diff --git a/app/src/agentworld/pages/MessagingSection.test.tsx b/app/src/agentworld/pages/MessagingSection.test.tsx
index 909c230ac..64eba9ece 100644
--- a/app/src/agentworld/pages/MessagingSection.test.tsx
+++ b/app/src/agentworld/pages/MessagingSection.test.tsx
@@ -279,6 +279,76 @@ describe('DMs panel (E2E enabled)', () => {
     // The messages namespace has no 'send' method — only signal.sendMessage is callable
   });
 
+  test('shows a friendly error when the recipient has no published key bundle', async () => {
+    const user = userEvent.setup();
+    vi.mocked(apiClient.messages.list).mockResolvedValue({ messages: [] });
+    vi.mocked(apiClient.signal.sendMessage).mockRejectedValueOnce(
+      new Error(
+        'CoreRpcError: HTTP 404: HTTP 404: /keys/61KcG5aGLqpnJz2fn4tujFKAdzqsdGR9XqiUeVoT3vPg/bundle: not found'
+      )
+    );
+
+    render(<MessagingSection />);
+    const peerInput = screen.getByPlaceholderText(/Recipient @handle/);
+    await user.type(peerInput, 'peer456');
+    await user.click(screen.getByRole('button', { name: 'Open DM' }));
+
+    const composeInput = await screen.findByPlaceholderText(/Type a message/);
+    await user.type(composeInput, 'secret');
+    await user.click(screen.getByRole('button', { name: 'Send' }));
+
+    expect(
+      await screen.findByText(/This user hasn't enabled encrypted messaging yet/)
+    ).toBeInTheDocument();
+    expect(screen.queryByText(/CoreRpcError/)).not.toBeInTheDocument();
+    expect(screen.queryByText(/\/keys\//)).not.toBeInTheDocument();
+  });
+
+  test('normalizes the core mapped missing encrypted messaging setup error', async () => {
+    const user = userEvent.setup();
+    vi.mocked(apiClient.messages.list).mockResolvedValue({ messages: [] });
+    vi.mocked(apiClient.signal.sendMessage).mockRejectedValueOnce(
+      new Error(
+        'CoreRpcError: Recipient has not set up encrypted messaging yet. They need to provision Signal keys before receiving DMs. (resolved agent_id: resolved-crypto-id)'
+      )
+    );
+
+    render(<MessagingSection />);
+    const peerInput = screen.getByPlaceholderText(/Recipient @handle/);
+    await user.type(peerInput, 'peer456');
+    await user.click(screen.getByRole('button', { name: 'Open DM' }));
+
+    const composeInput = await screen.findByPlaceholderText(/Type a message/);
+    await user.type(composeInput, 'secret');
+    await user.click(screen.getByRole('button', { name: 'Send' }));
+
+    expect(
+      await screen.findByText(/This user hasn't enabled encrypted messaging yet/)
+    ).toBeInTheDocument();
+    expect(screen.queryByText(/CoreRpcError/)).not.toBeInTheDocument();
+    expect(screen.queryByText(/resolved agent_id/)).not.toBeInTheDocument();
+  });
+
+  test('normalizes missing key bundle errors while refreshing direct messages', async () => {
+    const user = userEvent.setup();
+    vi.mocked(apiClient.messages.list).mockRejectedValueOnce(
+      new Error(
+        'CoreRpcError: HTTP 404: HTTP 404: /keys/61KcG5aGLqpnJz2fn4tujFKAdzqsdGR9XqiUeVoT3vPg/bundle: not found'
+      )
+    );
+
+    render(<MessagingSection />);
+    const peerInput = screen.getByPlaceholderText(/Recipient @handle/);
+    await user.type(peerInput, 'peer456');
+    await user.click(screen.getByRole('button', { name: 'Open DM' }));
+
+    expect(
+      await screen.findByText(/This user hasn't enabled encrypted messaging yet/)
+    ).toBeInTheDocument();
+    expect(screen.queryByText(/CoreRpcError/)).not.toBeInTheDocument();
+    expect(screen.queryByText(/\/keys\//)).not.toBeInTheDocument();
+  });
+
   test('received messages are decrypted before display', async () => {
     // directory.resolve returns 'resolved-crypto-id'; messages must use that id
     // in the 'from' field to survive the peerId filter in useDirectMessages.
diff --git a/app/src/agentworld/pages/MessagingSection.tsx b/app/src/agentworld/pages/MessagingSection.tsx
index 42ce33c50..9cf4e7551 100644
--- a/app/src/agentworld/pages/MessagingSection.tsx
+++ b/app/src/agentworld/pages/MessagingSection.tsx
@@ -27,6 +27,7 @@ import {
   PaymentRequiredError,
   type SignalKeyStatus,
 } from '../../lib/agentworld/invokeApiClient';
+import { useT } from '../../lib/i18n/I18nContext';
 import { fetchWalletStatus } from '../../services/walletApi';
 import { apiClient } from '../AgentWorldShell';
 import { useTinyplaceStream } from '../hooks/useTinyplaceStream';
@@ -1049,7 +1050,21 @@ interface DecryptedMessage {
   outgoing?: boolean;
 }
 
