From 7566e3e382cf25dc54782bf57f13551faec9a4b3 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 21:13:53 +0000
Subject: [PATCH 01/16] Initial plan


From 30174f9a5c53bd418c284ff86982d8a849c4dec0 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 21:17:37 +0000
Subject: [PATCH 02/16] Fix duplicated system instructions in Python telemetry

---
 .../packages/core/agent_framework/observability.py | 14 ++++++++------
 .../packages/core/tests/core/test_observability.py | 10 ++++++++--
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 022008c05b..71dbf316ec 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2155,13 +2155,15 @@ def _capture_messages(
     """Log messages with extra information."""
     from ._types import normalize_messages, prepend_instructions_to_messages
 
-    prepped = prepend_instructions_to_messages(normalize_messages(messages), system_instructions)
-    otel_messages: list[dict[str, Any]] = []
+    normalized_messages = normalize_messages(messages)
+    prepped = prepend_instructions_to_messages(normalized_messages, system_instructions)
+    span_messages: list[dict[str, Any]] = []
     for index, message in enumerate(prepped):
+        otel_message = _to_otel_message(message)
+        if index >= len(prepped) - len(normalized_messages):
+            span_messages.append(otel_message)
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
-        otel_message = _to_otel_message(message)
-        otel_messages.append(otel_message)
         logger.info(
             otel_message,
             extra={
@@ -2171,9 +2173,9 @@ def _capture_messages(
             },
         )
     if finish_reason:
-        otel_messages[-1]["finish_reason"] = FINISH_REASON_MAP[finish_reason]
+        span_messages[-1]["finish_reason"] = FINISH_REASON_MAP[finish_reason]
     span.set_attribute(
-        OtelAttr.OUTPUT_MESSAGES if output else OtelAttr.INPUT_MESSAGES, json.dumps(otel_messages, ensure_ascii=False)
+        OtelAttr.OUTPUT_MESSAGES if output else OtelAttr.INPUT_MESSAGES, json.dumps(span_messages, ensure_ascii=False)
     )
     if system_instructions:
         if not isinstance(system_instructions, list):
diff --git a/python/packages/core/tests/core/test_observability.py b/python/packages/core/tests/core/test_observability.py
index 6185bccd44..7674c70800 100644
--- a/python/packages/core/tests/core/test_observability.py
+++ b/python/packages/core/tests/core/test_observability.py
@@ -290,9 +290,9 @@ async def test_chat_client_observability_with_instructions(
     assert len(system_instructions) == 1
     assert system_instructions[0]["content"] == "You are a helpful assistant."
 
-    # Verify input_messages contains system message
+    # Verify input_messages excludes system instructions
     input_messages = json.loads(span.attributes[OtelAttr.INPUT_MESSAGES])
-    assert any(msg.get("role") == "system" for msg in input_messages)
+    assert [msg.get("role") for msg in input_messages] == ["user"]
 
 
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)
@@ -2981,6 +2981,9 @@ async def test_system_instructions_preserves_non_ascii_characters(span_exporter:
     system_instructions = json.loads(system_instructions_json)
     assert system_instructions[0]["content"] == chinese_text
 
+    input_messages = json.loads(span.attributes[OtelAttr.INPUT_MESSAGES])
+    assert [msg.get("role") for msg in input_messages] == ["user"]
+
 
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)
 async def test_tool_arguments_preserves_non_ascii_characters(span_exporter: InMemorySpanExporter):
@@ -3104,6 +3107,9 @@ async def test_agent_instructions_from_default_options(
     assert len(system_instructions) == 1
     assert system_instructions[0]["content"] == "Default system instructions."
 
+    input_messages = json.loads(span.attributes[OtelAttr.INPUT_MESSAGES])
+    assert [msg.get("role") for msg in input_messages] == ["user"]
+
 
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)
 async def test_agent_instructions_from_options_override(

From 12c01642afb6169ffad5215959d76f407c9098cb Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 21:18:13 +0000
Subject: [PATCH 03/16] Clarify telemetry message filtering

---
 python/packages/core/agent_framework/observability.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 71dbf316ec..beded86e12 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2158,9 +2158,10 @@ def _capture_messages(
     normalized_messages = normalize_messages(messages)
     prepped = prepend_instructions_to_messages(normalized_messages, system_instructions)
     span_messages: list[dict[str, Any]] = []
+    span_message_start_index = len(prepped) - len(normalized_messages)
     for index, message in enumerate(prepped):
         otel_message = _to_otel_message(message)
-        if index >= len(prepped) - len(normalized_messages):
+        if index >= span_message_start_index:
             span_messages.append(otel_message)
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead

From 1b691ae6c7d5cb2d8dd169fdf525df23fd32745b Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 21:33:03 +0000
Subject: [PATCH 04/16] test: cover separate and in-history system messages

---
 .../core/tests/core/test_observability.py     | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/python/packages/core/tests/core/test_observability.py b/python/packages/core/tests/core/test_observability.py
index 7674c70800..55d6edfc34 100644
--- a/python/packages/core/tests/core/test_observability.py
+++ b/python/packages/core/tests/core/test_observability.py
@@ -324,6 +324,40 @@ async def test_chat_client_streaming_observability_with_instructions(
     assert len(system_instructions) == 1
     assert system_instructions[0]["content"] == "You are a helpful assistant."
 
