From 34dedf97d46af55bb307050d81ce80b4ebf96c15 Mon Sep 17 00:00:00 2001
From: James Abbott <james.abbott@kroll.com>
Date: Sun, 1 Mar 2026 11:26:49 +0000
Subject: [PATCH 1/7] feat: Add support for dimensions in Vertex AI embedding
 services and tests

---
 .../VertexAIEmbeddingGeneratorTests.cs        | 147 +++++++++++++++++-
 ...exAITextEmbeddingGenerationServiceTests.cs | 147 +++++++++++++++++-
 .../Core/VertexAI/VertexAIEmbeddingClient.cs  |  15 +-
 .../Core/VertexAI/VertexAIEmbeddingRequest.cs |  10 +-
 .../VertexAIKernelBuilderExtensions.cs        |  26 +++-
 ...ollectionExtensions.DependencyInjection.cs |  14 +-
 .../VertexAIServiceCollectionExtensions.cs    |  14 +-
 .../Services/VertexAIEmbeddingGenerator.cs    |  16 +-
 .../VertexAITextEmbeddingGenerationService.cs |  41 ++++-
 9 files changed, 383 insertions(+), 47 deletions(-)

diff --git a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAIEmbeddingGeneratorTests.cs b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAIEmbeddingGeneratorTests.cs
index d3304bb3bdd7..e293de580a7a 100644
--- a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAIEmbeddingGeneratorTests.cs
+++ b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAIEmbeddingGeneratorTests.cs
@@ -1,5 +1,9 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System;
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Text;
 using System.Threading.Tasks;
 using Microsoft.Extensions.AI;
 using Microsoft.SemanticKernel.Connectors.Google;
@@ -7,27 +11,156 @@
 
 namespace SemanticKernel.Connectors.Google.UnitTests.Services;
 
-public sealed class VertexAIEmbeddingGeneratorTests
+public sealed class VertexAIEmbeddingGeneratorTests : IDisposable
 {
+    private const string Model = "fake-model";
+    private const string BearerKey = "fake-key";
+    private const int Dimensions = 512;
+    private readonly HttpMessageHandlerStub _messageHandlerStub;
+    private readonly HttpClient _httpClient;
+
+    public VertexAIEmbeddingGeneratorTests()
+    {
+        this._messageHandlerStub = new HttpMessageHandlerStub
+        {
+            ResponseToReturn = new HttpResponseMessage(System.Net.HttpStatusCode.OK)
+            {
+                Content = new StringContent(
+                    """
+                    {
+                        "predictions": [
+                            {
+                                "embeddings": {
+                                    "values": [0.1, 0.2, 0.3, 0.4, 0.5]
+                                }
+                            }
+                        ]
+                    }
+                    """,
+                    Encoding.UTF8,
+                    "application/json"
+                )
+            }
+        };
+
+        this._httpClient = new HttpClient(this._messageHandlerStub, disposeHandler: false);
+    }
+
     [Fact]
     public void AttributesShouldContainModelIdBearerAsString()
     {
         // Arrange & Act
-        string model = "fake-model";
-        using var service = new VertexAIEmbeddingGenerator(model, "key", "location", "project");
+        using var service = new VertexAIEmbeddingGenerator(Model, BearerKey, "location", "project");
 
         // Assert
-        Assert.Equal(model, service.GetService<EmbeddingGeneratorMetadata>()!.DefaultModelId);
+        Assert.Equal(Model, service.GetService<EmbeddingGeneratorMetadata>()!.DefaultModelId);
     }
 
     [Fact]
     public void AttributesShouldContainModelIdBearerAsFunc()
     {
         // Arrange & Act
-        string model = "fake-model";
-        using var service = new VertexAIEmbeddingGenerator(model, () => ValueTask.FromResult("key"), "location", "project");
+        using var service = new VertexAIEmbeddingGenerator(Model, () => ValueTask.FromResult(BearerKey), "location", "project");
 
         // Assert
-        Assert.Equal(model, service.GetService<EmbeddingGeneratorMetadata>()!.DefaultModelId);
+        Assert.Equal(Model, service.GetService<EmbeddingGeneratorMetadata>()!.DefaultModelId);
+    }
+
+    [Fact]
+    public void AttributesShouldNotContainDimensionsWhenNotProvided()
+    {
+        // Arrange & Act
+        using var service = new VertexAIEmbeddingGenerator(Model, BearerKey, "location", "project");
+
+        // Assert
+        Assert.Null(service.GetService<EmbeddingGeneratorMetadata>()!.DefaultModelDimensions);
+    }
+
+    [Fact]
+    public void AttributesShouldContainDimensionsWhenProvided()
+    {
+        // Arrange & Act
+        using var service = new VertexAIEmbeddingGenerator(Model, BearerKey, "location", "project", dimensions: Dimensions);
+
+        // Assert
+        Assert.Equal(Dimensions, service.GetService<EmbeddingGeneratorMetadata>()!.DefaultModelDimensions);
+    }
+
+    [Fact]
+    public void GetDimensionsReturnsCorrectValue()
+    {
+        // Arrange
+        using var service = new VertexAIEmbeddingGenerator(Model, BearerKey, "location", "project", dimensions: Dimensions);
+
+        // Act
+        var result = service.GetService<EmbeddingGeneratorMetadata>()!.DefaultModelDimensions;
+
+        // Assert
+        Assert.Equal(Dimensions, result);
+    }
+
+    [Fact]
+    public void GetDimensionsReturnsNullWhenNotProvided()
+    {
+        // Arrange
+        using var service = new VertexAIEmbeddingGenerator(Model, BearerKey, "location", "project");
+
+        // Act
+        var result = service.GetService<EmbeddingGeneratorMetadata>()!.DefaultModelDimensions;
+
+        // Assert
+        Assert.Null(result);
+    }
+
+    [Fact]
+    public async Task ShouldNotIncludeDimensionsInRequestWhenNotProvidedAsync()
+    {
+        // Arrange
+        using var service = new VertexAIEmbeddingGenerator(
+            modelId: Model,
+            bearerKey: BearerKey,
+            location: "location",
+            projectId: "project",
+            dimensions: null,
+            httpClient: this._httpClient);
+        var dataToEmbed = new List<string> { "Text to embed" };
+
+        // Act
+        await service.GenerateAsync(dataToEmbed);
+
+        // Assert
+        Assert.NotNull(this._messageHandlerStub.RequestContent);
+        var requestBody = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent);
+        Assert.DoesNotContain("outputDimensionality", requestBody);
+    }
+
+    [Theory]
+    [InlineData(Dimensions)]
+    [InlineData(Dimensions * 2)]
+    public async Task ShouldIncludeDimensionsInRequestWhenProvidedAsync(int? dimensions)
+    {
+        // Arrange
+        using var service = new VertexAIEmbeddingGenerator(
+            modelId: Model,
+            bearerKey: BearerKey,
+            location: "location",
+            projectId: "project",
+            dimensions: dimensions,
+            httpClient: this._httpClient);
+        var dataToEmbed = new List<string> { "Text to embed" };
+
+        // Act
+        await service.GenerateAsync(dataToEmbed);
+
+        // Assert
+        Assert.NotNull(this._messageHandlerStub.RequestContent);
+        var requestBody = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent);
+        Assert.Contains($"\"outputDimensionality\":{dimensions}", requestBody);
+    }
+
+    public void Dispose()
+    {
+        this._messageHandlerStub.Dispose();
+        this._httpClient.Dispose();
     }
 }
diff --git a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
index fbc3579fbfe7..3a076c32e001 100644
--- a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
+++ b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
@@ -1,35 +1,168 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System;
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Text;
 using System.Threading.Tasks;
 using Microsoft.SemanticKernel.Connectors.Google;
+using Microsoft.SemanticKernel.Embeddings;
 using Microsoft.SemanticKernel.Services;
 using Xunit;
 
