nanobot/agent/loop.py

@@ -430,11 +430,23 @@ class AgentLoop:
             session.add_raw_message(chain_msg)
         self.sessions.save(session)
 
+        # Check for suppress mode
+        suppress_output = msg.metadata.get("suppress_output", False) if msg.metadata else False
+
+        if suppress_output:
+            # Prefix content for session visibility
+            final_content_for_session = f"[HIDDEN] {final_content}"
+            # Mark as suppressed for channel handler
+            outbound_metadata = {**(msg.metadata or {}), "suppressed": True}
+        else:
+            final_content_for_session = final_content
+            outbound_metadata = msg.metadata or {}
+
         return OutboundMessage(
             channel=msg.channel,
             chat_id=msg.chat_id,
-            content=final_content,
-            metadata=msg.metadata or {},  # Pass through for channel-specific needs (e.g. Slack thread_ts)
+            content=final_content_for_session,
+            metadata=outbound_metadata,
         )
     
     async def _process_system_message(self, msg: InboundMessage) -> OutboundMessage | None:

tests/test_agent_loop_metadata.py

@@ -14,10 +14,10 @@ async def test_process_direct_passes_metadata():
     provider = MagicMock(spec=LLMProvider)
     provider.chat = AsyncMock(return_value=LLMResponse(
         content="test response",
-        has_tool_calls=False,
         tool_calls=[]
     ))
     provider.get_default_model = MagicMock(return_value="test-model")
+    provider.thinking_budget = 0
 
     workspace = Path("/tmp/test-workspace")
     workspace.mkdir(exist_ok=True)
@@ -41,3 +41,56 @@ async def test_process_direct_passes_metadata():
     # the flow worked by checking the session was created)
     session = loop.sessions.get_or_create("cli:direct")
     assert len(session.messages) > 0
+
+
+@pytest.mark.asyncio
+async def test_suppress_mode_adds_hidden_prefix():
+    """Test that suppress_output metadata adds [HIDDEN] prefix."""
+    bus = MessageBus()
+    provider = MagicMock(spec=LLMProvider)
+    provider.chat = AsyncMock(return_value=LLMResponse(
+        content="This is the agent response",
+        tool_calls=[]
+    ))
+    provider.get_default_model = MagicMock(return_value="test-model")
+    provider.thinking_budget = 0
+
+    workspace = Path("/tmp/test-workspace")
+    workspace.mkdir(exist_ok=True)
+
+    loop = AgentLoop(bus=bus, provider=provider, workspace=workspace)
+
+    # Call with suppress_output=True
+    response = await loop.process_direct(
+        content="test message",
+        metadata={"suppress_output": True}
+    )
+
+    # Response content should have [HIDDEN] prefix
+    assert response.startswith("[HIDDEN]")
+    assert "This is the agent response" in response
+
+
+@pytest.mark.asyncio
+async def test_normal_mode_no_hidden_prefix():
+    """Test that normal messages don't get [HIDDEN] prefix."""
+    bus = MessageBus()
+    provider = MagicMock(spec=LLMProvider)
+    provider.chat = AsyncMock(return_value=LLMResponse(
+        content="Normal response",
+        tool_calls=[]
+    ))
+    provider.get_default_model = MagicMock(return_value="test-model")
+    provider.thinking_budget = 0
+
+    workspace = Path("/tmp/test-workspace")
+    workspace.mkdir(exist_ok=True)
+
+    loop = AgentLoop(bus=bus, provider=provider, workspace=workspace)
+
+    # Call without suppress_output
+    response = await loop.process_direct(content="test message")
+
+    # Response should NOT have [HIDDEN] prefix
+    assert not response.startswith("[HIDDEN]")
+    assert response == "Normal response"