fix(restart): add explicit restart mode

docs/configuration.md

@@ -191,6 +191,8 @@ These variables are process-level switches. Set them in the same terminal, servi
 
 Internal variables such as `NANOBOT_RESTART_*` and `NANOBOT_PATH_*` are set by nanobot itself and are not a supported user configuration surface.
 
+For Windows service wrappers such as WinSW or nssm, set `gateway.restartMode` to `exit` so `/restart` exits and lets the service manager perform the restart. The default `auto` uses `spawn` on Windows foreground runs and `exec` elsewhere.
+
 ## Langfuse Observability
 
 nanobot can trace OpenAI-compatible provider calls through Langfuse's OpenAI SDK wrapper. This is configured with environment variables, not `config.json`.

nanobot/agent/loop.py

@@ -218,6 +218,7 @@ class AgentLoop:
         preset_snapshot_loader: preset_helpers.PresetSnapshotLoader | None = None,
         runtime_events: RuntimeEventBus | None = None,
         runtime_model_publisher: Callable[[str, str | None], None] | None = None,
+        restart_mode: str = "auto",
     ):
         from nanobot.config.schema import ToolsConfig
 
@@ -227,6 +228,7 @@ class AgentLoop:
         self.runtime_events = runtime_events or RuntimeEventBus()
         self.runtime_event_publisher = RuntimeEventPublisher(self.runtime_events)
         self.channels_config = channels_config
+        self.restart_mode = restart_mode
         self.provider = provider
         self._provider_snapshot_loader = provider_snapshot_loader
         self._preset_snapshot_loader = preset_snapshot_loader
@@ -396,6 +398,7 @@ class AgentLoop:
             tools_config=config.tools,
             model_presets=preset_helpers.configured_model_presets(config),
             model_preset=defaults.model_preset,
+            restart_mode=config.gateway.restart_mode,
             provider_snapshot_loader=provider_snapshot_loader,
             preset_snapshot_loader=preset_snapshot_loader,
             **extra,

nanobot/command/builtin.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import asyncio
 import os
+import subprocess
 import sys
 import time
 from contextlib import suppress
@@ -50,7 +51,7 @@ BUILTIN_COMMAND_SPECS: tuple[BuiltinCommandSpec, ...] = (
     BuiltinCommandSpec(
         "/restart",
         "Restart nanobot",
-        "Restart the bot process in place.",
+        "Restart the bot process.",
         "rotate-cw",
     ),
     BuiltinCommandSpec(
@@ -147,7 +148,7 @@ async def cmd_stop(ctx: CommandContext) -> OutboundMessage:
 
 
 async def cmd_restart(ctx: CommandContext) -> OutboundMessage:
-    """Restart the process in-place via os.execv."""
+    """Restart the process."""
     msg = ctx.msg
     set_restart_notice_to_env(
         channel=msg.channel,
@@ -157,7 +158,19 @@ async def cmd_restart(ctx: CommandContext) -> OutboundMessage:
 
     async def _do_restart():
         await asyncio.sleep(1)
-        os.execv(sys.executable, [sys.executable, "-m", "nanobot"] + sys.argv[1:])
+        argv = [sys.executable, "-m", "nanobot"] + sys.argv[1:]
+        mode = getattr(ctx.loop, "restart_mode", "auto") or "auto"
+        if mode == "auto":
+            mode = "spawn" if sys.platform == "win32" else "exec"
+        if mode == "exec":
+            os.execv(sys.executable, argv)
+            return
+        if mode == "spawn":
+            kwargs = {}
+            if sys.platform == "win32":
+                kwargs["creationflags"] = subprocess.CREATE_NEW_PROCESS_GROUP
+            subprocess.Popen(argv, **kwargs)
+        os._exit(0)
 
     asyncio.create_task(_do_restart())
     return OutboundMessage(

nanobot/config/schema.py

@@ -313,6 +313,7 @@ class GatewayConfig(Base):
 
     host: str = "127.0.0.1"  # Safer default: local-only bind.
     port: int = 18790
+    restart_mode: Literal["auto", "exec", "spawn", "exit"] = "auto"
     heartbeat: HeartbeatConfig = Field(default_factory=HeartbeatConfig)
 
 

tests/cli/test_restart_command.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import asyncio
 import os
+import sys
 import time
 from types import SimpleNamespace
 from unittest.mock import AsyncMock, MagicMock, patch
@@ -44,7 +45,8 @@ class TestRestartCommand:
             RESTART_STARTED_AT_ENV,
         )
 
