diff --git a/app/layout.tsx b/app/layout.tsx
index 9530eb3a..184ab8f9 100644
--- a/app/layout.tsx
+++ b/app/layout.tsx
@@ -8,6 +8,7 @@ import { AudioPlayerProvider, FloatingPlayer } from "@/components/audio-player";
 import { AuthProvider } from "@/components/auth/auth-provider";
 import { AuthGateProvider } from "@/components/auth/auth-gate";
 import { NotificationsProvider } from "@/components/notifications/notifications-provider";
+import { BroadcastModal } from "@/components/notifications/broadcast-modal";
 import { SharePostProvider } from "@/components/social/share-post-provider";
 import { Toaster } from "@/components/ui/toaster";
 import { ServiceWorkerRegistrar } from "@/components/pwa/sw-register";
@@ -115,6 +116,9 @@ export default function RootLayout({
                       {/* Toaster and FloatingPlayer are global — toasts and
                         currently-playing audio survive navigation between
                         route groups. */}
+                      {/* Announcements: at most one modal, only when signed
+                          in, dismissed server-side so it never repeats. */}
+                      <BroadcastModal />
                       <FloatingPlayer />
                       <Toaster />
                       <ServiceWorkerRegistrar />
diff --git a/components/notifications/broadcast-modal.tsx b/components/notifications/broadcast-modal.tsx
new file mode 100644
index 00000000..b1662a25
--- /dev/null
+++ b/components/notifications/broadcast-modal.tsx
@@ -0,0 +1,116 @@
+"use client";
+
+/**
+ * The announcement surface: a modal on desktop, a drawer on mobile.
+ *
+ * Shown at most once per user, and that guarantee lives on the server — the
+ * dismissal is a row, not local storage — so it survives a new device, a
+ * cleared browser, and two tabs racing.
+ *
+ * It appears on load and on the realtime nudge, but never over a signed-out
+ * page: an announcement is addressed to a person, and there is nobody to
+ * address until they're signed in.
+ */
+
+import { useCallback, useEffect, useState } from "react";
+import Image from "next/image";
+import { useAuth } from "@/components/auth/auth-provider";
+import { useNotifications } from "@/components/notifications/notifications-provider";
+import { ResponsiveDialog } from "@/components/chat/responsive-dialog";
+import { MessageText } from "@/components/chat/message-text";
+import { Button } from "@/components/ui/button";
+import { broadcasts, type Broadcast } from "@/lib/broadcasts";
+
+export function BroadcastModal() {
+  const { user } = useAuth();
+  const { lastBroadcastAt } = useNotifications();
+  const [item, setItem] = useState<Broadcast | null>(null);
+  const [dismissing, setDismissing] = useState(false);
+
+  const load = useCallback(() => {
+    if (!user?.id) return;
+    broadcasts
+      .pending()
+      .then(setItem)
+      .catch(() => {
+        /* announcements are never worth an error surface */
+      });
+  }, [user?.id]);
+
+  // On sign-in, and again whenever the realtime nudge fires. lastBroadcastAt
+  // changes on each publish, so this refetches without the event carrying any
+  // content of its own.
+  useEffect(() => {
+    load();
+  }, [load, lastBroadcastAt]);
+
+  const dismiss = useCallback(async () => {
+    if (!item || dismissing) return;
+    setDismissing(true);
+    // Close first: the dismissal is idempotent and the server already knows
+    // what this user has seen, so a failed write costs at most one repeat
+    // rather than a modal that won't go away.
+    const id = item.id;
+    setItem(null);
+    setDismissing(false);
+    try {
+      await broadcasts.markSeen(id);
+    } catch {
+      /* it will simply be offered again */
+    }
+  }, [item, dismissing]);
+
+  if (!item) return null;
+
+  return (
+    <ResponsiveDialog
+      title={item.title}
+      description=""
+      onClose={dismiss}
+      footer={
+        <div className="flex gap-2">
+          {item.cta_url && item.cta_label ? (
+            <>
+              <Button variant="outline" className="flex-1" onClick={dismiss}>
+                Not now
+              </Button>
+              <a
+                href={item.cta_url}
+                // Dismiss on the way out, so following the link also counts as
+                // having seen it.
