From 6fb2f27afa7f33ddc339bb7ce25f41e51955335e Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 17:58:04 +0000
Subject: [PATCH 1/4] Initial plan


From fe969a0ceae4a58164bc4209487f172b2ea895de Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 18:06:07 +0000
Subject: [PATCH 2/4] Add Obsolete attribute to all public methods of
 OpenAIAssistantClientExtensions

Co-authored-by: SergeyMenshykh <68852919+SergeyMenshykh@users.noreply.github.com>
---
 .../Extensions/OpenAIAssistantClientExtensions.cs    | 12 ++++++++++++
 .../OpenAIAssistantClientExtensionsTests.cs          |  2 ++
 2 files changed, 14 insertions(+)

diff --git a/dotnet/src/Microsoft.Agents.AI.OpenAI/Extensions/OpenAIAssistantClientExtensions.cs b/dotnet/src/Microsoft.Agents.AI.OpenAI/Extensions/OpenAIAssistantClientExtensions.cs
index fb464fdc398..a3ca550257e 100644
--- a/dotnet/src/Microsoft.Agents.AI.OpenAI/Extensions/OpenAIAssistantClientExtensions.cs
+++ b/dotnet/src/Microsoft.Agents.AI.OpenAI/Extensions/OpenAIAssistantClientExtensions.cs
@@ -30,6 +30,7 @@ public static class OpenAIAssistantClientExtensions
     /// <param name="clientFactory">Provides a way to customize the creation of the underlying <see cref="IChatClient"/> used by the agent.</param>
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant.</returns>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         ClientResult<Assistant> assistantClientResult,
@@ -54,6 +55,7 @@ public static ChatClientAgent GetAIAgent(
     /// <param name="clientFactory">Provides a way to customize the creation of the underlying <see cref="IChatClient"/> used by the agent.</param>
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant.</returns>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         Assistant assistantMetadata,
@@ -102,6 +104,7 @@ public static ChatClientAgent GetAIAgent(
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant agent.</returns>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         string agentId,
@@ -134,6 +137,7 @@ public static ChatClientAgent GetAIAgent(
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant agent.</returns>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static async Task<ChatClientAgent> GetAIAgentAsync(
         this AssistantClient assistantClient,
         string agentId,
@@ -166,6 +170,7 @@ public static async Task<ChatClientAgent> GetAIAgentAsync(
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="assistantClientResult"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         ClientResult<Assistant> assistantClientResult,
@@ -191,6 +196,7 @@ public static ChatClientAgent GetAIAgent(
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="assistantMetadata"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         Assistant assistantMetadata,
@@ -252,6 +258,7 @@ public static ChatClientAgent GetAIAgent(
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant agent.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="assistantClient"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException"><paramref name="agentId"/> is empty or whitespace.</exception>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         string agentId,
@@ -291,6 +298,7 @@ public static ChatClientAgent GetAIAgent(
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant agent.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="assistantClient"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException"><paramref name="agentId"/> is empty or whitespace.</exception>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static async Task<ChatClientAgent> GetAIAgentAsync(
         this AssistantClient assistantClient,
         string agentId,
@@ -333,6 +341,7 @@ public static async Task<ChatClientAgent> GetAIAgentAsync(
     /// <returns>An <see cref="ChatClientAgent"/> instance backed by the OpenAI Assistant service.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="client"/> or <paramref name="model"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException">Thrown when <paramref name="model"/> is empty or whitespace.</exception>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static ChatClientAgent CreateAIAgent(
         this AssistantClient client,
         string model,
@@ -371,6 +380,7 @@ public static ChatClientAgent CreateAIAgent(
     /// <returns>An <see cref="ChatClientAgent"/> instance backed by the OpenAI Assistant service.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="client"/> or <paramref name="model"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException">Thrown when <paramref name="model"/> is empty or whitespace.</exception>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static ChatClientAgent CreateAIAgent(
         this AssistantClient client,
         string model,
@@ -437,6 +447,7 @@ public static ChatClientAgent CreateAIAgent(
     /// <returns>An <see cref="ChatClientAgent"/> instance backed by the OpenAI Assistant service.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="client"/> or <paramref name="model"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException">Thrown when <paramref name="model"/> is empty or whitespace.</exception>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static async Task<ChatClientAgent> CreateAIAgentAsync(
         this AssistantClient client,
         string model,
@@ -477,6 +488,7 @@ await client.CreateAIAgentAsync(model,
     /// <returns>An <see cref="ChatClientAgent"/> instance backed by the OpenAI Assistant service.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="client"/> or <paramref name="model"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException">Thrown when <paramref name="model"/> is empty or whitespace.</exception>
+    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
     public static async Task<ChatClientAgent> CreateAIAgentAsync(
         this AssistantClient client,
         string model,
diff --git a/dotnet/tests/Microsoft.Agents.AI.OpenAI.UnitTests/Extensions/OpenAIAssistantClientExtensionsTests.cs b/dotnet/tests/Microsoft.Agents.AI.OpenAI.UnitTests/Extensions/OpenAIAssistantClientExtensionsTests.cs
index 26f855d59e1..c75d72cf343 100644
--- a/dotnet/tests/Microsoft.Agents.AI.OpenAI.UnitTests/Extensions/OpenAIAssistantClientExtensionsTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.OpenAI.UnitTests/Extensions/OpenAIAssistantClientExtensionsTests.cs
@@ -1,5 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+#pragma warning disable CS0618 // Type or member is obsolete - This is intentional as we are testing deprecated methods
+
 using System;
 using System.ClientModel;
 using System.ClientModel.Primitives;

