diff --git a/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientAgent.cs b/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientAgent.cs
index 5f714be24f..cc5ddf31c3 100644
--- a/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientAgent.cs
+++ b/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientAgent.cs
@@ -35,7 +35,8 @@ public sealed class ChatClientAgent : AIAgent
     /// <param name="description">Optional description for the agent.</param>
     /// <param name="tools">Optional list of tools that the agent can use during invocation.</param>
     /// <param name="loggerFactory">Optional logger factory to use for logging.</param>
-    public ChatClientAgent(IChatClient chatClient, string? instructions = null, string? name = null, string? description = null, IList<AITool>? tools = null, ILoggerFactory? loggerFactory = null)
+    /// <param name="functionInvocationServices">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
+    public ChatClientAgent(IChatClient chatClient, string? instructions = null, string? name = null, string? description = null, IList<AITool>? tools = null, ILoggerFactory? loggerFactory = null, IServiceProvider? functionInvocationServices = null)
         : this(
               chatClient,
               new ChatClientAgentOptions
@@ -48,7 +49,8 @@ public sealed class ChatClientAgent : AIAgent
                       Tools = tools,
                   }
               },
-              loggerFactory)
+              loggerFactory,
+              functionInvocationServices)
     {
     }
 
@@ -58,7 +60,8 @@ public sealed class ChatClientAgent : AIAgent
     /// <param name="chatClient">The chat client to use for invoking the agent.</param>
     /// <param name="options">Full set of options to configure the agent.</param>
     /// <param name="loggerFactory">Optional logger factory to use for logging.</param>
-    public ChatClientAgent(IChatClient chatClient, ChatClientAgentOptions? options, ILoggerFactory? loggerFactory = null)
+    /// <param name="functionInvocationServices">An optional <see cref="IServiceProvider"/> to use for resolving services required by the <see cref="AIFunction"/> instances being invoked.</param>
+    public ChatClientAgent(IChatClient chatClient, ChatClientAgentOptions? options, ILoggerFactory? loggerFactory = null, IServiceProvider? functionInvocationServices = null)
     {
         _ = Throw.IfNull(chatClient);
 
@@ -71,7 +74,7 @@ public sealed class ChatClientAgent : AIAgent
         this._chatClientType = chatClient.GetType();
 
         // If the user has not opted out of using our default decorators, we wrap the chat client.
-        this.ChatClient = options?.UseProvidedChatClientAsIs is true ? chatClient : chatClient.WithDefaultAgentMiddleware(options);
+        this.ChatClient = options?.UseProvidedChatClientAsIs is true ? chatClient : chatClient.WithDefaultAgentMiddleware(options, functionInvocationServices);
 
         this._logger = (loggerFactory ?? chatClient.GetService<ILoggerFactory>() ?? NullLoggerFactory.Instance).CreateLogger<ChatClientAgent>();
     }
diff --git a/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientExtensions.cs b/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientExtensions.cs
index 80d3347d1f..67cd7c0d54 100644
--- a/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientExtensions.cs
+++ b/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientExtensions.cs
@@ -1,5 +1,6 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System;
 using System.Diagnostics;
 using Microsoft.Agents.AI;
 using Microsoft.Extensions.AI;
@@ -10,7 +11,7 @@ namespace Microsoft.Extensions.AI;
 
 internal static class ChatClientExtensions
 {
-    internal static IChatClient WithDefaultAgentMiddleware(this IChatClient chatClient, ChatClientAgentOptions? options)
+    internal static IChatClient WithDefaultAgentMiddleware(this IChatClient chatClient, ChatClientAgentOptions? options, IServiceProvider? functionInvocationServices = null)
     {
         var chatBuilder = chatClient.AsBuilder();
 
@@ -24,7 +25,7 @@ internal static class ChatClientExtensions
             });
         }
 
-        var agentChatClient = chatBuilder.Build();
+        var agentChatClient = chatBuilder.Build(functionInvocationServices);
 
         if (options?.ChatOptions?.Tools is { Count: > 0 })
         {