diff --git a/eng/packages/General.props b/eng/packages/General.props
index b7066789238..5be4031ad4d 100644
--- a/eng/packages/General.props
+++ b/eng/packages/General.props
@@ -16,7 +16,7 @@
     <PackageVersion Include="Microsoft.ML.Tokenizers" Version="$(MicrosoftMLTokenizersVersion)" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageVersion Include="OllamaSharp" Version="5.1.9" />
-    <PackageVersion Include="OpenAI" Version="2.4.0" />
+    <PackageVersion Include="OpenAI" Version="2.5.0" />
     <PackageVersion Include="Polly" Version="8.4.2" />
     <PackageVersion Include="Polly.Core" Version="8.4.2" />
     <PackageVersion Include="Polly.Extensions" Version="8.4.2" />
diff --git a/src/Libraries/Microsoft.Extensions.AI.OpenAI/CHANGELOG.md b/src/Libraries/Microsoft.Extensions.AI.OpenAI/CHANGELOG.md
index a50aea8dea3..8c1febc6bc8 100644
--- a/src/Libraries/Microsoft.Extensions.AI.OpenAI/CHANGELOG.md
+++ b/src/Libraries/Microsoft.Extensions.AI.OpenAI/CHANGELOG.md
@@ -2,12 +2,13 @@
 
 ## NOT YET RELEASED
 
+- Updated to depend on OpenAI 2.5.0.
 - Added M.E.AI to OpenAI conversions for response format types.
 - Added `ResponseTool` to `AITool` conversions.
 
 ## 9.9.0-preview.1.25458.4
 
-- Updated to depend on OpenAI 2.4.0
+- Updated to depend on OpenAI 2.4.0.
 - Updated tool mappings to recognize any `AIFunctionDeclaration`.
 - Updated to accommodate the additions in `Microsoft.Extensions.AI.Abstractions`.
 - Fixed handling of annotated but empty content in the `AsIChatClient` for `AssistantClient`.
diff --git a/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIEmbeddingGenerator.cs b/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIEmbeddingGenerator.cs
index dbe9bf10237..9c3da231065 100644
--- a/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIEmbeddingGenerator.cs
+++ b/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIEmbeddingGenerator.cs
@@ -2,8 +2,11 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.ClientModel;
+using System.ClientModel.Primitives;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Shared.Diagnostics;
@@ -11,12 +14,25 @@
 
 #pragma warning disable S1067 // Expressions should not be too complex
 #pragma warning disable S3011 // Reflection should not be used to increase accessibility of classes, methods, or fields
+#pragma warning disable EA0011 // Consider removing unnecessary conditional access operator (?)
 
 namespace Microsoft.Extensions.AI;
 
 /// <summary>An <see cref="IEmbeddingGenerator{String, Embedding}"/> for an OpenAI <see cref="EmbeddingClient"/>.</summary>
 internal sealed class OpenAIEmbeddingGenerator : IEmbeddingGenerator<string, Embedding<float>>
 {
+    // This delegate instance is used to call the internal overload of GenerateEmbeddingsAsync that accepts
+    // a RequestOptions. This should be replaced once a better way to pass RequestOptions is available.
+    private static readonly Func<EmbeddingClient, IEnumerable<string>, OpenAI.Embeddings.EmbeddingGenerationOptions, RequestOptions, Task<ClientResult<OpenAIEmbeddingCollection>>>?
+        _generateEmbeddingsAsync =
+        (Func<EmbeddingClient, IEnumerable<string>, OpenAI.Embeddings.EmbeddingGenerationOptions, RequestOptions, Task<ClientResult<OpenAIEmbeddingCollection>>>?)
+        typeof(EmbeddingClient)
+        .GetMethod(
+            nameof(EmbeddingClient.GenerateEmbeddingsAsync), BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance,
+            null, [typeof(IEnumerable<string>), typeof(OpenAI.Embeddings.EmbeddingGenerationOptions), typeof(RequestOptions)], null)
+        ?.CreateDelegate(
+            typeof(Func<EmbeddingClient, IEnumerable<string>, OpenAI.Embeddings.EmbeddingGenerationOptions, RequestOptions, Task<ClientResult<OpenAIEmbeddingCollection>>>));
+
     /// <summary>Metadata about the embedding generator.</summary>
     private readonly EmbeddingGeneratorMetadata _metadata;
 
