diff --git a/dotnet/src/Microsoft.Agents.AI/OpenTelemetryAgent.cs b/dotnet/src/Microsoft.Agents.AI/OpenTelemetryAgent.cs
index fd1c2fd7f5..cffde717e4 100644
--- a/dotnet/src/Microsoft.Agents.AI/OpenTelemetryAgent.cs
+++ b/dotnet/src/Microsoft.Agents.AI/OpenTelemetryAgent.cs
@@ -3,10 +3,12 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.AI;
+using Microsoft.Shared.DiagnosticIds;
 
 namespace Microsoft.Agents.AI;
 
@@ -32,6 +34,13 @@ public sealed class OpenTelemetryAgent : DelegatingAIAgent, IDisposable
     private readonly OpenTelemetryChatClient _otelClient;
     /// <summary>The provider name extracted from <see cref="AIAgentMetadata"/>.</summary>
     private readonly string? _providerName;
+    /// <summary>The resolved source name for telemetry. Always non-empty; defaults to <see cref="OpenTelemetryConsts.DefaultSourceName"/>.</summary>
+    private readonly string _sourceName;
+    /// <summary>
+    /// Indicates whether the underlying <see cref="IChatClient"/> of a <see cref="ChatClientAgent"/> inner agent
+    /// should be automatically wrapped with <see cref="OpenTelemetryChatClient"/> on each invocation.
+    /// </summary>
+    private readonly bool _autoWireChatClient;
 
     /// <summary>Initializes a new instance of the <see cref="OpenTelemetryAgent"/> class.</summary>
     /// <param name="innerAgent">The underlying <see cref="AIAgent"/> to be augmented with telemetry capabilities.</param>
@@ -44,13 +53,44 @@ public sealed class OpenTelemetryAgent : DelegatingAIAgent, IDisposable
     /// The constructor automatically extracts provider metadata from the inner agent and configures
     /// telemetry collection according to OpenTelemetry semantic conventions for AI systems.
     /// </remarks>
-    public OpenTelemetryAgent(AIAgent innerAgent, string? sourceName = null) : base(innerAgent)
+    public OpenTelemetryAgent(AIAgent innerAgent, string? sourceName = null)
+#pragma warning disable MAAI001 // Auto-wiring is the new default; the experimental opt-out lives on the 3-arg overload.
+        : this(innerAgent, sourceName, autoWireChatClient: true)
+#pragma warning restore MAAI001
+    {
+    }
+
+    /// <summary>Initializes a new instance of the <see cref="OpenTelemetryAgent"/> class.</summary>
+    /// <param name="innerAgent">The underlying <see cref="AIAgent"/> to be augmented with telemetry capabilities.</param>
+    /// <param name="sourceName">
+    /// An optional source name that will be used to identify telemetry data from this agent.
+    /// If not provided, a default source name will be used for telemetry identification.
+    /// </param>
+    /// <param name="autoWireChatClient">
+    /// When <see langword="true"/> and the inner agent is a <see cref="ChatClientAgent"/>, the underlying
+    /// <see cref="IChatClient"/> is automatically wrapped with <see cref="OpenTelemetryChatClient"/> for each invocation
+    /// so that chat-level telemetry flows alongside agent-level telemetry. If the underlying chat client is already
+    /// instrumented, no additional wrapping is applied. Set to <see langword="false"/> to opt-out of this behavior.
+    /// </param>
+    /// <exception cref="ArgumentNullException"><paramref name="innerAgent"/> is <see langword="null"/>.</exception>
+    /// <remarks>
+    /// The constructor automatically extracts provider metadata from the inner agent and configures
+    /// telemetry collection according to OpenTelemetry semantic conventions for AI systems.
