,6 +37,7 @@ import VerifyBanner from "./VerifyBanner";
 // pulls the release-notes loader into the eager App chunk and defeats the lazy ReleaseNotes
 // split. FRONTEND_VERSION equals the newest release note's version by release convention (both bump together).
 import { FRONTEND_VERSION } from "../lib/version";
+import { msg } from "../lib/notifications";
 
 // The page modules (and their side rails) are code-split per route: each module's definition imports
 // them lazily (features/navigation/moduleRegistry), and so does the feed's for the channel page. App
@@ -94,7 +95,7 @@ export default function App() {
     // Also from the signed-out login page, where the save 401s — `req` marks that as handled, so
     // the reporter stays quiet there.
     saveLanguage(queryClient, code).catch((e: unknown) =>
-      notifyActionError(e, t("errors.writeFailed.prefs")),
+      notifyActionError(e, msg("errors.writeFailed.prefs")),
     );
   }
 
diff --git a/frontend/src/shell/ErrorBoundary.message.dom.test.tsx b/frontend/src/shell/ErrorBoundary.message.dom.test.tsx
index 86af687e..beca99ba 100644
--- a/frontend/src/shell/ErrorBoundary.message.dom.test.tsx
+++ b/frontend/src/shell/ErrorBoundary.message.dom.test.tsx
@@ -7,9 +7,13 @@ import { afterEach, expect, it, vi } from "vitest";
 import { cleanup, render } from "@testing-library/react";
 
 const notify = vi.fn();
-vi.mock("../lib/notifications", () => ({ notify: (...args: unknown[]) => notify(...args) }));
+vi.mock("../lib/notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../lib/notifications")>()),
+  notify: (...args: unknown[]) => notify(...args),
+}));
 
 import i18n from "../i18n";
+import { msg, sayNotif, type NotifText } from "../lib/notifications";
 import { clear, events } from "../lib/log";
 import ErrorBoundary from "./ErrorBoundary";
 
@@ -31,8 +35,10 @@ it("a crash is reported in words the reader reads; the engine's text goes to the
   );
 
   expect(notify).toHaveBeenCalledWith(
-    expect.objectContaining({ level: "fatal", message: i18n.t("errors.boundary.notifMessage") }),
+    expect.objectContaining({ level: "fatal", message: msg("errors.boundary.notifMessage") }),
   );
+  const [shown] = notify.mock.calls[0] as [{ message: NotifText }];
+  expect(sayNotif(shown.message)).toBe(i18n.t("errors.boundary.notifMessage"));
   expect(JSON.stringify(events().filter((e) => e.event === "ui.crash"))).toContain(
     "Cannot read properties of undefined",
   );
diff --git a/frontend/src/shell/ErrorBoundary.staleBuild.dom.test.tsx b/frontend/src/shell/ErrorBoundary.staleBuild.dom.test.tsx
index 3bbc1323..c02485af 100644
--- a/frontend/src/shell/ErrorBoundary.staleBuild.dom.test.tsx
+++ b/frontend/src/shell/ErrorBoundary.staleBuild.dom.test.tsx
@@ -8,7 +8,10 @@ import { afterEach, expect, it, vi } from "vitest";
 import { cleanup, render } from "@testing-library/react";
 
 const notify = vi.fn();
-vi.mock("../lib/notifications", () => ({ notify: (...args: unknown[]) => notify(...args) }));
+vi.mock("../lib/notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../lib/notifications")>()),
+  notify: (...args: unknown[]) => notify(...args),
+}));
 
 import { clear, events } from "../lib/log";
 import { installStaleBuildReload } from "../lib/staleBuild";
diff --git a/frontend/src/shell/ErrorBoundary.tsx b/frontend/src/shell/ErrorBoundary.tsx
index 2a68684f..2f6dcf7e 100644
--- a/frontend/src/shell/ErrorBoundary.tsx
+++ b/frontend/src/shell/ErrorBoundary.tsx
@@ -1,6 +1,6 @@
 import type { ReactNode } from "react";
 import i18n from "../i18n";
-import { notify } from "../lib/notifications";
+import { msg, notify } from "../lib/notifications";
 import { CrashBoundary, type CrashCopy } from "../components/ui/CrashBoundary";
 
