.Net: Bug: ChatHistory function call ordering is broken in streaming mode

[bjornhandersson]

When using GetStreamingChatMessageContentsAsync with function calls, the results are added to ChatHistory in order of completion rather than order of execution causing error when submitting history in subsequence "chats" to bedrock.

Expected toolResult blocks at messages.7.content for the following Ids: tooluse_DiChMHwyRF2Ww0ib_XXXXX, but found: tooluse_IH0P-g2aTgi_ufQ0OXXXXX

To Reproduce
See code in comment below

Expected behavior
Bedrock tool use and tool result should maintain the order in the history.

Platform

• Language: C#
• AI model: Bedrock - claude sonnet 4.5
• Versions
  • Microsoft.SemanticKernel: 1.65
  • Microsoft.SemanticKernel.Connectors.Amazon: 1.65-alpha

[bjornhandersson]

Reproduce:

using System.ComponentModel;
using System.Text;
using System.Text.Json;
using Amazon;
using Amazon.BedrockAgent;
using Amazon.BedrockAgentRuntime;
using Amazon.BedrockRuntime;
using Microsoft.Extensions.AI;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.SemanticKernel;
using Microsoft.SemanticKernel.ChatCompletion;

var builder = Kernel.CreateBuilder();
builder.AddBedrockChatClient(modelId: "us.anthropic.claude-sonnet-4-5-20250929-v1:0");

builder
    .Services.AddSingleton<AmazonBedrockAgentClient>()
    .AddSingleton<AmazonBedrockAgentRuntimeClient>()
    .AddTransient(s => s.GetRequiredService<IChatClient>().AsChatCompletionService());

builder.Plugins.AddFromType<GreetingsPlugin>();
builder.Plugins.AddFromType<RandomNamePlugin>();

var kernel = builder.Build();

var executionSettings = new PromptExecutionSettings
{
    FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(
        autoInvoke: false,
        options: new FunctionChoiceBehaviorOptions
        {
            AllowParallelCalls = false,
            AllowConcurrentInvocation = false,
        }
    ),
};

var chatService = kernel.GetRequiredService<IChatCompletionService>();
var history = new ChatHistory();
history.AddUserMessage("Greet 5 random persons");

try
{
    while (true)
    {
        var responses = chatService.GetStreamingChatMessageContentsAsync(
            history,
            executionSettings,
            kernel,
            CancellationToken.None
        );

        var assistantMessage = new StringBuilder();
        await foreach (var response in responses)
        {
            if (response.Content != null)
            {
                Console.Write(response.Content);
                assistantMessage.Append(response.Content);
            }
        }

        var assistantMessageStr = assistantMessage.ToString();
        if (string.IsNullOrEmpty(assistantMessageStr))
        {
            history.AddUserMessage(assistantMessageStr);
        }

        history.AddUserMessage("Greet 5 more");
    }
}
catch (Exception ex)
{
    Console.WriteLine(
        JsonSerializer.Serialize(history, new JsonSerializerOptions { WriteIndented = true })
    );
}

public class GreetingsPlugin
{
    [KernelFunction, Description("Greet a person by name")]
    public string Greet(string name)
    {
        return $"Hello, {name}!";
    }
}

public class RandomNamePlugin
{
    private static readonly string[] Names =
    {
        "Alice",
        "Bob",
        "Charlie",
        "Diana",
        "Ethan",
        "Fiona",
        "George",
        "Hannah",
        "Ian",
        "Julia",
    };

    [KernelFunction, Description("Get a random name")]
    public string GetRandomName()
    {
        var random = new Random();
        var name = Names[random.Next(Names.Length)];
        Console.WriteLine($"Tool called: GetRandomName() -> {name}");
        return name;
    }
}

Serialized history from above code:

[
  {
    "Role": {
      "Label": "user"
    },
    "Items": [
      {
        "$type": "TextContent",
        "Text": "Greet 5 random person s"
      }
    ]
  },
  {
    "Role": {
      "Label": "assistant"
    },
    "Items": [
      {
        "$type": "FunctionCallContent",
        "Id": "tooluse_t-7l3xEeTUacH0QC0jcmng",
        "FunctionName": "RandomNamePlugin_GetRandomName"
      }
    ],
    "Metadata": {
      "Usage": null
    }
  },
  {
    "Role": {
      "Label": "assistant"
    },
    "Items": [
      {
        "$type": "FunctionCallContent",
        "Id": "tooluse_nUOe7NH7Q3ynXiAOhWZNmg",
        "FunctionName": "RandomNamePlugin_GetRandomName"
      }
    ],
    "Metadata": {
      "Usage": null
    }
  },
  {
    "Role": {
      "Label": "assistant"
    },
    "Items": [
      {
        "$type": "FunctionCallContent",
        "Id": "tooluse_Lj3yYrwJSVi_mA9fQ-qhyQ",
        "FunctionName": "RandomNamePlugin_GetRandomName"
      }
    ],
    "Metadata": {
      "Usage": null
    }
  },
  {
    "Role": {
      "Label": "assistant"
    },
    "Items": [
      {
        "$type": "FunctionCallContent",
        "Id": "tooluse_3DZKKlTGSSegGYI9QgyOFg",
        "FunctionName": "RandomNamePlugin_GetRandomName"
      }
    ],
    "Metadata": {
      "Usage": null
    }
  },
  {
    "Role": {
      "Label": "assistant"
    },
    "Items": [
      {
        "$type": "FunctionCallContent",
        "Id": "tooluse_9_DauDhvR92JNivoBOweYA",
        "FunctionName": "RandomNamePlugin_GetRandomName"
      }
    ],
    "Metadata": {
      "Usage": null
    }
  },
  {
    "Role": {
      "Label": "user"
    },
    "Items": [
      {
        "$type": "TextContent",
        "Text": "Greet 5 more"
      }
    ]
  }
]