Update to latest M.E.AI version

Directory.Packages.props

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <System10Version>10.0.0-preview.3.25171.5</System10Version>
-    <MicrosoftExtensionsAIVersion>9.4.3-preview.1.25230.7</MicrosoftExtensionsAIVersion>
+    <MicrosoftExtensionsAIVersion>9.4.4-preview.1.25259.16</MicrosoftExtensionsAIVersion>
   </PropertyGroup>
 
   <!-- Product dependencies netstandard -->
@@ -31,7 +31,7 @@
 
   <!-- Product dependencies shared -->
   <ItemGroup>
-    <PackageVersion Include="Microsoft.Extensions.AI.Abstractions" Version="$(MicrosoftExtensionsAIVersion)" />
+    <PackageVersion Include="Microsoft.Extensions.AI.Abstractions" Version="9.4.4-preview.1.25259.16" />
     <PackageVersion Include="Microsoft.Extensions.AI" Version="$(MicrosoftExtensionsAIVersion)" />
     <PackageVersion Include="System.Net.ServerSentEvents" Version="$(System10Version)" />
   </ItemGroup>

src/ModelContextProtocol/ModelContextProtocol.csproj

@@ -34,7 +34,6 @@
   <!-- Dependencies needed by all -->
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.AI.Abstractions" />
-    <PackageReference Include="Microsoft.Extensions.AI" />
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" />
     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" />
     <PackageReference Include="System.Net.ServerSentEvents" />

src/ModelContextProtocol/Server/AIFunctionMcpServerPrompt.cs

@@ -1,4 +1,5 @@
 using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
 using ModelContextProtocol.Protocol.Types;
 using ModelContextProtocol.Utils;
 using ModelContextProtocol.Utils.Json;
@@ -68,7 +69,7 @@ private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
             Description = options?.Description,
             MarshalResult = static (result, _, cancellationToken) => new ValueTask<object?>(result),
             SerializerOptions = options?.SerializerOptions ?? McpJsonUtilities.DefaultOptions,
-            Services = options?.Services,
+            CreateInstance = AIFunctionMcpServerTool.GetCreateInstanceFunc(),
             ConfigureParameterBinding = pi =>
             {
                 if (pi.ParameterType == typeof(RequestContext<GetPromptRequestParams>))
@@ -110,6 +111,32 @@ private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
                     };
                 }
 
+                if (options?.Services is { } services &&
+                    services.GetService<IServiceProviderIsService>() is { } ispis &&
+                    ispis.IsService(pi.ParameterType))
+                {
+                    return new()
+                    {
+                        ExcludeFromSchema = true,
+                        BindParameter = (pi, args) =>
+                            GetRequestContext(args)?.Services?.GetService(pi.ParameterType) ??
+                            (pi.HasDefaultValue ? null :
+                             throw new ArgumentException("No service of the requested type was found.")),
+                    };
+                }
+
+                if (pi.GetCustomAttribute<FromKeyedServicesAttribute>() is { } keyedAttr)
+                {
+                    return new()
+                    {
+                        ExcludeFromSchema = true,
+                        BindParameter = (pi, args) =>
+                            (GetRequestContext(args)?.Services as IKeyedServiceProvider)?.GetKeyedService(pi.ParameterType, keyedAttr.Key) ??
+                            (pi.HasDefaultValue ? null :
+                             throw new ArgumentException("No service of the requested type was found.")),
+                    };
+                }
+
                 return default;
 
                 static RequestContext<GetPromptRequestParams>? GetRequestContext(AIFunctionArguments args)

