diff --git a/tests/webui/test_settings_api.py b/tests/webui/test_settings_api.py
index b6fd99a8..1ad2bec9 100644
--- a/tests/webui/test_settings_api.py
+++ b/tests/webui/test_settings_api.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import builtins
 import json
 from types import SimpleNamespace
 
@@ -880,6 +881,42 @@ def test_openai_codex_oauth_login_passes_configured_proxy(
     assert captured == {"get_proxy": proxy, "login_proxy": proxy}
 
 
+def test_openai_codex_oauth_login_reports_missing_oauth_cli_kit(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    real_import = builtins.__import__
+
+    def fake_import(name, *args, **kwargs):
+        if name == "oauth_cli_kit":
+            raise ImportError("missing")
+        return real_import(name, *args, **kwargs)
+
+    monkeypatch.setattr(builtins, "__import__", fake_import)
+
+    with pytest.raises(WebUISettingsError) as exc:
+        login_oauth_provider({"provider": ["openai-codex"]})
+
+    assert "oauth_cli_kit not installed. Run: pip install oauth-cli-kit" in str(exc.value)
+
+
+def test_github_copilot_oauth_login_reports_missing_oauth_cli_kit(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    real_import = builtins.__import__
+
+    def fake_import(name, *args, **kwargs):
+        if name == "nanobot.providers.github_copilot_provider":
+            raise ImportError("missing")
+        return real_import(name, *args, **kwargs)
+
+    monkeypatch.setattr(builtins, "__import__", fake_import)
+
+    with pytest.raises(WebUISettingsError) as exc:
+        login_oauth_provider({"provider": ["github-copilot"]})
+
+    assert "oauth_cli_kit not installed. Run: pip install oauth-cli-kit" in str(exc.value)
+
+
 def test_provider_models_payload_fetches_openai_compatible_models(
     tmp_path,
     monkeypatch: pytest.MonkeyPatch,