+    input_messages = json.loads(span.attributes[OtelAttr.INPUT_MESSAGES])
+    assert [msg.get("role") for msg in input_messages] == ["user"]
+
+
+@pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)
+async def test_chat_client_observability_with_system_message_and_instructions(
+    mock_chat_client, span_exporter: InMemorySpanExporter, enable_sensitive_data
+):
+    """Test input chat-history system messages stay in input_messages when instructions are separate."""
+    import json
+
+    client = mock_chat_client()
+
+    messages = [
+        Message(role="system", contents=["Original system message"]),
+        Message(role="user", contents=["Test message"]),
+    ]
+    options = {"model": "Test", "instructions": "Framework system instruction"}
+    span_exporter.clear()
+    response = await client.get_response(messages=messages, options=options)
+
+    assert response is not None
+    spans = span_exporter.get_finished_spans()
+    assert len(spans) == 1
+    span = spans[0]
+
+    system_instructions = json.loads(span.attributes[OtelAttr.SYSTEM_INSTRUCTIONS])
+    assert system_instructions == [{"type": "text", "content": "Framework system instruction"}]
+
+    input_messages = json.loads(span.attributes[OtelAttr.INPUT_MESSAGES])
+    assert [msg.get("role") for msg in input_messages] == ["system", "user"]
+    assert input_messages[0]["parts"][0]["content"] == "Original system message"
+    assert input_messages[1]["parts"][0]["content"] == "Test message"
+
 
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)
 async def test_chat_client_observability_without_instructions(
@@ -3111,6 +3145,37 @@ async def test_agent_instructions_from_default_options(
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
 
+@pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)
+async def test_agent_instructions_preserve_system_messages_in_history(
+    mock_chat_agent, span_exporter: InMemorySpanExporter, enable_sensitive_data
+):
+    """Test agent spans keep chat-history system messages separate from framework instructions."""
+    import json
+
+    agent = mock_chat_agent()
+    agent.default_options = {"model": "TestModel", "instructions": "Default system instructions."}
+
+    messages = [
+        Message(role="system", contents=["Original system message"]),
+        Message(role="user", contents=["Test message"]),
+    ]
+    span_exporter.clear()
+    response = await agent.run(messages)
+
+    assert response is not None
+    spans = span_exporter.get_finished_spans()
+    assert len(spans) == 1
+    span = spans[0]
+
+    system_instructions = json.loads(span.attributes[OtelAttr.SYSTEM_INSTRUCTIONS])
+    assert system_instructions == [{"type": "text", "content": "Default system instructions."}]
+
+    input_messages = json.loads(span.attributes[OtelAttr.INPUT_MESSAGES])
+    assert [msg.get("role") for msg in input_messages] == ["system", "user"]
+    assert input_messages[0]["parts"][0]["content"] == "Original system message"
+    assert input_messages[1]["parts"][0]["content"] == "Test message"
+
+
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)
 async def test_agent_instructions_from_options_override(
     mock_chat_agent, span_exporter: InMemorySpanExporter, enable_sensitive_data

From 016cc1a80c26c2aa57f668fe3071cae85dec2b26 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:03:33 +0000
Subject: [PATCH 05/16] Clarify observability message logging split

---
 .../core/agent_framework/observability.py     | 12 +++----
 .../core/tests/core/test_observability.py     | 33 +++++++++++++++++++
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index beded86e12..6f981b4ada 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2156,13 +2156,11 @@ def _capture_messages(
     from ._types import normalize_messages, prepend_instructions_to_messages
 
     normalized_messages = normalize_messages(messages)
-    prepped = prepend_instructions_to_messages(normalized_messages, system_instructions)
-    span_messages: list[dict[str, Any]] = []
-    span_message_start_index = len(prepped) - len(normalized_messages)
-    for index, message in enumerate(prepped):
-        otel_message = _to_otel_message(message)
-        if index >= span_message_start_index:
-            span_messages.append(otel_message)
+    logging_messages = prepend_instructions_to_messages(normalized_messages, system_instructions)
+    span_messages = [_to_otel_message(message) for message in normalized_messages]
+    prepended_count = len(logging_messages) - len(normalized_messages)
+    for index, message in enumerate(logging_messages):
+        otel_message = span_messages[index - prepended_count] if index >= prepended_count else _to_otel_message(message)
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
         logger.info(
diff --git a/python/packages/core/tests/core/test_observability.py b/python/packages/core/tests/core/test_observability.py
index 55d6edfc34..3e9cf40cf9 100644
--- a/python/packages/core/tests/core/test_observability.py
+++ b/python/packages/core/tests/core/test_observability.py
@@ -3019,6 +3019,39 @@ async def test_system_instructions_preserves_non_ascii_characters(span_exporter:
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
 