src/ModelContextProtocol/Server/AIFunctionMcpServerResource.cs

@@ -1,10 +1,10 @@
 using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
 using ModelContextProtocol.Protocol.Types;
 using ModelContextProtocol.Utils;
 using ModelContextProtocol.Utils.Json;
 using System.Collections.Concurrent;
 using System.ComponentModel;
-using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Reflection;
@@ -76,7 +76,7 @@ private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
             Description = options?.Description,
             MarshalResult = static (result, _, cancellationToken) => new ValueTask<object?>(result),
             SerializerOptions = McpJsonUtilities.DefaultOptions,
-            Services = options?.Services,
+            CreateInstance = AIFunctionMcpServerTool.GetCreateInstanceFunc(),
             ConfigureParameterBinding = pi =>
             {
                 if (pi.ParameterType == typeof(RequestContext<ReadResourceRequestParams>))
@@ -118,6 +118,32 @@ private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
                     };
                 }
 
+                if (options?.Services is { } services &&
+                    services.GetService<IServiceProviderIsService>() is { } ispis &&
+                    ispis.IsService(pi.ParameterType))
+                {
+                    return new()
+                    {
+                        ExcludeFromSchema = true,
+                        BindParameter = (pi, args) =>
+                            GetRequestContext(args)?.Services?.GetService(pi.ParameterType) ??
+                            (pi.HasDefaultValue ? null :
+                             throw new ArgumentException("No service of the requested type was found.")),
+                    };
+                }
+
+                if (pi.GetCustomAttribute<FromKeyedServicesAttribute>() is { } keyedAttr)
+                {
+                    return new()
+                    {
+                        ExcludeFromSchema = true,
+                        BindParameter = (pi, args) =>
+                            (GetRequestContext(args)?.Services as IKeyedServiceProvider)?.GetKeyedService(pi.ParameterType, keyedAttr.Key) ??
+                            (pi.HasDefaultValue ? null :
+                             throw new ArgumentException("No service of the requested type was found.")),
+                    };
+                }
+
                 // These parameters are the ones and only ones to include in the schema. The schema
                 // won't be consumed by anyone other than this instance, which will use it to determine
                 // which properties should show up in the URI template.

src/ModelContextProtocol/Server/AIFunctionMcpServerTool.cs

@@ -1,4 +1,5 @@
 using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
 using ModelContextProtocol.Protocol.Types;
 using ModelContextProtocol.Utils;
 using ModelContextProtocol.Utils.Json;
@@ -60,6 +61,14 @@ internal sealed class AIFunctionMcpServerTool : McpServerTool
             options);
     }
 
+    // TODO: Fix the need for this suppression.
+    [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2111:ReflectionToDynamicallyAccessedMembers",
+        Justification = "AIFunctionFactory ensures that the Type passed to AIFunctionFactoryOptions.CreateInstance has public constructors preserved")]
+    internal static Func<Type, AIFunctionArguments, object> GetCreateInstanceFunc() =>
+        static ([DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] type, args) => args.Services is { } services ?
+            ActivatorUtilities.CreateInstance(services, type) :
+            Activator.CreateInstance(type)!;
+
     private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
         MethodInfo method, McpServerToolCreateOptions? options) =>
         new()
@@ -68,7 +77,7 @@ private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
             Description = options?.Description,
             MarshalResult = static (result, _, cancellationToken) => new ValueTask<object?>(result),
             SerializerOptions = options?.SerializerOptions ?? McpJsonUtilities.DefaultOptions,
-            Services = options?.Services,
+            CreateInstance = GetCreateInstanceFunc(),
             ConfigureParameterBinding = pi =>
             {
                 if (pi.ParameterType == typeof(RequestContext<CallToolRequestParams>))
@@ -110,6 +119,32 @@ private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
                     };
                 }
 
