Add content to represent service-side actions

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

@@ -293,7 +293,7 @@ internal static void CoalesceContent(IList<AIContent> contents)
         Coalesce<CodeInterpreterToolCallContent>(
             contents,
             mergeSingle: true,
-            canMerge: static (r1, r2) => r1.CallId == r2.CallId,
+            canMerge: static (r1, r2) => r1.Id == r2.Id,
             static (contents, start, end) =>
             {
                 var firstContent = (CodeInterpreterToolCallContent)contents[start];
@@ -320,9 +320,8 @@ internal static void CoalesceContent(IList<AIContent> contents)
                     CoalesceContent(inputs);
                 }
 
-                return new()
+                return new(firstContent.Id)
                 {
-                    CallId = firstContent.CallId,
                     Inputs = inputs,
                     AdditionalProperties = firstContent.AdditionalProperties?.Clone(),
                 };
@@ -331,7 +330,7 @@ internal static void CoalesceContent(IList<AIContent> contents)
         Coalesce<CodeInterpreterToolResultContent>(
             contents,
             mergeSingle: true,
-            canMerge: static (r1, r2) => r1.CallId is not null && r2.CallId is not null && r1.CallId == r2.CallId,
+            canMerge: static (r1, r2) => r1.Id == r2.Id,
             static (contents, start, end) =>
             {
                 var firstContent = (CodeInterpreterToolResultContent)contents[start];
@@ -358,9 +357,8 @@ internal static void CoalesceContent(IList<AIContent> contents)
                     CoalesceContent(output);
                 }
 
-                return new()
+                return new(firstContent.Id)
                 {
-                    CallId = firstContent.CallId,
                     Outputs = output,
                     AdditionalProperties = firstContent.AdditionalProperties?.Clone(),
                 };

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

@@ -32,6 +32,7 @@ namespace Microsoft.Extensions.AI;
 // [JsonDerivedType(typeof(McpServerToolApprovalResponseContent), typeDiscriminator: "mcpServerToolApprovalResponse")]
 // [JsonDerivedType(typeof(CodeInterpreterToolCallContent), typeDiscriminator: "codeInterpreterToolCall")]
 // [JsonDerivedType(typeof(CodeInterpreterToolResultContent), typeDiscriminator: "codeInterpreterToolResult")]
+// [JsonDerivedType(typeof(ServiceActionContent), typeDiscriminator: "serviceAction")]
 
 public class AIContent
 {

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

@@ -14,20 +14,14 @@ namespace Microsoft.Extensions.AI;
 /// It is informational only and represents the call itself, not the result.
 /// </remarks>
 [Experimental("MEAI001")]
-public sealed class CodeInterpreterToolCallContent : AIContent
+public sealed class CodeInterpreterToolCallContent : ServiceActionContent
 {
-    /// <summary>
-    /// Initializes a new instance of the <see cref="CodeInterpreterToolCallContent"/> class.
-    /// </summary>
-    public CodeInterpreterToolCallContent()
+    /// <inheritdoc/>
+    public CodeInterpreterToolCallContent(string id)
+        : base(id)
     {
     }
 
-    /// <summary>
-    /// Gets or sets the tool call ID.
-    /// </summary>
-    public string? CallId { get; set; }
-
     /// <summary>
     /// Gets or sets the inputs to the code interpreter tool.
     /// </summary>

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

@@ -10,20 +10,14 @@ namespace Microsoft.Extensions.AI;
 /// Represents the result of a code interpreter tool invocation by a hosted service.
 /// </summary>
 [Experimental("MEAI001")]
-public sealed class CodeInterpreterToolResultContent : AIContent
+public sealed class CodeInterpreterToolResultContent : ServiceActionContent
 {
-    /// <summary>
-    /// Initializes a new instance of the <see cref="CodeInterpreterToolResultContent"/> class.
-    /// </summary>
-    public CodeInterpreterToolResultContent()
+    /// <inheritdoc/>
+    public CodeInterpreterToolResultContent(string id)
+        : base(id)
     {
     }
 
-    /// <summary>
-    /// Gets or sets the tool call ID that this result corresponds to.
-    /// </summary>
-    public string? CallId { get; set; }
-
     /// <summary>
     /// Gets or sets the output of code interpreter tool.
     /// </summary>

