[BUG]: CreateResponseStreamingAsync StreamingResponseErrorUpdate updates don't provide the error

[replaysMike]

Describe the bug

When using CreateResponseStreamingAsync() and an error occurs the object of type StreamingResponseErrorUpdate should be providing access to the error but it doesn't seem to.

I don't know if it's related, but the Status property is empty too when I receive StreamingResponseOutputItemAddedUpdate messages.

Steps to reproduce

1. Perform a query using the WebSearch tool
2. Use a streamed response
3. Cause an error to occur and try to fetch information about it

Code snippets

var client = openAi.GetOpenAIResponseClient("gpt-5-mini");
var userQuestion = "";
var options = new ResponseCreationOptions {
  Instructions = "...",
  Tools = {
    ResponseTool.CreateWebSearchTool(null, WebSearchContextSize.Low)
  }
};
await foreach (var update in client.CreateResponseStreamingAsync(userInputText: userQuestion, options))
{
  switch (update)
  {
     case StreamingResponseErrorUpdate error:
        // error.Code and error.Message are blank, but if I dig into the private fields the error is there (such as a throttle error) I just don't have access to it.

        Console.WriteLine($"Error: [{error.Code}] {error.Message}");
      break;
  }
}

OS

Windows

.NET version

9.0

Library version

2.3.0

[jsquire]

Hi @replaysMike. Thanks for reaching out and we regret that you're experiencing difficulties. I'm unable to reproduce based on the available context. The StreamingResponseErrorUpdate type is based on the format of a streaming error response documented in the OpenAI Platform docs. I'm seeing that format returned and properly parsed.

Can you please share more information about what internal members you're seeing the data in, and in what format? The only non-public member that exists should be _additionalBinaryDataProperties and if you're seeing the data there, it would indicate the service is not honoring its contract in some cases. If you're able to provide deterministic repro steps or a stand-alone sample, that would be quite helpful and greatly appreciated.

[jsquire]

Assistance has been blocked for 2+ weeks waiting for additional information. If you are still in need of help, please add the requested information and let us know that you'd like to reopen.