+                onClick={dismiss}
+                {...(item.cta_url.startsWith("/")
+                  ? {}
+                  : { target: "_blank", rel: "noopener noreferrer" })}
+                className="inline-flex flex-1 items-center justify-center rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground transition-colors hover:bg-primary/90 dark:text-white"
+              >
+                {item.cta_label}
+              </a>
+            </>
+          ) : (
+            <Button className="w-full" onClick={dismiss}>
+              Got it
+            </Button>
+          )}
+        </div>
+      }
+    >
+      <div className="space-y-3 p-4">
+        {item.banner_url && (
+          <div className="relative aspect-[2/1] w-full overflow-hidden rounded-lg bg-muted">
+            <Image
+              src={item.banner_url}
+              alt=""
+              fill
+              sizes="(max-width: 768px) 100vw, 28rem"
+              className="object-cover"
+            />
+          </div>
+        )}
+        <div className="text-sm leading-relaxed text-foreground">
+          <MessageText body={item.body} entities={item.entities ?? []} />
+        </div>
+      </div>
+    </ResponsiveDialog>
+  );
+}
diff --git a/components/notifications/notifications-provider.tsx b/components/notifications/notifications-provider.tsx
index bb2b290d..61f16611 100644
--- a/components/notifications/notifications-provider.tsx
+++ b/components/notifications/notifications-provider.tsx
@@ -52,6 +52,9 @@ type NotificationsContextValue = {
    * event name and is surfaced here rather than bumping `unread`.
    */
   lastChatActivity: ChatActivity | null;
+  /** Bumps when an announcement is published. Carries no content — consumers
+   *  refetch /broadcasts/pending, which answers per user. */
+  lastBroadcastAt: number;
   /** Threads holding unread messages — the Chats nav badge. Muted threads are
    *  excluded by the BFF, so muting a busy group clears the badge. */
   chatUnread: number;
@@ -115,6 +118,7 @@ export function NotificationsProvider({
   const { user } = useAuth();
   const [unread, setUnread] = useState(0);
   const [chatUnread, setChatUnread] = useState(0);
+  const [lastBroadcastAt, setLastBroadcastAt] = useState(0);
   const [lastEventAt, setLastEventAt] = useState(0);
   const [lastChatActivity, setLastChatActivity] = useState<ChatActivity | null>(
     null,
@@ -249,7 +253,18 @@ export function NotificationsProvider({
           });
         },
       );
+      // Announcements ride a PUBLIC channel: one publish reaches everyone in
+      // a single Soketi call rather than one per user, and the event is safe
+      // to broadcast because it carries nothing — the content comes from the
+      // authenticated fetch it triggers.
+      const announcements = pusher.subscribe("broadcasts");
+      announcements.bind("broadcast_published", () =>
+        setLastBroadcastAt(Date.now()),
+      );
+
       cleanup = () => {
+        announcements.unbind_all();
+        pusher.unsubscribe("broadcasts");
         channel.unbind_all();
         pusher.unsubscribe(channelName);
         pusher.disconnect();
@@ -272,6 +287,7 @@ export function NotificationsProvider({
         lastChatActivity,
         chatUnread,
         refreshChatUnread,
+        lastBroadcastAt,
       }}
     >
       {children}
diff --git a/lib/broadcasts.ts b/lib/broadcasts.ts
new file mode 100644
index 00000000..7f5883a1
--- /dev/null
+++ b/lib/broadcasts.ts
@@ -0,0 +1,45 @@
+/**
+ * Browser-side client for admin announcements.
+ *
+ * Deliberately thin: an announcement is fetched, shown once, and dismissed.
+ * Nothing is cached client-side — "have I seen this?" is the server's answer,
+ * so it survives a new device, a cleared browser, and a second tab.
+ */
+
+import type { MessageEntity } from "@/lib/chat";
+
+const BFF_BASE = process.env.NEXT_PUBLIC_BFF_URL || "http://localhost:8080";
+
+async function call<T>(path: string, init?: RequestInit): Promise<T> {
+  const res = await fetch(`${BFF_BASE}/api/v1${path}`, {
+    credentials: "include",
+    headers: { "Content-Type": "application/json" },
+    ...init,
+  });
+  if (!res.ok) throw new Error(`broadcast request failed: ${res.status}`);
+  if (res.status === 204) return undefined as T;
+  const json = await res.json();
+  return (json?.data ?? json) as T;
+}
+
+export type Broadcast = {
+  id: string;
+  title: string;
+  body: string;
+  /** Formatting spans over `body`, same shape chat messages use. */
+  entities: MessageEntity[];
+  banner_url?: string | null;
+  cta_label?: string | null;
+  cta_url?: string | null;
+  published_at?: string | null;
+  expires_at?: string | null;
+};
+
+export const broadcasts = {
+  /** The announcement waiting for this user, or null. */
+  pending: () => call<Broadcast | null>("/broadcasts/pending"),
+
+  /** Dismiss it. Idempotent, so a double-tap or two tabs are both fine. */
+  markSeen: (id: string) =>
+    call<void>(`/broadcasts/${id}/seen`, { method: "POST" }),
+};