fix(runtime): restore standalone runtime compatibility

src/langbot/pkg/api/http/controller/groups/plugins.py

@@ -398,7 +398,16 @@ class PluginsRouterGroup(group.RouterGroup):
 
             # Get debug URL from config
             plugin_config = self.ap.instance_config.data.get('plugin', {})
-            debug_url = plugin_config.get('display_plugin_debug_url', 'http://localhost:5401')
+            debug_url = plugin_config.get(
+                'display_plugin_debug_url',
+                'ws://localhost:5401/plugin/debug/ws',
+            )
+            parsed_debug_url = urlparse(debug_url)
+            if parsed_debug_url.scheme in {'http', 'https'}:
+                debug_url = parsed_debug_url._replace(
+                    scheme='wss' if parsed_debug_url.scheme == 'https' else 'ws',
+                    path=parsed_debug_url.path or '/plugin/debug/ws',
+                ).geturl()
 
             return self.success(
                 data={

src/langbot/pkg/box/connector.py

@@ -367,6 +367,8 @@ class BoxRuntimeConnector(ManagedRuntimeConnector):
     def _ensure_control_token(self, *, allow_generate: bool) -> str:
         if not self._control_token and allow_generate:
             self._control_token = secrets.token_urlsafe(48)
+        if not self._control_token:
+            return ''
         try:
             self._control_token = validate_control_token(self._control_token)
         except ValueError as exc:
@@ -376,19 +378,19 @@ class BoxRuntimeConnector(ManagedRuntimeConnector):
         return self._control_token
 
     def get_control_headers(self) -> dict[str, str]:
-        """Headers for the instance-authenticated RPC control handshake."""
+        """Return instance-scoped RPC headers and the optional shared secret."""
 
         self._ensure_control_token(allow_generate=False)
-        return {
-            BOX_CONTROL_TOKEN_HEADER: self._control_token,
-            BOX_INSTANCE_HEADER: self._trusted_instance_uuid,
-        }
+        headers = {BOX_INSTANCE_HEADER: self._trusted_instance_uuid}
+        if self._control_token:
+            headers[BOX_CONTROL_TOKEN_HEADER] = self._control_token
+        return headers
 
     def get_relay_headers(
         self,
         action_context: ActionContext,
     ) -> dict[str, str]:
-        """Return authenticated, placement-scoped relay handshake headers."""
+        """Return instance- and placement-scoped relay handshake headers."""
 
         context = ActionContext.model_validate(action_context).without_installation()
         if context.instance_uuid != self._trusted_instance_uuid:

src/langbot/pkg/plugin/handler.py

@@ -1962,11 +1962,16 @@ class RuntimeConnectionHandler(handler.Handler):
 
     async def get_debug_info(self, execution_context: ExecutionContext) -> dict[str, Any]:
         """Get debug information including debug key and WS URL"""
+        action_context = ActionContext(
+            instance_uuid=execution_context.instance_uuid,
+            workspace_uuid=execution_context.workspace_uuid,
+            placement_generation=execution_context.placement_generation,
+        )
         result = await self.call_action(
             LangBotToRuntimeAction.GET_DEBUG_INFO,
             {},
             timeout=10,
-            action_context=execution_context,
+            action_context=action_context,
         )
         return result
 

src/langbot/templates/config.yaml

@@ -328,8 +328,9 @@ box:
     enabled: true
     backend: 'local'  # 'local' (Docker/nsjail), 'docker', 'nsjail', or 'e2b'. Can be written via BOX__BACKEND.
     runtime:
-        # External WebSocket runtimes also require LANGBOT_BOX_CONTROL_TOKEN in
-        # both LangBot and Box. Keep the shared secret out of this config file.
+        # LANGBOT_BOX_CONTROL_TOKEN is optional for OSS external WebSocket
+        # runtimes. To protect an exposed endpoint, set the same strong secret
+        # in both LangBot and Box. Keep it out of this config file.
         endpoint: ''  # External Box Runtime base URL, e.g. 'ws://127.0.0.1:5410'. Leave empty for local auto-managed runtime.
     limits:
         max_sessions: 64