 namespace SemanticKernel.Connectors.Google.UnitTests.Services;
 
 [Obsolete("Temporary test for Obsolete ITextEmbeddingGenerationService")]
-public sealed class VertexAITextEmbeddingGenerationServiceTests
+public sealed class VertexAITextEmbeddingGenerationServiceTests : IDisposable
 {
+    private const string Model = "fake-model";
+    private const string BearerKey = "fake-key";
+    private const int Dimensions = 512;
+    private readonly HttpMessageHandlerStub _messageHandlerStub;
+    private readonly HttpClient _httpClient;
+
+    public VertexAITextEmbeddingGenerationServiceTests()
+    {
+        this._messageHandlerStub = new HttpMessageHandlerStub
+        {
+            ResponseToReturn = new HttpResponseMessage(System.Net.HttpStatusCode.OK)
+            {
+                Content = new StringContent(
+                    """
+                    {
+                        "predictions": [
+                            {
+                                "embeddings": {
+                                    "values": [0.1, 0.2, 0.3, 0.4, 0.5]
+                                }
+                            }
+                        ]
+                    }
+                    """,
+                    Encoding.UTF8,
+                    "application/json"
+                )
+            }
+        };
+
+        this._httpClient = new HttpClient(this._messageHandlerStub, disposeHandler: false);
+    }
+
     [Fact]
     public void AttributesShouldContainModelIdBearerAsString()
     {
         // Arrange & Act
-        string model = "fake-model";
-        var service = new VertexAITextEmbeddingGenerationService(model, "key", "location", "project");
+        var service = new VertexAITextEmbeddingGenerationService(Model, BearerKey, "location", "project");
 
         // Assert
-        Assert.Equal(model, service.Attributes[AIServiceExtensions.ModelIdKey]);
+        Assert.Equal(Model, service.Attributes[AIServiceExtensions.ModelIdKey]);
     }
 
     [Fact]
     public void AttributesShouldContainModelIdBearerAsFunc()
     {
         // Arrange & Act
-        string model = "fake-model";
-        var service = new VertexAITextEmbeddingGenerationService(model, () => ValueTask.FromResult("key"), "location", "project");
+        var service = new VertexAITextEmbeddingGenerationService(Model, () => ValueTask.FromResult(BearerKey), "location", "project");
 
         // Assert
-        Assert.Equal(model, service.Attributes[AIServiceExtensions.ModelIdKey]);
+        Assert.Equal(Model, service.Attributes[AIServiceExtensions.ModelIdKey]);
+    }
+
+    [Fact]
+    public void AttributesShouldNotContainDimensionsWhenNotProvided()
+    {
+        // Arrange & Act
+        var service = new VertexAITextEmbeddingGenerationService(Model, BearerKey, "location", "project");
+
+        // Assert
+        Assert.False(service.Attributes.ContainsKey(EmbeddingGenerationExtensions.DimensionsKey));
+    }
+
+    [Fact]
+    public void AttributesShouldContainDimensionsWhenProvided()
+    {
+        // Arrange & Act
+        var service = new VertexAITextEmbeddingGenerationService(Model, BearerKey, "location", "project", dimensions: Dimensions);
+
+        // Assert
+        Assert.Equal(Dimensions, service.Attributes[EmbeddingGenerationExtensions.DimensionsKey]);
+    }
+
+    [Fact]
+    public void GetDimensionsReturnsCorrectValue()
+    {
+        // Arrange
+        var service = new VertexAITextEmbeddingGenerationService(Model, BearerKey, "location", "project", dimensions: Dimensions);
+
+        // Act
+        var result = service.GetDimensions();
+
+        // Assert
+        Assert.Equal(Dimensions, result);
+    }
+
+    [Fact]
+    public void GetDimensionsReturnsNullWhenNotProvided()
+    {
+        // Arrange
+        var service = new VertexAITextEmbeddingGenerationService(Model, BearerKey, "location", "project");
+
+        // Act
+        var result = service.GetDimensions();
+
+        // Assert
+        Assert.Null(result);
+    }
+
+    [Fact]
+    public async Task ShouldNotIncludeDimensionsInRequestWhenNotProvidedAsync()
+    {
+        // Arrange
+        var service = new VertexAITextEmbeddingGenerationService(
+            modelId: Model,
+            bearerKey: BearerKey,
+            location: "location",
+            projectId: "project",
+            dimensions: null,
+            httpClient: this._httpClient);
+        var dataToEmbed = new List<string> { "Text to embed" };
+
+        // Act
+        await service.GenerateEmbeddingsAsync(dataToEmbed);
+
+        // Assert
+        Assert.NotNull(this._messageHandlerStub.RequestContent);
+        var requestBody = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent);
+        Assert.DoesNotContain("outputDimensionality", requestBody);
+    }
+
+    [Theory]
+    [InlineData(Dimensions)]
+    [InlineData(Dimensions * 2)]
+    public async Task ShouldIncludeDimensionsInRequestWhenProvidedAsync(int? dimensions)
+    {
+        // Arrange
+        var service = new VertexAITextEmbeddingGenerationService(
+            modelId: Model,
+            bearerKey: BearerKey,
+            location: "location",
+            projectId: "project",
+            dimensions: dimensions,
+            httpClient: this._httpClient);
+        var dataToEmbed = new List<string> { "Text to embed" };
+
+        // Act
+        await service.GenerateEmbeddingsAsync(dataToEmbed);
+
+        // Assert
+        Assert.NotNull(this._messageHandlerStub.RequestContent);
+        var requestBody = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent);
+        Assert.Contains($"\"outputDimensionality\":{dimensions}", requestBody);
+    }
+
+    public void Dispose()
+    {
+        this._messageHandlerStub.Dispose();
+        this._httpClient.Dispose();
     }
 }
diff --git a/dotnet/src/Connectors/Connectors.Google/Core/VertexAI/VertexAIEmbeddingClient.cs b/dotnet/src/Connectors/Connectors.Google/Core/VertexAI/VertexAIEmbeddingClient.cs
index 0791de9d6262..e7b1c5343b61 100644
--- a/dotnet/src/Connectors/Connectors.Google/Core/VertexAI/VertexAIEmbeddingClient.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Core/VertexAI/VertexAIEmbeddingClient.cs
@@ -6,6 +6,7 @@
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Extensions.AI;
 using Microsoft.Extensions.Logging;
 