-        loop, bus = _make_loop()
+        loop, _bus = _make_loop()
+        loop.restart_mode = "exec"
         msg = InboundMessage(channel="cli", sender_id="user", chat_id="direct", content="/restart")
         ctx = CommandContext(msg=msg, session=None, key=msg.session_key, raw="/restart", loop=loop)
 
@@ -76,10 +78,75 @@ class TestRestartCommand:
             await scheduled[0]
             mock_execv.assert_called_once()
 
+    @pytest.mark.asyncio
+    async def test_restart_windows_auto_spawns_and_exits(self):
+        from nanobot.command.builtin import cmd_restart
+        from nanobot.command.router import CommandContext
+
+        loop, _bus = _make_loop()
+        msg = InboundMessage(channel="cli", sender_id="user", chat_id="direct", content="/restart")
+        ctx = CommandContext(msg=msg, session=None, key=msg.session_key, raw="/restart", loop=loop)
+
+        async def _fast_sleep(_delay: float) -> None:
+            return None
+
+        scheduled: list[asyncio.Task] = []
+        fake_asyncio = SimpleNamespace(
+            sleep=_fast_sleep,
+            create_task=lambda coro: scheduled.append(asyncio.create_task(coro)) or scheduled[-1],
+        )
+
+        with patch("nanobot.command.builtin.asyncio", new=fake_asyncio), \
+             patch("nanobot.command.builtin.sys.platform", "win32"), \
+             patch("nanobot.command.builtin.subprocess.CREATE_NEW_PROCESS_GROUP", 512, create=True), \
+             patch("nanobot.command.builtin.subprocess.Popen") as mock_popen, \
+             patch("nanobot.command.builtin.os._exit") as mock_exit, \
+             patch("nanobot.command.builtin.os.execv") as mock_execv:
+            await cmd_restart(ctx)
+            await scheduled[0]
+
+        mock_popen.assert_called_once_with(
+            [sys.executable, "-m", "nanobot"] + sys.argv[1:],
+            creationflags=512,
+        )
+        mock_exit.assert_called_once_with(0)
+        mock_execv.assert_not_called()
+
+    @pytest.mark.asyncio
+    async def test_restart_exit_mode_does_not_spawn(self):
+        from nanobot.command.builtin import cmd_restart
+        from nanobot.command.router import CommandContext
+
+        loop, _bus = _make_loop()
+        loop.restart_mode = "exit"
+        msg = InboundMessage(channel="cli", sender_id="user", chat_id="direct", content="/restart")
+        ctx = CommandContext(msg=msg, session=None, key=msg.session_key, raw="/restart", loop=loop)
+
+        async def _fast_sleep(_delay: float) -> None:
+            return None
+
+        scheduled: list[asyncio.Task] = []
+        fake_asyncio = SimpleNamespace(
+            sleep=_fast_sleep,
+            create_task=lambda coro: scheduled.append(asyncio.create_task(coro)) or scheduled[-1],
+        )
+
+        with patch("nanobot.command.builtin.asyncio", new=fake_asyncio), \
+             patch("nanobot.command.builtin.subprocess.Popen") as mock_popen, \
+             patch("nanobot.command.builtin.os._exit") as mock_exit, \
+             patch("nanobot.command.builtin.os.execv") as mock_execv:
+            await cmd_restart(ctx)
+            await scheduled[0]
+
+        mock_exit.assert_called_once_with(0)
+        mock_popen.assert_not_called()
+        mock_execv.assert_not_called()
+
     @pytest.mark.asyncio
     async def test_restart_intercepted_in_run_loop(self):
         """Verify /restart is handled at the run-loop level, not inside _dispatch."""
         loop, bus = _make_loop()
+        loop.restart_mode = "exec"
         msg = InboundMessage(channel="telegram", sender_id="u1", chat_id="c1", content="/restart")
 
         async def _fast_sleep(_delay: float) -> None:

tests/config/test_gateway_config.py

@@ -0,0 +1,15 @@
+import pytest
+
+from nanobot.config.schema import Config, GatewayConfig
+
+
+def test_gateway_restart_mode_accepts_camel_alias():
+    config = Config.model_validate({"gateway": {"restartMode": "exit"}})
+
+    assert config.gateway.restart_mode == "exit"
+    assert config.model_dump(by_alias=True)["gateway"]["restartMode"] == "exit"
+
+
+def test_gateway_restart_mode_rejects_unknown_value():
+    with pytest.raises(ValueError):
+        GatewayConfig(restart_mode="service")