From 918c54538a205fe09475df3db4165d8c62372c10 Mon Sep 17 00:00:00 2001
From: Yufeng He <40085740+he-yufeng@users.noreply.github.com>
Date: Thu, 21 May 2026 00:05:32 +0800
Subject: [PATCH] fix: avoid ApiServer scope shadowing in web reload

---
 src/google/adk/cli/fast_api.py       |  5 +----
 tests/unittests/cli/test_fast_api.py | 25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/src/google/adk/cli/fast_api.py b/src/google/adk/cli/fast_api.py
index 4e07994394..48a8cab223 100644
--- a/src/google/adk/cli/fast_api.py
+++ b/src/google/adk/cli/fast_api.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import annotations
 
 from contextlib import asynccontextmanager
 import importlib
@@ -526,12 +527,8 @@ def get_fast_api_app(
           "DevServer not found, falling back to ApiServer. "
           "Dev-only endpoints will not be available."
       )
-      from .api_server import ApiServer
-
       ServerClass = ApiServer
   else:
-    from .api_server import ApiServer
-
     ServerClass = ApiServer
 
   adk_web_server = ServerClass(
diff --git a/tests/unittests/cli/test_fast_api.py b/tests/unittests/cli/test_fast_api.py
index a80644a9b6..44c0db1fa7 100755
--- a/tests/unittests/cli/test_fast_api.py
+++ b/tests/unittests/cli/test_fast_api.py
@@ -540,6 +540,31 @@ def _create_test_client(
     return TestClient(app)
 
 
+def test_web_reload_agents_uses_module_api_server_import(
+    mock_session_service,
+    mock_artifact_service,
+    mock_memory_service,
+    mock_agent_loader,
+    mock_eval_sets_manager,
+    mock_eval_set_results_manager,
+):
+  """Regression test for web reload mode with DevServer available."""
+  with patch("google.adk.cli.api_server.Observer") as mock_observer_class:
+    _create_test_client(
+        mock_session_service,
+        mock_artifact_service,
+        mock_memory_service,
+        mock_agent_loader,
+        mock_eval_sets_manager,
+        mock_eval_set_results_manager,
+        reload_agents=True,
+    )
+
+  observer = mock_observer_class.return_value
+  observer.schedule.assert_called_once()
+  observer.start.assert_called_once()
+
+
 def test_agent_with_bigquery_analytics_plugin(
     tmp_path,
     mock_session_service,