diff --git a/wwwroot/api/cockpit_chat.dspy b/wwwroot/api/cockpit_chat.dspy
index 8b66fce..e3a39d6 100644
--- a/wwwroot/api/cockpit_chat.dspy
+++ b/wwwroot/api/cockpit_chat.dspy
@@ -478,9 +478,11 @@ if action == 'send_message':
             for h in (await sor.sqlExe("SELECT role,content FROM pipeline_conversations WHERE created_by=${u}$ ORDER BY created_at ASC LIMIT 20",{"u":uid}) or []):
                 c = getattr(h,'content','') or ''
                 r = getattr(h,'role','') or ''
-                # Skip raw tool_call JSON — prevents LLM from mimicking old tool calls
+                # Skip raw tool_call JSON and contaminated old messages
                 if c.startswith('{"action":"tool_call"') or c.startswith('{"action": "tool_call"'):
                     continue
+                if 'tetris' in c.lower() or '俄罗斯方块' in c:
+                    continue
                 msgs.append({"role":'user' if r=='user' else 'assistant',"content":c})
             msgs.append({"role":"user","content":message_text})
             await sor.C('pipeline_conversations',{'id':getID(),'role':'user','content':message_text,'msg_type':'text','org_id':org_id,'created_by':uid})