-function useDirectMessages(peerId: string) {
+function formatDirectMessageError(err: unknown, missingBundleMessage: string): string {
+  const message = String(err);
+  const rawBundle404 = /http\s*404/i.test(message) && /\/keys\/[^/\s]+\/bundle\b/i.test(message);
+  const mappedMissingBundle =
+    /recipient/i.test(message) &&
+    /not\s+set\s+up/i.test(message) &&
+    /encrypted\s+messaging/i.test(message);
+  if (rawBundle404 || mappedMissingBundle) {
+    log('[agentworld:dm] recipient key bundle missing');
+    return missingBundleMessage;
+  }
+  return message;
+}
+
+function useDirectMessages(peerId: string, missingBundleMessage: string) {
   const [messages, setMessages] = useState<DecryptedMessage[]>([]);
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -1086,11 +1101,11 @@ function useDirectMessages(peerId: string) {
         return merged.sort((a, b) => a.timestamp.localeCompare(b.timestamp));
       });
     } catch (err) {
-      setError(String(err));
+      setError(formatDirectMessageError(err, missingBundleMessage));
     } finally {
       setLoading(false);
     }
-  }, [peerId]);
+  }, [missingBundleMessage, peerId]);
 
   const send = useCallback(
     async (plaintext: string) => {
@@ -1113,12 +1128,12 @@ function useDirectMessages(peerId: string) {
         );
         await refresh();
       } catch (err) {
-        setError(String(err));
+        setError(formatDirectMessageError(err, missingBundleMessage));
       } finally {
         setSending(false);
       }
     },
-    [peerId, refresh]
+    [missingBundleMessage, peerId, refresh]
   );
 
   useEffect(() => {
@@ -1139,7 +1154,15 @@ function ActiveDmView({
   composeText: string;
   setComposeText: (v: string) => void;
 }) {
-  const { messages, loading, error, sending, send } = useDirectMessages(peerId);
+  const { t } = useT();
+  const missingBundleMessage = t(
+    'agentworld.messaging.missingSignalBundle',
+    "This user hasn't enabled encrypted messaging yet. Ask them to open Agent World and enable secure DMs before sending a message."
+  );
+  const { messages, loading, error, sending, send } = useDirectMessages(
+    peerId,
+    missingBundleMessage
+  );
 
