diff --git a/agent-node/src/agent_node/core/watcher.py b/agent-node/src/agent_node/core/watcher.py
index 191d912..5c8d6ee 100644
--- a/agent-node/src/agent_node/core/watcher.py
+++ b/agent-node/src/agent_node/core/watcher.py
@@ -48,6 +48,11 @@
             # Resolve real paths to handle symlinks (e.g. /tmp -> /private/tmp on macOS)
             real_src = os.path.realpath(event.src_path)
             rel_path = os.path.normpath(os.path.relpath(real_src, self.root_path))
+            # Critical: Do NOT send DELETE for internal temp/lock files.
+            # When sync does os.replace(tmp -> final), the OS fires a delete for .cortex_tmp.
+            # Without this filter, the watcher would relay a spurious DELETE to the Hub server.
+            if rel_path.endswith(".cortex_tmp") or rel_path.endswith(".cortex_lock"):
+                return
             if not self.ignore_filter.is_ignored(rel_path):
                 self.callback(self.session_id, agent_pb2.FileSyncMessage(
                     session_id=self.session_id,
diff --git a/ai-hub/app/core/grpc/services/assistant.py b/ai-hub/app/core/grpc/services/assistant.py
index 41257b4..9a6f94d 100644
--- a/ai-hub/app/core/grpc/services/assistant.py
+++ b/ai-hub/app/core/grpc/services/assistant.py
@@ -220,6 +220,30 @@
             for nid in destinations:
                 _send_to_node(nid)
 
+    def broadcast_delete(self, session_id: str, sender_node_id: str, rel_path: str):
+        """Broadcasts a file deletion from one node to all other nodes in the session mesh."""
+        with self.membership_lock:
+            session_members = self.memberships.get(session_id, [])
+            destinations = [n for n in session_members if n != sender_node_id]
+
+        if destinations:
+            print(f"    [📁🗑️📢] Broadcasting DELETE {rel_path} from {sender_node_id} to: {', '.join(destinations)}")
+
+        tid = f"fs-rm-bcast-{int(time.time()*1000)}"
+        for nid in destinations:
+            node = self.registry.get_node(nid)
+            if node:
+                node.send_message(agent_pb2.ServerTaskMessage(
+                    file_sync=agent_pb2.FileSyncMessage(
+                        session_id=session_id,
+                        task_id=tid,
+                        control=agent_pb2.SyncControl(
+                            action=agent_pb2.SyncControl.DELETE,
+                            path=rel_path
+                        )
+                    )
+                ), priority=2)
+
     def lock_workspace(self, node_id, session_id):
         """Disables user-side synchronization from a node during AI refactors."""
         self.control_sync(node_id, session_id, action="LOCK")
diff --git a/ai-hub/app/core/grpc/services/grpc_server.py b/ai-hub/app/core/grpc/services/grpc_server.py
index 37a5546..1a2d8bd 100644
--- a/ai-hub/app/core/grpc/services/grpc_server.py
+++ b/ai-hub/app/core/grpc/services/grpc_server.py
@@ -422,9 +422,16 @@
             elif fs.HasField("control"):
                 ctrl = fs.control
                 if ctrl.action == agent_pb2.SyncControl.DELETE:
-                    print(f"    [📁🗑️] Node requested DELETE on mirror: {ctrl.path}")
-                    self.mirror.delete_file(fs.session_id, ctrl.path)
-                    # Broadcast to other nodes (optional M7)
+                    path_to_del = ctrl.path
+                    # Guard: never process deletes for internal temp/lock files.
+                    # Nodes may fire spurious DELETE events for these when os.replace() is used.
+                    if path_to_del.endswith(".cortex_tmp") or path_to_del.endswith(".cortex_lock"):
+                        print(f"    [📁🚫] Ignored temp/lock DELETE from {node_id}: {path_to_del}")
+                    else:
+                        print(f"    [📁🗑️] Node requested DELETE on mirror: {path_to_del}")
+                        self.mirror.delete_file(fs.session_id, path_to_del)
+                        # Broadcast delete to all other session nodes for mesh consistency
+                        self.assistant.broadcast_delete(fs.session_id, node_id, path_to_del)
 
     def ReportHealth(self, request_iterator, context):
         """Collect Health Metrics and Feed Policy Updates."""