+def test_capture_messages_logs_prepended_instructions_without_serializing_them(
+    span_exporter: InMemorySpanExporter,
+):
+    """Test prepended instructions still emit log events while span input_messages stays chat-history only."""
+    import json
+
+    from opentelemetry import trace
+
+    tracer = trace.get_tracer("test")
+    span_exporter.clear()
+
+    with (
+        patch("agent_framework.observability.logger.info") as mock_logger_info,
+        tracer.start_as_current_span("test_span") as span,
+    ):
+        _capture_messages(
+            span=span,
+            provider_name="test_provider",
+            messages=[Message(role="user", contents=["Test"])],
+            system_instructions="Framework system instruction",
+        )
+
+    spans = span_exporter.get_finished_spans()
+    assert len(spans) == 1
+    input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
+    assert [msg.get("role") for msg in input_messages] == ["user"]
+
+    logged_messages = [call.args[0] for call in mock_logger_info.call_args_list]
+    assert [msg["role"] for msg in logged_messages] == ["system", "user"]
+    assert logged_messages[0]["parts"][0]["content"] == "Framework system instruction"
+    assert logged_messages[1]["parts"][0]["content"] == "Test"
+
+
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)
 async def test_tool_arguments_preserves_non_ascii_characters(span_exporter: InMemorySpanExporter):
     """Test that non-ASCII characters are preserved in tool arguments span attribute."""

From ece3db8cfde14654d5609e255cf4e07cb533a52e Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:04:19 +0000
Subject: [PATCH 06/16] Simplify observability logging serialization

---
 python/packages/core/agent_framework/observability.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 6f981b4ada..8a5ff14bbf 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2158,9 +2158,8 @@ def _capture_messages(
     normalized_messages = normalize_messages(messages)
     logging_messages = prepend_instructions_to_messages(normalized_messages, system_instructions)
     span_messages = [_to_otel_message(message) for message in normalized_messages]
-    prepended_count = len(logging_messages) - len(normalized_messages)
     for index, message in enumerate(logging_messages):
-        otel_message = span_messages[index - prepended_count] if index >= prepended_count else _to_otel_message(message)
+        otel_message = _to_otel_message(message)
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
         logger.info(

From f16a6295fbfc54a24ff294f9b65ecdd46b4a58e7 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:04:55 +0000
Subject: [PATCH 07/16] Harden observability regression test

---
 python/packages/core/tests/core/test_observability.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/python/packages/core/tests/core/test_observability.py b/python/packages/core/tests/core/test_observability.py
index 3e9cf40cf9..8801d65c65 100644
--- a/python/packages/core/tests/core/test_observability.py
+++ b/python/packages/core/tests/core/test_observability.py
@@ -3046,7 +3046,11 @@ def test_capture_messages_logs_prepended_instructions_without_serializing_them(
     input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
-    logged_messages = [call.args[0] for call in mock_logger_info.call_args_list]
+    assert mock_logger_info.call_count == 2
+    first_call, second_call = mock_logger_info.call_args_list
+    assert first_call.args
+    assert second_call.args
+    logged_messages = [first_call.args[0], second_call.args[0]]
     assert [msg["role"] for msg in logged_messages] == ["system", "user"]
     assert logged_messages[0]["parts"][0]["content"] == "Framework system instruction"
     assert logged_messages[1]["parts"][0]["content"] == "Test"

From f6db62e07bce492f977194788af035852506dcf3 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:05:40 +0000
Subject: [PATCH 08/16] Reuse observability span message serialization

---
 python/packages/core/agent_framework/observability.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 8a5ff14bbf..7c63581c19 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2158,8 +2158,10 @@ def _capture_messages(
     normalized_messages = normalize_messages(messages)
     logging_messages = prepend_instructions_to_messages(normalized_messages, system_instructions)
     span_messages = [_to_otel_message(message) for message in normalized_messages]
+    span_message_iter = iter(span_messages)
+    prepended_count = len(logging_messages) - len(normalized_messages)
     for index, message in enumerate(logging_messages):
-        otel_message = _to_otel_message(message)
+        otel_message = _to_otel_message(message) if index < prepended_count else next(span_message_iter)
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
         logger.info(

From ecf5341ca0d945f43775344b63f7cd673dfd1400 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:06:35 +0000
Subject: [PATCH 09/16] Clarify observability logging loops

