Example

{
    "event_id": "event_3536",
    "type": "response.output_item.done",
    "response_id": "resp_001",
    "output_index": 0,
    "item": {
        "id": "msg_007",
        "object": "realtime.item",
        "type": "message",
        "status": "completed",
        "role": "assistant",
        "content": [
            {
                "type": "text",
                "text": "Sure, I can help with that."
            }
        ]
    }
}

response.content_part.added

Returned when a new content part is added to an assistant message item during response generation.