[QUESTION] Response API, using reasoning and streaming: StreamingResponseItemUpdate type missing

[geo-bontognali]

How can we help?

Hi there

I'm trying to implment streaming responses with reasoning.
In the example given in the Readme, I see the following block:

if (update is StreamingResponseItemUpdate itemUpdate
&& itemUpdate.Item is ReasoningResponseItem reasoningItem)
{
Console.WriteLine($"[Reasoning] ({reasoningItem.Status})");
}

I can't find any definition for StreamingResponseItemUpdate in this package.
Am I doing something wrong or is this documentation outdated?

Thank you for your help!

https://github.com/openai/openai-dotnet?tab=readme-ov-file#how-to-use-responses-with-streaming-and-reasoning

[jamesgurung]

The correct streaming response update types seem to be:

• StreamingResponseOutputItemAddedUpdate when reasoning starts
• StreamingResponseOutputItemDoneUpdate when reasoning is completed

In both cases, still check itemUpdate.Item is ReasoningResponseItem.

[jsquire]

Hi @geo-bontognali. Thanks for reaching out and we regret that you're experiencing difficulties. With apologies, it looks like the documentation has gotten out of sync with the API and is no longer accurate. We'll get that fixed up.

In the meantime, @jamesgurung's suggestion is correct (thanks, James!) and an updated form of that snippet would look something like:

    var client = new OpenAIResponseClient("o3-mini", "<< YOUR API KEY >>");

    OpenAIResponse response = await client.CreateResponseAsync(
        userInputText: "What's the optimal strategy to win at poker?",
        new ResponseCreationOptions()
        {
            ReasoningOptions = new ResponseReasoningOptions()
            {
                ReasoningEffortLevel = ResponseReasoningEffortLevel.High,
            },
        });

    await foreach (StreamingResponseUpdate update
        in client.CreateResponseStreamingAsync(
            userInputText: "What's the optimal strategy to win at poker?",
            new ResponseCreationOptions()
            {
                ReasoningOptions = new ResponseReasoningOptions()
                {
                    ReasoningEffortLevel = ResponseReasoningEffortLevel.High,
                },
            }))
    {
        if (update is StreamingResponseOutputItemAddedUpdate itemUpdate
            && itemUpdate.Item is ReasoningResponseItem reasoningItem)
        {
            Console.WriteLine($"[Reasoning] ({reasoningItem.Status})");
        }
        else if (update is StreamingResponseOutputItemAddedUpdate itemDone
            && itemDone.Item is ReasoningResponseItem reasoningDone)
        {
            Console.WriteLine($"[Reasoning DONE] ({reasoningDone.Status})");
        }
        else if (update is StreamingResponseOutputTextDeltaUpdate delta)
        {
            Console.Write(delta.Delta);
        }
    }

[geo-bontognali]

Thank you @jsquire & @jamesgurung, that's perfect!

[jsquire]

Fixed by #600. Going forward, we're going to pull in a snippets tool which allows these to live in code that is compiled with each build. Once the existing snippets get ported over, this kind of drift would be caught during builds. This work is tracked by #602.