Merged PR 55051: Backport MEAI libraries updates into release/10.0

The following PRs are included in this backport:

- [MEDI] start producing NuGet packages (dotnet/extensions/#7016)
- Update version numbers in AI changelogs (dotnet/extensions/#7008)
- [MEDI] Don't stop document processing on enricher error (dotnet/extensions/#7005)
- [MEDI] add PackageTags (dotnet/extensions/#7022)
- Add MarkItDownMcpReader for MCP server support (dotnet/extensions/#7025)
- Image generation tool (dotnet/extensions/#6749)
- Make MEAI packages use 10.0 runtime packages (dotnet/extensions/#7028)

----
#### AI description  (iteration 1)
#### PR Classification
This pull request backports multiple MEAI library updates, including new image generation features, refactoring of data ingestion enrichers, removal of legacy exporter code, and updated OpenTelemetry instrumentation.

#### PR Summary
The changes integrate new image generation tool support into chat clients with corresponding types and integration tests, refactor data ingestion enrichers to use a unified `EnricherOptions` abstraction with batching, and remove outdated JSON schema exporter and nullability helper files while updating OpenTelemetry metrics and project metadata.
- `src/Libraries/Microsoft.Extensions.AI`: Added new types (`HostedImageGenerationTool.cs`, `ImageGenerationToolCallContent.cs`, `ImageGenerationToolResultContent.cs`) and integration tests to enable hosted image generation across AI providers.
- `src/Libraries/Microsoft.Extensions.DataIngestion`: Refactored enrichers (Sentiment, Keyword, Classification, Summary) to use the new `EnricherOptions` and batching via the `Batching.cs` utility, with updated tests.
- Removed legacy schema exporter files (e.g. files under `src/Shared/JsonSchemaExporter/` and `NullabilityInfoContext/`) to clean up unused functionality.
- Updated OpenTelemetry instrumentation in OpenAI, Azure AI, Embedding, and SpeechToText clients to align with the latest semantic conventions.
- Revised project and package configuration files with updated metadata, preview stage tags, and code quality settings.
<!-- GitOpsUserAgent=GitOps.Apps.Server.pullrequestcopilot -->

Author: jeffhandley

Directory.Build.targets

@@ -8,6 +8,11 @@
   <Import Project="$(MSBuildThisFileDirectory)\eng\MSBuild\Generators.targets" />
   <Import Project="$(MSBuildThisFileDirectory)\eng\MSBuild\ProjectStaging.targets" />
 
+  <PropertyGroup>
+    <!-- Workaround https://github.com/dotnet/sdk/issues/51265 - can be removed when updating to .NET 10.0.100 (GA) SDK -->
+    <RestoreEnablePackagePruning Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">false</RestoreEnablePackagePruning>
+  </PropertyGroup>
+  
   <!-- Warning stuff -->
   <PropertyGroup>
     <MSBuildWarningsAsMessages>$(MSBuildWarningsAsMessages);NETSDK1138;MSB3270</MSBuildWarningsAsMessages>

