diff --git a/dev/test_dashboard_modes.py b/dev/test_dashboard_modes.py
new file mode 100644
index 0000000..ccadbfb
--- /dev/null
+++ b/dev/test_dashboard_modes.py
@@ -0,0 +1,65 @@
+import importlib.util
+import json
+import os
+import tempfile
+import unittest
+from pathlib import Path
+from unittest.mock import patch
+
+
+ROOT = Path(__file__).resolve().parents[1]
+MODULE_PATH = ROOT / "platform/llama-dashboard/app.py"
+
+
+class _Response:
+    status = 202
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *_args):
+        return False
+
+    def read(self):
+        return b'{"status":"accepted"}'
+
+
+class DashboardModeTests(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.tempdir = tempfile.TemporaryDirectory()
+        with patch.dict(os.environ, {
+            "DASHBOARD_HISTORY_DB": str(Path(cls.tempdir.name) / "history.sqlite3"),
+            "ROUTER_URL": "http://router.test:8081",
+            "ROUTER_API_KEY": "test-key",
+        }):
+            spec = importlib.util.spec_from_file_location("dashboard_app_test", MODULE_PATH)
+            cls.dashboard = importlib.util.module_from_spec(spec)
+            assert spec.loader is not None
+            spec.loader.exec_module(cls.dashboard)
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.tempdir.cleanup()
+
+    def test_separation_mode_is_forwarded_to_router(self):
+        with patch.object(self.dashboard.urllib.request, "urlopen", return_value=_Response()) as urlopen:
+            status, body = self.dashboard.change_mode("separation")
+
+        self.assertEqual(status, 202)
+        self.assertEqual(body, {"status": "accepted"})
+        request = urlopen.call_args.args[0]
+        self.assertEqual(json.loads(request.data), {"mode": "separation"})
+        self.assertEqual(request.get_header("Authorization"), "Bearer test-key")
+
+    def test_unknown_mode_is_rejected_without_router_request(self):
+        with patch.object(self.dashboard.urllib.request, "urlopen") as urlopen:
+            status, body = self.dashboard.change_mode("unknown")
+
+        self.assertEqual(status, 400)
+        self.assertEqual(body, {"error": "invalid mode"})
+        urlopen.assert_not_called()
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/platform/llama-dashboard/app.py b/platform/llama-dashboard/app.py
index f1b9d32..eb5f61e 100644
--- a/platform/llama-dashboard/app.py
+++ b/platform/llama-dashboard/app.py
@@ -277,7 +277,7 @@ def router_status() -> tuple[dict[str, Any], str | None]:
 
 
 def change_mode(mode: str) -> tuple[int, dict[str, Any]]:
-    if mode not in {"llm", "music"}:
+    if mode not in {"llm", "music", "separation"}:
         return 400, {"error": "invalid mode"}
     headers = {"Accept": "application/json", "Content-Type": "application/json"}
     if ROUTER_API_KEY: