diff --git a/components/chat/message-group.tsx b/components/chat/message-group.tsx
index 6a308819..6d4dce3b 100644
--- a/components/chat/message-group.tsx
+++ b/components/chat/message-group.tsx
@@ -190,7 +190,7 @@ export function MessageGroup({
                     {/* An optimistic bubble for a captionless attachment has
                       nothing to draw until the server answers — say so rather
                       than render an empty box. */}
-                    {m.pending && !m.body && m.attachments.length === 0 && (
+                    {m.pending && !m.body && !m.attachments?.length && (
                       <span className="italic opacity-80">
                         Sending attachment…
                       </span>
diff --git a/components/notifications/broadcast-modal.tsx b/components/notifications/broadcast-modal.tsx
index b1662a25..1d8441e0 100644
--- a/components/notifications/broadcast-modal.tsx
+++ b/components/notifications/broadcast-modal.tsx
@@ -60,7 +60,9 @@ export function BroadcastModal() {
     }
   }, [item, dismissing]);
 
-  if (!item) return null;
+  // Guard on the shape, not just presence: a malformed payload must not put
+  // an empty modal over every page in the app.
+  if (!item?.id || !item.title) return null;
 
   return (
     <ResponsiveDialog
diff --git a/lib/broadcasts.ts b/lib/broadcasts.ts
index 7f5883a1..806d81ea 100644
--- a/lib/broadcasts.ts
+++ b/lib/broadcasts.ts
@@ -18,8 +18,14 @@ async function call<T>(path: string, init?: RequestInit): Promise<T> {
   });
   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;
+  const body = (await res.json().catch(() => ({}))) as {
+    data?: T;
+    success?: boolean;
+  };
+  // NOT `body.data ?? body`: /pending answers {data: null} when nothing is
+  // waiting, and `??` would fall through and hand back the whole envelope —
+  // which is truthy, so the modal would try to render it as an announcement.
+  return (body.data ?? (null as unknown as T)) as T;
 }
 
 export type Broadcast = {
diff --git a/lib/chat-format.ts b/lib/chat-format.ts
index 120839b6..86555414 100644
--- a/lib/chat-format.ts
+++ b/lib/chat-format.ts
@@ -29,10 +29,15 @@ export function buildEntityTree(
   body: string,
   entities: MessageEntity[],
 ): EntityNode[] {
+  // Defensive on both inputs: this renders content from the network, and a
+  // missing body should show nothing rather than take down the screen it is
+  // on. The broadcast modal renders through here too, and it mounts on every
+  // page — so a crash here is not confined to chat.
+  const text = body ?? "";
   const sorted = [...(entities ?? [])].sort(
     (a, b) => a.offset - b.offset || b.length - a.length,
   );
-  return build(body, 0, body.length, sorted);
+  return build(text, 0, text.length, sorted);
 }
 
 function build(