[BREAKING] Remove unused AgentThreadMetadata (#3067)

* Remove unused AgentThreadMetadata

* Update DurableTask Changelog

dotnet/src/Microsoft.Agents.AI.Abstractions/AgentThread.cs

@@ -68,7 +68,7 @@ public abstract class AgentThread
     /// <exception cref="ArgumentNullException"><paramref name="serviceType"/> is <see langword="null"/>.</exception>
     /// <remarks>
     /// The purpose of this method is to allow for the retrieval of strongly-typed services that might be provided by the <see cref="AgentThread"/>,
-    /// including itself or any services it might be wrapping. For example, to access the <see cref="AgentThreadMetadata"/> for the instance,
+    /// including itself or any services it might be wrapping. For example, to access a <see cref="ChatMessageStore"/> if available for the instance,
     /// <see cref="GetService"/> may be used to request it.
     /// </remarks>
     public virtual object? GetService(Type serviceType, object? serviceKey = null)

dotnet/src/Microsoft.Agents.AI.Abstractions/AgentThreadMetadata.cs

@@ -1,29 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System.Diagnostics;
-
-namespace Microsoft.Agents.AI;
-
-/// <summary>
-/// Provides metadata information about an <see cref="AgentThread"/> instance.
-/// </summary>
-[DebuggerDisplay("ConversationId = {ConversationId}")]
-public class AgentThreadMetadata
-{
-    /// <summary>
-    /// Initializes a new instance of the <see cref="AgentThreadMetadata"/> class.
-    /// </summary>
-    /// <param name="conversationId">The unique identifier for the conversation, if available.</param>
-    public AgentThreadMetadata(string? conversationId)
-    {
-        this.ConversationId = conversationId;
-    }
-
-    /// <summary>
-    /// Gets the unique identifier for the conversation, if available.
-    /// </summary>
-    /// <remarks>
-    /// The meaning of this ID may vary depending on the agent implementation.
-    /// </remarks>
-    public string? ConversationId { get; }
-}

dotnet/src/Microsoft.Agents.AI.DurableTask/CHANGELOG.md

@@ -6,6 +6,7 @@
 
 - Added TTL configuration for durable agent entities ([#2679](https://github.com/microsoft/agent-framework/pull/2679))
 - Switch to new "Run" method name ([#2843](https://github.com/microsoft/agent-framework/pull/2843))
+- Removed AgentThreadMetadata and used AgentSessionId directly instead ([#3067](https://github.com/microsoft/agent-framework/pull/3067));
 
 ## v1.0.0-preview.251204.1
 

dotnet/src/Microsoft.Agents.AI.DurableTask/DurableAgentThread.cs

@@ -55,12 +55,6 @@ public sealed class DurableAgentThread : AgentThread
     /// <inheritdoc/>
     public override object? GetService(Type serviceType, object? serviceKey = null)
     {
-        // This is a common convention for MAF agents.
-        if (serviceType == typeof(AgentThreadMetadata))
-        {
-            return new AgentThreadMetadata(conversationId: this.SessionId.ToString());
-        }
-
         if (serviceType == typeof(AgentSessionId))
         {
             return this.SessionId;

dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientAgentThread.cs

@@ -171,9 +171,7 @@ public class ChatClientAgentThread : AgentThread
 
     /// <inheritdoc/>
     public override object? GetService(Type serviceType, object? serviceKey = null) =>
-        serviceType == typeof(AgentThreadMetadata)
-            ? new AgentThreadMetadata(this.ConversationId)
-            : base.GetService(serviceType, serviceKey)
+        base.GetService(serviceType, serviceKey)
             ?? this.AIContextProvider?.GetService(serviceType, serviceKey)
             ?? this.MessageStore?.GetService(serviceType, serviceKey);