> This page is for version v2024-12-23.
> For other versions, use one of these documentation indexes:
> - v2026-02-09 (default): https://docs.extend.ai/2026-02-09/llms.txt
> - v2025-04-21: https://docs.extend.ai/2025-04-21/llms.txt
> - v2024-12-23: https://docs.extend.ai/2024-12-23/llms.txt

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.extend.ai/llms.txt
> Use this file to discover all available pages before exploring further.
>
> ## API version
> The current API version is `2026-02-09`, served at the site root (no version prefix in URLs).
> If this page URL contains `/2025-04-21/` or `/2024-12-23/`, you are reading an older API version.
> Prefer the current docs at https://docs.extend.ai/llms.txt unless the user explicitly needs that older version.
> Do not treat older-version pages as the source of truth for new integrations.

# Bounding Boxes & Citations

> How to leverage bounding box and citation references when reviewing documents in Extend.

Extend provides references to locate extracted data within your documents. The specific format and availability depend on your processor's configuration type: JSON Schema (recommended) or Fields Array (legacy).

While traditional OCR products often include bounding boxes, Extend uses a mix of multimodal large language models and traditional vision models. Due to this mixture, providing references isn't always possible, and coverage for all fields isn't guaranteed, even when enabled. However, we are always working to improve coverage.

These references are currently only available for `Extract` output fields and are supported for the following file/document types:

* `PDF`
* `IMG` (jpeg, png, etc)

## Citations (JSON Schema Config)

> **Note**
>
> This section is relevant for processors using the **JSON Schema** config type.
> If you are using the legacy Fields Array config type, please see the [Bounding Boxes (Legacy Fields Array Config)](#bounding-boxes-legacy-fields-array-config) section. If you aren't
> sure which config type you are using, please see the [Migrating to JSON Schema](/2024-12-23/product/migrating-to-json-schema) documentation.

For processors configured with JSON Schema, Extend uses **Citations**. Citations provide a polygon reference to a specific location in the document.

**Key Points:**

* **Availability:** Citations are returned in the `metadata` object for each field **only if** the `includeBoundingBoxCitations` option is enabled in the processor config. You can enable this in the Studio via the Build tab under "Advanced options".
* **Field Type Coverage:** When enabled, Citations can potentially be returned for **all field types**.
* **Schema:** Citations use a `polygon` structure representing points on the page. For detailed schema information and usage examples, see the API Reference.