 namespace Microsoft.SemanticKernel.Connectors.Google.Core;
@@ -17,6 +18,7 @@ internal sealed class VertexAIEmbeddingClient : ClientBase
 {
     private readonly string _embeddingModelId;
     private readonly Uri _embeddingEndpoint;
+    private readonly int? _dimensions;
 
     /// <summary>
     /// Represents a client for interacting with the embeddings models by Vertex AI.
@@ -28,6 +30,7 @@ internal sealed class VertexAIEmbeddingClient : ClientBase
     /// <param name="projectId">Project ID from google cloud</param>
     /// <param name="apiVersion">Version of the Vertex API</param>
     /// <param name="logger">Logger instance used for logging (optional)</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     public VertexAIEmbeddingClient(
         HttpClient httpClient,
         string modelId,
@@ -35,7 +38,8 @@ public VertexAIEmbeddingClient(
         string location,
         string projectId,
         VertexAIVersion apiVersion,
-        ILogger? logger = null)
+        ILogger? logger = null,
+        int? dimensions = null)
         : base(
             httpClient: httpClient,
             logger: logger,
@@ -50,21 +54,24 @@ public VertexAIEmbeddingClient(
 
         this._embeddingModelId = modelId;
         this._embeddingEndpoint = new Uri($"https://{location}-aiplatform.googleapis.com/{versionSubLink}/projects/{projectId}/locations/{location}/publishers/google/models/{this._embeddingModelId}:predict");
+        this._dimensions = dimensions;
     }
 
     /// <summary>
     /// Generates embeddings for the given data asynchronously.
     /// </summary>
     /// <param name="data">The list of strings to generate embeddings for.</param>
+    /// <param name="options">The embedding generation options.</param>
     /// <param name="cancellationToken">The cancellation token to cancel the operation.</param>
     /// <returns>Result contains a list of read-only memories of floats representing the generated embeddings.</returns>
     public async Task<IList<ReadOnlyMemory<float>>> GenerateEmbeddingsAsync(
         IList<string> data,
+        EmbeddingGenerationOptions? options = null,
         CancellationToken cancellationToken = default)
     {
         Verify.NotNullOrEmpty(data);
 
-        var geminiRequest = GetEmbeddingRequest(data);
+        var geminiRequest = this.GetEmbeddingRequest(data, options);
         using var httpRequestMessage = await this.CreateHttpRequestAsync(geminiRequest, this._embeddingEndpoint).ConfigureAwait(false);
 
         string body = await this.SendRequestAndGetStringBodyAsync(httpRequestMessage, cancellationToken)
@@ -73,8 +80,8 @@ public async Task<IList<ReadOnlyMemory<float>>> GenerateEmbeddingsAsync(
         return DeserializeAndProcessEmbeddingsResponse(body);
     }
 
-    private static VertexAIEmbeddingRequest GetEmbeddingRequest(IEnumerable<string> data)
-        => VertexAIEmbeddingRequest.FromData(data);
+    private VertexAIEmbeddingRequest GetEmbeddingRequest(IEnumerable<string> data, EmbeddingGenerationOptions? options = null)
+        => VertexAIEmbeddingRequest.FromData(data, options?.Dimensions ?? this._dimensions);
 
     private static List<ReadOnlyMemory<float>> DeserializeAndProcessEmbeddingsResponse(string body)
         => ProcessEmbeddingsResponse(DeserializeResponse<VertexAIEmbeddingResponse>(body));
diff --git a/dotnet/src/Connectors/Connectors.Google/Core/VertexAI/VertexAIEmbeddingRequest.cs b/dotnet/src/Connectors/Connectors.Google/Core/VertexAI/VertexAIEmbeddingRequest.cs
index b93f95cc9d2c..b9a42c9b0bd5 100644
--- a/dotnet/src/Connectors/Connectors.Google/Core/VertexAI/VertexAIEmbeddingRequest.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Core/VertexAI/VertexAIEmbeddingRequest.cs
@@ -15,7 +15,7 @@ internal sealed class VertexAIEmbeddingRequest
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
     public RequestParameters? Parameters { get; set; }
 
-    public static VertexAIEmbeddingRequest FromData(IEnumerable<string> data) => new()
+    public static VertexAIEmbeddingRequest FromData(IEnumerable<string> data, int? dimensions = null) => new()
     {
         Requests = data.Select(text => new RequestContent
         {
@@ -23,8 +23,8 @@ internal sealed class VertexAIEmbeddingRequest
         }).ToList(),
         Parameters = new RequestParameters
         {
-            // todo make configurable when ITextEmbeddingGenerationService will support parameters
-            AutoTruncate = false
+            AutoTruncate = false,
+            OutputDimensionality = dimensions
         }
     };
 