 const copy = (): CrashCopy => ({
@@ -13,10 +13,10 @@ const copy = (): CrashCopy => ({
 const onCrash = () =>
   notify({
     level: "fatal",
-    title: i18n.t("errors.boundary.notifTitle"),
+    title: msg("errors.boundary.notifTitle"),
     // Never the raw `error.message`: a JS engine's English ("Cannot read properties of undefined…")
     // is no message for the reader — the `ui.crash` log carries it for diagnosis.
-    message: i18n.t("errors.boundary.notifMessage"),
+    message: msg("errors.boundary.notifMessage"),
     requiresInteraction: true,
   });
 
diff --git a/frontend/src/shell/NavSidebar.account.dom.test.tsx b/frontend/src/shell/NavSidebar.account.dom.test.tsx
index b3dc6e92..23dd2924 100644
--- a/frontend/src/shell/NavSidebar.account.dom.test.tsx
+++ b/frontend/src/shell/NavSidebar.account.dom.test.tsx
@@ -9,6 +9,7 @@ import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import i18n from "../i18n";
 import { api, HttpError, type Me } from "../lib/api";
 import * as actionErrors from "../lib/actionErrors";
+import { sayNotif } from "../lib/notifications";
 import NavSidebar from "./NavSidebar";
 
 vi.mock("../features/navigation/navigationContext", () => ({
@@ -119,7 +120,7 @@ describe("the account panel", () => {
     fireEvent.click(row(panel, "Sign out"));
 
     await vi.waitFor(() => expect(report).toHaveBeenCalledOnce());
-    expect(report.mock.calls[0]![1]).toBe("Couldn't sign you out");
+    expect(sayNotif(report.mock.calls[0]![1])).toBe("Couldn't sign you out");
     expect(reload).not.toHaveBeenCalled();
   });
 });
diff --git a/frontend/src/shell/NavSidebar.tsx b/frontend/src/shell/NavSidebar.tsx
index 3ec1da14..57132351 100644
--- a/frontend/src/shell/NavSidebar.tsx
+++ b/frontend/src/shell/NavSidebar.tsx
@@ -6,7 +6,7 @@ import { ArrowLeftRight, Info, LogOut, Settings, Shield, type LucideIcon } from
 import { api, type Me } from "../lib/api";
 import { displayName, roleKey } from "../lib/api/account";
 import { useLiveQuery } from "../lib/useLiveQuery";
-import { getUnreadCount, subscribe } from "../lib/notifications";
+import { getUnreadCount, msg, subscribe } from "../lib/notifications";
 import type { Page } from "../lib/urlState";
 import {
   moduleDef,
@@ -80,7 +80,7 @@ export default function NavSidebar({
     const signedOut = await api.logout().then(
       () => true,
       (err: unknown) => {
-        notifyActionError(err, t("errors.writeFailed.signOut"));
+        notifyActionError(err, msg("errors.writeFailed.signOut"));
         return false;
       },
     );
diff --git a/frontend/src/shell/clientLogWiring.dom.test.tsx b/frontend/src/shell/clientLogWiring.dom.test.tsx
index 64fbee37..2f4981b6 100644
--- a/frontend/src/shell/clientLogWiring.dom.test.tsx
+++ b/frontend/src/shell/clientLogWiring.dom.test.tsx
@@ -7,7 +7,7 @@ import { afterEach, describe, expect, it, vi } from "vitest";
 import { cleanup, render } from "@testing-library/react";
 
 import { clear, events } from "../lib/log";
-import { notify } from "../lib/notifications";
+import { notify, raw } from "../lib/notifications";
 import { reportError } from "../lib/errorDialog";
 import { createQueryClient } from "../lib/queryClient";
 import ErrorBoundary from "./ErrorBoundary";
@@ -23,8 +23,8 @@ const logged = (code: string) => events().filter((e) => e.event === code);
 