---
 .../core/agent_framework/observability.py         | 15 ++++++++++++---
 .../core/tests/core/test_observability.py         |  2 +-
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 7c63581c19..391c77a3c5 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2158,10 +2158,9 @@ def _capture_messages(
     normalized_messages = normalize_messages(messages)
     logging_messages = prepend_instructions_to_messages(normalized_messages, system_instructions)
     span_messages = [_to_otel_message(message) for message in normalized_messages]
-    span_message_iter = iter(span_messages)
     prepended_count = len(logging_messages) - len(normalized_messages)
-    for index, message in enumerate(logging_messages):
-        otel_message = _to_otel_message(message) if index < prepended_count else next(span_message_iter)
+    for index, message in enumerate(logging_messages[:prepended_count]):
+        otel_message = _to_otel_message(message)
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
         logger.info(
@@ -2172,6 +2171,16 @@ def _capture_messages(
                 MessageListTimestampFilter.INDEX_KEY: index,
             },
         )
+    for index, message in enumerate(normalized_messages, start=prepended_count):
+        otel_message = span_messages[index - prepended_count]
+        logger.info(
+            otel_message,
+            extra={
+                OtelAttr.EVENT_NAME: OtelAttr.CHOICE if output else ROLE_EVENT_MAP.get(message.role),
+                OtelAttr.PROVIDER_NAME: provider_name,
+                MessageListTimestampFilter.INDEX_KEY: index,
+            },
+        )
     if finish_reason:
         span_messages[-1]["finish_reason"] = FINISH_REASON_MAP[finish_reason]
     span.set_attribute(
diff --git a/python/packages/core/tests/core/test_observability.py b/python/packages/core/tests/core/test_observability.py
index 8801d65c65..c139f1a115 100644
--- a/python/packages/core/tests/core/test_observability.py
+++ b/python/packages/core/tests/core/test_observability.py
@@ -3046,7 +3046,7 @@ def test_capture_messages_logs_prepended_instructions_without_serializing_them(
     input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
-    assert mock_logger_info.call_count == 2
+    assert mock_logger_info.call_count == 2, f"Expected 2 log calls, got {mock_logger_info.call_count}"
     first_call, second_call = mock_logger_info.call_args_list
     assert first_call.args
     assert second_call.args

From 40e4a0b0ff27f83330610267dd23f38e23846e96 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:07:31 +0000
Subject: [PATCH 10/16] Polish observability message serialization

---
 python/packages/core/agent_framework/observability.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 391c77a3c5..9d36003bee 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2159,8 +2159,10 @@ def _capture_messages(
     logging_messages = prepend_instructions_to_messages(normalized_messages, system_instructions)
     span_messages = [_to_otel_message(message) for message in normalized_messages]
     prepended_count = len(logging_messages) - len(normalized_messages)
-    for index, message in enumerate(logging_messages[:prepended_count]):
-        otel_message = _to_otel_message(message)
+    prepended_messages = [_to_otel_message(message) for message in logging_messages[:prepended_count]]
+    for index, (message, otel_message) in enumerate(
+        zip(logging_messages[:prepended_count], prepended_messages, strict=False)
+    ):
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
         logger.info(
@@ -2171,8 +2173,9 @@ def _capture_messages(
                 MessageListTimestampFilter.INDEX_KEY: index,
             },
         )
-    for index, message in enumerate(normalized_messages, start=prepended_count):
-        otel_message = span_messages[index - prepended_count]
+    for index, (message, otel_message) in enumerate(
+        zip(normalized_messages, span_messages, strict=False), start=prepended_count
+    ):
         logger.info(
             otel_message,
             extra={

From 25ceb87d7255554c194d820e06f1b2fa32537e0a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:08:11 +0000
Subject: [PATCH 11/16] Tighten observability zip checks

---
 python/packages/core/agent_framework/observability.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 9d36003bee..42c1fd4308 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2161,7 +2161,7 @@ def _capture_messages(
     prepended_count = len(logging_messages) - len(normalized_messages)
     prepended_messages = [_to_otel_message(message) for message in logging_messages[:prepended_count]]
     for index, (message, otel_message) in enumerate(
-        zip(logging_messages[:prepended_count], prepended_messages, strict=False)
+        zip(logging_messages[:prepended_count], prepended_messages, strict=True)
     ):
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
@@ -2174,7 +2174,7 @@ def _capture_messages(
             },
         )
     for index, (message, otel_message) in enumerate(
-        zip(normalized_messages, span_messages, strict=False), start=prepended_count
+        zip(normalized_messages, span_messages, strict=True), start=prepended_count
     ):
         logger.info(
             otel_message,

From 84e5a62d8716ba4cb7466a5ba2fea8e5f70db061 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:21:17 +0000
Subject: [PATCH 12/16] Refactor observability message capture loop

---
 .../core/agent_framework/observability.py     | 21 +++-------
 .../core/tests/core/test_observability.py     | 38 +++++++++++++++++++
 2 files changed, 43 insertions(+), 16 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 42c1fd4308..bd1ae56340 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2157,14 +2157,12 @@ def _capture_messages(
 
     normalized_messages = normalize_messages(messages)
     logging_messages = prepend_instructions_to_messages(normalized_messages, system_instructions)
-    span_messages = [_to_otel_message(message) for message in normalized_messages]
     prepended_count = len(logging_messages) - len(normalized_messages)
-    prepended_messages = [_to_otel_message(message) for message in logging_messages[:prepended_count]]
-    for index, (message, otel_message) in enumerate(
-        zip(logging_messages[:prepended_count], prepended_messages, strict=True)
-    ):
+    span_messages = []
+    for index, message in enumerate(logging_messages):
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
+        otel_message = _to_otel_message(message)
         logger.info(
             otel_message,
             extra={
@@ -2173,17 +2171,8 @@ def _capture_messages(
                 MessageListTimestampFilter.INDEX_KEY: index,
             },
         )
-    for index, (message, otel_message) in enumerate(
-        zip(normalized_messages, span_messages, strict=True), start=prepended_count
-    ):
-        logger.info(
-            otel_message,
-            extra={
-                OtelAttr.EVENT_NAME: OtelAttr.CHOICE if output else ROLE_EVENT_MAP.get(message.role),
-                OtelAttr.PROVIDER_NAME: provider_name,
-                MessageListTimestampFilter.INDEX_KEY: index,
-            },
-        )
+        if index >= prepended_count:
+            span_messages.append(otel_message)
     if finish_reason:
         span_messages[-1]["finish_reason"] = FINISH_REASON_MAP[finish_reason]
     span.set_attribute(
diff --git a/python/packages/core/tests/core/test_observability.py b/python/packages/core/tests/core/test_observability.py
index c139f1a115..28223dbbec 100644
--- a/python/packages/core/tests/core/test_observability.py
+++ b/python/packages/core/tests/core/test_observability.py
@@ -3056,6 +3056,44 @@ def test_capture_messages_logs_prepended_instructions_without_serializing_them(
     assert logged_messages[1]["parts"][0]["content"] == "Test"
 