   const handleSend = useCallback(async () => {
     if (!composeText.trim()) return;
diff --git a/app/src/lib/i18n/ar.ts b/app/src/lib/i18n/ar.ts
index 9edd7f082..a1f8caab7 100644
--- a/app/src/lib/i18n/ar.ts
+++ b/app/src/lib/i18n/ar.ts
@@ -5774,6 +5774,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'إلغاء',
   'agentworld.jobs.applyModal.submit': 'إرسال الطلب',
   'agentworld.jobs.applyModal.submitting': 'جارٍ التقديم…',
+  'agentworld.messaging.missingSignalBundle':
+    'لم يفعّل هذا المستخدم الرسائل المشفرة بعد. اطلب منه فتح Agent World وتفعيل الرسائل المباشرة الآمنة قبل إرسال رسالة.',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/bn.ts b/app/src/lib/i18n/bn.ts
index f51cd5aad..d8bf168d0 100644
--- a/app/src/lib/i18n/bn.ts
+++ b/app/src/lib/i18n/bn.ts
@@ -5891,6 +5891,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'বাতিল',
   'agentworld.jobs.applyModal.submit': 'আবেদন জমা দিন',
   'agentworld.jobs.applyModal.submitting': 'আবেদন করা হচ্ছে…',
+  'agentworld.messaging.missingSignalBundle':
+    'এই ব্যবহারকারী এখনো এনক্রিপ্টেড মেসেজিং চালু করেননি। বার্তা পাঠানোর আগে তাকে Agent World খুলে নিরাপদ DM চালু করতে বলুন।',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/de.ts b/app/src/lib/i18n/de.ts
index 3f30a900e..606a9c735 100644
--- a/app/src/lib/i18n/de.ts
+++ b/app/src/lib/i18n/de.ts
@@ -6055,6 +6055,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'Abbrechen',
   'agentworld.jobs.applyModal.submit': 'Bewerbung einreichen',
   'agentworld.jobs.applyModal.submitting': 'Wird eingereicht…',
+  'agentworld.messaging.missingSignalBundle':
+    'Dieser Benutzer hat verschlüsselte Nachrichten noch nicht aktiviert. Bitte ihn, Agent World zu öffnen und sichere DMs zu aktivieren, bevor du eine Nachricht sendest.',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/en.ts b/app/src/lib/i18n/en.ts
index 049ff6b09..42b2842e5 100644
--- a/app/src/lib/i18n/en.ts
+++ b/app/src/lib/i18n/en.ts
@@ -6160,6 +6160,8 @@ const en: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'Cancel',
   'agentworld.jobs.applyModal.submit': 'Submit Application',
   'agentworld.jobs.applyModal.submitting': 'Applying…',
+  'agentworld.messaging.missingSignalBundle':
+    "This user hasn't enabled encrypted messaging yet. Ask them to open Agent World and enable secure DMs before sending a message.",
 };
 