+    /// </remarks>
+    [Experimental(DiagnosticIds.Experiments.AgentsAIExperiments)]
+    public OpenTelemetryAgent(AIAgent innerAgent, string? sourceName, bool autoWireChatClient) : base(innerAgent)
     {
         this._providerName = innerAgent.GetService<AIAgentMetadata>()?.ProviderName;
 
+        // Resolve once so the outer OpenTelemetryChatClient and the auto-wired inner
+        // OpenTelemetryChatClient always emit spans under the same ActivitySource, even when
+        // the caller passes "" or whitespace (which neither client should treat as a real source).
+        this._sourceName = string.IsNullOrWhiteSpace(sourceName) ? OpenTelemetryConsts.DefaultSourceName : sourceName!;
+        this._autoWireChatClient = autoWireChatClient;
+
         this._otelClient = new OpenTelemetryChatClient(
             new ForwardingChatClient(this),
-            sourceName: string.IsNullOrEmpty(sourceName) ? OpenTelemetryConsts.DefaultSourceName : sourceName!);
+            sourceName: this._sourceName);
     }
 
     /// <inheritdoc/>
@@ -163,6 +203,85 @@ public ForwardedOptions(AgentRunOptions? options, AgentSession? session, Activit
         public Activity? CurrentActivity { get; }
     }
 
+    /// <summary>
+    /// If auto-wiring is enabled and the inner agent is a <see cref="ChatClientAgent"/> whose underlying
+    /// <see cref="IChatClient"/> is not already instrumented with <see cref="OpenTelemetryChatClient"/>, returns a
+    /// new <see cref="ChatClientAgentRunOptions"/> with a <see cref="ChatClientAgentRunOptions.ChatClientFactory"/>
+    /// that wraps the chat client with <see cref="OpenTelemetryChatClient"/>. When <paramref name="options"/> is a
+    /// plain <see cref="AgentRunOptions"/> (the base type, not <see cref="ChatClientAgentRunOptions"/>), the base
+    /// properties are copied onto the new <see cref="ChatClientAgentRunOptions"/> so high-level callers that pass
+    /// the abstract <see cref="AgentRunOptions"/> still benefit from auto-wiring and propagate their settings to
+    /// the inner agent. Otherwise, returns <paramref name="options"/> unchanged.
+    /// </summary>
+    private AgentRunOptions? GetRunOptionsWithChatClientWiring(AgentRunOptions? options)
+    {
+        if (!this._autoWireChatClient)
+        {
+            return options;
+        }
+
+        // The auto-wiring only applies when a ChatClientAgent is reachable from the inner agent. Otherwise, no-op.
+        // Use GetService rather than a type check so wrapping agents that expose a nested ChatClientAgent are supported.
+        var chatClientAgent = this.InnerAgent.GetService<ChatClientAgent>();
+        if (chatClientAgent is null)
+        {
+            return options;
+        }
+
+        // Respect ChatClientAgentOptions.UseProvidedChatClientAsIs: don't decorate the chat client when the user opted out.
+        if (chatClientAgent.GetService<ChatClientAgentOptions>()?.UseProvidedChatClientAsIs is true)
+        {
+            return options;
+        }
+
+        // Capture the underlying IChatClient and check whether it is already instrumented.
+        var chatClient = chatClientAgent.GetService<IChatClient>();
+        if (chatClient is null || chatClient.GetService(typeof(OpenTelemetryChatClient)) is not null)
+        {
+            return options;
+        }
+
+        string sourceName = this._sourceName;
+        static IChatClient WrapIfNeeded(IChatClient cc, string sourceName) =>
+            cc.GetService(typeof(OpenTelemetryChatClient)) is not null
+                ? cc
+                : cc.AsBuilder().UseOpenTelemetry(sourceName: sourceName).Build();
+
+        if (options is ChatClientAgentRunOptions ccOptions)
+        {
+            // Don't mutate the caller's options; clone and chain any caller-provided factory.
+            // If the user factory already returns an OpenTelemetry-instrumented client, don't double-wrap.