From d1ac53d5e4d21cb8d1f206e88e7392426729e66f Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 20:25:14 +0000
Subject: [PATCH 3/4] Add pragma warning disable CS0618 to files using
 deprecated OpenAI Assistants API

Co-authored-by: SergeyMenshykh <68852919+SergeyMenshykh@users.noreply.github.com>
---
 .../AgentProviders/Agent_With_OpenAIAssistants/Program.cs       | 2 ++
 .../OpenAIAssistantClientExtensionsTests.cs                     | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/dotnet/samples/GettingStarted/AgentProviders/Agent_With_OpenAIAssistants/Program.cs b/dotnet/samples/GettingStarted/AgentProviders/Agent_With_OpenAIAssistants/Program.cs
index 9a91e43d378..b39a21f71fc 100644
--- a/dotnet/samples/GettingStarted/AgentProviders/Agent_With_OpenAIAssistants/Program.cs
+++ b/dotnet/samples/GettingStarted/AgentProviders/Agent_With_OpenAIAssistants/Program.cs
@@ -5,6 +5,8 @@
 // WARNING: The Assistants API is deprecated and will be shut down.
 // For more information see the OpenAI documentation: https://platform.openai.com/docs/assistants/migration
 
+#pragma warning disable CS0618 // Type or member is obsolete - OpenAI Assistants API is deprecated but still used in this sample
+
 using Microsoft.Agents.AI;
 using OpenAI;
 
diff --git a/dotnet/tests/OpenAIAssistant.IntegrationTests/OpenAIAssistantClientExtensionsTests.cs b/dotnet/tests/OpenAIAssistant.IntegrationTests/OpenAIAssistantClientExtensionsTests.cs
index f1373bd98b0..0c8d6b80dd6 100644
--- a/dotnet/tests/OpenAIAssistant.IntegrationTests/OpenAIAssistantClientExtensionsTests.cs
+++ b/dotnet/tests/OpenAIAssistant.IntegrationTests/OpenAIAssistantClientExtensionsTests.cs
@@ -1,5 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+#pragma warning disable CS0618 // Type or member is obsolete - Testing deprecated OpenAI Assistants API extension methods
+
 using System;
 using System.Diagnostics;
 using System.IO;

From dd56f501033c4c05a2f3e4fe57e3d32930996844 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 5 Dec 2025 09:32:39 +0000
Subject: [PATCH 4/4] Update Obsolete attribute message to use requested text