 describe("client log wiring", () => {
   it("records every notification at its level", () => {
-    notify({ level: "success", title: "Saved", message: "Playlist renamed" });
-    notify({ level: "error", message: "Could not reach someone@mail.example" });
+    notify({ level: "success", title: raw("Saved"), message: raw("Playlist renamed") });
+    notify({ level: "error", message: raw("Could not reach someone@mail.example") });
     expect(logged("ui.notify").map((e) => [e.level, e.msg, e.attrs])).toEqual([
       ["INFO", "Playlist renamed", { level: "success", title: "Saved" }],
       ["ERROR", "Could not reach [email]", { level: "error" }],
diff --git a/frontend/src/shell/useAccessRequestsNudge.ts b/frontend/src/shell/useAccessRequestsNudge.ts
index b9853960..4fec2375 100644
--- a/frontend/src/shell/useAccessRequestsNudge.ts
+++ b/frontend/src/shell/useAccessRequestsNudge.ts
@@ -2,7 +2,7 @@ import { useEffect } from "react";
 import { useTranslation } from "react-i18next";
 import type { Me } from "../lib/api";
 import type { Page } from "../lib/urlState";
-import { notify, removeByMetaKind } from "../lib/notifications";
+import { msg, notify, removeByMetaKind } from "../lib/notifications";
 import { focusAccessRequestsTab } from "../lib/adminUsersTab";
 
 type SetPage = (next: Page, then?: () => void) => void;
@@ -30,8 +30,8 @@ export function useAccessRequestsNudge(me: Me | null | undefined, setPage: SetPa
     if (pending > 0) {
       notify({
         level: "warning",
-        title: t("common.accessRequestsTitle"),
-        message: t("common.accessRequestsMessage", { count: pending }),
+        title: msg("common.accessRequestsTitle"),
+        message: msg("common.accessRequestsMessage", { count: pending }),
         // Durable inbox link (survives reload, unlike a live action callback); the toast also
         // gets a click via the action.
         meta: { kind: "access-requests" },
diff --git a/frontend/src/shell/useEntryParams.ts b/frontend/src/shell/useEntryParams.ts
index cea9aa53..e12b2050 100644
--- a/frontend/src/shell/useEntryParams.ts
+++ b/frontend/src/shell/useEntryParams.ts
@@ -3,7 +3,7 @@ import { useTranslation } from "react-i18next";
 import type { Me } from "../lib/api";
 import { clearParams, type Page } from "../lib/urlState";
 import { useAccountSwitchNotice } from "../lib/useAccountSwitchNotice";
-import { notify } from "../lib/notifications";
+import { msg, notify } from "../lib/notifications";
 import { focusAccessRequestsTab } from "../lib/adminUsersTab";
 import { focusSettingsTab } from "../lib/settingsTab";
 
@@ -46,13 +46,13 @@ export function useEntryParams(
     if (!result) return;
     linkAnswered.current = true;
     if (result === "ok") {
-      notify({ level: "success", message: t("settings.account.googleLink.linked") });
+      notify({ level: "success", message: msg("settings.account.googleLink.linked") });
       void refetchMe();
       focusSettingsTab("account");
       setPage("settings");
     } else {
       const key = result === "conflict" || result === "mismatch" ? result : "error";
-      notify({ level: "error", message: t(`settings.account.googleLink.${key}`) });
+      notify({ level: "error", message: msg(`settings.account.googleLink.${key}`) });
     }
     clearParams("link");
   }, [t, setPage, refetchMe]);
@@ -66,7 +66,7 @@ export function useEntryParams(
     if (oauthAnswered.current) return;
     if (new URLSearchParams(window.location.search).get("oauth") !== "cancelled") return;
     oauthAnswered.current = true;
-    notify({ level: "info", message: t("settings.account.googleCancelled") });
+    notify({ level: "info", message: msg("settings.account.googleCancelled") });
     clearParams("oauth");
   }, [t]);