+            var clone = (ChatClientAgentRunOptions)ccOptions.Clone();
+            var userFactory = clone.ChatClientFactory;
+            clone.ChatClientFactory = cc => WrapIfNeeded(userFactory is null ? cc : userFactory(cc), sourceName);
+            return clone;
+        }
+
+        // For a plain AgentRunOptions (or null), create a ChatClientAgentRunOptions and preserve
+        // any base AgentRunOptions properties from the caller so they reach the inner agent.
+        var newOptions = new ChatClientAgentRunOptions
+        {
+            ChatClientFactory = cc => WrapIfNeeded(cc, sourceName),
+        };
+
+        if (options is not null)
+        {
+            CopyBaseAgentRunOptions(options, newOptions);
+        }
+
+        return newOptions;
+    }
+
+#pragma warning disable MEAI001 // ContinuationToken is experimental; copy it through to preserve caller-provided value.
+    private static void CopyBaseAgentRunOptions(AgentRunOptions source, AgentRunOptions target)
+    {
+        target.ContinuationToken = source.ContinuationToken;
+        target.AllowBackgroundResponses = source.AllowBackgroundResponses;
+        target.AdditionalProperties = source.AdditionalProperties?.Clone();
+        target.ResponseFormat = source.ResponseFormat;
+    }
+#pragma warning restore MEAI001
+
     /// <summary>The stub <see cref="IChatClient"/> used to delegate from the <see cref="OpenTelemetryChatClient"/> into the inner <see cref="AIAgent"/>.</summary>
     /// <param name="parentAgent"></param>
     private sealed class ForwardingChatClient(OpenTelemetryAgent parentAgent) : IChatClient
@@ -175,8 +294,11 @@ public async Task<ChatResponse> GetResponseAsync(
             // Update the current activity to reflect the agent invocation.
             parentAgent.UpdateCurrentActivity(fo?.CurrentActivity);
 
+            // If enabled, wire the underlying chat client with OpenTelemetryChatClient via ChatClientFactory.
+            var runOptions = parentAgent.GetRunOptionsWithChatClientWiring(fo?.Options);
+
             // Invoke the inner agent.
-            var response = await parentAgent.InnerAgent.RunAsync(messages, fo?.Session, fo?.Options, cancellationToken).ConfigureAwait(false);
+            var response = await parentAgent.InnerAgent.RunAsync(messages, fo?.Session, runOptions, cancellationToken).ConfigureAwait(false);
 
             // Wrap the response in a ChatResponse so we can pass it back through OpenTelemetryChatClient.
             return response.AsChatResponse();
@@ -190,8 +312,11 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
             // Update the current activity to reflect the agent invocation.
             parentAgent.UpdateCurrentActivity(fo?.CurrentActivity);
 
+            // If enabled, wire the underlying chat client with OpenTelemetryChatClient via ChatClientFactory.
+            var runOptions = parentAgent.GetRunOptionsWithChatClientWiring(fo?.Options);
+
             // Invoke the inner agent.
-            await foreach (var update in parentAgent.InnerAgent.RunStreamingAsync(messages, fo?.Session, fo?.Options, cancellationToken).ConfigureAwait(false))
+            await foreach (var update in parentAgent.InnerAgent.RunStreamingAsync(messages, fo?.Session, runOptions, cancellationToken).ConfigureAwait(false))
             {
                 // Wrap the response updates in ChatResponseUpdates so we can pass them back through OpenTelemetryChatClient.
