Allow retrieving native client options from chat client

src/Extensions/ChatClientProviders.cs

@@ -1,5 +1,7 @@
 using System.ClientModel;
 using Azure;
+using Azure.AI.Inference;
+using Azure.AI.OpenAI;
 using Devlooped.Extensions.AI.OpenAI;
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.Configuration;
@@ -29,7 +31,9 @@
         Throw.IfNullOrEmpty(options.ApiKey, $"{section.Path}:apikey");
         Throw.IfNullOrEmpty(options.ModelId, $"{section.Path}:modelid");
 
-        return new OpenAIClient(new ApiKeyCredential(options.ApiKey), options).GetChatClient(options.ModelId).AsIChatClient();
+        return new ProviderOptionsChatClient<OpenAIClientOptions>(
+            new OpenAIClient(new ApiKeyCredential(options.ApiKey), options).GetChatClient(options.ModelId).AsIChatClient(),
+            options);
     }
 
     internal sealed class OpenAIProviderOptions : OpenAIClientOptions
@@ -61,7 +65,9 @@
         Throw.IfNullOrEmpty(options.ModelId, $"{section.Path}:modelid");
         Throw.IfNull(options.Endpoint, $"{section.Path}:endpoint");
 
-        return new AzureOpenAIChatClient(options.Endpoint, new AzureKeyCredential(options.ApiKey), options.ModelId, options);
+        return new ProviderOptionsChatClient<AzureOpenAIClientOptions>(
+            new AzureOpenAIChatClient(options.Endpoint, new AzureKeyCredential(options.ApiKey), options.ModelId, options),
+            options);
     }
 
     internal sealed class AzureOpenAIProviderOptions : Azure.AI.OpenAI.AzureOpenAIClientOptions
@@ -94,8 +100,10 @@
         Throw.IfNullOrEmpty(options.ModelId, $"{section.Path}:modelid");
         Throw.IfNull(options.Endpoint, $"{section.Path}:endpoint");
 
-        return new Azure.AI.Inference.ChatCompletionsClient(options.Endpoint, new AzureKeyCredential(options.ApiKey), options)
-            .AsIChatClient(options.ModelId);
+        return new ProviderOptionsChatClient<AzureAIInferenceClientOptions>(
+            new Azure.AI.Inference.ChatCompletionsClient(options.Endpoint, new AzureKeyCredential(options.ApiKey), options)
+                .AsIChatClient(options.ModelId),
+            options);
     }
 
     internal sealed class AzureInferenceProviderOptions : Azure.AI.Inference.AzureAIInferenceClientOptions
@@ -127,13 +135,26 @@
         Throw.IfNullOrEmpty(options.ApiKey, $"{section.Path}:apikey");
         Throw.IfNullOrEmpty(options.ModelId, $"{section.Path}:modelid");
 
-        return new GrokClient(options.ApiKey, section.Get<GrokClientOptions>() ?? new())
-            .AsIChatClient(options.ModelId);
+        return new ProviderOptionsChatClient<GrokClientOptions>(
+            new GrokClient(options.ApiKey, options).AsIChatClient(options.ModelId),
+            options);
     }
 
-    internal sealed class GrokProviderOptions
+    internal sealed class GrokProviderOptions : GrokClientOptions
     {
         public string? ApiKey { get; set; }
         public string? ModelId { get; set; }
     }
 }
+
+sealed class ProviderOptionsChatClient<TOptions>(IChatClient inner, TOptions options) : DelegatingChatClient(inner)
+    where TOptions : notnull
+{
+    public override object? GetService(Type serviceType, object? serviceKey = null)
+        => IsOptionsRequest(serviceType, serviceKey) ? options : inner.GetService(serviceType, serviceKey);
+
+    bool IsOptionsRequest(Type serviceType, object? serviceKey)
+        => serviceType == typeof(object) ?
+           serviceKey is string key && string.Equals(key, "options", StringComparison.OrdinalIgnoreCase) :
+           typeof(TOptions).IsAssignableFrom(serviceType);
+}

src/Tests/ConfigurableClientTests.cs

@@ -1,6 +1,8 @@
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using OpenAI;
+using xAI;
 
 namespace Devlooped.Extensions.AI;
 
@@ -32,6 +34,37 @@ public void CanConfigureClients()
         Assert.Equal("xai", grok.GetRequiredService<ChatClientMetadata>().ProviderName);
     }
 