@@ -49,7 +65,10 @@ public async Task<GeneratedEmbeddings<Embedding<float>>> GenerateAsync(IEnumerab
     {
         OpenAI.Embeddings.EmbeddingGenerationOptions? openAIOptions = ToOpenAIOptions(options);
 
-        var embeddings = (await _embeddingClient.GenerateEmbeddingsAsync(values, openAIOptions, cancellationToken).ConfigureAwait(false)).Value;
+        var t = _generateEmbeddingsAsync is not null ?
+            _generateEmbeddingsAsync(_embeddingClient, values, openAIOptions, cancellationToken.ToRequestOptions(streaming: false)) :
+            _embeddingClient.GenerateEmbeddingsAsync(values, openAIOptions, cancellationToken);
+        var embeddings = (await t.ConfigureAwait(false)).Value;
 
         return new(embeddings.Select(e =>
                 new Embedding<float>(e.ToFloats())
diff --git a/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIResponsesChatClient.cs b/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIResponsesChatClient.cs
index d094f5f8581..ec662a68891 100644
--- a/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIResponsesChatClient.cs
+++ b/src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIResponsesChatClient.cs
@@ -65,12 +65,7 @@ public OpenAIResponsesChatClient(OpenAIResponseClient responseClient)
 
         _responseClient = responseClient;
 
-        // https://github.com/openai/openai-dotnet/issues/662
-        // Update to avoid reflection once OpenAIResponseClient.Model is exposed publicly.
-        string? model = typeof(OpenAIResponseClient).GetField("_model", BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)
-            ?.GetValue(responseClient) as string;
-
-        _metadata = new("openai", responseClient.Endpoint, model);
+        _metadata = new("openai", responseClient.Endpoint, responseClient.Model);
     }
 
     /// <inheritdoc />
@@ -469,27 +464,19 @@ private ResponseCreationOptions ToOpenAIResponseCreationOptions(ChatOptions? opt
                         break;
 
                     case HostedCodeInterpreterTool codeTool:
-                        string json;
-                        if (codeTool.Inputs is { Count: > 0 } inputs)
-                        {
-                            string jsonArray = JsonSerializer.Serialize(
-                                inputs.OfType<HostedFileContent>().Select(c => c.FileId),
-                                OpenAIJsonContext.Default.IEnumerableString);
-                            json = $$"""{"type":"code_interpreter","container":{"type":"auto",files:{{jsonArray}}} }""";
-                        }
-                        else
-                        {
-                            json = """{"type":"code_interpreter","container":{"type":"auto"}}""";
-                        }
-
-                        result.Tools.Add(ModelReaderWriter.Read<ResponseTool>(BinaryData.FromString(json)));
+                        result.Tools.Add(
+                            ResponseTool.CreateCodeInterpreterTool(
+                                new CodeInterpreterToolContainer(codeTool.Inputs?.OfType<HostedFileContent>().Select(f => f.FileId).ToList() is { Count: > 0 } ids ?
+                                    CodeInterpreterToolContainerConfiguration.CreateAutomaticContainerConfiguration(ids) :
+                                    new())));
                         break;
 
                     case HostedMcpServerTool mcpTool:
                         McpTool responsesMcpTool = ResponseTool.CreateMcpTool(
                             mcpTool.ServerName,
                             mcpTool.Url,
-                            mcpTool.Headers);
+                            serverDescription: mcpTool.ServerDescription,
+                            headers: mcpTool.Headers);
 
                         if (mcpTool.AllowedTools is not null)
                         {
@@ -673,8 +660,8 @@ internal static IEnumerable<ResponseItem> ToOpenAIResponseItems(IEnumerable<Chat
                             break;
 
