[QUESTION] StreamingResponseOutputItemAddedUpdate Data

[didrh]

How can we help?

Reading this response i noticed the response.output_item.added event has way more data than the corresponding type in the library:
StreamingResponseOutputItemAddedUpdate: {"OutputIndex":19,"Item":{"Id":"ws_0e3df96bcf0970fa0068e4c2e89a048197b789efb1401f7daf"},"SequenceNumber":1087}

Two questions:
a) is it possible or planed to bring at least the type of the Item to the front? At the moment we do things differently depending on the ID start ("ws_" or "rs_") for some cases.
b) is it possible or planed to bring the whole Item to the front? There seems to be extensive de-serializing code in the generated models?

[jsquire]

@joseharriaga: Can you please take a look and share your thoughts?

[joseharriaga]

Thank you for reaching out, @didrh ! The Item property of StreamingResponseOutputItemAddedUpdate is a ResponseItem. As such, you can cast it to the corresponding derived type (e.g., MessageResponseItem, WebSearchCallResponseItem, etc), and this will expose the properties that are specific to that derived type.

Here's one example:
🔗 https://github.com/openai/openai-dotnet/blob/main/examples/Responses/Example04_FunctionCallingStreamingAsync.cs#L48

[ShivangiReja]

For streaming, the SDK uses typed events via inheritance. Each derived type maps 1:1 to an event, so you branch on the .NET type, not a raw "type" string.

• StreamingResponseOutputItemAddedUpdate ↔ response.output_item.added
• StreamingResponseOutputTextDeltaUpdate ↔ response.output_text.delta
• …and so on.

We don’t expose item.type because the intent is to switch on the concrete update/item types. We also don’t expose StreamingResponseUpdate.Type; you should pattern-match on the concrete types. Same for items: ResponseItem is a polymorphic base with derived types like MessageResponseItem, ToolCallResponseItem, etc., so branch on those rather than reading a raw item.type string.

Example:

var responseUpdates = client.CreateResponseStreaming(inputItems, options);

foreach (StreamingResponseUpdate update in responseUpdates)
{
     if (update is StreamingResponseOutputItemAddedUpdate outputItemAddedUpdated)
     {
           if (outputItemAddedUpdated.Item is MessageResponseItem message && message.Role == MessageRole.Assistant)
           {
                   Console.WriteLine($"[ASSISTANT]:");
            }
     }

    if (update is StreamingResponseOutputTextDeltaUpdate delta)
    {
        Console.Write(delta.Delta);
    }
}

If you need the raw payload, use GetRawPagesAsync() as noted here.