@@ -46,5 +46,9 @@ internal sealed class RequestParameters
     {
         [JsonPropertyName("autoTruncate")]
         public bool AutoTruncate { get; set; }
+
+        [JsonPropertyName("outputDimensionality")]
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+        public int? OutputDimensionality { get; set; }
     }
 }
diff --git a/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIKernelBuilderExtensions.cs b/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIKernelBuilderExtensions.cs
index 109f145569fb..e727d339a44d 100644
--- a/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIKernelBuilderExtensions.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIKernelBuilderExtensions.cs
@@ -114,6 +114,7 @@ public static IKernelBuilder AddVertexAIGeminiChatCompletion(
     /// <param name="apiVersion">The version of the Vertex API.</param>
     /// <param name="serviceId">The optional service ID.</param>
     /// <param name="httpClient">The optional custom HttpClient.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <returns>The updated kernel builder.</returns>
     /// <remarks>
     /// This <paramref name="bearerTokenProvider"/> will be called on every request,
@@ -129,7 +130,8 @@ public static IKernelBuilder AddVertexAIEmbeddingGeneration(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         string? serviceId = null,
-        HttpClient? httpClient = null)
+        HttpClient? httpClient = null,
+        int? dimensions = null)
     {
         Verify.NotNull(builder);
         Verify.NotNull(modelId);
@@ -145,7 +147,8 @@ public static IKernelBuilder AddVertexAIEmbeddingGeneration(
                 projectId: projectId,
                 apiVersion: apiVersion,
                 httpClient: HttpClientProvider.GetHttpClient(httpClient, serviceProvider),
-                loggerFactory: serviceProvider.GetService<ILoggerFactory>()));
+                loggerFactory: serviceProvider.GetService<ILoggerFactory>(),
+                dimensions: dimensions));
         return builder;
     }
 
@@ -160,6 +163,7 @@ public static IKernelBuilder AddVertexAIEmbeddingGeneration(
     /// <param name="apiVersion">The version of the Vertex API.</param>
     /// <param name="serviceId">The optional service ID.</param>
     /// <param name="httpClient">The optional custom HttpClient.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <returns>The updated kernel builder.</returns>
     [Obsolete("Use AddVertexAIEmbeddingGenerator instead.")]
     public static IKernelBuilder AddVertexAIEmbeddingGeneration(
@@ -170,7 +174,8 @@ public static IKernelBuilder AddVertexAIEmbeddingGeneration(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         string? serviceId = null,
-        HttpClient? httpClient = null)
+        HttpClient? httpClient = null,
+        int? dimensions = null)
     {
         Verify.NotNull(builder);
         Verify.NotNull(modelId);
@@ -186,7 +191,8 @@ public static IKernelBuilder AddVertexAIEmbeddingGeneration(
                 projectId: projectId,
                 apiVersion: apiVersion,
                 httpClient: HttpClientProvider.GetHttpClient(httpClient, serviceProvider),
-                loggerFactory: serviceProvider.GetService<ILoggerFactory>()));
+                loggerFactory: serviceProvider.GetService<ILoggerFactory>(),
+                dimensions: dimensions));
         return builder;
     }
 
@@ -201,6 +207,7 @@ public static IKernelBuilder AddVertexAIEmbeddingGeneration(
     /// <param name="apiVersion">The version of the Vertex API.</param>
     /// <param name="serviceId">The optional service ID.</param>
     /// <param name="httpClient">The optional custom HttpClient.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <returns>The updated kernel builder.</returns>
     /// <remarks>
     /// This <paramref name="bearerTokenProvider"/> will be called on every request,
@@ -215,7 +222,8 @@ public static IKernelBuilder AddVertexAIEmbeddingGenerator(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         string? serviceId = null,
-        HttpClient? httpClient = null)
+        HttpClient? httpClient = null,
+        int? dimensions = null)
     {
         Verify.NotNull(builder);
         Verify.NotNull(modelId);
@@ -223,7 +231,7 @@ public static IKernelBuilder AddVertexAIEmbeddingGenerator(
         Verify.NotNull(location);
         Verify.NotNull(projectId);
 
-        builder.Services.AddVertexAIEmbeddingGenerator(modelId, bearerTokenProvider, location, projectId, apiVersion, serviceId, httpClient);
+        builder.Services.AddVertexAIEmbeddingGenerator(modelId, bearerTokenProvider, location, projectId, apiVersion, serviceId, httpClient, dimensions);
 
         return builder;
     }
@@ -239,6 +247,7 @@ public static IKernelBuilder AddVertexAIEmbeddingGenerator(
     /// <param name="apiVersion">The version of the Vertex API.</param>
     /// <param name="serviceId">The optional service ID.</param>
     /// <param name="httpClient">The optional custom HttpClient.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <returns>The updated kernel builder.</returns>
     public static IKernelBuilder AddVertexAIEmbeddingGenerator(
         this IKernelBuilder builder,
@@ -248,7 +257,8 @@ public static IKernelBuilder AddVertexAIEmbeddingGenerator(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         string? serviceId = null,
-        HttpClient? httpClient = null)
+        HttpClient? httpClient = null,
+        int? dimensions = null)
     {
         Verify.NotNull(builder);
         Verify.NotNull(modelId);
@@ -256,7 +266,7 @@ public static IKernelBuilder AddVertexAIEmbeddingGenerator(
         Verify.NotNull(location);
         Verify.NotNull(projectId);
 
-        builder.Services.AddVertexAIEmbeddingGenerator(modelId, bearerKey, location, projectId, apiVersion, serviceId, httpClient);
+        builder.Services.AddVertexAIEmbeddingGenerator(modelId, bearerKey, location, projectId, apiVersion, serviceId, httpClient, dimensions);
 
         return builder;
     }
diff --git a/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIServiceCollectionExtensions.DependencyInjection.cs b/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIServiceCollectionExtensions.DependencyInjection.cs
index fff117e0a76c..d94896056cfa 100644
--- a/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIServiceCollectionExtensions.DependencyInjection.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIServiceCollectionExtensions.DependencyInjection.cs
@@ -27,6 +27,7 @@ public static class VertexAIServiceCollectionExtensions
     /// <param name="apiVersion">The version of the Vertex API.</param>
     /// <param name="serviceId">Optional service ID.</param>
     /// <param name="httpClient">The optional custom HttpClient.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <returns>The updated service collection.</returns>
     /// <remarks>
     /// This <paramref name="bearerTokenProvider"/> will be called on every request,
@@ -41,7 +42,8 @@ public static IServiceCollection AddVertexAIEmbeddingGenerator(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         string? serviceId = null,
-        HttpClient? httpClient = null)
+        HttpClient? httpClient = null,
+        int? dimensions = null)
     {
         Verify.NotNull(services);
         Verify.NotNull(modelId);
@@ -57,7 +59,8 @@ public static IServiceCollection AddVertexAIEmbeddingGenerator(
                 projectId: projectId,
                 apiVersion: apiVersion,
                 httpClient: HttpClientProvider.GetHttpClient(httpClient, serviceProvider),
-                loggerFactory: serviceProvider.GetService<ILoggerFactory>()));
+                loggerFactory: serviceProvider.GetService<ILoggerFactory>(),
+                dimensions: dimensions));
     }
 
