Merge PR #1824: feat(tools): enhance ExecTool with enable flag

feat(tools): enhance ExecTool with enable flag

README.md

@@ -1163,6 +1163,7 @@ MCP tools are automatically discovered and registered on startup. The LLM can us
 | Option | Default | Description |
 |--------|---------|-------------|
 | `tools.restrictToWorkspace` | `false` | When `true`, restricts **all** agent tools (shell, file read/write/edit, list) to the workspace directory. Prevents path traversal and out-of-scope access. |
+| `tools.exec.enable` | `true` | When `false`, the shell `exec` tool is not registered at all. Use this to completely disable shell command execution. |
 | `tools.exec.pathAppend` | `""` | Extra directories to append to `PATH` when running shell commands (e.g. `/usr/sbin` for `ufw`). |
 | `channels.*.allowFrom` | `[]` (deny all) | Whitelist of user IDs. Empty denies all; use `["*"]` to allow everyone. |
 

nanobot/agent/loop.py

@@ -120,12 +120,13 @@ class AgentLoop:
         self.tools.register(ReadFileTool(workspace=self.workspace, allowed_dir=allowed_dir, extra_allowed_dirs=extra_read))
         for cls in (WriteFileTool, EditFileTool, ListDirTool):
             self.tools.register(cls(workspace=self.workspace, allowed_dir=allowed_dir))
-        self.tools.register(ExecTool(
-            working_dir=str(self.workspace),
-            timeout=self.exec_config.timeout,
-            restrict_to_workspace=self.restrict_to_workspace,
-            path_append=self.exec_config.path_append,
-        ))
+        if self.exec_config.enable:
+            self.tools.register(ExecTool(
+                working_dir=str(self.workspace),
+                timeout=self.exec_config.timeout,
+                restrict_to_workspace=self.restrict_to_workspace,
+                path_append=self.exec_config.path_append,
+            ))
         self.tools.register(WebSearchTool(config=self.web_search_config, proxy=self.web_proxy))
         self.tools.register(WebFetchTool(proxy=self.web_proxy))
         self.tools.register(MessageTool(send_callback=self.bus.publish_outbound))

nanobot/config/schema.py

@@ -118,10 +118,10 @@ class WebToolsConfig(Base):
 class ExecToolConfig(Base):
     """Shell exec tool configuration."""
 
+    enable: bool = True
     timeout: int = 60
     path_append: str = ""
 
-
 class MCPServerConfig(Base):
     """MCP server connection configuration (stdio or HTTP)."""
 

tests/test_task_cancel.py

@@ -8,7 +8,7 @@ from unittest.mock import AsyncMock, MagicMock, patch
 import pytest
 
 
-def _make_loop():
+def _make_loop(*, exec_config=None):
     """Create a minimal AgentLoop with mocked dependencies."""
     from nanobot.agent.loop import AgentLoop
     from nanobot.bus.queue import MessageBus
@@ -23,7 +23,7 @@ def _make_loop():
          patch("nanobot.agent.loop.SessionManager"), \
          patch("nanobot.agent.loop.SubagentManager") as MockSubMgr:
         MockSubMgr.return_value.cancel_by_session = AsyncMock(return_value=0)
-        loop = AgentLoop(bus=bus, provider=provider, workspace=workspace)
+        loop = AgentLoop(bus=bus, provider=provider, workspace=workspace, exec_config=exec_config)
     return loop, bus
 
 
@@ -90,6 +90,13 @@ class TestHandleStop:
 
 
 class TestDispatch:
+    def test_exec_tool_not_registered_when_disabled(self):
+        from nanobot.config.schema import ExecToolConfig
+
+        loop, _bus = _make_loop(exec_config=ExecToolConfig(enable=False))
+
+        assert loop.tools.get("exec") is None
+
     @pytest.mark.asyncio
     async def test_dispatch_processes_and_publishes(self):
         from nanobot.bus.events import InboundMessage, OutboundMessage