> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# ExtractionAsset

An image or PDF sent once and referenced by its key in the `assets` map. `data_base64` is the file in standard base64 with no `data:` prefix. PDF is read by document models only.

## Fields

| Field | Type | Required | Description |
| - | - | - | - |
| `data_base64` | *str* | ✔️ | N/A |
| `format_` | [components.ExtractionAssetFormat](../components/extractionassetformat.mdx) | ✔️ | N/A |
| `type` | [Optional\[components.ExtractionAssetType\]](../components/extractionassettype.mdx) | ➖ | N/A |