# OpenResponsesReasoningDeltaEvent Event emitted when reasoning text delta is streamed ## Fields | Field | Type | Required | Description | | ------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------ | | `type` | [models.OpenResponsesReasoningDeltaEventType](../models/openresponsesreasoningdeltaeventtype.md) | :heavy_check_mark: | N/A | | `output_index` | *float* | :heavy_check_mark: | N/A | | `item_id` | *str* | :heavy_check_mark: | N/A | | `content_index` | *float* | :heavy_check_mark: | N/A | | `delta` | *str* | :heavy_check_mark: | N/A | | `sequence_number` | *float* | :heavy_check_mark: | N/A |