Python: [Feature Branch] Added use_latest_version parameter to AzureAIClient (#1959)

* Added use_latest_version parameter to AzureAIClient

* Added unit tests

* Update python/samples/getting_started/agents/azure_ai/azure_ai_use_latest_version.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

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

Co-authored-by: Evan Mattson <35585003+moonbox3@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Evan Mattson <35585003+moonbox3@users.noreply.github.com>

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

@@ -58,6 +58,7 @@ class AzureAIClient(OpenAIBaseResponsesClient):
         project_endpoint: str | None = None,
         model_deployment_name: str | None = None,
         async_credential: AsyncTokenCredential | None = None,
+        use_latest_version: bool | None = None,
         env_file_path: str | None = None,
         env_file_encoding: str | None = None,
         **kwargs: Any,
@@ -76,6 +77,8 @@ class AzureAIClient(OpenAIBaseResponsesClient):
             model_deployment_name: The model deployment name to use for agent creation.
                 Can also be set via environment variable AZURE_AI_MODEL_DEPLOYMENT_NAME.
             async_credential: Azure async credential to use for authentication.
+            use_latest_version: Boolean flag that indicates whether to use latest agent version
+                if it exists in the service.
             env_file_path: Path to environment file for loading settings.
             env_file_encoding: Encoding of the environment file.
             kwargs: Additional keyword arguments passed to the parent class.
@@ -139,6 +142,7 @@ class AzureAIClient(OpenAIBaseResponsesClient):
         # Initialize instance variables
         self.agent_name = agent_name
         self.agent_version = agent_version
+        self.use_latest_version = use_latest_version
         self.project_client = project_client
         self.credential = async_credential
         self.model_id = azure_ai_settings.model_deployment_name
@@ -188,8 +192,19 @@ class AzureAIClient(OpenAIBaseResponsesClient):
         """
         agent_name = self.agent_name or "UnnamedAgent"
 
-        # If no agent_version is provided, create a new agent
+        # If no agent_version is provided, either use latest version or create a new agent:
         if self.agent_version is None:
+            # Try to use latest version if requested and agent exists
+            if self.use_latest_version:
+                try:
+                    existing_agent = await self.project_client.agents.retrieve(agent_name)
+                    self.agent_name = existing_agent.name
+                    self.agent_version = existing_agent.versions.latest.version
+                    return {"name": self.agent_name, "version": self.agent_version, "type": "agent_reference"}
+                except ResourceNotFoundError:
+                    # Agent doesn't exist, fall through to creation logic
+                    pass
+
             if "model" not in run_options or not run_options["model"]:
                 raise ServiceInitializationError(
                     "Model deployment name is required for agent creation, "

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

@@ -23,6 +23,7 @@ def create_test_azure_ai_client(
     conversation_id: str | None = None,
     azure_ai_settings: AzureAISettings | None = None,
     should_close_client: bool = False,
+    use_latest_version: bool | None = None,
 ) -> AzureAIClient:
     """Helper function to create AzureAIClient instances for testing, bypassing normal validation."""
     if azure_ai_settings is None:
@@ -36,6 +37,7 @@ def create_test_azure_ai_client(
     client.credential = None
     client.agent_name = agent_name
     client.agent_version = agent_version
+    client.use_latest_version = use_latest_version
     client.model_id = azure_ai_settings.model_deployment_name
     client.conversation_id = conversation_id
     client._should_close_client = should_close_client  # type: ignore
@@ -437,6 +439,98 @@ async def test_azure_ai_client_agent_creation_with_tools(
     assert call_args[1]["definition"].tools == test_tools
 