                         case McpServerToolApprovalRequestContent mcpApprovalRequestContent:
-                            // BUG https://github.com/openai/openai-dotnet/issues/664: Needs to be able to set an approvalRequestId
                             yield return ResponseItem.CreateMcpApprovalRequestItem(
+                                mcpApprovalRequestContent.Id,
                                 mcpApprovalRequestContent.ToolCall.ServerName,
                                 mcpApprovalRequestContent.ToolCall.ToolName,
                                 BinaryData.FromBytes(JsonSerializer.SerializeToUtf8Bytes(mcpApprovalRequestContent.ToolCall.Arguments!, OpenAIJsonContext.Default.IReadOnlyDictionaryStringObject)));
diff --git a/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIChatClientTests.cs b/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIChatClientTests.cs
index bdf3b2e7c0a..067539b9fe4 100644
--- a/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIChatClientTests.cs
+++ b/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIChatClientTests.cs
@@ -1586,6 +1586,19 @@ private static async Task DataContentMessage_Image_AdditionalPropertyDetail_NonS
         }, response.Usage.AdditionalCounts);
     }
 
+    [Fact]
+    public async Task RequestHeaders_UserAgent_ContainsMEAI()
+    {
+        using var handler = new ThrowUserAgentExceptionHandler();
+        using HttpClient httpClient = new(handler);
+        using IChatClient client = CreateChatClient(httpClient, "gpt-4o-mini");
+
+        InvalidOperationException e = await Assert.ThrowsAsync<InvalidOperationException>(() => client.GetResponseAsync("hello"));
+
+        Assert.StartsWith("User-Agent header: OpenAI", e.Message);
+        Assert.Contains("MEAI", e.Message);
+    }
+
     private static IChatClient CreateChatClient(HttpClient httpClient, string modelId) =>
         new OpenAIClient(new ApiKeyCredential("apikey"), new OpenAIClientOptions { Transport = new HttpClientPipelineTransport(httpClient) })
         .GetChatClient(modelId)
diff --git a/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIEmbeddingGeneratorTests.cs b/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIEmbeddingGeneratorTests.cs
index 43112fa88e3..0db88d499e1 100644
--- a/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIEmbeddingGeneratorTests.cs
+++ b/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIEmbeddingGeneratorTests.cs
@@ -125,10 +125,7 @@ public async Task GetEmbeddingsAsync_ExpectedRequestResponse()
 
         using VerbatimHttpHandler handler = new(Input, Output);
         using HttpClient httpClient = new(handler);
-        using IEmbeddingGenerator<string, Embedding<float>> generator = new OpenAIClient(new ApiKeyCredential("apikey"), new OpenAIClientOptions
-        {
-            Transport = new HttpClientPipelineTransport(httpClient),
-        }).GetEmbeddingClient("text-embedding-3-small").AsIEmbeddingGenerator();
+        using IEmbeddingGenerator<string, Embedding<float>> generator = CreateEmbeddingGenerator(httpClient, "text-embedding-3-small");
 
         var response = await generator.GenerateAsync([
             "hello, world!",
@@ -188,10 +185,7 @@ public async Task EmbeddingGenerationOptions_DoNotOverwrite_NotNullPropertiesInR
 
         using VerbatimHttpHandler handler = new(Input, Output);
         using HttpClient httpClient = new(handler);
-        using IEmbeddingGenerator<string, Embedding<float>> generator = new OpenAIClient(new ApiKeyCredential("apikey"), new OpenAIClientOptions
-        {
-            Transport = new HttpClientPipelineTransport(httpClient),
-        }).GetEmbeddingClient("text-embedding-3-small").AsIEmbeddingGenerator();
+        using IEmbeddingGenerator<string, Embedding<float>> generator = CreateEmbeddingGenerator(httpClient, "text-embedding-3-small");
 