+    [Fact]
+    public void CanGetClientOptions()
+    {
+        var configuration = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                ["ai:clients:openai:modelid"] = "gpt-4.1.nano",
+                ["ai:clients:openai:ApiKey"] = "sk-asdfasdf",
+                ["ai:clients:grok:modelid"] = "grok-4-fast",
+                ["ai:clients:grok:ApiKey"] = "xai-asdfasdf",
+                ["ai:clients:grok:endpoint"] = "https://api.x.ai",
+            })
+            .Build();
+
+        var services = new ServiceCollection()
+            .AddSingleton<IConfiguration>(configuration)
+            .AddChatClients(configuration)
+            .BuildServiceProvider();
+
+        var openai = services.GetRequiredKeyedService<IChatClient>("openai");
+        var grok = services.GetRequiredKeyedService<IChatClient>("grok");
+
+        // Untyped by name+object
+        Assert.NotNull(openai.GetService<object>("options"));
+        // Typed to concrete options, no need for key
+        Assert.NotNull(openai.GetService<OpenAIClientOptions>());
+
+        Assert.NotNull(grok.GetService<object>("Options"));
+        Assert.NotNull(grok.GetService<GrokClientOptions>());
+    }
+
     [Fact]
     public void CanGetFromAlternativeKey()
     {
@@ -259,4 +292,108 @@ public void CanConfigureAzureOpenAI()
         Assert.Equal("azure.ai.openai", client.GetRequiredService<ChatClientMetadata>().ProviderName);
         Assert.Equal("gpt-5", client.GetRequiredService<ChatClientMetadata>().DefaultModelId);
     }
+
+    [Fact]
+    public void CanInspectOpenAIProviderOptions()
+    {
+        var configuration = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                ["ai:clients:openai:modelid"] = "gpt-4.1.nano",
+                ["ai:clients:openai:apikey"] = "sk-asdfasdf",
+                ["ai:clients:openai:UserAgentApplicationId"] = "myapp/1.0",
+            })
+            .Build();
+
+        var services = new ServiceCollection()
+            .AddSingleton<IConfiguration>(configuration)
+            .AddChatClients(configuration)
+            .BuildServiceProvider();
+
+        var client = services.GetRequiredKeyedService<IChatClient>("openai");
+        var options = Assert.IsType<OpenAIChatClientProvider.OpenAIProviderOptions>(
+            client.GetService(typeof(object), "OpTiOnS"));
+
+        Assert.Same(options, client.GetService(typeof(OpenAIChatClientProvider.OpenAIProviderOptions), "options"));
+        Assert.Equal("gpt-4.1.nano", options.ModelId);
+        Assert.Equal("myapp/1.0", options.UserAgentApplicationId);
+    }
+
+    [Fact]
+    public void CanInspectAzureOpenAIProviderOptions()
+    {
+        var configuration = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                ["ai:clients:chat:modelid"] = "gpt-5",
+                ["ai:clients:chat:apikey"] = "asdfasdf",
+                ["ai:clients:chat:endpoint"] = "https://chat.openai.azure.com/",
+                ["ai:clients:chat:UserAgentApplicationId"] = "myapp/1.0",
+            })
+            .Build();
+
+        var services = new ServiceCollection()
+            .AddSingleton<IConfiguration>(configuration)
+            .AddChatClients(configuration)
+            .BuildServiceProvider();
+
+        var client = services.GetRequiredKeyedService<IChatClient>("chat");
+        var options = Assert.IsType<AzureOpenAIChatClientProvider.AzureOpenAIProviderOptions>(
+            client.GetService(typeof(object), "options"));
+
+        Assert.Same(options, client.GetService(typeof(AzureOpenAIChatClientProvider.AzureOpenAIProviderOptions), "OPTIONS"));
+        Assert.Equal(new Uri("https://chat.openai.azure.com/"), options.Endpoint);
+        Assert.Equal("myapp/1.0", options.UserAgentApplicationId);
+    }
+
+    [Fact]
+    public void CanInspectAzureInferenceProviderOptions()
+    {
+        var configuration = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                ["ai:clients:chat:modelid"] = "gpt-5",
+                ["ai:clients:chat:apikey"] = "asdfasdf",
+                ["ai:clients:chat:endpoint"] = "https://ai.azure.com/.default",
+            })
+            .Build();
+
+        var services = new ServiceCollection()
+            .AddSingleton<IConfiguration>(configuration)
+            .AddChatClients(configuration)
+            .BuildServiceProvider();
+
+        var client = services.GetRequiredKeyedService<IChatClient>("chat");
+        var options = Assert.IsType<AzureAIInferenceChatClientProvider.AzureInferenceProviderOptions>(
+            client.GetService(typeof(object), "options"));
+
+        Assert.Same(options, client.GetService(typeof(AzureAIInferenceChatClientProvider.AzureInferenceProviderOptions), "OPTIONS"));
+        Assert.Equal(new Uri("https://ai.azure.com/.default"), options.Endpoint);
+        Assert.Equal("gpt-5", options.ModelId);
+    }
+
+    [Fact]
+    public void CanInspectGrokProviderOptions()
+    {
+        var configuration = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                ["ai:clients:grok:modelid"] = "grok-4-fast",
+                ["ai:clients:grok:apikey"] = "xai-asdfasdf",
+                ["ai:clients:grok:endpoint"] = "https://api.x.ai",
+            })
+            .Build();
+
+        var services = new ServiceCollection()
+            .AddSingleton<IConfiguration>(configuration)
+            .AddChatClients(configuration)
+            .BuildServiceProvider();
+
+        var client = services.GetRequiredKeyedService<IChatClient>("grok");
+        var options = Assert.IsType<GrokChatClientProvider.GrokProviderOptions>(
+            client.GetService(typeof(object), "options"));
+
+        Assert.Same(options, client.GetService(typeof(GrokChatClientProvider.GrokProviderOptions), "OPTIONS"));
+        Assert.Equal("grok-4-fast", options.ModelId);
+    }
 }