 
+def test_capture_messages_logs_framework_and_chat_history_system_messages_once(
+    span_exporter: InMemorySpanExporter,
+):
+    """Test framework instructions and chat-history system messages each log once."""
+    import json
+
+    from opentelemetry import trace
+
+    tracer = trace.get_tracer("test")
+    span_exporter.clear()
+
+    with (
+        patch("agent_framework.observability.logger.info") as mock_logger_info,
+        tracer.start_as_current_span("test_span") as span,
+    ):
+        _capture_messages(
+            span=span,
+            provider_name="test_provider",
+            messages=[
+                Message(role="system", contents=["Original system message"]),
+                Message(role="user", contents=["Test"]),
+            ],
+            system_instructions="Framework system instruction",
+        )
+
+    spans = span_exporter.get_finished_spans()
+    assert len(spans) == 1
+    input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
+    assert [msg.get("role") for msg in input_messages] == ["system", "user"]
+
+    assert mock_logger_info.call_count == 3, f"Expected 3 log calls, got {mock_logger_info.call_count}"
+    logged_messages = [call.args[0] for call in mock_logger_info.call_args_list]
+    assert [msg["role"] for msg in logged_messages] == ["system", "system", "user"]
+    assert logged_messages[0]["parts"][0]["content"] == "Framework system instruction"
+    assert logged_messages[1]["parts"][0]["content"] == "Original system message"
+    assert logged_messages[2]["parts"][0]["content"] == "Test"
+
+
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)
 async def test_tool_arguments_preserves_non_ascii_characters(span_exporter: InMemorySpanExporter):
     """Test that non-ASCII characters are preserved in tool arguments span attribute."""

From 5e039d1251038c7c81c49f7d463191004322c9cc Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:34:00 +0000
Subject: [PATCH 13/16] Fix telemetry logging for separate system instructions

---
 .../core/agent_framework/observability.py     |  9 ++----
 .../core/tests/core/test_observability.py     | 29 +++++++++----------
 2 files changed, 16 insertions(+), 22 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index bd1ae56340..422f9e3a9d 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2153,13 +2153,11 @@ def _capture_messages(
     finish_reason: FinishReason | None = None,
 ) -> None:
     """Log messages with extra information."""
-    from ._types import normalize_messages, prepend_instructions_to_messages
+    from ._types import normalize_messages
 
     normalized_messages = normalize_messages(messages)
-    logging_messages = prepend_instructions_to_messages(normalized_messages, system_instructions)
-    prepended_count = len(logging_messages) - len(normalized_messages)
     span_messages = []
-    for index, message in enumerate(logging_messages):
+    for index, message in enumerate(normalized_messages):
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
         otel_message = _to_otel_message(message)
@@ -2171,8 +2169,7 @@ def _capture_messages(
                 MessageListTimestampFilter.INDEX_KEY: index,
             },
         )
-        if index >= prepended_count:
-            span_messages.append(otel_message)
+        span_messages.append(otel_message)
     if finish_reason:
         span_messages[-1]["finish_reason"] = FINISH_REASON_MAP[finish_reason]
     span.set_attribute(
diff --git a/python/packages/core/tests/core/test_observability.py b/python/packages/core/tests/core/test_observability.py
index 28223dbbec..d4403043af 100644
--- a/python/packages/core/tests/core/test_observability.py
+++ b/python/packages/core/tests/core/test_observability.py
@@ -3019,10 +3019,10 @@ async def test_system_instructions_preserves_non_ascii_characters(span_exporter:
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
 
-def test_capture_messages_logs_prepended_instructions_without_serializing_them(
+def test_capture_messages_keeps_framework_instructions_out_of_logs_and_span_messages(
     span_exporter: InMemorySpanExporter,
 ):
-    """Test prepended instructions still emit log events while span input_messages stays chat-history only."""
+    """Test separate framework instructions do not appear in chat-history logs or span messages."""
     import json
 
     from opentelemetry import trace
@@ -3046,20 +3046,18 @@ def test_capture_messages_logs_prepended_instructions_without_serializing_them(
     input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
-    assert mock_logger_info.call_count == 2, f"Expected 2 log calls, got {mock_logger_info.call_count}"
-    first_call, second_call = mock_logger_info.call_args_list
+    assert mock_logger_info.call_count == 1, f"Expected 1 log call, got {mock_logger_info.call_count}"
+    (first_call,) = mock_logger_info.call_args_list
     assert first_call.args
-    assert second_call.args
-    logged_messages = [first_call.args[0], second_call.args[0]]
-    assert [msg["role"] for msg in logged_messages] == ["system", "user"]
-    assert logged_messages[0]["parts"][0]["content"] == "Framework system instruction"
-    assert logged_messages[1]["parts"][0]["content"] == "Test"
+    logged_message = first_call.args[0]
+    assert logged_message["role"] == "user"
+    assert logged_message["parts"][0]["content"] == "Test"
 
