From e98bba290ca2d0a683a8e45627d289bdb9c396ae Mon Sep 17 00:00:00 2001
From: Jeeho Lee <jeeholife2@gmail.com>
Date: Thu, 8 Oct 2026 00:06:09 +0000
Subject: [PATCH] fix(runners): hide thoughts from nonverbose debug output

Keep thought text out of run_debug's final-response display while preserving
verbose output and all parts in returned events.

Assisted-by: OpenAI Codex
---
 src/google/adk/utils/_debug_output.py      |  5 +++-
 tests/unittests/test_runners.py            | 28 ++++++++++++++++++++++
 tests/unittests/utils/test_debug_output.py | 23 ++++++++++++++++++
 3 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/src/google/adk/utils/_debug_output.py b/src/google/adk/utils/_debug_output.py
index ab435805ebc..3cfd0dd0c33 100644
--- a/src/google/adk/utils/_debug_output.py
+++ b/src/google/adk/utils/_debug_output.py
@@ -60,7 +60,10 @@ def flush_text() -> None:
       text_buffer.clear()
 
   for part in event.content.parts:
-    # Text parts are always shown regardless of verbose setting
+    if part.thought and not verbose:
+      continue
+
+    # Response text is shown regardless of verbose setting
     # because they contain the actual agent responses users expect
     if part.text:
       text_buffer.append(part.text)
diff --git a/tests/unittests/test_runners.py b/tests/unittests/test_runners.py
index 27c205ba630..d2df33ba3c8 100644
--- a/tests/unittests/test_runners.py
+++ b/tests/unittests/test_runners.py
@@ -2853,6 +2853,34 @@ async def test_run_debug_passes_get_session_config():
   assert events[0].author == "test_agent"
 
 
+@pytest.mark.parametrize("verbose", [False, True])
+async def test_run_debug_hides_thoughts_unless_verbose(capsys, verbose):
+  """Console verbosity does not remove thoughts from the returned events."""
+
+  class ThoughtAgent(BaseAgent):
+
+    async def _run_async_impl(self, ctx):
+      yield Event(
+          invocation_id=ctx.invocation_id,
+          author=self.name,
+          content=types.Content(
+              role="model",
+              parts=[
+                  types.Part(text="thinking ", thought=True),
+                  types.Part(text="answer"),
+              ],
+          ),
+      )
+
+  runner = runners.InMemoryRunner(agent=ThoughtAgent(name="test_agent"))
+
+  events = await runner.run_debug("hello", verbose=verbose)
+
+  expected = "thinking answer" if verbose else "answer"
+  assert capsys.readouterr().out == f"test_agent > {expected}\n"
+  assert events[0].content.parts[0].thought is True
+
+
 @pytest.mark.asyncio
 async def test_get_session_config_limits_events():
   """Verify that num_recent_events actually limits loaded events."""
diff --git a/tests/unittests/utils/test_debug_output.py b/tests/unittests/utils/test_debug_output.py
index 6e105ff3d4a..7d83de76e62 100644
--- a/tests/unittests/utils/test_debug_output.py
+++ b/tests/unittests/utils/test_debug_output.py
@@ -48,6 +48,29 @@ def test_print_event_prints_text_with_author_prefix(capsys):
   assert _lines(capsys) == ['agent > hello']
 
 
+def test_print_event_hides_thought_text_when_not_verbose(capsys):
+  """Thoughts are not concatenated into the final answer."""
+  print_event(
+      _event(
+          types.Part(text='thinking', thought=True),
+          types.Part(text='answer'),
+      )
+  )
+  assert _lines(capsys) == ['agent > answer']
+
+
+def test_print_event_with_only_thoughts_prints_nothing(capsys):
+  """An event containing only thoughts has no final answer to display."""
+  print_event(_event(types.Part(text='thinking', thought=True)))
+  assert _lines(capsys) == []
+
+
+def test_print_event_keeps_thought_text_when_verbose(capsys):
+  """Verbose output retains thought text for debugging."""
+  print_event(_event(types.Part(text='thinking', thought=True)), verbose=True)
+  assert _lines(capsys) == ['agent > thinking']
+
+
 def test_print_event_coalesces_consecutive_text_parts_into_one_line(capsys):
   # A streamed answer arrives as several text parts; repeating the author
   # prefix per part would fragment one sentence across many lines.