                 yield return update.AsChatResponseUpdate();
diff --git a/dotnet/tests/Microsoft.Agents.AI.UnitTests/OpenTelemetryAgentTests.cs b/dotnet/tests/Microsoft.Agents.AI.UnitTests/OpenTelemetryAgentTests.cs
index b8ddd2feaa..1f04d09ba3 100644
--- a/dotnet/tests/Microsoft.Agents.AI.UnitTests/OpenTelemetryAgentTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.UnitTests/OpenTelemetryAgentTests.cs
@@ -627,4 +627,455 @@ async static IAsyncEnumerable<AgentResponseUpdate> CallbackAsync(
     }
 
     private static string ReplaceWhitespace(string? input) => Regex.Replace(input ?? "", @"\s+", "").Trim();
+
+    #region AutoWireChatClient
+
+    [Fact]
+    public async Task AutoWireChatClient_DefaultsToEnabled_EmitsChatSpan_Async()
+    {
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        var fakeChatClient = new AutoWireTestChatClient();
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        _ = await agent.RunAsync("hi");
+
+        // Expect 2 activities: the inner chat span (from auto-wired OpenTelemetryChatClient) and the invoke_agent span.
+        Assert.Equal(2, activities.Count);
+        Assert.Contains(activities, a => a.DisplayName.StartsWith("invoke_agent", StringComparison.Ordinal));
+        Assert.Contains(activities, a => string.Equals(a.GetTagItem("gen_ai.operation.name") as string, "chat", StringComparison.Ordinal));
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_Streaming_EmitsChatSpan_Async()
+    {
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        var fakeChatClient = new AutoWireTestChatClient();
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        await foreach (var _ in agent.RunStreamingAsync("hi"))
+        {
+        }
+
+        Assert.Equal(2, activities.Count);
+        Assert.Contains(activities, a => a.DisplayName.StartsWith("invoke_agent", StringComparison.Ordinal));
+        Assert.Contains(activities, a => string.Equals(a.GetTagItem("gen_ai.operation.name") as string, "chat", StringComparison.Ordinal));
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_Disabled_DoesNotEmitChatSpan_Async()
+    {
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        var fakeChatClient = new AutoWireTestChatClient();
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName, autoWireChatClient: false);
+
+        _ = await agent.RunAsync("hi");
+
+        // Only the invoke_agent activity should be emitted; no chat span.
+        var activity = Assert.Single(activities);
+        Assert.StartsWith("invoke_agent", activity.DisplayName);
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_NonChatClientAgent_NoOp_Async()
+    {
+        // Inner is not a ChatClientAgent — auto-wiring must be a no-op and options must remain null.
+        AgentRunOptions? observedOptions = null;
+        var inner = new TestAIAgent
+        {
+            RunAsyncFunc = (messages, session, options, ct) =>
+            {
+                observedOptions = options;
+                return Task.FromResult(new AgentResponse(new ChatMessage(ChatRole.Assistant, "ok")));
+            },
+        };
+
+        using var agent = new OpenTelemetryAgent(inner);
+
+        _ = await agent.RunAsync("hi");
+
+        Assert.Null(observedOptions);
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_UseProvidedChatClientAsIs_DoesNotEmitChatSpan_Async()
+    {
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        var fakeChatClient = new AutoWireTestChatClient();
+        var inner = new ChatClientAgent(fakeChatClient, new ChatClientAgentOptions { UseProvidedChatClientAsIs = true });
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        _ = await agent.RunAsync("hi");
+
+        // UseProvidedChatClientAsIs opts out of auto-wiring, so only the invoke_agent span should be emitted.
+        var activity = Assert.Single(activities);
+        Assert.StartsWith("invoke_agent", activity.DisplayName);
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_AlreadyInstrumented_DoesNotDoubleWrap_Async()
+    {
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        var fakeChatClient = new AutoWireTestChatClient();
+        // Pre-wrap with OpenTelemetryChatClient on the same source so spans flow through the tracer.
+        IChatClient preWrapped = fakeChatClient.AsBuilder().UseOpenTelemetry(sourceName: sourceName).Build();
+        var inner = new ChatClientAgent(preWrapped);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        _ = await agent.RunAsync("hi");
+
+        // Expect exactly 2 activities (one invoke_agent + one chat from the pre-existing wrapper). If we had double-wrapped, we would see 3.