+                if (options?.Services is { } services &&
+                    services.GetService<IServiceProviderIsService>() is { } ispis &&
+                    ispis.IsService(pi.ParameterType))
+                {
+                    return new()
+                    {
+                        ExcludeFromSchema = true,
+                        BindParameter = (pi, args) =>
+                            GetRequestContext(args)?.Services?.GetService(pi.ParameterType) ??
+                            (pi.HasDefaultValue ? null :
+                             throw new ArgumentException("No service of the requested type was found.")),
+                    };
+                }
+
+                if (pi.GetCustomAttribute<FromKeyedServicesAttribute>() is { } keyedAttr)
+                {
+                    return new()
+                    {
+                        ExcludeFromSchema = true,
+                        BindParameter = (pi, args) =>
+                            (GetRequestContext(args)?.Services as IKeyedServiceProvider)?.GetKeyedService(pi.ParameterType, keyedAttr.Key) ??
+                            (pi.HasDefaultValue ? null :
+                             throw new ArgumentException("No service of the requested type was found.")),
+                    };
+                }
+
                 return default;
 
                 static RequestContext<CallToolRequestParams>? GetRequestContext(AIFunctionArguments args)

tests/ModelContextProtocol.Tests/Server/McpServerPromptTests.cs

@@ -60,7 +60,7 @@ public async Task SupportsServiceFromDI()
         Assert.Contains("something", prompt.ProtocolPrompt.Arguments?.Select(a => a.Name) ?? []);
         Assert.DoesNotContain("actualMyService", prompt.ProtocolPrompt.Arguments?.Select(a => a.Name) ?? []);
 
-        await Assert.ThrowsAsync<ArgumentNullException>(async () => await prompt.GetAsync(
+        await Assert.ThrowsAnyAsync<ArgumentException>(async () => await prompt.GetAsync(
             new RequestContext<GetPromptRequestParams>(new Mock<IMcpServer>().Object),
             TestContext.Current.CancellationToken));
 

tests/ModelContextProtocol.Tests/Server/McpServerResourceTests.cs

@@ -375,7 +375,7 @@ public async Task SupportsServiceFromDI(ServiceLifetime injectedArgumentLifetime
 
         Mock<IMcpServer> mockServer = new();
 
-        await Assert.ThrowsAsync<ArgumentNullException>(async () => await resource.ReadAsync(
+        await Assert.ThrowsAnyAsync<ArgumentException>(async () => await resource.ReadAsync(
             new RequestContext<ReadResourceRequestParams>(mockServer.Object) { Params = new() { Uri = "resource://Test" } },
             TestContext.Current.CancellationToken));
 

tests/ModelContextProtocol.Tests/Server/McpServerToolTests.cs

@@ -156,14 +156,18 @@ public async Task SupportsAsyncDisposingInstantiatedAsyncDisposableTargets()
     [Fact]
     public async Task SupportsAsyncDisposingInstantiatedAsyncDisposableAndDisposableTargets()
     {
+        ServiceCollection sc = new();
+        sc.AddSingleton<MyService>();
+        IServiceProvider services = sc.BuildServiceProvider();
+
         McpServerToolCreateOptions options = new() { SerializerOptions = JsonContext2.Default.Options };
         McpServerTool tool1 = McpServerTool.Create(
             typeof(AsyncDisposableAndDisposableToolType).GetMethod(nameof(AsyncDisposableAndDisposableToolType.InstanceMethod))!,
             typeof(AsyncDisposableAndDisposableToolType),
             options);
 
         var result = await tool1.InvokeAsync(
-            new RequestContext<CallToolRequestParams>(new Mock<IMcpServer>().Object),
+            new RequestContext<CallToolRequestParams>(new Mock<IMcpServer>().Object) { Services = services },
             TestContext.Current.CancellationToken);
         Assert.Equal("""{"asyncDisposals":1,"disposals":0}""", result.Content[0].Text);
     }
@@ -428,6 +432,11 @@ public object InstanceMethod()
 
     private class AsyncDisposableAndDisposableToolType : IAsyncDisposable, IDisposable
     {
+        public AsyncDisposableAndDisposableToolType(MyService service)
+        {
+            Assert.NotNull(service);
+        }
+
         [JsonPropertyOrder(0)]
         public int AsyncDisposals { get; private set; }