From 7ebd8c27ba4fd3eb532842c0b135c761fe5cfab3 Mon Sep 17 00:00:00 2001
From: doug <110487462+doughayden@users.noreply.github.com>
Date: Thu, 7 May 2026 19:46:57 -0400
Subject: [PATCH] fix(flows): terminate invocation at tool-level EUC

- Set end_invocation after auth event in postprocess
- Mirrors _resolve_toolset_auth's interrupt signal
- Tests assert single LLM call when auth requested
- events[-3] -> events[-2] in resume tests (tail trimmed)
---
 src/google/adk/flows/llm_flows/base_llm_flow.py        |  3 +++
 .../flows/llm_flows/test_functions_request_euc.py      | 10 ++++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/google/adk/flows/llm_flows/base_llm_flow.py b/src/google/adk/flows/llm_flows/base_llm_flow.py
index 31f998a588..9b6eda7dbb 100644
--- a/src/google/adk/flows/llm_flows/base_llm_flow.py
+++ b/src/google/adk/flows/llm_flows/base_llm_flow.py
@@ -1123,6 +1123,9 @@ async def _postprocess_handle_function_calls_async(
       if auth_event:
         yield auth_event
 
+        # Interrupt invocation (mirrors _resolve_toolset_auth behavior)
+        invocation_context.end_invocation = True
+
       tool_confirmation_event = functions.generate_request_confirmation_event(
           invocation_context, function_call_event, function_response_event
       )
diff --git a/tests/unittests/flows/llm_flows/test_functions_request_euc.py b/tests/unittests/flows/llm_flows/test_functions_request_euc.py
index f1e1d1f610..5ef81c8748 100644
--- a/tests/unittests/flows/llm_flows/test_functions_request_euc.py
+++ b/tests/unittests/flows/llm_flows/test_functions_request_euc.py
@@ -152,6 +152,8 @@ def call_external_api2(tool_context: ToolContext) -> Optional[int]:
         == auth_configs[idx].raw_auth_credential
     )
 
+  assert len(mock_model.requests) == 1
+
 
 def test_function_get_auth_response():
   id_1 = 'id_1'
@@ -309,7 +311,7 @@ def call_external_api2(tool_context: ToolContext) -> int:
   )
   runner = testing_utils.InMemoryRunner(agent)
   runner.run('test')
-  request_euc_function_call_event = runner.session.events[-3]
+  request_euc_function_call_event = runner.session.events[-2]
   function_response1 = types.FunctionResponse(
       name=request_euc_function_call_event.content.parts[0].function_call.name,
       response=auth_response1.model_dump(),
@@ -505,7 +507,7 @@ def call_external_api2(tool_context: ToolContext) -> int:
   )
   runner = testing_utils.InMemoryRunner(agent)
   runner.run('test')
-  request_euc_function_call_event = runner.session.events[-3]
+  request_euc_function_call_event = runner.session.events[-2]
   function_response1 = types.FunctionResponse(
       name=request_euc_function_call_event.content.parts[0].function_call.name,
       response=auth_response1.model_dump(),
@@ -531,7 +533,7 @@ def call_external_api2(tool_context: ToolContext) -> int:
   )
 
   assert function_invoked == 3
-  assert len(mock_model.requests) == 3
+  assert len(mock_model.requests) == 2
   request = mock_model.requests[-1]
   content = request.contents[-1]
   parts = content.parts
@@ -550,7 +552,7 @@ def call_external_api2(tool_context: ToolContext) -> int:
       ),
   )
   assert function_invoked == 4
-  assert len(mock_model.requests) == 4
+  assert len(mock_model.requests) == 3
   request = mock_model.requests[-1]
   content = request.contents[-1]
   parts = content.parts