         var response = await generator.GenerateAsync([
             "hello, world!",
@@ -221,4 +215,24 @@ public async Task EmbeddingGenerationOptions_DoNotOverwrite_NotNullPropertiesInR
             Assert.Contains(e.Vector.ToArray(), f => !f.Equals(0));
         }
     }
+
+    [Fact]
+    public async Task RequestHeaders_UserAgent_ContainsMEAI()
+    {
+        using var handler = new ThrowUserAgentExceptionHandler();
+        using HttpClient httpClient = new(handler);
+        using IEmbeddingGenerator<string, Embedding<float>> generator = CreateEmbeddingGenerator(httpClient, "text-embedding-3-small");
+
+        InvalidOperationException e = await Assert.ThrowsAsync<InvalidOperationException>(() => generator.GenerateAsync("hello"));
+
+        Assert.StartsWith("User-Agent header: OpenAI", e.Message);
+        Assert.Contains("MEAI", e.Message);
+    }
+
+    private static IEmbeddingGenerator<string, Embedding<float>> CreateEmbeddingGenerator(HttpClient httpClient, string modelId) =>
+        new OpenAIClient(
+            new ApiKeyCredential("apikey"),
+            new OpenAIClientOptions { Transport = new HttpClientPipelineTransport(httpClient) })
+        .GetEmbeddingClient(modelId)
+        .AsIEmbeddingGenerator();
 }
diff --git a/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIResponseClientTests.cs b/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIResponseClientTests.cs
index 866e43e172d..79e63162923 100644
--- a/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIResponseClientTests.cs
+++ b/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/OpenAIResponseClientTests.cs
@@ -1034,7 +1034,7 @@ public async Task McpToolCall_ApprovalNotRequired_NonStreaming(bool rawTool)
         using IChatClient client = CreateResponseClient(httpClient, "gpt-4o-mini");
 
         AITool mcpTool = rawTool ?
-            ResponseTool.CreateMcpTool("deepwiki", new("https://mcp.deepwiki.com/mcp"), toolCallApprovalPolicy: new McpToolCallApprovalPolicy(GlobalMcpToolCallApprovalPolicy.NeverRequireApproval)).AsAITool() :
+            ResponseTool.CreateMcpTool("deepwiki", serverUri: new("https://mcp.deepwiki.com/mcp"), toolCallApprovalPolicy: new McpToolCallApprovalPolicy(GlobalMcpToolCallApprovalPolicy.NeverRequireApproval)).AsAITool() :
             new HostedMcpServerTool("deepwiki", "https://mcp.deepwiki.com/mcp")
             {
                 ApprovalMode = HostedMcpServerToolApprovalMode.NeverRequire,
@@ -1506,6 +1506,19 @@ public async Task McpToolCall_ApprovalNotRequired_Streaming()
         Assert.Equal(1569, response.Usage.TotalTokenCount);
     }
 
+    [Fact]
+    public async Task RequestHeaders_UserAgent_ContainsMEAI()
+    {
+        using var handler = new ThrowUserAgentExceptionHandler();
+        using HttpClient httpClient = new(handler);
+        using IChatClient client = CreateResponseClient(httpClient, "gpt-4o-mini");
+
+        InvalidOperationException e = await Assert.ThrowsAsync<InvalidOperationException>(() => client.GetResponseAsync("hello"));
+
+        Assert.StartsWith("User-Agent header: OpenAI", e.Message);
+        Assert.Contains("MEAI", e.Message);
+    }
+
     private static IChatClient CreateResponseClient(HttpClient httpClient, string modelId) =>
         new OpenAIClient(
             new ApiKeyCredential("apikey"),
diff --git a/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/ThrowUserAgentExceptionHandler.cs b/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/ThrowUserAgentExceptionHandler.cs
new file mode 100644
index 00000000000..6b4b0fa0f1c
--- /dev/null
+++ b/test/Libraries/Microsoft.Extensions.AI.OpenAI.Tests/ThrowUserAgentExceptionHandler.cs
@@ -0,0 +1,15 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.Extensions.AI;
+
+internal sealed class ThrowUserAgentExceptionHandler : HttpMessageHandler
+{
+    protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) =>
+        throw new InvalidOperationException($"User-Agent header: {request.Headers.UserAgent}");
+}