.Net: Ensure Required Headers in Mistral ChatCompletion HttpClient

dotnet/src/Connectors/Connectors.MistralAI.UnitTests/MistralAIExtensionTests.cs

@@ -1,5 +1,8 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System;
+using System.Net.Http;
+using System.Reflection;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.SemanticKernel;
 using Microsoft.SemanticKernel.ChatCompletion;
@@ -81,4 +84,58 @@ public void AddMistralTextEmbeddingGenerationToKernelBuilder()
         Assert.NotNull(service);
         Assert.IsType<MistralAITextEmbeddingGenerationService>(service);
     }
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void AddMistralChatCompletionInjectsExtraParametersHeader(bool useServiceCollection)
+    {
+        // Arrange
+        var collection = new ServiceCollection();
+        var kernelBuilder = collection.AddKernel();
+
+        if (useServiceCollection)
+        {
+            // Use the service collection to add the Mistral chat completion
+            kernelBuilder.Services.AddMistralChatCompletion(
+                modelId: "model",
+                apiKey: "key",
+                endpoint: new Uri("https://example.com"));
+        }
+        else
+        {
+            // Use the kernel builder directly
+            kernelBuilder.AddMistralChatCompletion(
+                modelId: "model",
+                apiKey: "key",
+                endpoint: new Uri("https://example.com"));
+        }
+
+        // Act
+        var kernel = collection.BuildServiceProvider().GetRequiredService<Kernel>();
+        var service = kernel.GetRequiredService<IChatCompletionService>();
+
+        // Assert
+        Assert.NotNull(service);
+        Assert.IsType<MistralAIChatCompletionService>(service);
+
+        // Use reflection to get the private 'Client' field
+        var clientField = typeof(MistralAIChatCompletionService)
+            .GetField("<Client>k__BackingField", BindingFlags.NonPublic | BindingFlags.Instance);
+        Assert.NotNull(clientField);
+
+        var mistralClient = clientField.GetValue(service);
+        Assert.NotNull(mistralClient);
+
+        // Use reflection to get the private '_httpClient' field from MistralClient
+        var httpClientField = mistralClient.GetType()
+            .GetField("_httpClient", BindingFlags.NonPublic | BindingFlags.Instance);
+        Assert.NotNull(httpClientField);
+
+        var httpClient = (HttpClient)httpClientField.GetValue(mistralClient)!;
+        Assert.True(httpClient.DefaultRequestHeaders.Contains("extra-parameters"));
+
+        var headerValues = httpClient.DefaultRequestHeaders.GetValues("extra-parameters");
+        Assert.Contains("pass-through", headerValues);
+    }
 }

dotnet/src/Connectors/Connectors.MistralAI/MistralAIKernelBuilderExtensions.cs

@@ -2,12 +2,6 @@
 
 using System;
 using System.Net.Http;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
-using Microsoft.SemanticKernel.ChatCompletion;
-using Microsoft.SemanticKernel.Connectors.MistralAI;
-using Microsoft.SemanticKernel.Embeddings;
-using Microsoft.SemanticKernel.Http;
 
 namespace Microsoft.SemanticKernel;
 
@@ -38,8 +32,7 @@ public static IKernelBuilder AddMistralChatCompletion(
         Verify.NotNullOrWhiteSpace(modelId);
         Verify.NotNullOrWhiteSpace(apiKey);
 
-        builder.Services.AddKeyedSingleton<IChatCompletionService>(serviceId, (serviceProvider, _) =>
-            new MistralAIChatCompletionService(modelId, apiKey, endpoint, HttpClientProvider.GetHttpClient(httpClient, serviceProvider), serviceProvider.GetService<ILoggerFactory>()));
+        builder.Services.AddMistralChatCompletion(modelId, apiKey, endpoint, serviceId, httpClient);
 
         return builder;
     }
@@ -64,8 +57,7 @@ public static IKernelBuilder AddMistralTextEmbeddingGeneration(
     {
         Verify.NotNull(builder);
 
