From 3d7dfbeb68a3c7006731eb6ba8a0eabc31ad5b34 Mon Sep 17 00:00:00 2001
From: Sylvester Kaczmarek
 <16242628+sylvesterkaczmarek@users.noreply.github.com>
Date: Fri, 21 Aug 2026 01:26:57 +0100
Subject: [PATCH 1/2] fix: fail closed on invalid debug logging flags

---
 src/agents/_debug.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/agents/_debug.py b/src/agents/_debug.py
index 963c296b80..6806b05173 100644
--- a/src/agents/_debug.py
+++ b/src/agents/_debug.py
@@ -5,8 +5,13 @@ def _debug_flag_enabled(flag: str, default: bool = False) -> bool:
     flag_value = os.getenv(flag)
     if flag_value is None:
         return default
-    else:
-        return flag_value == "1" or flag_value.lower() == "true"
+
+    normalized = flag_value.strip().lower()
+    if normalized in {"1", "true"}:
+        return True
+    if normalized in {"0", "false"}:
+        return False
+    return default
 
 
 def _load_dont_log_model_data() -> bool:

From 39ba9d3f34e5eaaf1280b8cbd6996bd0575bfe1b Mon Sep 17 00:00:00 2001
From: Sylvester Kaczmarek
 <16242628+sylvesterkaczmarek@users.noreply.github.com>
Date: Fri, 21 Aug 2026 01:27:08 +0100
Subject: [PATCH 2/2] test: cover fail-closed debug flag parsing

---
 tests/test_debug_flag_parsing.py | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 tests/test_debug_flag_parsing.py

diff --git a/tests/test_debug_flag_parsing.py b/tests/test_debug_flag_parsing.py
new file mode 100644
index 0000000000..8da4a3a5c1
--- /dev/null
+++ b/tests/test_debug_flag_parsing.py
@@ -0,0 +1,30 @@
+import pytest
+
+from agents._debug import _load_dont_log_model_data, _load_dont_log_tool_data
+
+
+@pytest.mark.parametrize(
+    ("env_name", "loader"),
+    [
+        ("OPENAI_AGENTS_DONT_LOG_MODEL_DATA", _load_dont_log_model_data),
+        ("OPENAI_AGENTS_DONT_LOG_TOOL_DATA", _load_dont_log_tool_data),
+    ],
+)
+def test_dont_log_flags_strip_whitespace(env_name, loader, monkeypatch) -> None:
+    monkeypatch.setenv(env_name, " true ")
+    assert loader() is True
+
+    monkeypatch.setenv(env_name, " false ")
+    assert loader() is False
+
+
+@pytest.mark.parametrize(
+    ("env_name", "loader"),
+    [
+        ("OPENAI_AGENTS_DONT_LOG_MODEL_DATA", _load_dont_log_model_data),
+        ("OPENAI_AGENTS_DONT_LOG_TOOL_DATA", _load_dont_log_tool_data),
+    ],
+)
+def test_dont_log_flags_use_safe_default_for_invalid_values(env_name, loader, monkeypatch) -> None:
+    monkeypatch.setenv(env_name, "tru")
+    assert loader() is True