Draft: Add M.E.AI.IChatClient adapter to OpenAI

src/Custom/Audio/AudioClient.cs

@@ -20,6 +20,9 @@ public partial class AudioClient
 {
     private readonly string _model;
 
+    internal Uri Endpoint => _endpoint;
+    internal string Model => _model;
+
     // CUSTOM: Added as a convenience.
     /// <summary> Initializes a new instance of <see cref="AudioClient"/>. </summary>
     /// <param name="model"> The name of the model to use in requests sent to the service. To learn more about the available models, see <see href="https://platform.openai.com/docs/models"/>. </param>

src/Custom/Chat/ChatClient.cs

@@ -23,6 +23,9 @@ public partial class ChatClient
     private readonly string _model;
     private readonly OpenTelemetrySource _telemetry;
 
+    internal Uri Endpoint => _endpoint;
+    internal string Model => _model;
+
     // CUSTOM: Added as a convenience.
     /// <summary> Initializes a new instance of <see cref="ChatClient"/>. </summary>
     /// <param name="model"> The name of the model to use in requests sent to the service. To learn more about the available models, see <see href="https://platform.openai.com/docs/models"/>. </param>

src/Custom/Embeddings/EmbeddingClient.cs

@@ -23,6 +23,9 @@ public partial class EmbeddingClient
 {
     private readonly string _model;
 
+    internal Uri Endpoint => _endpoint;
+    internal string Model => _model;
+
     // CUSTOM: Added as a convenience.
     /// <summary> Initializes a new instance of <see cref="EmbeddingClient"/>. </summary>
     /// <param name="model"> The name of the model to use in requests sent to the service. To learn more about the available models, see <see href="https://platform.openai.com/docs/models"/>. </param>

src/Custom/Microsoft.Extensions.AI/OpenAIClientExtensions.cs

@@ -0,0 +1,45 @@
+#nullable enable
+
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.Extensions.AI;
+using OpenAI.Audio;
+using OpenAI.Chat;
+using OpenAI.Embeddings;
+using OpenAI.Responses;
+
+namespace OpenAI.Custom.Microsoft.Extensions.AI;
+
+
+/// <summary>Provides extension methods for working with <see cref="OpenAIClient"/>s.</summary>
+public static class OpenAIClientExtensions
+{
+
+    /// <summary>Gets an <see cref="IChatClient"/> for use with this <see cref="ChatClient"/>.</summary>
+    /// <param name="chatClient">The client.</param>
+    /// <returns>An <see cref="IChatClient"/> that can be used to converse via the <see cref="ChatClient"/>.</returns>
+    [Experimental("OPENAI003")]
+    public static IChatClient AsIChatClient(this ChatClient chatClient) =>
+        new OpenAIChatClient(chatClient);
+
+    /// <summary>Gets an <see cref="IChatClient"/> for use with this <see cref="OpenAIResponseClient"/>.</summary>
+    /// <param name="responseClient">The client.</param>
+    /// <returns>An <see cref="IChatClient"/> that can be used to converse via the <see cref="OpenAIResponseClient"/>.</returns>
+    [Experimental("OPENAI003")]
+    public static IChatClient AsIChatClient(this OpenAIResponseClient responseClient) =>
+        new OpenAIResponseChatClient(responseClient);
+
+    /// <summary>Gets an <see cref="ISpeechToTextClient"/> for use with this <see cref="AudioClient"/>.</summary>
+    /// <param name="audioClient">The client.</param>
+    /// <returns>An <see cref="ISpeechToTextClient"/> that can be used to transcribe audio via the <see cref="AudioClient"/>.</returns>
+    [Experimental("OPENAI003")]
+    public static ISpeechToTextClient AsISpeechToTextClient(this AudioClient audioClient) =>
+        new OpenAISpeechToTextClient(audioClient);
+
+    /// <summary>Gets an <see cref="IEmbeddingGenerator{String, Single}"/> for use with this <see cref="EmbeddingClient"/>.</summary>
+    /// <param name="embeddingClient">The client.</param>
+    /// <param name="defaultModelDimensions">The number of dimensions to generate in each embedding.</param>
+    /// <returns>An <see cref="IEmbeddingGenerator{String, Embedding}"/> that can be used to generate embeddings via the <see cref="EmbeddingClient"/>.</returns>
+    [Experimental("OPENAI003")]
+    public static IEmbeddingGenerator<string, Embedding<float>> AsIEmbeddingGenerator(this EmbeddingClient embeddingClient, int? defaultModelDimensions = null) =>
+        new OpenAIEmbeddingGenerator(embeddingClient, defaultModelDimensions);
+}

