Python: Implemented FoundryChatClient (#193)

* Initial version of FoundryChatClient

* Updates to the tool call streaming wrapper

* Small fixes

* Small updates and addressed PR feedback

* Handle automatic client creation

* Small improvement

* Added credential parameter

* Small improvements

* Made FoundryChatClient disposable

* Small fixes

* Added unit tests

* Refactored samples

* Small improvements

* Small fix

* Addressed PR feedback

* Small fixes

* Small updates

* Small fix

* Addressed PR feedback

python/packages/main/agent_framework/_agents.py

@@ -1,10 +1,16 @@
 # Copyright (c) Microsoft. All rights reserved.
 
+import sys
 from collections.abc import AsyncIterable, Callable, MutableMapping, Sequence
 from enum import Enum
 from typing import Any, Literal, Protocol, TypeVar, runtime_checkable
 from uuid import uuid4
 
+if sys.version_info >= (3, 11):
+    from typing import Self  # pragma: no cover
+else:
+    from typing_extensions import Self  # pragma: no cover
+
 from pydantic import BaseModel, Field
 
 from ._clients import ChatClient
@@ -359,6 +365,23 @@ class ChatClientAgent(AgentBase):
 
         super().__init__(**args)
 
+    async def __aenter__(self) -> "Self":
+        """Async context manager entry.
+
+        If the chat_client supports async context management, enter its context.
+        """
+        if hasattr(self.chat_client, "__aenter__") and hasattr(self.chat_client, "__aexit__"):
+            await self.chat_client.__aenter__()  # type: ignore[reportUnknownMemberType]
+        return self
+
+    async def __aexit__(self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: Any) -> None:
+        """Async context manager exit.
+
+        If the chat_client supports async context management, exit its context.
+        """
+        if hasattr(self.chat_client, "__aenter__") and hasattr(self.chat_client, "__aexit__"):
+            await self.chat_client.__aexit__(exc_type, exc_val, exc_tb)  # type: ignore[reportUnknownMemberType]
+
     async def run(
         self,
         messages: str | ChatMessage | list[str] | list[ChatMessage] | None = None,