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

@@ -16,28 +16,23 @@ namespace Microsoft.Extensions.AI;
 /// It is informational only.
 /// </remarks>
 [Experimental("MEAI001")]
-public sealed class McpServerToolCallContent : AIContent
+public sealed class McpServerToolCallContent : ServiceActionContent
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="McpServerToolCallContent"/> class.
     /// </summary>
-    /// <param name="callId">The tool call ID.</param>
+    /// <param name="id">The tool call ID.</param>
     /// <param name="toolName">The tool name.</param>
     /// <param name="serverName">The MCP server name that hosts the tool.</param>
-    /// <exception cref="ArgumentNullException"><paramref name="callId"/> or <paramref name="toolName"/> is <see langword="null"/>.</exception>
-    /// <exception cref="ArgumentException"><paramref name="callId"/> or <paramref name="toolName"/> is empty or composed entirely of whitespace.</exception>
-    public McpServerToolCallContent(string callId, string toolName, string? serverName)
+    /// <exception cref="ArgumentNullException"><paramref name="id"/> or <paramref name="toolName"/> is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentException"><paramref name="id"/> or <paramref name="toolName"/> is empty or composed entirely of whitespace.</exception>
+    public McpServerToolCallContent(string id, string toolName, string? serverName)
+        : base(id)
     {
-        CallId = Throw.IfNullOrWhitespace(callId);
         ToolName = Throw.IfNullOrWhitespace(toolName);
         ServerName = serverName;
     }
 
-    /// <summary>
-    /// Gets the tool call ID.
-    /// </summary>
-    public string CallId { get; }
-
     /// <summary>
     /// Gets the name of the tool called.
     /// </summary>

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

@@ -1,10 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Extensions.AI;
 
@@ -16,24 +14,14 @@ namespace Microsoft.Extensions.AI;
 /// It is informational only.
 /// </remarks>
 [Experimental("MEAI001")]
-public sealed class McpServerToolResultContent : AIContent
+public sealed class McpServerToolResultContent : ServiceActionContent
 {
-    /// <summary>
-    /// Initializes a new instance of the <see cref="McpServerToolResultContent"/> class.
-    /// </summary>
-    /// <param name="callId">The tool call ID.</param>
-    /// <exception cref="ArgumentNullException"><paramref name="callId"/> is <see langword="null"/>.</exception>
-    /// <exception cref="ArgumentException"><paramref name="callId"/> is empty or composed entirely of whitespace.</exception>
-    public McpServerToolResultContent(string callId)
+    /// <inheritdoc/>
+    public McpServerToolResultContent(string id)
+        : base(id)
     {
-        CallId = Throw.IfNullOrWhitespace(callId);
     }
 
-    /// <summary>
-    /// Gets the tool call ID.
-    /// </summary>
-    public string CallId { get; }
-
     /// <summary>
     /// Gets or sets the output of the tool call.
     /// </summary>

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

@@ -0,0 +1,35 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.Shared.Diagnostics;
+
+namespace Microsoft.Extensions.AI;
+
+/// <summary>
+/// Represents an action performed by a hosted service.
+/// </summary>
+/// <remarks>
+/// This content type is used to represent actions performed by the service such as calls to other services or invocation of service tools.
+/// It is informational only.
+/// </remarks>
+[Experimental("MEAI001")]
+public class ServiceActionContent : AIContent
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ServiceActionContent"/> class.
+    /// </summary>
+    /// <param name="id">The ID for the service-side action.</param>
+    /// <exception cref="ArgumentNullException"><paramref name="id"/> is <see langword="null"/>.</exception>
+    /// <exception cref="ArgumentException"><paramref name="id"/> is empty or composed entirely of whitespace.</exception>
+    public ServiceActionContent(string id)
+    {
+        Id = Throw.IfNullOrWhitespace(id);
+    }
+
+    /// <summary>
+    /// Gets the ID for the service-side action.
+    /// </summary>
+    public string Id { get; }
+}

src/Libraries/Microsoft.Extensions.AI.Abstractions/Utilities/AIJsonUtilities.Defaults.cs

