diff --git a/openviking/storage/queuefs/semantic_queue.py b/openviking/storage/queuefs/semantic_queue.py
index 4f412d9c..cafc8e8f 100644
--- a/openviking/storage/queuefs/semantic_queue.py
+++ b/openviking/storage/queuefs/semantic_queue.py
@@ -1,7 +1,9 @@
 # Copyright (c) 2026 Beijing Volcano Engine Technology Co., Ltd.
 # SPDX-License-Identifier: Apache-2.0
-"""SemanticQueue: Semantic extraction queue."""
+"""Semantic extraction queue."""
 
+import threading
+import time
 from typing import Optional
 
 from openviking_cli.utils.logger import get_logger
@@ -11,12 +13,44 @@
 
 logger = get_logger(__name__)
 
+# Coalesce rapid re-enqueues for the same memory parent directory (github #769).
+_MEMORY_PARENT_SEMANTIC_DEDUPE_SEC = 45.0
+
 
 class SemanticQueue(NamedQueue):
     """Semantic extraction queue for async generation of .abstract.md and .overview.md."""
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._memory_parent_semantic_last: dict[str, float] = {}
+        self._memory_parent_semantic_lock = threading.Lock()
+
+    @staticmethod
+    def _memory_parent_semantic_key(msg: SemanticMsg) -> str:
+        return f"{msg.account_id}|{msg.user_id}|{msg.agent_id}|{msg.uri}"
+
     async def enqueue(self, msg: SemanticMsg) -> str:
         """Serialize SemanticMsg object and store in queue."""
+        if msg.context_type == "memory":
+            key = self._memory_parent_semantic_key(msg)
+            now = time.monotonic()
+            with self._memory_parent_semantic_lock:
+                last = self._memory_parent_semantic_last.get(key, 0.0)
+                if now - last < _MEMORY_PARENT_SEMANTIC_DEDUPE_SEC:
+                    logger.debug(
+                        "[SemanticQueue] Skipping duplicate memory semantic enqueue for %s "
+                        "(within %.0fs dedupe window; see #769)",
+                        msg.uri,
+                        _MEMORY_PARENT_SEMANTIC_DEDUPE_SEC,
+                    )
+                    return "deduplicated"
+                self._memory_parent_semantic_last[key] = now
+                if len(self._memory_parent_semantic_last) > 2000:
+                    cutoff = now - (_MEMORY_PARENT_SEMANTIC_DEDUPE_SEC * 4)
+                    stale = [k for k, t in self._memory_parent_semantic_last.items() if t < cutoff]
+                    for k in stale[:800]:
+                        self._memory_parent_semantic_last.pop(k, None)
+
         return await super().enqueue(msg.to_dict())
 
     async def dequeue(self) -> Optional[SemanticMsg]:
@@ -39,7 +73,7 @@ async def dequeue(self) -> Optional[SemanticMsg]:
             return None
 
     async def peek(self) -> Optional[SemanticMsg]:
-        """Peek at queue head message."""
+        """Peek at message from queue."""
         data_dict = await super().peek()
         if not data_dict:
             return None
diff --git a/tests/storage/test_semantic_queue_memory_dedupe.py b/tests/storage/test_semantic_queue_memory_dedupe.py
new file mode 100644
index 00000000..5e66e914
--- /dev/null
+++ b/tests/storage/test_semantic_queue_memory_dedupe.py
@@ -0,0 +1,72 @@
+# Copyright (c) 2026 Beijing Volcano Engine Technology Co., Ltd.
+# SPDX-License-Identifier: Apache-2.0
+"""Tests for memory-context semantic enqueue deduplication (#769)."""
+
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from openviking.storage.queuefs.named_queue import NamedQueue
+from openviking.storage.queuefs.semantic_msg import SemanticMsg
+from openviking.storage.queuefs.semantic_queue import SemanticQueue
+
+
+@pytest.mark.asyncio
+async def test_memory_semantic_enqueue_deduped_within_window():
+    mock_agfs = MagicMock()
+    with patch.object(NamedQueue, "enqueue", new_callable=AsyncMock) as named_enqueue:
+        named_enqueue.return_value = "queued-id"
+        q = SemanticQueue(mock_agfs, "/queue", "semantic")
+        msg = SemanticMsg(
+            uri="viking://user/default/memories/entities",
+            context_type="memory",
+            account_id="acc",
+            user_id="u1",
+            agent_id="a1",
+        )
+        r1 = await q.enqueue(msg)
+        r2 = await q.enqueue(
+            SemanticMsg(
+                uri="viking://user/default/memories/entities",
+                context_type="memory",
+                account_id="acc",
+                user_id="u1",
+                agent_id="a1",
+            )
+        )
+        assert r1 == "queued-id"
+        assert r2 == "deduplicated"
+        assert named_enqueue.call_count == 1
+
+
+@pytest.mark.asyncio
+async def test_memory_semantic_enqueue_different_uri_not_deduped():
+    mock_agfs = MagicMock()
+    with patch.object(NamedQueue, "enqueue", new_callable=AsyncMock) as named_enqueue:
+        named_enqueue.return_value = "queued-id"
+        q = SemanticQueue(mock_agfs, "/queue", "semantic")
+        await q.enqueue(
+            SemanticMsg(
+                uri="viking://user/default/memories/entities",
+                context_type="memory",
+            )
+        )
+        await q.enqueue(
+            SemanticMsg(
+                uri="viking://user/default/memories/patterns",
+                context_type="memory",
+            )
+        )
+        assert named_enqueue.call_count == 2
+
+
+@pytest.mark.asyncio
+async def test_non_memory_context_not_deduped():
+    mock_agfs = MagicMock()
+    with patch.object(NamedQueue, "enqueue", new_callable=AsyncMock) as named_enqueue:
+        named_enqueue.return_value = "queued-id"
+        q = SemanticQueue(mock_agfs, "/queue", "semantic")
+        uri = "viking://resources/docs"
+        await q.enqueue(SemanticMsg(uri=uri, context_type="resource"))
+        await q.enqueue(SemanticMsg(uri=uri, context_type="resource"))
+        assert named_enqueue.call_count == 2