Python: [BREAKING] Simplify API: ChatAgent -> Agent, ChatMessage -> Message (#3747)

* [BREAKING] Rename ChatAgent -> Agent, ChatMessage -> Message, ChatClientProtocol -> SupportsChatGetResponse

Simplify the public API by removing redundant 'Chat' prefix from core types:
- ChatAgent -> Agent
- RawChatAgent -> RawAgent
- ChatMessage -> Message
- ChatClientProtocol -> SupportsChatGetResponse

Also renamed internal WorkflowMessage (was Message in _runner_context) to avoid collision.

No backward compatibility aliases - this is a clean breaking change.

* [BREAKING] Rename Agent chat_client parameter to client

* Fix rebase issues: WorkflowMessage references and broken markdown links

* Fix formatting and lint issues from code quality checks

* Fix import ordering in workflow sample files

* fixed rebase

* Fix test failures: use WorkflowMessage and A2AMessage after ChatMessage→Message rename

- Replace Message(data=..., source_id=...) with WorkflowMessage(...) in workflow tests
- Fix isinstance check in A2A agent to use A2AMessage instead of Message
- Fix import in test_workflow_observability.py (Message→WorkflowMessage)

* Fix lint, fmt, and sample errors after ChatMessage→Message rename

- Auto-fix 70+ ruff lint issues across samples (ChatMessage→Message refs)
- Fix HostedVectorStoreContent→Content.from_hosted_vector_store in file search sample
- Fix _normalize_messages→normalize_messages in custom agent sample
- Fix context.terminate→raise MiddlewareTermination in middleware samples
- Fix with_update_hook→with_transform_hook in override middleware sample
- Add TOptions_co import back to custom_chat_client sample
- Add noqa for FastAPI File() default in chatkit sample
- Fix B023 loop variable capture in weather agent sample

* fix: update Agent constructor calls from chat_client to client in declaration-only tool tests

* fix: add register_cleanup to devui lazy-loading proxy and type stub

* fixed tests and updated new pieces

* fix agui typevar

* fix merge errors

* fix merge conflicts

* fiux merge

* Remove unused links

---------

Co-authored-by: Evan Mattson <evan.mattson@microsoft.com>

python/packages/durabletask/tests/test_durable_entities.py

@@ -11,7 +11,7 @@ from typing import Any, TypeVar
 from unittest.mock import AsyncMock, Mock
 
 import pytest
-from agent_framework import AgentResponse, AgentResponseUpdate, ChatMessage, Content, ResponseStream
+from agent_framework import AgentResponse, AgentResponseUpdate, Content, Message, ResponseStream
 from pydantic import BaseModel
 
 from agent_framework_durabletask import (
@@ -71,7 +71,7 @@ def _make_entity(agent: Any, callback: Any = None, *, thread_id: str = "test-thr
 
 
 def _role_value(chat_message: DurableAgentStateMessage) -> str:
-    """Helper to extract the string role from a ChatMessage."""
+    """Helper to extract the string role from a Message."""
     role = getattr(chat_message, "role", None)
     role_value = getattr(role, "value", role)
     if role_value is None:
@@ -81,7 +81,7 @@ def _role_value(chat_message: DurableAgentStateMessage) -> str:
 
 def _agent_response(text: str | None) -> AgentResponse:
     """Create an AgentResponse with a single assistant message."""
-    message = ChatMessage(role="assistant", text=text) if text is not None else ChatMessage(role="assistant", text="")
+    message = Message(role="assistant", text=text) if text is not None else Message(role="assistant", text="")
     return AgentResponse(messages=[message], created_at="2024-01-01T00:00:00Z")
 
 

python/packages/durabletask/tests/test_shim.py

@@ -10,7 +10,7 @@ from typing import Any
 from unittest.mock import Mock
 
 import pytest
-from agent_framework import ChatMessage, SupportsAgentRun
+from agent_framework import Message, SupportsAgentRun
 from pydantic import BaseModel
 
 from agent_framework_durabletask import DurableAgentThread
@@ -76,8 +76,8 @@ class TestDurableAIAgentMessageNormalization:
         assert kwargs["run_request"].message == "Hello, world!"
 
     def test_run_accepts_chat_message(self, test_agent: DurableAIAgent[Any], mock_executor: Mock) -> None:
-        """Verify run accepts and normalizes ChatMessage objects."""
-        chat_msg = ChatMessage(role="user", text="Test message")
+        """Verify run accepts and normalizes Message objects."""
+        chat_msg = Message(role="user", text="Test message")
         test_agent.run(chat_msg)
 
         mock_executor.run_durable_agent.assert_called_once()
@@ -93,10 +93,10 @@ class TestDurableAIAgentMessageNormalization:
         assert kwargs["run_request"].message == "First message\nSecond message"
 
     def test_run_accepts_list_of_chat_messages(self, test_agent: DurableAIAgent[Any], mock_executor: Mock) -> None:
-        """Verify run accepts and joins list of ChatMessage objects."""
+        """Verify run accepts and joins list of Message objects."""
         messages = [
-            ChatMessage(role="user", text="Message 1"),
-            ChatMessage(role="assistant", text="Message 2"),
+            Message(role="user", text="Message 1"),
+            Message(role="assistant", text="Message 2"),
         ]
         test_agent.run(messages)