 
+async def test_azure_ai_client_use_latest_version_existing_agent(
+    mock_project_client: MagicMock,
+) -> None:
+    """Test _get_agent_reference_or_create when use_latest_version=True and agent exists."""
+    client = create_test_azure_ai_client(mock_project_client, agent_name="existing-agent", use_latest_version=True)
+
+    # Mock existing agent response
+    mock_existing_agent = MagicMock()
+    mock_existing_agent.name = "existing-agent"
+    mock_existing_agent.versions.latest.version = "2.5"
+    mock_project_client.agents.retrieve = AsyncMock(return_value=mock_existing_agent)
+
+    run_options = {"model": "test-model"}
+    agent_ref = await client._get_agent_reference_or_create(run_options, None)  # type: ignore
+
+    # Verify existing agent was retrieved and used
+    mock_project_client.agents.retrieve.assert_called_once_with("existing-agent")
+    mock_project_client.agents.create_version.assert_not_called()
+
+    assert agent_ref == {"name": "existing-agent", "version": "2.5", "type": "agent_reference"}
+    assert client.agent_name == "existing-agent"
+    assert client.agent_version == "2.5"
+
+
+async def test_azure_ai_client_use_latest_version_agent_not_found(
+    mock_project_client: MagicMock,
+) -> None:
+    """Test _get_agent_reference_or_create when use_latest_version=True but agent doesn't exist."""
+    from azure.core.exceptions import ResourceNotFoundError
+
+    client = create_test_azure_ai_client(mock_project_client, agent_name="non-existing-agent", use_latest_version=True)
+
+    # Mock ResourceNotFoundError when trying to retrieve agent
+    mock_project_client.agents.retrieve = AsyncMock(side_effect=ResourceNotFoundError("Agent not found"))
+
+    # Mock agent creation response for fallback
+    mock_created_agent = MagicMock()
+    mock_created_agent.name = "non-existing-agent"
+    mock_created_agent.version = "1.0"
+    mock_project_client.agents.create_version = AsyncMock(return_value=mock_created_agent)
+
+    run_options = {"model": "test-model"}
+    agent_ref = await client._get_agent_reference_or_create(run_options, None)  # type: ignore
+
+    # Verify retrieval was attempted and creation was used as fallback
+    mock_project_client.agents.retrieve.assert_called_once_with("non-existing-agent")
+    mock_project_client.agents.create_version.assert_called_once()
+
+    assert agent_ref == {"name": "non-existing-agent", "version": "1.0", "type": "agent_reference"}
+    assert client.agent_name == "non-existing-agent"
+    assert client.agent_version == "1.0"
+
+
+async def test_azure_ai_client_use_latest_version_false(
+    mock_project_client: MagicMock,
+) -> None:
+    """Test _get_agent_reference_or_create when use_latest_version=False (default behavior)."""
+    client = create_test_azure_ai_client(mock_project_client, agent_name="test-agent", use_latest_version=False)
+
+    # Mock agent creation response
+    mock_created_agent = MagicMock()
+    mock_created_agent.name = "test-agent"
+    mock_created_agent.version = "1.0"
+    mock_project_client.agents.create_version = AsyncMock(return_value=mock_created_agent)
+
+    run_options = {"model": "test-model"}
+    agent_ref = await client._get_agent_reference_or_create(run_options, None)  # type: ignore
+
+    # Verify retrieval was not attempted and creation was used directly
+    mock_project_client.agents.retrieve.assert_not_called()
+    mock_project_client.agents.create_version.assert_called_once()
+
+    assert agent_ref == {"name": "test-agent", "version": "1.0", "type": "agent_reference"}
+
+
+async def test_azure_ai_client_use_latest_version_with_existing_agent_version(
+    mock_project_client: MagicMock,
+) -> None:
+    """Test that use_latest_version is ignored when agent_version is already provided."""
+    client = create_test_azure_ai_client(
+        mock_project_client, agent_name="test-agent", agent_version="3.0", use_latest_version=True
+    )
+
+    agent_ref = await client._get_agent_reference_or_create({}, None)  # type: ignore
+
+    # Verify neither retrieval nor creation was attempted since version is already set
+    mock_project_client.agents.retrieve.assert_not_called()
+    mock_project_client.agents.create_version.assert_not_called()
+
+    assert agent_ref == {"name": "test-agent", "version": "3.0", "type": "agent_reference"}
+
+
 @pytest.fixture
 def mock_project_client() -> MagicMock:
     """Fixture that provides a mock AIProjectClient."""

python/samples/getting_started/agents/azure_ai/azure_ai_use_latest_version.py

@@ -0,0 +1,66 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import asyncio
+from random import randint
+from typing import Annotated
+
+from agent_framework.azure import AzureAIClient
+from azure.identity.aio import AzureCliCredential
+from pydantic import Field
+
+"""
+Azure AI Agent Basic Example
+
+This sample demonstrates how to reuse the latest version of an existing agent instead of creating a new agent version on each instantiation.
+The first call creates a new agent, while subsequent calls with `use_latest_version=True` reuse the latest agent version.
+"""
+
+
+def get_weather(
+    location: Annotated[str, Field(description="The location to get the weather for.")],
+) -> str:
+    """Get the weather for a given location."""
+    conditions = ["sunny", "cloudy", "rainy", "stormy"]
+    return f"The weather in {location} is {conditions[randint(0, 3)]} with a high of {randint(10, 30)}°C."
+
+
+async def main() -> None:
+    # For authentication, run `az login` command in terminal or replace AzureCliCredential with preferred
+    # authentication option.
+    async with AzureCliCredential() as credential:
+        async with (
+            AzureAIClient(
+                async_credential=credential,
+            ).create_agent(
+                name="MyWeatherAgent",
+                instructions="You are a helpful weather agent.",
+                tools=get_weather,
+            ) as agent,
+        ):
+            # First query will create a new agent
+            query = "What's the weather like in Seattle?"
+            print(f"User: {query}")
+            result = await agent.run(query)
+            print(f"Agent: {result}\n")
+
+        # Create a new agent instance
+        async with (
+            AzureAIClient(
+                async_credential=credential,
+                # This parameter will allow to re-use latest agent version
+                # instead of creating a new one
+                use_latest_version=True,
+            ).create_agent(
+                name="MyWeatherAgent",
+                instructions="You are a helpful weather agent.",
+                tools=get_weather,
+            ) as agent,
+        ):
+            query = "What's the weather like in Tokyo?"
+            print(f"User: {query}")
+            result = await agent.run(query)
+            print(f"Agent: {result}\n")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())