-        builder.Services.AddKeyedSingleton<ITextEmbeddingGenerationService>(serviceId, (serviceProvider, _) =>
-            new MistralAITextEmbeddingGenerationService(modelId, apiKey, endpoint, HttpClientProvider.GetHttpClient(httpClient, serviceProvider), serviceProvider.GetService<ILoggerFactory>()));
+        builder.Services.AddMistralTextEmbeddingGeneration(modelId, apiKey, endpoint, serviceId, httpClient);
 
         return builder;
     }

dotnet/src/Connectors/Connectors.MistralAI/MistralAIServiceCollectionExtensions.cs

@@ -1,7 +1,9 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System;
+using System.Net.Http;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
 using Microsoft.SemanticKernel.ChatCompletion;
 using Microsoft.SemanticKernel.Connectors.MistralAI;
 using Microsoft.SemanticKernel.Embeddings;
@@ -22,18 +24,39 @@ public static class MistralAIServiceCollectionExtensions
     /// <param name="apiKey">The API key required for accessing the Mistral service.</param>
     /// <param name="endpoint">Optional  uri endpoint including the port where MistralAI server is hosted. Default is https://api.mistral.ai.</param>
     /// <param name="serviceId">A local identifier for the given AI service.</param>
+    /// <param name="httpClient">The HttpClient to use with this service.</param>
     /// <returns>The same instance as <paramref name="services"/>.</returns>
     public static IServiceCollection AddMistralChatCompletion(
         this IServiceCollection services,
         string modelId,
         string apiKey,
         Uri? endpoint = null,
-        string? serviceId = null)
+        string? serviceId = null,
+        HttpClient? httpClient = null)
     {
         Verify.NotNull(services);
 
-        return services.AddKeyedSingleton<IChatCompletionService>(serviceId, (serviceProvider, _) =>
-            new MistralAIChatCompletionService(modelId, apiKey, endpoint, HttpClientProvider.GetHttpClient(serviceProvider)));
+        services.AddKeyedSingleton<IChatCompletionService>(serviceId, (serviceProvider, _) =>
+        {
+            var resolvedHttpClient = HttpClientProvider.GetHttpClient(httpClient, serviceProvider);
+
+            if (httpClient == null && serviceProvider?.GetService<HttpClient>() == null)
+            {
+                if (!resolvedHttpClient.DefaultRequestHeaders.Contains("extra-parameters"))
+                {
+                    resolvedHttpClient.DefaultRequestHeaders.Add("extra-parameters", "pass-through");
+                }
+            }
+
+            return new MistralAIChatCompletionService(
+                modelId,
+                apiKey,
+                endpoint,
+                resolvedHttpClient,
+                serviceProvider?.GetService<ILoggerFactory>());
+        });
+
+        return services;
     }
 
     /// <summary>
@@ -44,17 +67,19 @@ public static IServiceCollection AddMistralChatCompletion(
     /// <param name="apiKey">The API key required for accessing the Mistral service.</param>
     /// <param name="endpoint">Optional  uri endpoint including the port where MistralAI server is hosted. Default is https://api.mistral.ai.</param>
     /// <param name="serviceId">A local identifier for the given AI service.</param>
+    /// <param name="httpClient">The HttpClient to use with this service.</param>
     /// <returns>The same instance as <paramref name="services"/>.</returns>
     public static IServiceCollection AddMistralTextEmbeddingGeneration(
         this IServiceCollection services,
         string modelId,
         string apiKey,
         Uri? endpoint = null,
-        string? serviceId = null)
+        string? serviceId = null,
+        HttpClient? httpClient = null)
     {
         Verify.NotNull(services);
 
         return services.AddKeyedSingleton<ITextEmbeddingGenerationService>(serviceId, (serviceProvider, _) =>
-            new MistralAITextEmbeddingGenerationService(modelId, apiKey, endpoint, HttpClientProvider.GetHttpClient(serviceProvider)));
+            new MistralAITextEmbeddingGenerationService(modelId, apiKey, endpoint, HttpClientProvider.GetHttpClient(httpClient, serviceProvider)));
     }
 }