@@ -59,6 +59,7 @@ private static JsonSerializerOptions CreateDefaultOptions()
         AddAIContentType(options, typeof(McpServerToolApprovalResponseContent), typeDiscriminatorId: "mcpServerToolApprovalResponse", checkBuiltIn: false);
         AddAIContentType(options, typeof(CodeInterpreterToolCallContent), typeDiscriminatorId: "codeInterpreterToolCall", checkBuiltIn: false);
         AddAIContentType(options, typeof(CodeInterpreterToolResultContent), typeDiscriminatorId: "codeInterpreterToolResult", checkBuiltIn: false);
+        AddAIContentType(options, typeof(ServiceActionContent), typeDiscriminatorId: "serviceAction", checkBuiltIn: false);
 
         if (JsonSerializer.IsReflectionEnabledByDefault)
         {
@@ -133,6 +134,7 @@ private static JsonSerializerOptions CreateDefaultOptions()
     [JsonSerializable(typeof(McpServerToolApprovalResponseContent))]
     [JsonSerializable(typeof(CodeInterpreterToolCallContent))]
     [JsonSerializable(typeof(CodeInterpreterToolResultContent))]
+    [JsonSerializable(typeof(ServiceActionContent))]
     [JsonSerializable(typeof(ResponseContinuationToken))]
 
     // IEmbeddingGenerator

src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIAssistantsChatClient.cs

@@ -199,9 +199,8 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
                 case RunStepDetailsUpdate details:
                     if (!string.IsNullOrEmpty(details.CodeInterpreterInput))
                     {
-                        CodeInterpreterToolCallContent hcitcc = new()
+                        CodeInterpreterToolCallContent hcitcc = new(details.ToolCallId)
                         {
-                            CallId = details.ToolCallId,
                             Inputs = [new DataContent(Encoding.UTF8.GetBytes(details.CodeInterpreterInput), "text/x-python")],
                             RawRepresentation = details,
                         };
@@ -218,9 +217,8 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
 
                     if (details.CodeInterpreterOutputs is { Count: > 0 })
                     {
-                        CodeInterpreterToolResultContent hcitrc = new()
+                        CodeInterpreterToolResultContent hcitrc = new(details.ToolCallId)
                         {
-                            CallId = details.ToolCallId,
                             RawRepresentation = details,
                         };
 

src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIResponsesChatClient.cs

@@ -1099,14 +1099,14 @@ static FunctionCallOutputResponseItem SerializeAIContent(string callId, IEnumera
                             break;
 
                         case McpServerToolCallContent mstcc:
-                            (idToContentMapping ??= [])[mstcc.CallId] = mstcc;
+                            (idToContentMapping ??= [])[mstcc.Id] = mstcc;
                             break;
 
                         case McpServerToolResultContent mstrc:
-                            if (idToContentMapping?.TryGetValue(mstrc.CallId, out AIContent? callContentFromMapping) is true &&
+                            if (idToContentMapping?.TryGetValue(mstrc.Id, out AIContent? callContentFromMapping) is true &&
                                 callContentFromMapping is McpServerToolCallContent associatedCall)
                             {
-                                _ = idToContentMapping.Remove(mstrc.CallId);
+                                _ = idToContentMapping.Remove(mstrc.Id);
                                 McpToolCallItem mtci = ResponseItem.CreateMcpToolCallItem(
                                     associatedCall.ServerName,
                                     associatedCall.ToolName,
@@ -1287,19 +1287,17 @@ private static void AddAllMcpFilters(IList<string> toolNames, McpToolFilter filt
     /// <summary>Adds new <see cref="AIContent"/> for the specified <paramref name="cicri"/> into <paramref name="contents"/>.</summary>
     private static void AddCodeInterpreterContents(CodeInterpreterCallResponseItem cicri, IList<AIContent> contents)
     {
-        contents.Add(new CodeInterpreterToolCallContent
+        contents.Add(new CodeInterpreterToolCallContent(cicri.Id)
         {
-            CallId = cicri.Id,
             Inputs = !string.IsNullOrWhiteSpace(cicri.Code) ? [new DataContent(Encoding.UTF8.GetBytes(cicri.Code), "text/x-python")] : null,
 
             // We purposefully do not set the RawRepresentation on the HostedCodeInterpreterToolCallContent, only on the HostedCodeInterpreterToolResultContent, to avoid
             // the same CodeInterpreterCallResponseItem being included on two different AIContent instances. When these are roundtripped, we want only one
             // CodeInterpreterCallResponseItem sent back for the pair.
         });
 
