> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter-d02e98a0-mintlify-7021d5f4.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# AnnotationAddedEvent - Python SDK

> AnnotationAddedEvent method reference

<Warning>
  The Python SDK and docs are currently in beta.
  Report issues on [GitHub](https://github.com/OpenRouterTeam/python-sdk/issues).
</Warning>

Event emitted when a text annotation is added to output

## Fields

| Field              | Type                                                                                                           | Required             | Description | Example                                                                                          |
| ------------------ | -------------------------------------------------------------------------------------------------------------- | -------------------- | ----------- | ------------------------------------------------------------------------------------------------ |
| `annotation`       | [components.OpenAIResponsesAnnotation](/client-sdks/python/api-reference/components/openairesponsesannotation) | :heavy\_check\_mark: | N/A         | `{"file_id": "file-abc123","filename": "research_paper.pdf","index": 0,"type": "file_citation"}` |
| `annotation_index` | *int*                                                                                                          | :heavy\_check\_mark: | N/A         |                                                                                                  |
| `content_index`    | *int*                                                                                                          | :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.AnnotationAddedEventType](/client-sdks/python/api-reference/components/annotationaddedeventtype)   | :heavy\_check\_mark: | N/A         |                                                                                                  |