 
-def test_capture_messages_logs_framework_and_chat_history_system_messages_once(
+def test_capture_messages_logs_only_chat_history_when_framework_instructions_are_separate(
     span_exporter: InMemorySpanExporter,
 ):
-    """Test framework instructions and chat-history system messages each log once."""
+    """Test chat-history logging preserves original system messages without prepending framework instructions."""
     import json
 
     from opentelemetry import trace
@@ -3086,12 +3084,11 @@ def test_capture_messages_logs_framework_and_chat_history_system_messages_once(
     input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
     assert [msg.get("role") for msg in input_messages] == ["system", "user"]
 
-    assert mock_logger_info.call_count == 3, f"Expected 3 log calls, got {mock_logger_info.call_count}"
+    assert mock_logger_info.call_count == 2, f"Expected 2 log calls, got {mock_logger_info.call_count}"
     logged_messages = [call.args[0] for call in mock_logger_info.call_args_list]
-    assert [msg["role"] for msg in logged_messages] == ["system", "system", "user"]
-    assert logged_messages[0]["parts"][0]["content"] == "Framework system instruction"
-    assert logged_messages[1]["parts"][0]["content"] == "Original system message"
-    assert logged_messages[2]["parts"][0]["content"] == "Test"
+    assert [msg["role"] for msg in logged_messages] == ["system", "user"]
+    assert logged_messages[0]["parts"][0]["content"] == "Original system message"
+    assert logged_messages[1]["parts"][0]["content"] == "Test"
 
 
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)

From 589fad0876ae0625b400eb0352ba258211442b8a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 20 May 2026 22:54:45 +0000
Subject: [PATCH 14/16] Refine observability OTEL message typing

---
 python/packages/core/agent_framework/observability.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 422f9e3a9d..362be2146e 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2156,7 +2156,7 @@ def _capture_messages(
     from ._types import normalize_messages
 
     normalized_messages = normalize_messages(messages)
-    span_messages = []
+    otel_messages: list[dict[str, Any]] = []
     for index, message in enumerate(normalized_messages):
         # Reuse the otel message representation for logging instead of calling to_dict()
         # to avoid expensive Pydantic serialization overhead
@@ -2169,11 +2169,11 @@ def _capture_messages(
                 MessageListTimestampFilter.INDEX_KEY: index,
             },
         )
-        span_messages.append(otel_message)
+        otel_messages.append(otel_message)
     if finish_reason:
-        span_messages[-1]["finish_reason"] = FINISH_REASON_MAP[finish_reason]
+        otel_messages[-1]["finish_reason"] = FINISH_REASON_MAP[finish_reason]
     span.set_attribute(
-        OtelAttr.OUTPUT_MESSAGES if output else OtelAttr.INPUT_MESSAGES, json.dumps(span_messages, ensure_ascii=False)
+        OtelAttr.OUTPUT_MESSAGES if output else OtelAttr.INPUT_MESSAGES, json.dumps(otel_messages, ensure_ascii=False)
     )
     if system_instructions:
         if not isinstance(system_instructions, list):

From 5d8565ae01e44918f942710d911ac2d8bed205ac Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 21 May 2026 17:46:10 +0000
Subject: [PATCH 15/16] Restore prepended-instruction logging path in
 _capture_messages

---
 .../core/agent_framework/observability.py     | 17 +++++-----
 .../core/tests/core/test_observability.py     | 32 +++++++++++--------
 2 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 362be2146e..0fa017a2ed 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2153,23 +2153,24 @@ def _capture_messages(
     finish_reason: FinishReason | None = None,
 ) -> None:
     """Log messages with extra information."""
-    from ._types import normalize_messages
+    from ._types import normalize_messages, prepend_instructions_to_messages
 
     normalized_messages = normalize_messages(messages)
-    otel_messages: list[dict[str, Any]] = []
-    for index, message in enumerate(normalized_messages):
-        # Reuse the otel message representation for logging instead of calling to_dict()
-        # to avoid expensive Pydantic serialization overhead
-        otel_message = _to_otel_message(message)
+    # For logging: prepend framework instructions as messages so the log record
+    # mirrors the full message list as sent to the provider.
+    log_messages = prepend_instructions_to_messages(normalized_messages, system_instructions)
+    for index, message in enumerate(log_messages):
         logger.info(
-            otel_message,
+            _to_otel_message(message),
             extra={
                 OtelAttr.EVENT_NAME: OtelAttr.CHOICE if output else ROLE_EVENT_MAP.get(message.role),
                 OtelAttr.PROVIDER_NAME: provider_name,
                 MessageListTimestampFilter.INDEX_KEY: index,
             },
         )
-        otel_messages.append(otel_message)
+    # For the span attribute, only include the original chat history so that
+    # framework/options instructions are not duplicated into gen_ai.input.messages.
+    otel_messages: list[dict[str, Any]] = [_to_otel_message(message) for message in normalized_messages]
     if finish_reason:
         otel_messages[-1]["finish_reason"] = FINISH_REASON_MAP[finish_reason]
     span.set_attribute(
diff --git a/python/packages/core/tests/core/test_observability.py b/python/packages/core/tests/core/test_observability.py
index d4403043af..1966c7164b 100644
--- a/python/packages/core/tests/core/test_observability.py
+++ b/python/packages/core/tests/core/test_observability.py
@@ -3019,10 +3019,10 @@ async def test_system_instructions_preserves_non_ascii_characters(span_exporter:
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
 