     /// <summary>
@@ -71,6 +74,7 @@ public static IServiceCollection AddVertexAIEmbeddingGenerator(
     /// <param name="apiVersion">The version of the Vertex API.</param>
     /// <param name="serviceId">Optional service ID.</param>
     /// <param name="httpClient">The optional custom HttpClient.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <returns>The updated service collection.</returns>
     public static IServiceCollection AddVertexAIEmbeddingGenerator(
         this IServiceCollection services,
@@ -80,7 +84,8 @@ public static IServiceCollection AddVertexAIEmbeddingGenerator(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         string? serviceId = null,
-        HttpClient? httpClient = null)
+        HttpClient? httpClient = null,
+        int? dimensions = null)
     {
         Verify.NotNull(services);
         Verify.NotNull(modelId);
@@ -96,6 +101,7 @@ public static IServiceCollection AddVertexAIEmbeddingGenerator(
                 projectId: projectId,
                 apiVersion: apiVersion,
                 httpClient: HttpClientProvider.GetHttpClient(httpClient, serviceProvider),
-                loggerFactory: serviceProvider.GetService<ILoggerFactory>()));
+                loggerFactory: serviceProvider.GetService<ILoggerFactory>(),
+                dimensions: dimensions));
     }
 }
diff --git a/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIServiceCollectionExtensions.cs b/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIServiceCollectionExtensions.cs
index 34457730aca5..b9a435119de3 100644
--- a/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIServiceCollectionExtensions.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Extensions/VertexAIServiceCollectionExtensions.cs
@@ -107,6 +107,7 @@ public static IServiceCollection AddVertexAIGeminiChatCompletion(
     /// <param name="projectId">Your project ID</param>
     /// <param name="apiVersion">The version of the Vertex API.</param>
     /// <param name="serviceId">Optional service ID.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <returns>The updated service collection.</returns>
     /// <remarks>
     /// This <paramref name="bearerTokenProvider"/> will be called on every request,
@@ -121,7 +122,8 @@ public static IServiceCollection AddVertexAIEmbeddingGeneration(
         string location,
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
-        string? serviceId = null)
+        string? serviceId = null,
+        int? dimensions = null)
     {
         Verify.NotNull(services);
         Verify.NotNull(modelId);
@@ -137,7 +139,8 @@ public static IServiceCollection AddVertexAIEmbeddingGeneration(
                 projectId: projectId,
                 apiVersion: apiVersion,
                 httpClient: HttpClientProvider.GetHttpClient(serviceProvider),
-                loggerFactory: serviceProvider.GetService<ILoggerFactory>()));
+                loggerFactory: serviceProvider.GetService<ILoggerFactory>(),
+                dimensions: dimensions));
     }
 