+        Assert.Equal(2, activities.Count);
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_PreservesUserChatClientFactory_Async()
+    {
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        bool userFactoryCalled = false;
+        var fakeChatClient = new AutoWireTestChatClient();
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        var runOptions = new ChatClientAgentRunOptions
+        {
+            ChatClientFactory = cc =>
+            {
+                userFactoryCalled = true;
+                return cc;
+            },
+        };
+
+        _ = await agent.RunAsync("hi", options: runOptions);
+
+        Assert.True(userFactoryCalled);
+        // Auto-wiring should still produce a chat span on top of the user's factory.
+        Assert.Equal(2, activities.Count);
+        Assert.Contains(activities, a => string.Equals(a.GetTagItem("gen_ai.operation.name") as string, "chat", StringComparison.Ordinal));
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_PlainAgentRunOptions_PreservesBaseProperties_Async()
+    {
+        // Auto-wiring converts a plain AgentRunOptions into a ChatClientAgentRunOptions. The base
+        // properties (ContinuationToken, AllowBackgroundResponses, AdditionalProperties, ResponseFormat)
+        // must be preserved so they reach the inner agent.
+        AgentRunOptions? observedOptions = null;
+        var fakeChatClient = new AutoWireTestChatClient();
+        var innerChatClientAgent = new ChatClientAgent(fakeChatClient);
+
+        // Wrapping agent: surfaces the ChatClientAgent via GetService (so auto-wiring activates),
+        // but captures the AgentRunOptions passed to RunAsync by the OpenTelemetryAgent.
+        var wrapper = new TestAIAgent
+        {
+            GetServiceFunc = (type, key) =>
+                type == typeof(ChatClientAgent) ? innerChatClientAgent : null,
+            RunAsyncFunc = (messages, session, options, ct) =>
+            {
+                observedOptions = options;
+                return Task.FromResult(new AgentResponse(new ChatMessage(ChatRole.Assistant, "ok")));
+            },
+        };
+
+        using var agent = new OpenTelemetryAgent(wrapper);
+
+        var additionalProps = new AdditionalPropertiesDictionary { ["customKey"] = "customValue" };
+        var inputOptions = new AgentRunOptions
+        {
+            AllowBackgroundResponses = true,
+            AdditionalProperties = additionalProps,
+            ResponseFormat = ChatResponseFormat.Json,
+        };
+
+        _ = await agent.RunAsync("hi", options: inputOptions);
+
+        Assert.NotNull(observedOptions);
+        Assert.IsType<ChatClientAgentRunOptions>(observedOptions);
+        Assert.Equal(true, observedOptions!.AllowBackgroundResponses);
+        Assert.Same(ChatResponseFormat.Json, observedOptions.ResponseFormat);
+        Assert.NotNull(observedOptions.AdditionalProperties);
+        Assert.Equal("customValue", observedOptions.AdditionalProperties!["customKey"]);
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_UserFactoryReturnsInstrumentedClient_DoesNotDoubleWrap_Async()
+    {
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        var fakeChatClient = new AutoWireTestChatClient();
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        // User factory wraps the chat client with OpenTelemetryChatClient itself.
+        var runOptions = new ChatClientAgentRunOptions
+        {
+            ChatClientFactory = cc => cc.AsBuilder().UseOpenTelemetry(sourceName: sourceName).Build(),
+        };
+
+        _ = await agent.RunAsync("hi", options: runOptions);
+
+        // Expect 2 activities (invoke_agent + a single chat span). If we double-wrapped, we would see 3.
+        Assert.Equal(2, activities.Count);
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    [InlineData("\t")]
+    public async Task Ctor_NullOrWhitespaceSourceName_AutoWiredChatClientUsesDefaultSource_Async(string? sourceName)
+    {
+        // Both the agent-level invoke_agent span and the auto-wired chat span must be emitted under
+        // OpenTelemetryConsts.DefaultSourceName when the caller passes null, "", or whitespace, so they reach
+        // the same ActivitySource and are not silently dropped by the exporter.