eng/MSBuild/LegacySupport.props

@@ -2,7 +2,7 @@
   <ItemGroup Condition="'$(InjectCompilerFeatureRequiredOnLegacy)' == 'true' AND ('$(TargetFramework)' == 'net462' or '$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netcoreapp3.1')">
     <Compile Include="$(MSBuildThisFileDirectory)\..\..\src\LegacySupport\CompilerFeatureRequiredAttribute\*.cs" LinkBase="LegacySupport\CompilerFeatureRequiredAttribute" />
   </ItemGroup>
-  
+
   <ItemGroup Condition="'$(InjectRequiredMemberOnLegacy)' == 'true' AND ('$(TargetFramework)' == 'net462' or '$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netcoreapp3.1')">
     <Compile Include="$(MSBuildThisFileDirectory)\..\..\src\LegacySupport\RequiredMemberAttribute\*.cs" LinkBase="LegacySupport\RequiredMemberAttribute" />
   </ItemGroup>
@@ -47,10 +47,6 @@
     <Compile Include="$(MSBuildThisFileDirectory)\..\..\src\LegacySupport\StringSyntaxAttribute\*.cs" LinkBase="LegacySupport\StringSyntaxAttribute" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(InjectJsonSchemaExporterOnLegacy)' == 'true' AND ('$(TargetFramework)' == 'net462' or '$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netcoreapp3.1' or '$(TargetFramework)' == 'net6.0' or '$(TargetFramework)' == 'net7.0' or '$(TargetFramework)' == 'net8.0')">
-    <Compile Include="$(MSBuildThisFileDirectory)\..\..\src\Shared\JsonSchemaExporter\**\*.cs" LinkBase="Shared\EmptyCollections" />
-  </ItemGroup>
-
   <ItemGroup Condition="'$(InjectGetOrAddOnLegacy)' == 'true' AND ('$(TargetFramework)' == 'net462' or '$(TargetFramework)' == 'netstandard2.0')">
     <Compile Include="$(MSBuildThisFileDirectory)\..\..\src\LegacySupport\GetOrAdd\*.cs" LinkBase="LegacySupport\GetOrAdd" />
   </ItemGroup>

eng/packages/General.props

@@ -18,6 +18,7 @@
     <PackageVersion Include="Microsoft.Extensions.VectorData.Abstractions" Version="$(MicrosoftExtensionsVectorDataAbstractionsVersion)" />
     <PackageVersion Include="Microsoft.IO.RecyclableMemoryStream" Version="3.0.0" />
     <PackageVersion Include="Microsoft.ML.Tokenizers" Version="$(MicrosoftMLTokenizersVersion)" />
+    <PackageVersion Include="ModelContextProtocol.Core" Version="0.4.0-preview.3" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageVersion Include="OllamaSharp" Version="5.1.9" />
     <PackageVersion Include="OpenAI" Version="2.6.0" />

src/Libraries/Microsoft.Extensions.AI.Abstractions/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Release History
 
-## NOT YET RELEASED
+## 9.10.2
 
 - Updated `AIFunctionFactory` to respect `[DisplayName(...)]` on functions as a way to override the function name.
 - Updated `AIFunctionFactory` to respect `[DefaultValue(...)]` on function parameters as a way to specify default values.

src/Libraries/Microsoft.Extensions.AI.Abstractions/ChatCompletion/ChatResponseExtensions.cs

@@ -184,6 +184,47 @@ static async Task<ChatResponse> ToChatResponseAsync(
         }
     }
 
+    /// <summary>
+    /// Coalesces image result content elements in the provided list of <see cref="AIContent"/> items.
+    /// Unlike other content coalescing methods, this will coalesce non-sequential items based on their Name property, 
+    /// and it will replace earlier items with later ones when duplicates are found.
+    /// </summary>
+    private static void CoalesceImageResultContent(IList<AIContent> contents)
+    {
+        Dictionary<string, int>? imageResultIndexById = null;
+        bool hasRemovals = false;
+
+        for (int i = 0; i < contents.Count; i++)
+        {
+            if (contents[i] is ImageGenerationToolResultContent imageResult && !string.IsNullOrEmpty(imageResult.ImageId))
+            {
+                // Check if there's an existing ImageGenerationToolResultContent with the same ImageId to replace
+                if (imageResultIndexById is null)
+                {
+                    imageResultIndexById = new(StringComparer.Ordinal);
+                }
+
+                if (imageResultIndexById.TryGetValue(imageResult.ImageId!, out int existingIndex))
+                {
+                    // Replace the existing imageResult with the new one
+                    contents[existingIndex] = imageResult;
+                    contents[i] = null!; // Mark the current one for removal, then remove in single o(n) pass
+                    hasRemovals = true;
+                }
+                else
+                {
+                    imageResultIndexById[imageResult.ImageId!] = i;
+                }
+            }
+        }
+
+        // Remove all of the null slots left over from the coalescing process.
+        if (hasRemovals)
+        {
+            RemoveNullContents(contents);
+        }
+    }
+
     /// <summary>Coalesces sequential <see cref="AIContent"/> content elements.</summary>
     internal static void CoalesceContent(IList<AIContent> contents)
     {
@@ -219,6 +260,8 @@ internal static void CoalesceContent(IList<AIContent> contents)
                 return content;
             });
 