     /// <summary>
@@ -150,6 +153,7 @@ public static IServiceCollection AddVertexAIEmbeddingGeneration(
     /// <param name="projectId">Your project ID</param>
     /// <param name="apiVersion">The version of the Vertex API.</param>
     /// <param name="serviceId">Optional service ID.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <returns>The updated service collection.</returns>
     [Obsolete("Use AddVertexAIEmbeddingGenerator instead.")]
     public static IServiceCollection AddVertexAIEmbeddingGeneration(
@@ -159,7 +163,8 @@ public static IServiceCollection AddVertexAIEmbeddingGeneration(
         string location,
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
-        string? serviceId = null)
+        string? serviceId = null,
+        int? dimensions = null)
     {
         Verify.NotNull(services);
         Verify.NotNull(modelId);
@@ -175,6 +180,7 @@ public static IServiceCollection AddVertexAIEmbeddingGeneration(
                 projectId: projectId,
                 apiVersion: apiVersion,
                 httpClient: HttpClientProvider.GetHttpClient(serviceProvider),
-                loggerFactory: serviceProvider.GetService<ILoggerFactory>()));
+                loggerFactory: serviceProvider.GetService<ILoggerFactory>(),
+                dimensions: dimensions));
     }
 }
diff --git a/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs b/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs
index 46b1e4edae7f..86b04311e36d 100644
--- a/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs
@@ -28,6 +28,7 @@ public sealed class VertexAIEmbeddingGenerator : IEmbeddingGenerator<string, Emb
     /// <param name="apiVersion">Version of the Vertex API</param>
     /// <param name="httpClient">The optional HTTP client.</param>
     /// <param name="loggerFactory">Optional logger factory to be used for logging.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     public VertexAIEmbeddingGenerator(
         string modelId,
         string bearerKey,
@@ -35,8 +36,9 @@ public VertexAIEmbeddingGenerator(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         HttpClient? httpClient = null,
-        ILoggerFactory? loggerFactory = null)
-        : this(modelId, () => new ValueTask<string>(bearerKey), location, projectId, apiVersion, httpClient, loggerFactory)
+        ILoggerFactory? loggerFactory = null,
+        int? dimensions = null)
+        : this(modelId, () => new ValueTask<string>(bearerKey), location, projectId, apiVersion, httpClient, loggerFactory, dimensions)
     {
 #pragma warning disable CS0618 // Type or member is obsolete
         this._generator = new VertexAITextEmbeddingGenerationService(
@@ -46,7 +48,8 @@ public VertexAIEmbeddingGenerator(
             projectId: projectId,
             apiVersion: apiVersion,
             httpClient: httpClient,
-            loggerFactory: loggerFactory)
+            loggerFactory: loggerFactory,
+            dimensions: dimensions)
             .AsEmbeddingGenerator();
 #pragma warning restore CS0618 // Type or member is obsolete
     }
@@ -61,6 +64,7 @@ public VertexAIEmbeddingGenerator(
     /// <param name="apiVersion">Version of the Vertex API</param>
     /// <param name="httpClient">The optional HTTP client.</param>
     /// <param name="loggerFactory">Optional logger factory to be used for logging.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <remarks>
     /// This <paramref name="bearerTokenProvider"/> will be called on every request,
     /// when providing the token consider using caching strategy and refresh token logic
@@ -73,7 +77,8 @@ public VertexAIEmbeddingGenerator(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         HttpClient? httpClient = null,
-        ILoggerFactory? loggerFactory = null)
+        ILoggerFactory? loggerFactory = null,
+        int? dimensions = null)
     {
 #pragma warning disable CS0618 // Type or member is obsolete
         this._generator = new VertexAITextEmbeddingGenerationService(
@@ -83,7 +88,8 @@ public VertexAIEmbeddingGenerator(
             projectId: projectId,
             apiVersion: apiVersion,
             httpClient: httpClient,
-            loggerFactory: loggerFactory)
+            loggerFactory: loggerFactory,
+            dimensions: dimensions)
             .AsEmbeddingGenerator();
 #pragma warning restore CS0618 // Type or member is obsolete
     }
diff --git a/dotnet/src/Connectors/Connectors.Google/Services/VertexAITextEmbeddingGenerationService.cs b/dotnet/src/Connectors/Connectors.Google/Services/VertexAITextEmbeddingGenerationService.cs
index 0f14fd2a22bf..3fab8a4cfb4e 100644
--- a/dotnet/src/Connectors/Connectors.Google/Services/VertexAITextEmbeddingGenerationService.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Services/VertexAITextEmbeddingGenerationService.cs
@@ -5,6 +5,7 @@
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Extensions.AI;
 using Microsoft.Extensions.Logging;
 using Microsoft.SemanticKernel.Connectors.Google.Core;
 using Microsoft.SemanticKernel.Embeddings;
@@ -32,6 +33,7 @@ public sealed class VertexAITextEmbeddingGenerationService : ITextEmbeddingGener
     /// <param name="apiVersion">Version of the Vertex API</param>
     /// <param name="httpClient">The optional HTTP client.</param>
     /// <param name="loggerFactory">Optional logger factory to be used for logging.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     public VertexAITextEmbeddingGenerationService(
         string modelId,
         string bearerKey,
@@ -39,8 +41,9 @@ public VertexAITextEmbeddingGenerationService(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         HttpClient? httpClient = null,
-        ILoggerFactory? loggerFactory = null)
-        : this(modelId, () => new ValueTask<string>(bearerKey), location, projectId, apiVersion, httpClient, loggerFactory)
+        ILoggerFactory? loggerFactory = null,
+        int? dimensions = null)
+        : this(modelId, () => new ValueTask<string>(bearerKey), location, projectId, apiVersion, httpClient, loggerFactory, dimensions)
     {
         Verify.NotNullOrWhiteSpace(bearerKey);
     }
@@ -55,6 +58,7 @@ public VertexAITextEmbeddingGenerationService(
     /// <param name="apiVersion">Version of the Vertex API</param>
     /// <param name="httpClient">The optional HTTP client.</param>
     /// <param name="loggerFactory">Optional logger factory to be used for logging.</param>
+    /// <param name="dimensions">The number of dimensions that the model should use. If not specified, the default number of dimensions will be used.</param>
     /// <remarks>
     /// This <paramref name="bearerTokenProvider"/> will be called on every request,
     /// when providing the token consider using caching strategy and refresh token logic
@@ -67,7 +71,8 @@ public VertexAITextEmbeddingGenerationService(
         string projectId,
         VertexAIVersion apiVersion = VertexAIVersion.V1,
         HttpClient? httpClient = null,
-        ILoggerFactory? loggerFactory = null)
+        ILoggerFactory? loggerFactory = null,
+        int? dimensions = null)
     {
         Verify.NotNullOrWhiteSpace(modelId);
         Verify.NotNull(bearerTokenProvider);
@@ -83,8 +88,14 @@ public VertexAITextEmbeddingGenerationService(
             location: location,
             projectId: projectId,
             apiVersion: apiVersion,
-            logger: loggerFactory?.CreateLogger(typeof(VertexAITextEmbeddingGenerationService)));
+            logger: loggerFactory?.CreateLogger(typeof(VertexAITextEmbeddingGenerationService)),
+            dimensions: dimensions);
         this._attributesInternal.Add(AIServiceExtensions.ModelIdKey, modelId);
+
+        if (dimensions.HasValue)
+        {
+            this._attributesInternal.Add(EmbeddingGenerationExtensions.DimensionsKey, dimensions);
+        }
     }
 
     /// <inheritdoc />
@@ -96,6 +107,26 @@ public Task<IList<ReadOnlyMemory<float>>> GenerateEmbeddingsAsync(
         Kernel? kernel = null,
         CancellationToken cancellationToken = default)
     {
-        return this._embeddingClient.GenerateEmbeddingsAsync(data, cancellationToken);
+        return this._embeddingClient.GenerateEmbeddingsAsync(data, null, cancellationToken);
+    }
+
+    /// <summary>
+    /// Generates an embedding from the given <paramref name="data"/>.
+    /// </summary>
+    /// <param name="data">List of strings to generate embeddings for</param>
+    /// <param name="options">Additional options for embedding generation</param>
+    /// <param name="kernel">The <see cref="Kernel"/> containing services, plugins, and other state for use throughout the operation.</param>
+    /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
+    /// <returns>List of embeddings</returns>
+    /// <remarks>
+    /// The <paramref name="options"/> parameter can be used to override default settings such as <see cref="EmbeddingGenerationOptions.ModelId"/> and <see cref="EmbeddingGenerationOptions.Dimensions"/>
+    /// </remarks>
+    public Task<IList<ReadOnlyMemory<float>>> GenerateEmbeddingsAsync(
+        IList<string> data,
+        EmbeddingGenerationOptions? options,
+        Kernel? kernel = null,
+        CancellationToken cancellationToken = default)
+    {
+        return this._embeddingClient.GenerateEmbeddingsAsync(data, options, cancellationToken);
     }
 }

From bafdb29d1ffc9da6cc78ff4e60e52289ee4c2385 Mon Sep 17 00:00:00 2001
From: James Abbott <jamesbabbott@gmail.com>
Date: Fri, 20 Mar 2026 11:06:37 +0000
Subject: [PATCH 2/7] fix: Improve JSON assertions for Vertex AI tests.