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource("Experimental.Microsoft.Agents.AI")
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        var fakeChatClient = new AutoWireTestChatClient();
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        _ = await agent.RunAsync("hi");
+
+        Assert.Equal(2, activities.Count);
+        Assert.All(activities, a => Assert.Equal("Experimental.Microsoft.Agents.AI", a.Source.Name));
+        Assert.Contains(activities, a => a.DisplayName.StartsWith("invoke_agent", StringComparison.Ordinal));
+        Assert.Contains(activities, a => string.Equals(a.GetTagItem("gen_ai.operation.name") as string, "chat", StringComparison.Ordinal));
+    }
+
+#pragma warning disable MEAI001 // ResponseContinuationToken is experimental.
+    [Fact]
+    public async Task AutoWireChatClient_PlainAgentRunOptions_PreservesContinuationToken_Async()
+    {
+        // ContinuationToken is the fourth base AgentRunOptions property copied by CopyBaseAgentRunOptions
+        // and is not exercised by AutoWireChatClient_PlainAgentRunOptions_PreservesBaseProperties_Async.
+        AgentRunOptions? observedOptions = null;
+        var fakeChatClient = new AutoWireTestChatClient();
+        var innerChatClientAgent = new ChatClientAgent(fakeChatClient);
+
+        var wrapper = new TestAIAgent
+        {
+            GetServiceFunc = (type, key) =>
+                type == typeof(ChatClientAgent) ? innerChatClientAgent : null,
+            RunAsyncFunc = (messages, session, options, ct) =>
+            {
+                observedOptions = options;
+                return Task.FromResult(new AgentResponse(new ChatMessage(ChatRole.Assistant, "ok")));
+            },
+        };
+
+        using var agent = new OpenTelemetryAgent(wrapper);
+
+        var token = ResponseContinuationToken.FromBytes(new byte[] { 1, 2, 3 });
+        var inputOptions = new AgentRunOptions
+        {
+            ContinuationToken = token,
+        };
+
+        _ = await agent.RunAsync("hi", options: inputOptions);
+
+        Assert.NotNull(observedOptions);
+        Assert.IsType<ChatClientAgentRunOptions>(observedOptions);
+        Assert.Same(token, observedOptions!.ContinuationToken);
+    }
+#pragma warning restore MEAI001
+
+    [Fact]
+    public async Task AutoWireChatClient_ChatClientAgentRunOptions_NoUserFactory_PreservesChatOptions_Async()
+    {
+        // When the caller passes a ChatClientAgentRunOptions without a ChatClientFactory, the auto-wiring
+        // must clone (not mutate) the caller's options, set the factory, and preserve nested ChatOptions.
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        ChatOptions? observedChatOptions = null;
+        var fakeChatClient = new AutoWireTestChatClient
+        {
+            OnGetResponseAsync = (msgs, opts) => observedChatOptions = opts,
+        };
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        var inputChatOptions = new ChatOptions { Temperature = 0.42f, ModelId = "test-model" };
+        var inputOptions = new ChatClientAgentRunOptions(inputChatOptions);
+
+        _ = await agent.RunAsync("hi", options: inputOptions);
+
+        // Caller's options must not have been mutated (no factory installed on the caller's instance).
+        Assert.Null(inputOptions.ChatClientFactory);
+
+        // Inner chat client must observe the caller-supplied ChatOptions.
+        Assert.NotNull(observedChatOptions);
+        Assert.Equal(0.42f, observedChatOptions!.Temperature);
+        Assert.Equal("test-model", observedChatOptions.ModelId);
+
+        // Auto-wiring still produces a chat span.
+        Assert.Equal(2, activities.Count);
+        Assert.Contains(activities, a => string.Equals(a.GetTagItem("gen_ai.operation.name") as string, "chat", StringComparison.Ordinal));
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_StreamingDisabled_DoesNotEmitChatSpan_Async()
+    {
+        // Symmetry with AutoWireChatClient_Disabled_DoesNotEmitChatSpan_Async for the streaming path.
