---
title: "ReasoningDeltaEvent"
---

Event emitted when reasoning text delta is streamed


## Fields

| Field                                                                          | Type                                                                           | Required                                                                       | Description                                                                    |
| ------------------------------------------------------------------------------ | ------------------------------------------------------------------------------ | ------------------------------------------------------------------------------ | ------------------------------------------------------------------------------ |
| `content_index`                                                                | *int*                                                                          | :heavy_check_mark:                                                             | N/A                                                                            |
| `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                                                                            |
| `type`                                                                         | [components.ReasoningDeltaEventType](../components/reasoningdeltaeventtype.mdx) | :heavy_check_mark:                                                             | N/A                                                                            |