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 ...texAITextEmbeddingGenerationServiceTests.cs | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
index 3a076c32e001..b497ae555338 100644
--- a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
+++ b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
@@ -5,6 +5,7 @@
 using System.Net.Http;
 using System.Text;
 using System.Threading.Tasks;
+using System.Text.Json;
 using Microsoft.SemanticKernel.Connectors.Google;
 using Microsoft.SemanticKernel.Embeddings;
 using Microsoft.SemanticKernel.Services;
@@ -133,7 +134,14 @@ public async Task ShouldNotIncludeDimensionsInRequestWhenNotProvidedAsync()
         // Assert
         Assert.NotNull(this._messageHandlerStub.RequestContent);
         var requestBody = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent);
-        Assert.DoesNotContain("outputDimensionality", requestBody);
+        using (var document = JsonDocument.Parse(requestBody))
+        {
+            var root = document.RootElement;
+            if (root.TryGetProperty("parameters", out var parametersElement))
+            {
+                Assert.False(parametersElement.TryGetProperty("outputDimensionality", out _));
+            }
+        }
     }
 
     [Theory]
@@ -157,7 +165,13 @@ public async Task ShouldIncludeDimensionsInRequestWhenProvidedAsync(int? dimensi
         // Assert
         Assert.NotNull(this._messageHandlerStub.RequestContent);
         var requestBody = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent);
-        Assert.Contains($"\"outputDimensionality\":{dimensions}", requestBody);
+        using (var document = JsonDocument.Parse(requestBody))
+        {
+            var root = document.RootElement;
+            Assert.True(root.TryGetProperty("parameters", out var parametersElement));
+            Assert.True(parametersElement.TryGetProperty("outputDimensionality", out var outputDimensionalityElement));
+            Assert.Equal(dimensions!.Value, outputDimensionalityElement.GetInt32());
+        }
     }
 
     public void Dispose()

From 0fa0efd0eada74d7694ac2fb0d4a33de3289b753 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 20 Mar 2026 11:08:54 +0000
Subject: [PATCH 3/7] Initial plan


From 637ff9f687424aab9fbf573474e6ccd22db31d8b Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 20 Mar 2026 11:20:57 +0000
Subject: [PATCH 4/7] Add missing namespace and precedence tests for Vertex AI
 dimensions

Co-authored-by: abbottdev <3226335+abbottdev@users.noreply.github.com>
---
 .../VertexAIEmbeddingGeneratorTests.cs        | 24 +++++++++++
 ...exAITextEmbeddingGenerationServiceTests.cs | 29 +++++++++++++
 .../Services/VertexAIEmbeddingGenerator.cs    | 42 +++++++++++++------
 3 files changed, 82 insertions(+), 13 deletions(-)

diff --git a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAIEmbeddingGeneratorTests.cs b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAIEmbeddingGeneratorTests.cs
index e293de580a7a..efdbf680e948 100644
--- a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAIEmbeddingGeneratorTests.cs
+++ b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAIEmbeddingGeneratorTests.cs
@@ -158,6 +158,30 @@ public async Task ShouldIncludeDimensionsInRequestWhenProvidedAsync(int? dimensi
         Assert.Contains($"\"outputDimensionality\":{dimensions}", requestBody);
     }
 
+    [Fact]
+    public async Task OptionsDimensionsShouldOverrideConstructorDefaultAsync()
+    {
+        // Arrange
+        const int OptionsDimensions = Dimensions * 2;
+        using var service = new VertexAIEmbeddingGenerator(
+            modelId: Model,
+            bearerKey: BearerKey,
+            location: "location",
+            projectId: "project",
+            dimensions: Dimensions,
+            httpClient: this._httpClient);
+        var dataToEmbed = new List<string> { "Text to embed" };
+        var options = new EmbeddingGenerationOptions { Dimensions = OptionsDimensions };
+
+        // Act
+        await service.GenerateAsync(dataToEmbed, options);
+
+        // Assert
+        Assert.NotNull(this._messageHandlerStub.RequestContent);
+        var requestBody = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent);
+        Assert.Contains($"\"outputDimensionality\":{OptionsDimensions}", requestBody);
+    }
+
     public void Dispose()
     {
         this._messageHandlerStub.Dispose();
diff --git a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
index b497ae555338..8416882fa2e8 100644
--- a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
+++ b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
@@ -6,6 +6,7 @@
 using System.Text;
 using System.Threading.Tasks;
 using System.Text.Json;
+using Microsoft.Extensions.AI;
 using Microsoft.SemanticKernel.Connectors.Google;
 using Microsoft.SemanticKernel.Embeddings;
 using Microsoft.SemanticKernel.Services;
@@ -174,6 +175,34 @@ public async Task ShouldIncludeDimensionsInRequestWhenProvidedAsync(int? dimensi
         }
     }
 
+    [Fact]
+    public async Task OptionsDimensionsShouldOverrideConstructorDefaultAsync()
+    {
+        // Arrange
+        const int OptionsDimensions = Dimensions * 2;
+        var service = new VertexAITextEmbeddingGenerationService(
+            modelId: Model,
+            bearerKey: BearerKey,
+            location: "location",
+            projectId: "project",
+            dimensions: Dimensions,
+            httpClient: this._httpClient);
+        var dataToEmbed = new List<string> { "Text to embed" };
+        var options = new EmbeddingGenerationOptions { Dimensions = OptionsDimensions };
+
+        // Act
+        await service.GenerateEmbeddingsAsync(dataToEmbed, options);
+
+        // Assert
+        Assert.NotNull(this._messageHandlerStub.RequestContent);
+        var requestBody = Encoding.UTF8.GetString(this._messageHandlerStub.RequestContent);
+        using var document = JsonDocument.Parse(requestBody);
+        var root = document.RootElement;
+        Assert.True(root.TryGetProperty("parameters", out var parametersElement));
+        Assert.True(parametersElement.TryGetProperty("outputDimensionality", out var outputDimensionalityElement));
+        Assert.Equal(OptionsDimensions, outputDimensionalityElement.GetInt32());
+    }
+
     public void Dispose()
     {
         this._messageHandlerStub.Dispose();
diff --git a/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs b/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs
index 86b04311e36d..d08afae2e8e3 100644
--- a/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs
@@ -2,12 +2,12 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.Logging;
-using Microsoft.SemanticKernel.Embeddings;
 
 namespace Microsoft.SemanticKernel.Connectors.Google;
 
@@ -16,7 +16,11 @@ namespace Microsoft.SemanticKernel.Connectors.Google;
 /// </summary>
 public sealed class VertexAIEmbeddingGenerator : IEmbeddingGenerator<string, Embedding<float>>
 {
-    private readonly IEmbeddingGenerator<string, Embedding<float>> _generator;
+    private readonly EmbeddingGeneratorMetadata _metadata;
+
+#pragma warning disable CS0618 // Type or member is obsolete
+    private readonly VertexAITextEmbeddingGenerationService _service;
+#pragma warning restore CS0618 // Type or member is obsolete
 