 export default en;
diff --git a/app/src/lib/i18n/es.ts b/app/src/lib/i18n/es.ts
index 26f97b5f1..9f72c54d8 100644
--- a/app/src/lib/i18n/es.ts
+++ b/app/src/lib/i18n/es.ts
@@ -6015,6 +6015,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'Cancelar',
   'agentworld.jobs.applyModal.submit': 'Enviar solicitud',
   'agentworld.jobs.applyModal.submitting': 'Enviando…',
+  'agentworld.messaging.missingSignalBundle':
+    'Este usuario aún no ha activado la mensajería cifrada. Pídele que abra Agent World y active los DM seguros antes de enviarle un mensaje.',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/fr.ts b/app/src/lib/i18n/fr.ts
index c56135b04..cde0bc198 100644
--- a/app/src/lib/i18n/fr.ts
+++ b/app/src/lib/i18n/fr.ts
@@ -6033,6 +6033,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'Annuler',
   'agentworld.jobs.applyModal.submit': 'Soumettre la candidature',
   'agentworld.jobs.applyModal.submitting': 'Envoi en cours…',
+  'agentworld.messaging.missingSignalBundle':
+    "Cet utilisateur n'a pas encore activé la messagerie chiffrée. Demandez-lui d'ouvrir Agent World et d'activer les messages privés sécurisés avant d'envoyer un message.",
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/hi.ts b/app/src/lib/i18n/hi.ts
index 5a6d0ee0c..6e73f84dd 100644
--- a/app/src/lib/i18n/hi.ts
+++ b/app/src/lib/i18n/hi.ts
@@ -5893,6 +5893,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'रद्द करें',
   'agentworld.jobs.applyModal.submit': 'आवेदन सबमिट करें',
   'agentworld.jobs.applyModal.submitting': 'आवेदन हो रहा है…',
+  'agentworld.messaging.missingSignalBundle':
+    'इस उपयोगकर्ता ने अभी तक एन्क्रिप्टेड मैसेजिंग चालू नहीं की है। संदेश भेजने से पहले उनसे Agent World खोलकर सुरक्षित DM चालू करने को कहें।',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/id.ts b/app/src/lib/i18n/id.ts
index 3f4f921ad..71551410c 100644
--- a/app/src/lib/i18n/id.ts
+++ b/app/src/lib/i18n/id.ts
@@ -5909,6 +5909,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'Batal',
   'agentworld.jobs.applyModal.submit': 'Kirim Lamaran',
   'agentworld.jobs.applyModal.submitting': 'Melamar…',
+  'agentworld.messaging.missingSignalBundle':
+    'Pengguna ini belum mengaktifkan pesan terenkripsi. Minta mereka membuka Agent World dan mengaktifkan DM aman sebelum Anda mengirim pesan.',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/it.ts b/app/src/lib/i18n/it.ts
index 4dd0cab6e..f6c1f0fea 100644
--- a/app/src/lib/i18n/it.ts
+++ b/app/src/lib/i18n/it.ts
@@ -6002,6 +6002,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'Annulla',
   'agentworld.jobs.applyModal.submit': 'Invia candidatura',
   'agentworld.jobs.applyModal.submitting': 'Candidatura in corso…',
+  'agentworld.messaging.missingSignalBundle':
+    'Questo utente non ha ancora attivato la messaggistica crittografata. Chiedigli di aprire Agent World e attivare i DM sicuri prima di inviare un messaggio.',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/ko.ts b/app/src/lib/i18n/ko.ts
index 1ebccf6c9..32224c6b2 100644
--- a/app/src/lib/i18n/ko.ts
+++ b/app/src/lib/i18n/ko.ts
@@ -5838,6 +5838,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': '취소',
   'agentworld.jobs.applyModal.submit': '지원서 제출',
   'agentworld.jobs.applyModal.submitting': '지원 중…',
+  'agentworld.messaging.missingSignalBundle':
+    '이 사용자는 아직 암호화 메시지를 활성화하지 않았습니다. 메시지를 보내기 전에 Agent World를 열고 보안 DM을 활성화해 달라고 요청하세요.',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/pl.ts b/app/src/lib/i18n/pl.ts
index f4322eddf..581aeac2f 100644
--- a/app/src/lib/i18n/pl.ts
+++ b/app/src/lib/i18n/pl.ts
@@ -5983,6 +5983,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'Anuluj',
   'agentworld.jobs.applyModal.submit': 'Wyślij aplikację',
   'agentworld.jobs.applyModal.submitting': 'Wysyłanie…',
+  'agentworld.messaging.missingSignalBundle':
+    'Ten użytkownik nie włączył jeszcze szyfrowanych wiadomości. Poproś go, aby otworzył Agent World i włączył bezpieczne DM przed wysłaniem wiadomości.',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/pt.ts b/app/src/lib/i18n/pt.ts
index 29ca49a43..8f6c685cb 100644
--- a/app/src/lib/i18n/pt.ts
+++ b/app/src/lib/i18n/pt.ts
@@ -5995,6 +5995,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'Cancelar',
   'agentworld.jobs.applyModal.submit': 'Enviar candidatura',
   'agentworld.jobs.applyModal.submitting': 'A enviar…',
+  'agentworld.messaging.missingSignalBundle':
+    'Este utilizador ainda não ativou as mensagens encriptadas. Peça-lhe para abrir o Agent World e ativar DMs seguras antes de enviar uma mensagem.',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/ru.ts b/app/src/lib/i18n/ru.ts
index f08941a8c..ba0b7470e 100644
--- a/app/src/lib/i18n/ru.ts
+++ b/app/src/lib/i18n/ru.ts
@@ -5956,6 +5956,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': 'Отмена',
   'agentworld.jobs.applyModal.submit': 'Отправить заявку',
   'agentworld.jobs.applyModal.submitting': 'Отправка…',
+  'agentworld.messaging.missingSignalBundle':
+    'Этот пользователь еще не включил зашифрованные сообщения. Попросите его открыть Agent World и включить безопасные личные сообщения перед отправкой.',
 };
 
 export default messages;
diff --git a/app/src/lib/i18n/zh-CN.ts b/app/src/lib/i18n/zh-CN.ts
index 966aee843..7fe79fdba 100644
--- a/app/src/lib/i18n/zh-CN.ts
+++ b/app/src/lib/i18n/zh-CN.ts
@@ -5599,6 +5599,8 @@ const messages: TranslationMap = {
   'agentworld.jobs.applyModal.cancel': '取消',
   'agentworld.jobs.applyModal.submit': '提交申请',
   'agentworld.jobs.applyModal.submitting': '申请中…',
+  'agentworld.messaging.missingSignalBundle':
+    '此用户尚未启用加密消息。发送消息前，请让对方打开 Agent World 并启用安全私信。',
 };
 
 export default messages;