+        CoalesceImageResultContent(contents);
+
         Coalesce<DataContent>(
             contents,
             mergeSingle: false,
@@ -394,29 +437,35 @@ static bool TryAsCoalescable(AIContent content, [NotNullWhen(true)] out TContent
             }
 
             // Remove all of the null slots left over from the coalescing process.
-            if (contents is List<AIContent> contentsList)
-            {
-                _ = contentsList.RemoveAll(u => u is null);
-            }
-            else
-            {
-                int nextSlot = 0;
-                int contentsCount = contents.Count;
-                for (int i = 0; i < contentsCount; i++)
-                {
-                    if (contents[i] is { } content)
-                    {
-                        contents[nextSlot++] = content;
-                    }
-                }
+            RemoveNullContents(contents);
+        }
+    }
 
-                for (int i = contentsCount - 1; i >= nextSlot; i--)
+    private static void RemoveNullContents<T>(IList<T> contents)
+        where T : class
+    {
+        if (contents is List<AIContent> contentsList)
+        {
+            _ = contentsList.RemoveAll(u => u is null);
+        }
+        else
+        {
+            int nextSlot = 0;
+            int contentsCount = contents.Count;
+            for (int i = 0; i < contentsCount; i++)
+            {
+                if (contents[i] is { } content)
                 {
-                    contents.RemoveAt(i);
+                    contents[nextSlot++] = content;
                 }
+            }
 
-                Debug.Assert(nextSlot == contents.Count, "Expected final count to equal list length.");
+            for (int i = contentsCount - 1; i >= nextSlot; i--)
+            {
+                contents.RemoveAt(i);
             }
+
+            Debug.Assert(nextSlot == contents.Count, "Expected final count to equal list length.");
         }
     }
 

src/Libraries/Microsoft.Extensions.AI.Abstractions/ChatCompletion/ChatResponseUpdate.cs

@@ -20,7 +20,7 @@ namespace Microsoft.Extensions.AI;
 /// </para>
 /// <para>
 /// The relationship between <see cref="ChatResponse"/> and <see cref="ChatResponseUpdate"/> is
-/// codified in the <see cref="ChatResponseExtensions.ToChatResponseAsync"/> and
+/// codified in the <see cref="ChatResponseExtensions.ToChatResponseAsync(IAsyncEnumerable{ChatResponseUpdate}, System.Threading.CancellationToken)"/> and
 /// <see cref="ChatResponse.ToChatResponseUpdates"/>, which enable bidirectional conversions
 /// between the two. Note, however, that the provided conversions might be lossy, for example, if multiple
 /// updates all have different <see cref="RawRepresentation"/> objects whereas there's only one slot for
@@ -58,6 +58,29 @@ public ChatResponseUpdate(ChatRole? role, IList<AIContent>? contents)
         _contents = contents;
     }
 
+    /// <summary>
+    /// Creates a new ChatResponseUpdate instance that is a copy of the current object.
+    /// </summary>
+    /// <remarks>The cloned object is a shallow copy; reference-type properties will reference the same
+    /// objects as the original. Use this method to duplicate the response update for further modification without
+    /// affecting the original instance.</remarks>
+    /// <returns>A new ChatResponseUpdate object with the same property values as the current instance.</returns>
+    public ChatResponseUpdate Clone() =>
+        new()
+        {
+            AdditionalProperties = AdditionalProperties,
+            AuthorName = AuthorName,
+            Contents = Contents,
+            CreatedAt = CreatedAt,
+            ConversationId = ConversationId,
+            FinishReason = FinishReason,
+            MessageId = MessageId,
+            ModelId = ModelId,
+            RawRepresentation = RawRepresentation,
+            ResponseId = ResponseId,
+            Role = Role,
+        };
+
     /// <summary>Gets or sets the name of the author of the response update.</summary>
     public string? AuthorName
     {

src/Libraries/Microsoft.Extensions.AI.Abstractions/Contents/ImageGenerationToolCallContent.cs