Co-authored-by: SergeyMenshykh <68852919+SergeyMenshykh@users.noreply.github.com>
---
 .../OpenAIAssistantClientExtensions.cs        | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/dotnet/src/Microsoft.Agents.AI.OpenAI/Extensions/OpenAIAssistantClientExtensions.cs b/dotnet/src/Microsoft.Agents.AI.OpenAI/Extensions/OpenAIAssistantClientExtensions.cs
index a3ca550257e..f103a7fc1c4 100644
--- a/dotnet/src/Microsoft.Agents.AI.OpenAI/Extensions/OpenAIAssistantClientExtensions.cs
+++ b/dotnet/src/Microsoft.Agents.AI.OpenAI/Extensions/OpenAIAssistantClientExtensions.cs
@@ -30,7 +30,7 @@ public static class OpenAIAssistantClientExtensions
     /// <param name="clientFactory">Provides a way to customize the creation of the underlying <see cref="IChatClient"/> used by the agent.</param>
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant.</returns>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         ClientResult<Assistant> assistantClientResult,
@@ -55,7 +55,7 @@ public static ChatClientAgent GetAIAgent(
     /// <param name="clientFactory">Provides a way to customize the creation of the underlying <see cref="IChatClient"/> used by the agent.</param>
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant.</returns>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         Assistant assistantMetadata,
@@ -104,7 +104,7 @@ public static ChatClientAgent GetAIAgent(
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant agent.</returns>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         string agentId,
@@ -137,7 +137,7 @@ public static ChatClientAgent GetAIAgent(
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant agent.</returns>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static async Task<ChatClientAgent> GetAIAgentAsync(
         this AssistantClient assistantClient,
         string agentId,
@@ -170,7 +170,7 @@ public static async Task<ChatClientAgent> GetAIAgentAsync(
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="assistantClientResult"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         ClientResult<Assistant> assistantClientResult,
@@ -196,7 +196,7 @@ public static ChatClientAgent GetAIAgent(
     /// <param name="services">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="assistantMetadata"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         Assistant assistantMetadata,
@@ -258,7 +258,7 @@ public static ChatClientAgent GetAIAgent(
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant agent.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="assistantClient"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException"><paramref name="agentId"/> is empty or whitespace.</exception>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static ChatClientAgent GetAIAgent(
         this AssistantClient assistantClient,
         string agentId,
@@ -298,7 +298,7 @@ public static ChatClientAgent GetAIAgent(
     /// <returns>A <see cref="ChatClientAgent"/> instance that can be used to perform operations on the assistant agent.</returns>
     /// <exception cref="ArgumentNullException"><paramref name="assistantClient"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException"><paramref name="agentId"/> is empty or whitespace.</exception>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static async Task<ChatClientAgent> GetAIAgentAsync(
         this AssistantClient assistantClient,
         string agentId,
@@ -341,7 +341,7 @@ public static async Task<ChatClientAgent> GetAIAgentAsync(
     /// <returns>An <see cref="ChatClientAgent"/> instance backed by the OpenAI Assistant service.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="client"/> or <paramref name="model"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException">Thrown when <paramref name="model"/> is empty or whitespace.</exception>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static ChatClientAgent CreateAIAgent(
         this AssistantClient client,
         string model,
@@ -380,7 +380,7 @@ public static ChatClientAgent CreateAIAgent(
     /// <returns>An <see cref="ChatClientAgent"/> instance backed by the OpenAI Assistant service.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="client"/> or <paramref name="model"/> or <paramref name="options"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException">Thrown when <paramref name="model"/> is empty or whitespace.</exception>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static ChatClientAgent CreateAIAgent(
         this AssistantClient client,
         string model,
@@ -447,7 +447,7 @@ public static ChatClientAgent CreateAIAgent(
     /// <returns>An <see cref="ChatClientAgent"/> instance backed by the OpenAI Assistant service.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="client"/> or <paramref name="model"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException">Thrown when <paramref name="model"/> is empty or whitespace.</exception>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static async Task<ChatClientAgent> CreateAIAgentAsync(
         this AssistantClient client,
         string model,
@@ -488,7 +488,7 @@ await client.CreateAIAgentAsync(model,
     /// <returns>An <see cref="ChatClientAgent"/> instance backed by the OpenAI Assistant service.</returns>
     /// <exception cref="ArgumentNullException">Thrown when <paramref name="client"/> or <paramref name="model"/> is <see langword="null"/>.</exception>
     /// <exception cref="ArgumentException">Thrown when <paramref name="model"/> is empty or whitespace.</exception>
-    [Obsolete("The OpenAI Assistants API has been deprecated. Please use OpenAI Responses API instead.")]
+    [Obsolete("The Assistants API has been deprecated. Please use the Responses API instead.")]
     public static async Task<ChatClientAgent> CreateAIAgentAsync(
         this AssistantClient client,
         string model,