Python: Fix AzureAIClient failure when conversation history contains assistant messages (#3076)

* Fix AzureAIClient failure when conversation history contains assistant messages

* Address PR review feedback: improve docstring and test assertions

* Remove redundant cast

python/packages/azure-ai/agent_framework_azure_ai/_client.py

@@ -2,7 +2,7 @@
 
 import sys
 from collections.abc import Mapping, MutableSequence
-from typing import Any, ClassVar, TypeVar
+from typing import Any, ClassVar, TypeVar, cast
 
 from agent_framework import (
     AGENT_FRAMEWORK_USER_AGENT,
@@ -379,6 +379,15 @@ class AzureAIClient(OpenAIBaseResponsesClient):
         """Take ChatOptions and create the specific options for Azure AI."""
         prepared_messages, instructions = self._prepare_messages_for_azure_ai(messages)
         run_options = await super()._prepare_options(prepared_messages, chat_options, **kwargs)
+
+        # WORKAROUND: Azure AI Projects 'create responses' API has schema divergence from OpenAI's
+        # Responses API. Azure requires 'type' at item level and 'annotations' in content items.
+        # See: https://github.com/Azure/azure-sdk-for-python/issues/44493
+        # See: https://github.com/microsoft/agent-framework/issues/2926
+        # TODO(agent-framework#2926): Remove this workaround when Azure SDK aligns with OpenAI schema.
+        if "input" in run_options and isinstance(run_options["input"], list):
+            run_options["input"] = self._transform_input_for_azure_ai(cast(list[dict[str, Any]], run_options["input"]))
+
         if not self._is_application_endpoint:
             # Application-scoped response APIs do not support "agent" property.
             agent_reference = await self._get_agent_reference_or_create(run_options, instructions)
@@ -393,6 +402,44 @@ class AzureAIClient(OpenAIBaseResponsesClient):
 
         return run_options
 
+    def _transform_input_for_azure_ai(self, input_items: list[dict[str, Any]]) -> list[dict[str, Any]]:
+        """Transform input items to match Azure AI Projects expected schema.
+
+        WORKAROUND: Azure AI Projects 'create responses' API expects a different schema than OpenAI's
+        Responses API. Azure requires 'type' at the item level, and requires 'annotations'
+        only for output_text content items (assistant messages), not for input_text content items
+        (user messages). This helper adapts the OpenAI-style input to the Azure schema.
+
+        See: https://github.com/Azure/azure-sdk-for-python/issues/44493
+        TODO(agent-framework#2926): Remove when Azure SDK aligns with OpenAI schema.
+        """
+        transformed: list[dict[str, Any]] = []
+        for item in input_items:
+            new_item: dict[str, Any] = dict(item)
+
+            # Add 'type': 'message' at item level for role-based items
+            if "role" in new_item and "type" not in new_item:
+                new_item["type"] = "message"
+
+            # Add 'annotations' only to output_text content items (assistant messages)
+            # User messages (input_text) do NOT support annotations in Azure AI
+            if "content" in new_item and isinstance(new_item["content"], list):
+                new_content: list[dict[str, Any] | Any] = []
+                for content_item in new_item["content"]:
+                    if isinstance(content_item, dict):
+                        new_content_item: dict[str, Any] = dict(content_item)
+                        # Only add annotations to output_text (assistant content)
+                        if new_content_item.get("type") == "output_text" and "annotations" not in new_content_item:
+                            new_content_item["annotations"] = []
+                        new_content.append(new_content_item)
+                    else:
+                        new_content.append(content_item)
+                new_item["content"] = new_content
+
+            transformed.append(new_item)
+
+        return transformed
+
     @override
     def _get_current_conversation_id(self, chat_options: ChatOptions, **kwargs: Any) -> str | None:
         """Get the current conversation ID from chat options or kwargs."""

python/packages/azure-ai/tests/test_azure_ai_client.py

@@ -286,6 +286,93 @@ async def test_azure_ai_client_prepare_messages_for_azure_ai_no_system_messages(
     assert instructions is None
 
 
+def test_azure_ai_client_transform_input_for_azure_ai(mock_project_client: MagicMock) -> None:
+    """Test _transform_input_for_azure_ai adds required fields for Azure AI schema.
+
+    WORKAROUND TEST: Azure AI Projects API requires 'type' at item level and
+    'annotations' in output_text content items, which OpenAI's Responses API does not require.
+    See: https://github.com/Azure/azure-sdk-for-python/issues/44493
+    See: https://github.com/microsoft/agent-framework/issues/2926
+    """
+    client = create_test_azure_ai_client(mock_project_client)
+
+    # Input in OpenAI Responses API format (what agent-framework generates)
+    openai_format_input = [
+        {
+            "role": "user",
+            "content": [
+                {"type": "input_text", "text": "Hello"},
+            ],
+        },
+        {
+            "role": "assistant",
+            "content": [
+                {"type": "output_text", "text": "Hi there!"},
+            ],
+        },
+    ]
+
+    result = client._transform_input_for_azure_ai(openai_format_input)  # type: ignore
+
+    # Verify 'type': 'message' added at item level
+    assert result[0]["type"] == "message"
+    assert result[1]["type"] == "message"
+
+    # Verify 'annotations' added ONLY to output_text (assistant) content, NOT input_text (user)
+    assert result[0]["content"][0]["type"] == "input_text"  # user content type preserved
+    assert "annotations" not in result[0]["content"][0]  # user message - no annotations
+    assert result[1]["content"][0]["type"] == "output_text"  # assistant content type preserved
+    assert result[1]["content"][0]["annotations"] == []  # assistant message - has annotations
+
+    # Verify original fields preserved
+    assert result[0]["role"] == "user"
+    assert result[0]["content"][0]["text"] == "Hello"
+    assert result[1]["role"] == "assistant"
+    assert result[1]["content"][0]["text"] == "Hi there!"
+
+
+def test_azure_ai_client_transform_input_preserves_existing_fields(mock_project_client: MagicMock) -> None:
+    """Test _transform_input_for_azure_ai preserves existing type and annotations."""
+    client = create_test_azure_ai_client(mock_project_client)
+
+    # Input that already has the fields (shouldn't duplicate)
+    input_with_fields = [
+        {
+            "type": "message",
+            "role": "assistant",
+            "content": [
+                {"type": "output_text", "text": "Hello", "annotations": [{"some": "annotation"}]},
+            ],
+        },
+    ]
+
+    result = client._transform_input_for_azure_ai(input_with_fields)  # type: ignore
+
+    # Should preserve existing values, not overwrite
+    assert result[0]["type"] == "message"
+    assert result[0]["content"][0]["annotations"] == [{"some": "annotation"}]
+
+
+def test_azure_ai_client_transform_input_handles_non_dict_content(mock_project_client: MagicMock) -> None:
+    """Test _transform_input_for_azure_ai handles non-dict content items."""
+    client = create_test_azure_ai_client(mock_project_client)
+
+    # Input with string content (edge case)
+    input_with_string_content = [
+        {
+            "role": "user",
+            "content": ["plain string content"],
+        },
+    ]
+
+    result = client._transform_input_for_azure_ai(input_with_string_content)  # type: ignore
+
+    # Should add 'type': 'message' at item level even with non-dict content
+    assert result[0]["type"] == "message"
+    # Non-dict content items should be preserved without modification
+    assert result[0]["content"] == ["plain string content"]
+
+
 async def test_azure_ai_client_prepare_options_basic(mock_project_client: MagicMock) -> None:
     """Test prepare_options basic functionality."""
     client = create_test_azure_ai_client(mock_project_client, agent_name="test-agent", agent_version="1.0")