diff --git a/tests/test_metis.py b/tests/test_metis.py
index 63f6b4d..510a7e1 100644
--- a/tests/test_metis.py
+++ b/tests/test_metis.py
@@ -111,3 +111,90 @@ def test_watch_sentinel_handles_http_error(monkeypatch) -> None:
     assert summary.status == "error"
     assert summary.detail == "upstream fail"
     assert summary.result["detail"] == "upstream fail"
+
+
+def test_normalize_payload_and_ready(monkeypatch) -> None:
+    monkeypatch.setattr(
+        "ariadne.services.metis.settings",
+        SimpleNamespace(metis_base_url="http://metis", metis_watch_url="", metis_timeout_sec=10.0),
+    )
+    service = metis_module.MetisService()
+
+    assert service.ready() is True
+    assert metis_module._normalize_payload(None) == {}
+    assert metis_module._normalize_payload(["watched"]) == {"result": ["watched"]}
+
+    monkeypatch.setattr(
+        "ariadne.services.metis.settings",
+        SimpleNamespace(metis_base_url="", metis_watch_url="", metis_timeout_sec=10.0),
+    )
+    assert service.ready() is False
+
+
+def test_watch_sentinel_handles_non_json_success(monkeypatch) -> None:
+    monkeypatch.setattr(
+        "ariadne.services.metis.settings",
+        SimpleNamespace(metis_base_url="http://metis", metis_watch_url="", metis_timeout_sec=10.0),
+    )
+    client = DummyClient(DummyResponse(payload=ValueError("not json")))
+    monkeypatch.setattr(metis_module.httpx, "Client", lambda **kwargs: client)
+
+    summary = metis_module.MetisService().watch_sentinel()
+
+    assert summary.status == "ok"
+    assert summary.result == {}
+
+
+def test_watch_sentinel_handles_http_error_without_json(monkeypatch) -> None:
+    monkeypatch.setattr(
+        "ariadne.services.metis.settings",
+        SimpleNamespace(metis_base_url="http://metis", metis_watch_url="", metis_timeout_sec=10.0),
+    )
+    client = DummyClient(DummyResponse(status_code=503, payload=ValueError("not json")))
+    monkeypatch.setattr(metis_module.httpx, "Client", lambda **kwargs: client)
+
+    summary = metis_module.MetisService().watch_sentinel()
+
+    assert summary.status == "error"
+    assert summary.detail == "metis watch failed with HTTP 503"
+
+
+def test_watch_sentinel_handles_client_exception(monkeypatch) -> None:
+    monkeypatch.setattr(
+        "ariadne.services.metis.settings",
+        SimpleNamespace(metis_base_url="http://metis", metis_watch_url="", metis_timeout_sec=10.0),
+    )
+
+    class FailingClient:
+        def __enter__(self):
+            raise RuntimeError("network down")
+
+        def __exit__(self, exc_type, exc, tb):
+            return False
+
+    monkeypatch.setattr(metis_module.httpx, "Client", lambda **kwargs: FailingClient())
+
+    summary = metis_module.MetisService().watch_sentinel()
+
+    assert summary.status == "error"
+    assert summary.detail == "network down"
+
+
+def test_watch_sentinel_normalizes_message_and_unknown_status(monkeypatch) -> None:
+    monkeypatch.setattr(
+        "ariadne.services.metis.settings",
+        SimpleNamespace(metis_base_url="http://metis", metis_watch_url="", metis_timeout_sec=10.0),
+    )
+    client = DummyClient(DummyResponse(payload={"status": "warning", "message": " watched with warnings "}))
+    monkeypatch.setattr(metis_module.httpx, "Client", lambda **kwargs: client)
+
+    summary = metis_module.MetisService().watch_sentinel()
+
+    assert summary.status == "ok"
+    assert summary.detail == "watched with warnings"
+
+    client.response = DummyResponse(payload={"status": "paused"})
+    summary = metis_module.MetisService().watch_sentinel()
+
+    assert summary.status == "ok"
+    assert summary.detail == "metis watch returned paused"