diff --git a/frontend/AGENTS.md b/frontend/AGENTS.md
index e49e94b..d7c1441 100644
--- a/frontend/AGENTS.md
+++ b/frontend/AGENTS.md
@@ -92,8 +92,8 @@ frontend/src/
     ├── useConversationMessages.test.ts
     ├── useConversationMessages.race.test.ts
     ├── useRepeaterMode.test.ts
-    ├── useWebSocket.lifecycle.test.ts
-    └── websocket.test.ts
+    ├── useWebSocket.dispatch.test.ts
+    └── useWebSocket.lifecycle.test.ts
 ```
 
 ## Architecture Notes
diff --git a/tests/test_event_handlers.py b/tests/test_event_handlers.py
index 4920df6..b06d92d 100644
--- a/tests/test_event_handlers.py
+++ b/tests/test_event_handlers.py
@@ -323,6 +323,75 @@ class TestContactMessageCLIFiltering:
             assert payload["acked"] is not False  # Ensure it's int, not bool
             assert isinstance(payload["acked"], int)
 
+    @pytest.mark.asyncio
+    async def test_broadcast_message_payload_matches_frontend_type(self, test_db):
+        """Broadcast payload keys must match the frontend Message interface in types.ts."""
+        from app.event_handlers import on_contact_message
+
+        # Keys the frontend Message interface expects (see frontend/src/types.ts)
+        EXPECTED_MESSAGE_KEYS = {
+            "id",
+            "type",
+            "conversation_key",
+            "text",
+            "sender_timestamp",
+            "received_at",
+            "paths",
+            "txt_type",
+            "signature",
+            "outgoing",
+            "acked",
+        }
+
+        with (
+            patch("app.event_handlers.broadcast_event") as mock_broadcast,
+            patch("app.bot.run_bot_for_message", new_callable=AsyncMock),
+        ):
+
+            class MockEvent:
+                payload = {
+                    "pubkey_prefix": "abc123def456",
+                    "text": "shape test",
+                    "txt_type": 0,
+                    "sender_timestamp": 1700000000,
+                }
+
+            await on_contact_message(MockEvent())
+
+            mock_broadcast.assert_called_once()
+            event_type, payload = mock_broadcast.call_args[0]
+            assert event_type == "message"
+            assert set(payload.keys()) == EXPECTED_MESSAGE_KEYS
+
+    @pytest.mark.asyncio
+    async def test_broadcast_ack_payload_matches_frontend_type(self, test_db):
+        """Broadcast payload keys for message_acked must match frontend expectations."""
+        from app.event_handlers import on_ack
+
+        msg_id = await MessageRepository.create(
+            msg_type="PRIV",
+            text="ack shape test",
+            received_at=1700000000,
+            conversation_key="bb" * 32,
+            sender_timestamp=1700000000,
+        )
+        track_pending_ack("ackshape", message_id=msg_id, timeout_ms=10000)
+
+        # Keys the frontend expects (see frontend/src/useWebSocket.ts:111-114)
+        EXPECTED_ACK_KEYS = {"message_id", "ack_count"}
+
+        with patch("app.event_handlers.broadcast_event") as mock_broadcast:
+
+            class MockEvent:
+                payload = {"code": "ackshape"}
+
+            await on_ack(MockEvent())
+
+            mock_broadcast.assert_called_once()
+            event_type, payload = mock_broadcast.call_args[0]
+            assert event_type == "message_acked"
+            assert set(payload.keys()) == EXPECTED_ACK_KEYS
+
     @pytest.mark.asyncio
     async def test_missing_txt_type_defaults_to_normal(self, test_db):
         """Messages without txt_type field are treated as normal (not filtered)."""