@@ -0,0 +1,25 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace Microsoft.Extensions.AI;
+
+/// <summary>
+/// Represents the invocation of an image generation tool call by a hosted service.
+/// </summary>
+[Experimental("MEAI001")]
+public sealed class ImageGenerationToolCallContent : AIContent
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImageGenerationToolCallContent"/> class.
+    /// </summary>
+    public ImageGenerationToolCallContent()
+    {
+    }
+
+    /// <summary>
+    /// Gets or sets the unique identifier of the image generation item.
+    /// </summary>
+    public string? ImageId { get; set; }
+}

src/Libraries/Microsoft.Extensions.AI.Abstractions/Contents/ImageGenerationToolResultContent.cs

@@ -0,0 +1,39 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Microsoft.Extensions.AI;
+
+/// <summary>
+/// Represents an image generation tool call invocation by a hosted service.
+/// </summary>
+/// <remarks>
+/// This content type represents when a hosted AI service invokes an image generation tool.
+/// It is informational only and represents the call itself, not the result.
+/// </remarks>
+[Experimental("MEAI001")]
+public sealed class ImageGenerationToolResultContent : AIContent
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ImageGenerationToolResultContent"/> class.
+    /// </summary>
+    public ImageGenerationToolResultContent()
+    {
+    }
+
+    /// <summary>
+    /// Gets or sets the unique identifier of the image generation item.
+    /// </summary>
+    public string? ImageId { get; set; }
+
+    /// <summary>
+    /// Gets or sets the generated content items.
+    /// </summary>
+    /// <remarks>
+    /// Content is typically <see cref="DataContent"/> for images streamed from the tool, or <see cref="UriContent"/> for remotely hosted images, but
+    /// can also be provider-specific content types that represent the generated images.
+    /// </remarks>
+    public IList<AIContent>? Outputs { get; set; }
+}

src/Libraries/Microsoft.Extensions.AI.Abstractions/Image/ImageGenerationOptions.cs

@@ -81,6 +81,11 @@ protected ImageGenerationOptions(ImageGenerationOptions? other)
     /// </summary>
     public ImageGenerationResponseFormat? ResponseFormat { get; set; }
 
+    /// <summary>
+    /// Gets or sets the number of intermediate streaming images to generate.
+    /// </summary>
+    public int? StreamingCount { get; set; }
+
     /// <summary>Gets or sets any additional properties associated with the options.</summary>
     public AdditionalPropertiesDictionary? AdditionalProperties { get; set; }
 

src/Libraries/Microsoft.Extensions.AI.Abstractions/Microsoft.Extensions.AI.Abstractions.csproj

@@ -4,6 +4,7 @@
     <RootNamespace>Microsoft.Extensions.AI</RootNamespace>
     <Description>Abstractions representing generative AI components.</Description>
     <Workstream>AI</Workstream>
+    <ForceLatestDotnetVersions>true</ForceLatestDotnetVersions>
   </PropertyGroup>
 
   <PropertyGroup>
@@ -21,21 +22,20 @@
 
   <PropertyGroup>
     <InjectExperimentalAttributeOnLegacy>true</InjectExperimentalAttributeOnLegacy>
-    <InjectJsonSchemaExporterOnLegacy>true</InjectJsonSchemaExporterOnLegacy>
     <InjectRequiredMemberOnLegacy>true</InjectRequiredMemberOnLegacy>
     <InjectSharedEmptyCollections>true</InjectSharedEmptyCollections>
     <InjectStringHashOnLegacy>true</InjectStringHashOnLegacy>
     <InjectStringSyntaxAttributeOnLegacy>true</InjectStringSyntaxAttributeOnLegacy>
     <InjectSystemIndexOnLegacy>true</InjectSystemIndexOnLegacy>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
+  <ItemGroup>
     <PackageReference Include="System.Text.Json" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net462'">
     <Reference Include="System.Net.Http" />
     <Reference Include="System.ComponentModel.DataAnnotations" />
   </ItemGroup>
-  
+
 </Project>