-def test_capture_messages_keeps_framework_instructions_out_of_logs_and_span_messages(
+def test_capture_messages_logs_prepended_instructions_excludes_them_from_span(
     span_exporter: InMemorySpanExporter,
 ):
-    """Test separate framework instructions do not appear in chat-history logs or span messages."""
+    """Test framework instructions are logged as prepended messages but excluded from the span attribute."""
     import json
 
     from opentelemetry import trace
@@ -3043,21 +3043,22 @@ def test_capture_messages_keeps_framework_instructions_out_of_logs_and_span_mess
 
     spans = span_exporter.get_finished_spans()
     assert len(spans) == 1
+    # Span attribute must not contain the framework instruction.
     input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
-    assert mock_logger_info.call_count == 1, f"Expected 1 log call, got {mock_logger_info.call_count}"
-    (first_call,) = mock_logger_info.call_args_list
-    assert first_call.args
-    logged_message = first_call.args[0]
-    assert logged_message["role"] == "user"
-    assert logged_message["parts"][0]["content"] == "Test"
+    # Logging path must include the prepended framework instruction.
+    assert mock_logger_info.call_count == 2, f"Expected 2 log calls, got {mock_logger_info.call_count}"
+    logged_messages = [call.args[0] for call in mock_logger_info.call_args_list]
+    assert [msg["role"] for msg in logged_messages] == ["system", "user"]
+    assert logged_messages[0]["parts"][0]["content"] == "Framework system instruction"
+    assert logged_messages[1]["parts"][0]["content"] == "Test"
 
 
-def test_capture_messages_logs_only_chat_history_when_framework_instructions_are_separate(
+def test_capture_messages_logs_prepended_instructions_when_chat_history_has_system_message(
     span_exporter: InMemorySpanExporter,
 ):
-    """Test chat-history logging preserves original system messages without prepending framework instructions."""
+    """Test framework instructions are prepended in logs; original system message stays in span attribute."""
     import json
 
     from opentelemetry import trace
@@ -3081,14 +3082,17 @@ def test_capture_messages_logs_only_chat_history_when_framework_instructions_are
 
     spans = span_exporter.get_finished_spans()
     assert len(spans) == 1
+    # Span attribute keeps the original chat history (including the original system message).
     input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
     assert [msg.get("role") for msg in input_messages] == ["system", "user"]
 
-    assert mock_logger_info.call_count == 2, f"Expected 2 log calls, got {mock_logger_info.call_count}"
+    # Logging path includes the prepended framework instruction before the chat history.
+    assert mock_logger_info.call_count == 3, f"Expected 3 log calls, got {mock_logger_info.call_count}"
     logged_messages = [call.args[0] for call in mock_logger_info.call_args_list]
-    assert [msg["role"] for msg in logged_messages] == ["system", "user"]
-    assert logged_messages[0]["parts"][0]["content"] == "Original system message"
-    assert logged_messages[1]["parts"][0]["content"] == "Test"
+    assert [msg["role"] for msg in logged_messages] == ["system", "system", "user"]
+    assert logged_messages[0]["parts"][0]["content"] == "Framework system instruction"
+    assert logged_messages[1]["parts"][0]["content"] == "Original system message"
+    assert logged_messages[2]["parts"][0]["content"] == "Test"
 
 
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)

From 068e38327515b46d7c199e48ab7bea5981061938 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 21 May 2026 18:03:48 +0000
Subject: [PATCH 16/16] Revert logging change in _capture_messages; keep
 chat-history-only logging

---
 .../core/agent_framework/observability.py     | 17 +++++-----
 .../core/tests/core/test_observability.py     | 32 ++++++++-----------
 2 files changed, 22 insertions(+), 27 deletions(-)

diff --git a/python/packages/core/agent_framework/observability.py b/python/packages/core/agent_framework/observability.py
index 0fa017a2ed..362be2146e 100644
--- a/python/packages/core/agent_framework/observability.py
+++ b/python/packages/core/agent_framework/observability.py
@@ -2153,24 +2153,23 @@ def _capture_messages(
     finish_reason: FinishReason | None = None,
 ) -> None:
     """Log messages with extra information."""
-    from ._types import normalize_messages, prepend_instructions_to_messages
+    from ._types import normalize_messages
 
