---
title: "ReasoningSummaryTextDeltaEvent"
---

Event emitted when reasoning summary text delta is streamed


## Fields

| Field                                                                                                | Type                                                                                                 | Required                                                                                             | Description                                                                                          |
| ---------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- |
| `delta`                                                                                              | *str*                                                                                                | :heavy_check_mark:                                                                                   | N/A                                                                                                  |
| `item_id`                                                                                            | *str*                                                                                                | :heavy_check_mark:                                                                                   | N/A                                                                                                  |
| `output_index`                                                                                       | *int*                                                                                                | :heavy_check_mark:                                                                                   | N/A                                                                                                  |
| `sequence_number`                                                                                    | *int*                                                                                                | :heavy_check_mark:                                                                                   | N/A                                                                                                  |
| `summary_index`                                                                                      | *int*                                                                                                | :heavy_check_mark:                                                                                   | N/A                                                                                                  |
| `type`                                                                                               | [components.ReasoningSummaryTextDeltaEventType](../components/reasoningsummarytextdeltaeventtype.mdx) | :heavy_check_mark:                                                                                   | N/A                                                                                                  |