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        var fakeChatClient = new AutoWireTestChatClient();
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName, autoWireChatClient: false);
+
+        await foreach (var _ in agent.RunStreamingAsync("hi"))
+        {
+        }
+
+        var activity = Assert.Single(activities);
+        Assert.StartsWith("invoke_agent", activity.DisplayName);
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_PlainAgentRunOptions_RealChatClientAgent_EmitsChatSpan_Async()
+    {
+        // High-level callers may pass the abstract base AgentRunOptions (not ChatClientAgentRunOptions) when
+        // wiring a ChatClientAgent. Auto-wiring must still kick in: convert to ChatClientAgentRunOptions,
+        // install the OTel-wrapping factory, and produce both the invoke_agent and chat spans end-to-end.
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        ChatOptions? observedChatOptions = null;
+        var fakeChatClient = new AutoWireTestChatClient
+        {
+            OnGetResponseAsync = (_, opts) => observedChatOptions = opts,
+        };
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        // Pass the base AgentRunOptions, not ChatClientAgentRunOptions.
+        var inputOptions = new AgentRunOptions { AllowBackgroundResponses = false };
+
+        _ = await agent.RunAsync("hi", options: inputOptions);
+
+        // Inner chat client was actually invoked (auto-wired factory ran without breaking the pipeline).
+        Assert.NotNull(observedChatOptions);
+
+        Assert.Equal(2, activities.Count);
+        Assert.Contains(activities, a => a.DisplayName.StartsWith("invoke_agent", StringComparison.Ordinal));
+        Assert.Contains(activities, a => string.Equals(a.GetTagItem("gen_ai.operation.name") as string, "chat", StringComparison.Ordinal));
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_PlainAgentRunOptions_RealChatClientAgent_StreamingEmitsChatSpan_Async()
+    {
+        // Same as the sync test above but for the streaming path so both invocation paths
+        // are covered when callers pass a base AgentRunOptions.
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        ChatOptions? observedChatOptions = null;
+        var fakeChatClient = new AutoWireTestChatClient
+        {
+            OnGetResponseAsync = (_, opts) => observedChatOptions = opts,
+        };
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        var inputOptions = new AgentRunOptions { AllowBackgroundResponses = false };
+
+        await foreach (var _ in agent.RunStreamingAsync("hi", options: inputOptions))
+        {
+        }
+
+        Assert.NotNull(observedChatOptions);
+
+        Assert.Equal(2, activities.Count);
+        Assert.Contains(activities, a => a.DisplayName.StartsWith("invoke_agent", StringComparison.Ordinal));
+        Assert.Contains(activities, a => string.Equals(a.GetTagItem("gen_ai.operation.name") as string, "chat", StringComparison.Ordinal));
+    }
+
+    private sealed class AutoWireTestChatClient : IChatClient
+    {
+        public Action<IEnumerable<ChatMessage>, ChatOptions?>? OnGetResponseAsync { get; set; }
+
+        public Task<ChatResponse> GetResponseAsync(IEnumerable<ChatMessage> messages, ChatOptions? options = null, CancellationToken cancellationToken = default)
+        {
+            this.OnGetResponseAsync?.Invoke(messages, options);
+            return Task.FromResult(new ChatResponse(new ChatMessage(ChatRole.Assistant, "ok")));
+        }
+
+        public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(IEnumerable<ChatMessage> messages, ChatOptions? options = null, [EnumeratorCancellation] CancellationToken cancellationToken = default)
+        {
+            this.OnGetResponseAsync?.Invoke(messages, options);
+            await Task.Yield();
+            yield return new ChatResponseUpdate(ChatRole.Assistant, "ok");
+        }
+
+        public object? GetService(Type serviceType, object? serviceKey = null) =>
+            serviceType?.IsInstanceOfType(this) == true ? this : null;
+
+        public void Dispose() { }
+    }
+
+    #endregion
 }