     normalized_messages = normalize_messages(messages)
-    # For logging: prepend framework instructions as messages so the log record
-    # mirrors the full message list as sent to the provider.
-    log_messages = prepend_instructions_to_messages(normalized_messages, system_instructions)
-    for index, message in enumerate(log_messages):
+    otel_messages: list[dict[str, Any]] = []
+    for index, message in enumerate(normalized_messages):
+        # Reuse the otel message representation for logging instead of calling to_dict()
+        # to avoid expensive Pydantic serialization overhead
+        otel_message = _to_otel_message(message)
         logger.info(
-            _to_otel_message(message),
+            otel_message,
             extra={
                 OtelAttr.EVENT_NAME: OtelAttr.CHOICE if output else ROLE_EVENT_MAP.get(message.role),
                 OtelAttr.PROVIDER_NAME: provider_name,
                 MessageListTimestampFilter.INDEX_KEY: index,
             },
         )
-    # For the span attribute, only include the original chat history so that
-    # framework/options instructions are not duplicated into gen_ai.input.messages.
-    otel_messages: list[dict[str, Any]] = [_to_otel_message(message) for message in normalized_messages]
+        otel_messages.append(otel_message)
     if finish_reason:
         otel_messages[-1]["finish_reason"] = FINISH_REASON_MAP[finish_reason]
     span.set_attribute(
diff --git a/python/packages/core/tests/core/test_observability.py b/python/packages/core/tests/core/test_observability.py
index 1966c7164b..d4403043af 100644
--- a/python/packages/core/tests/core/test_observability.py
+++ b/python/packages/core/tests/core/test_observability.py
@@ -3019,10 +3019,10 @@ async def test_system_instructions_preserves_non_ascii_characters(span_exporter:
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
 
-def test_capture_messages_logs_prepended_instructions_excludes_them_from_span(
+def test_capture_messages_keeps_framework_instructions_out_of_logs_and_span_messages(
     span_exporter: InMemorySpanExporter,
 ):
-    """Test framework instructions are logged as prepended messages but excluded from the span attribute."""
+    """Test separate framework instructions do not appear in chat-history logs or span messages."""
     import json
 
     from opentelemetry import trace
@@ -3043,22 +3043,21 @@ def test_capture_messages_logs_prepended_instructions_excludes_them_from_span(
 
     spans = span_exporter.get_finished_spans()
     assert len(spans) == 1
-    # Span attribute must not contain the framework instruction.
     input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
     assert [msg.get("role") for msg in input_messages] == ["user"]
 
-    # Logging path must include the prepended framework instruction.
-    assert mock_logger_info.call_count == 2, f"Expected 2 log calls, got {mock_logger_info.call_count}"
-    logged_messages = [call.args[0] for call in mock_logger_info.call_args_list]
-    assert [msg["role"] for msg in logged_messages] == ["system", "user"]
-    assert logged_messages[0]["parts"][0]["content"] == "Framework system instruction"
-    assert logged_messages[1]["parts"][0]["content"] == "Test"
+    assert mock_logger_info.call_count == 1, f"Expected 1 log call, got {mock_logger_info.call_count}"
+    (first_call,) = mock_logger_info.call_args_list
+    assert first_call.args
+    logged_message = first_call.args[0]
+    assert logged_message["role"] == "user"
+    assert logged_message["parts"][0]["content"] == "Test"
 
 
-def test_capture_messages_logs_prepended_instructions_when_chat_history_has_system_message(
+def test_capture_messages_logs_only_chat_history_when_framework_instructions_are_separate(
     span_exporter: InMemorySpanExporter,
 ):
-    """Test framework instructions are prepended in logs; original system message stays in span attribute."""
+    """Test chat-history logging preserves original system messages without prepending framework instructions."""
     import json
 
     from opentelemetry import trace
@@ -3082,17 +3081,14 @@ def test_capture_messages_logs_prepended_instructions_when_chat_history_has_syst
 
     spans = span_exporter.get_finished_spans()
     assert len(spans) == 1
-    # Span attribute keeps the original chat history (including the original system message).
     input_messages = json.loads(spans[0].attributes[OtelAttr.INPUT_MESSAGES])
     assert [msg.get("role") for msg in input_messages] == ["system", "user"]
 
-    # Logging path includes the prepended framework instruction before the chat history.
-    assert mock_logger_info.call_count == 3, f"Expected 3 log calls, got {mock_logger_info.call_count}"
+    assert mock_logger_info.call_count == 2, f"Expected 2 log calls, got {mock_logger_info.call_count}"
     logged_messages = [call.args[0] for call in mock_logger_info.call_args_list]
-    assert [msg["role"] for msg in logged_messages] == ["system", "system", "user"]
-    assert logged_messages[0]["parts"][0]["content"] == "Framework system instruction"
-    assert logged_messages[1]["parts"][0]["content"] == "Original system message"
-    assert logged_messages[2]["parts"][0]["content"] == "Test"
+    assert [msg["role"] for msg in logged_messages] == ["system", "user"]
+    assert logged_messages[0]["parts"][0]["content"] == "Original system message"
+    assert logged_messages[1]["parts"][0]["content"] == "Test"
 
 
 @pytest.mark.parametrize("enable_sensitive_data", [True], indirect=True)