     /// <summary>
     /// Initializes a new instance of the <see cref="VertexAITextEmbeddingGenerationService"/> class.
@@ -38,10 +42,9 @@ public VertexAIEmbeddingGenerator(
         HttpClient? httpClient = null,
         ILoggerFactory? loggerFactory = null,
         int? dimensions = null)
-        : this(modelId, () => new ValueTask<string>(bearerKey), location, projectId, apiVersion, httpClient, loggerFactory, dimensions)
     {
 #pragma warning disable CS0618 // Type or member is obsolete
-        this._generator = new VertexAITextEmbeddingGenerationService(
+        this._service = new VertexAITextEmbeddingGenerationService(
             modelId: modelId,
             bearerKey: bearerKey,
             location: location,
@@ -49,9 +52,9 @@ public VertexAIEmbeddingGenerator(
             apiVersion: apiVersion,
             httpClient: httpClient,
             loggerFactory: loggerFactory,
-            dimensions: dimensions)
-            .AsEmbeddingGenerator();
+            dimensions: dimensions);
 #pragma warning restore CS0618 // Type or member is obsolete
+        this._metadata = new EmbeddingGeneratorMetadata(nameof(VertexAIEmbeddingGenerator), providerUri: null, modelId, dimensions);
     }
 
     /// <summary>
@@ -81,7 +84,7 @@ public VertexAIEmbeddingGenerator(
         int? dimensions = null)
     {
 #pragma warning disable CS0618 // Type or member is obsolete
-        this._generator = new VertexAITextEmbeddingGenerationService(
+        this._service = new VertexAITextEmbeddingGenerationService(
             modelId: modelId,
             bearerTokenProvider: bearerTokenProvider,
             location: location,
@@ -89,20 +92,33 @@ public VertexAIEmbeddingGenerator(
             apiVersion: apiVersion,
             httpClient: httpClient,
             loggerFactory: loggerFactory,
-            dimensions: dimensions)
-            .AsEmbeddingGenerator();
+            dimensions: dimensions);
 #pragma warning restore CS0618 // Type or member is obsolete
+        this._metadata = new EmbeddingGeneratorMetadata(nameof(VertexAIEmbeddingGenerator), providerUri: null, modelId, dimensions);
     }
 
     /// <inheritdoc />
     public void Dispose()
-        => this._generator.Dispose();
+    {
+    }
 
     /// <inheritdoc />
-    public Task<GeneratedEmbeddings<Embedding<float>>> GenerateAsync(IEnumerable<string> values, EmbeddingGenerationOptions? options = null, CancellationToken cancellationToken = default)
-        => this._generator.GenerateAsync(values, options, cancellationToken);
+    public async Task<GeneratedEmbeddings<Embedding<float>>> GenerateAsync(IEnumerable<string> values, EmbeddingGenerationOptions? options = null, CancellationToken cancellationToken = default)
+    {
+        var result = await this._service.GenerateEmbeddingsAsync(values.ToList(), options, cancellationToken: cancellationToken).ConfigureAwait(false);
+        return new(result.Select(e => new Embedding<float>(e)));
+    }
 
     /// <inheritdoc />
     public object? GetService(Type serviceType, object? serviceKey = null)
-        => this._generator.GetService(serviceType, serviceKey);
+    {
+        Verify.NotNull(serviceType);
+
+        return
+            serviceKey is not null ? null :
+            serviceType.IsInstanceOfType(this) ? this :
+            serviceType.IsInstanceOfType(this._service) ? this._service :
+            serviceType.IsInstanceOfType(this._metadata) ? this._metadata :
+            null;
+    }
 }

From 0969e6c99930529a3743e7dcc02f73b6b6dc23d4 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 20 Mar 2026 11:36:58 +0000
Subject: [PATCH 5/7] Initial plan


From a6132bc20eb27222c88bc8b35d9f26ed0a66239c Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 20 Mar 2026 11:41:10 +0000
Subject: [PATCH 6/7] Apply review comments: delegate Dispose to underlying
 service, fix XML doc remark

Co-authored-by: abbottdev <3226335+abbottdev@users.noreply.github.com>
---
 .../Connectors.Google/Services/VertexAIEmbeddingGenerator.cs    | 1 +
 .../Services/VertexAITextEmbeddingGenerationService.cs          | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs b/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs
index d08afae2e8e3..2eedbff208d2 100644
--- a/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Services/VertexAIEmbeddingGenerator.cs
@@ -100,6 +100,7 @@ public VertexAIEmbeddingGenerator(
     /// <inheritdoc />
     public void Dispose()
     {
+        ((object)this._service as IDisposable)?.Dispose();
     }
 
     /// <inheritdoc />
diff --git a/dotnet/src/Connectors/Connectors.Google/Services/VertexAITextEmbeddingGenerationService.cs b/dotnet/src/Connectors/Connectors.Google/Services/VertexAITextEmbeddingGenerationService.cs
index 3fab8a4cfb4e..e35c9200acd9 100644
--- a/dotnet/src/Connectors/Connectors.Google/Services/VertexAITextEmbeddingGenerationService.cs
+++ b/dotnet/src/Connectors/Connectors.Google/Services/VertexAITextEmbeddingGenerationService.cs
@@ -119,7 +119,7 @@ public Task<IList<ReadOnlyMemory<float>>> GenerateEmbeddingsAsync(
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>List of embeddings</returns>
     /// <remarks>
-    /// The <paramref name="options"/> parameter can be used to override default settings such as <see cref="EmbeddingGenerationOptions.ModelId"/> and <see cref="EmbeddingGenerationOptions.Dimensions"/>
+    /// The <paramref name="options"/> parameter can be used to override default settings such as <see cref="EmbeddingGenerationOptions.Dimensions"/>.
     /// </remarks>
     public Task<IList<ReadOnlyMemory<float>>> GenerateEmbeddingsAsync(
         IList<string> data,

From 5b9c39e91901e231893fa9fc59fd036a159ed6f4 Mon Sep 17 00:00:00 2001
From: James Abbott <james.abbott@kroll.com>
Date: Fri, 20 Mar 2026 14:01:25 +0000
Subject: [PATCH 7/7] format: fix namespace ordering format

---
 .../Services/VertexAITextEmbeddingGenerationServiceTests.cs     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
index 8416882fa2e8..002b5bd4fcab 100644
--- a/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
+++ b/dotnet/src/Connectors/Connectors.Google.UnitTests/Services/VertexAITextEmbeddingGenerationServiceTests.cs
@@ -4,8 +4,8 @@
 using System.Collections.Generic;
 using System.Net.Http;
 using System.Text;
-using System.Threading.Tasks;
 using System.Text.Json;
+using System.Threading.Tasks;
 using Microsoft.Extensions.AI;
 using Microsoft.SemanticKernel.Connectors.Google;
 using Microsoft.SemanticKernel.Embeddings;