src/Custom/Microsoft.Extensions.AI/OpenAIEmbeddingGenerator.cs

@@ -0,0 +1,109 @@
+#nullable enable
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using OpenAI;
+using OpenAI.Embeddings;
+
+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>>
+{
+    /// <summary>Metadata about the embedding generator.</summary>
+    private readonly EmbeddingGeneratorMetadata _metadata;
+
+    /// <summary>The underlying <see cref="OpenAI.Chat.ChatClient" />.</summary>
+    private readonly EmbeddingClient _embeddingClient;
+
+    /// <summary>The number of dimensions produced by the generator.</summary>
+    private readonly int? _dimensions;
+
+    /// <summary>Initializes a new instance of the <see cref="OpenAIEmbeddingGenerator"/> class.</summary>
+    /// <param name="embeddingClient">The underlying client.</param>
+    /// <param name="defaultModelDimensions">The number of dimensions to generate in each embedding.</param>
+    /// <exception cref="ArgumentNullException"><paramref name="embeddingClient"/> is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentOutOfRangeException"><paramref name="defaultModelDimensions"/> is not positive.</exception>
+    public OpenAIEmbeddingGenerator(EmbeddingClient embeddingClient, int? defaultModelDimensions = null)
+    {
+        Argument.AssertNotNull(embeddingClient, nameof(embeddingClient));
+        if (defaultModelDimensions < 1)
+        {
+            throw new ArgumentOutOfRangeException(nameof(defaultModelDimensions), "Value must be greater than 0.");
+        }
+
+        _embeddingClient = embeddingClient;
+        _dimensions = defaultModelDimensions;
+        _metadata = CreateMetadata("openai",
+            embeddingClient.Endpoint ?? OpenAIChatClient.DefaultOpenAIEndpoint,
+            embeddingClient.Model,
+            defaultModelDimensions);
+    }
+
+    /// <inheritdoc />
+    public async Task<GeneratedEmbeddings<Embedding<float>>> GenerateAsync(IEnumerable<string> values, EmbeddingGenerationOptions? options = null, CancellationToken cancellationToken = default)
+    {
+        OpenAI.Embeddings.EmbeddingGenerationOptions? openAIOptions = ToOpenAIOptions(options);
+
+        var embeddings = (await _embeddingClient.GenerateEmbeddingsAsync(values, openAIOptions, cancellationToken).ConfigureAwait(false)).Value;
+
+        return new(embeddings.Select(e =>
+                new Embedding<float>(e.ToFloats())
+                {
+                    CreatedAt = DateTimeOffset.UtcNow,
+                    ModelId = embeddings.Model,
+                }))
+        {
+            Usage = new()
+            {
+                InputTokenCount = embeddings.Usage.InputTokenCount,
+                TotalTokenCount = embeddings.Usage.TotalTokenCount
+            },
+        };
+    }
+
+    /// <inheritdoc />
+    void IDisposable.Dispose()
+    {
+        // Nothing to dispose. Implementation required for the IEmbeddingGenerator interface.
+    }
+
+    /// <inheritdoc />
+    object? IEmbeddingGenerator.GetService(Type serviceType, object? serviceKey)
+    {
+        Argument.AssertNotNull(serviceType, nameof(serviceType));
+
+        return
+            serviceKey is not null ? null :
+            serviceType == typeof(EmbeddingGeneratorMetadata) ? _metadata :
+            serviceType == typeof(EmbeddingClient) ? _embeddingClient :
+            serviceType.IsInstanceOfType(this) ? this :
+            null;
+    }
+
+    /// <summary>Creates the <see cref="EmbeddingGeneratorMetadata"/> for this instance.</summary>
+    private static EmbeddingGeneratorMetadata CreateMetadata(string providerName, Uri providerUri, string? defaultModelId, int? defaultModelDimensions) =>
+        new(providerName, providerUri, defaultModelId, defaultModelDimensions);
+
+    /// <summary>Converts an extensions options instance to an OpenAI options instance.</summary>
+    private OpenAI.Embeddings.EmbeddingGenerationOptions? ToOpenAIOptions(EmbeddingGenerationOptions? options)
+    {
+        OpenAI.Embeddings.EmbeddingGenerationOptions openAIOptions = new()
+        {
+            Dimensions = options?.Dimensions ?? _dimensions,
+        };
+
+        if (options?.AdditionalProperties is { Count: > 0 } additionalProperties)
+        {
+            if (additionalProperties.TryGetValue(nameof(openAIOptions.EndUserId), out string? endUserId))
+            {
+                openAIOptions.EndUserId = endUserId;
+            }
+        }
+
+        return openAIOptions;
+    }
+}