-        contents.Add(new CodeInterpreterToolResultContent
+        contents.Add(new CodeInterpreterToolResultContent(cicri.Id)
         {
-            CallId = cicri.Id,
             Outputs = cicri.Outputs is { Count: > 0 } outputs ? outputs.Select<CodeInterpreterCallOutput, AIContent?>(o =>
                 o switch
                 {

test/Libraries/Microsoft.Extensions.AI.Abstractions.Tests/Contents/AIContentTests.cs

@@ -75,7 +75,8 @@ public void Serialization_DerivedTypes_Roundtrips()
             new McpServerToolCallContent("call123", "myTool", "myServer"),
             new McpServerToolResultContent("call123"),
             new McpServerToolApprovalRequestContent("request123", new McpServerToolCallContent("call123", "myTool", "myServer")),
-            new McpServerToolApprovalResponseContent("request123", approved: true)
+            new McpServerToolApprovalResponseContent("request123", approved: true),
+            new ServiceActionContent("action123")
         ]);
 
         var serialized = JsonSerializer.Serialize(message, AIJsonUtilities.DefaultOptions);

test/Libraries/Microsoft.Extensions.AI.Abstractions.Tests/Contents/CodeInterpreterToolCallContentTests.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.Collections.Generic;
 using System.Text.Json;
 using Xunit;
@@ -12,21 +13,19 @@ public class CodeInterpreterToolCallContentTests
     [Fact]
     public void Constructor_PropsDefault()
     {
-        CodeInterpreterToolCallContent c = new();
+        CodeInterpreterToolCallContent c = new("call123");
         Assert.Null(c.RawRepresentation);
         Assert.Null(c.AdditionalProperties);
-        Assert.Null(c.CallId);
+        Assert.Equal("call123", c.Id);
         Assert.Null(c.Inputs);
     }
 
     [Fact]
     public void Properties_Roundtrip()
     {
-        CodeInterpreterToolCallContent c = new();
+        CodeInterpreterToolCallContent c = new("call123");
 
-        Assert.Null(c.CallId);
-        c.CallId = "call123";
-        Assert.Equal("call123", c.CallId);
+        Assert.Equal("call123", c.Id);
 
         Assert.Null(c.Inputs);
         IList<AIContent> inputs = [new TextContent("print('hello')")];
@@ -47,9 +46,8 @@ public void Properties_Roundtrip()
     [Fact]
     public void Inputs_SupportsMultipleContentTypes()
     {
-        CodeInterpreterToolCallContent c = new()
+        CodeInterpreterToolCallContent c = new("call456")
         {
-            CallId = "call456",
             Inputs =
             [
                 new TextContent("import numpy as np"),
@@ -68,9 +66,8 @@ public void Inputs_SupportsMultipleContentTypes()
     [Fact]
     public void Serialization_Roundtrips()
     {
-        CodeInterpreterToolCallContent content = new()
+        CodeInterpreterToolCallContent content = new("call123")
         {
-            CallId = "call123",
             Inputs =
             [
                 new TextContent("print('hello')"),
@@ -82,12 +79,19 @@ public void Serialization_Roundtrips()
         var deserializedSut = JsonSerializer.Deserialize<CodeInterpreterToolCallContent>(json, AIJsonUtilities.DefaultOptions);
 
         Assert.NotNull(deserializedSut);
-        Assert.Equal("call123", deserializedSut.CallId);
+        Assert.Equal("call123", deserializedSut.Id);
         Assert.NotNull(deserializedSut.Inputs);
         Assert.Equal(2, deserializedSut.Inputs.Count);
         Assert.IsType<TextContent>(deserializedSut.Inputs[0]);
         Assert.Equal("print('hello')", ((TextContent)deserializedSut.Inputs[0]).Text);
         Assert.IsType<HostedFileContent>(deserializedSut.Inputs[1]);
         Assert.Equal("file456", ((HostedFileContent)deserializedSut.Inputs[1]).FileId);
     }
+
+    [Fact]
+    public void Constructor_Throws()
+    {
+        Assert.Throws<ArgumentNullException>("id", () => new CodeInterpreterToolCallContent(null!));
+        Assert.Throws<ArgumentException>("id", () => new CodeInterpreterToolCallContent(string.Empty));
+    }
 }