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

# Object model

> JavaScript object reference for writing Advanced Script Rules in Vantage — Context, Field, Document, and related types.

When writing Advanced Script Rules, you have access to a set of JavaScript objects representing the document, its fields, the execution context, image regions, and Vantage's data catalogs.

The Vantage JavaScript interpreter supports ECMAScript 5.1 and selected later features. For more information, see the [ECMAScript repository](https://github.com/sebastienros/jint#supported-features).

## Data access

Scripts can define custom functions and access Vantage data catalogs through the `Context` object.

<Note>
  Scripts cannot:

  * Send requests to databases other than Vantage data catalogs.
  * Send requests to external services.
  * Use third-party libraries such as jQuery.
</Note>

## Object reference

Use these objects when writing Advanced Script Rules.

### Execution context

| Object                                                                                                      | Description                                                                            |
| :---------------------------------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------- |
| [Context](/vantage/documentation/skill-designer/document/rule-verification/context)                         | Access the document, fields, catalog records, and skill parameters from inside a rule. |
| [Parameter](/vantage/documentation/skill-designer/document/rule-verification/parameter)                     | A parameter value.                                                                     |
| [SkillParameter](/vantage/documentation/skill-designer/document/rule-verification/skill-parameter)          | A skill parameter value.                                                               |
| [SkillParameterType](/vantage/documentation/skill-designer/document/rule-verification/skill-parameter-type) | Enumeration of the possible skill parameter types.                                     |

### Document structure

| Object                                                                                   | Description                                                                                            |
| :--------------------------------------------------------------------------------------- | :----------------------------------------------------------------------------------------------------- |
| [Document](/vantage/documentation/skill-designer/document/rule-verification/document)    | The document being processed, including its pages, source files, and the skill applied to it.          |
| [Page](/vantage/documentation/skill-designer/document/rule-verification/page)            | A single document page.                                                                                |
| [Field](/vantage/documentation/skill-designer/document/rule-verification/field)          | A document field, with properties and methods for inspecting and modifying it during rule execution.   |
| [FieldType](/vantage/documentation/skill-designer/document/rule-verification/field-type) | Enumeration of available field types and the data types each supports.                                 |
| [DataType](/vantage/documentation/skill-designer/document/rule-verification/data-type)   | Enumeration of data types a field can contain. Includes the `AmountOfMoney` class for currency values. |

### Image regions

| Object                                                                                                | Description                                                      |
| :---------------------------------------------------------------------------------------------------- | :--------------------------------------------------------------- |
| [ImageRegionList](/vantage/documentation/skill-designer/document/rule-verification/image-region-list) | A list of field regions on an image.                             |
| [ImageRegion](/vantage/documentation/skill-designer/document/rule-verification/image-region)          | A single field region, which may consist of multiple rectangles. |
| [RectangleList](/vantage/documentation/skill-designer/document/rule-verification/rectangle-list)      | A list of rectangle areas on an image.                           |
| [Rectangle](/vantage/documentation/skill-designer/document/rule-verification/rectangle)               | A rectangular area on an image. Coordinates are in pixels.       |
| [Symbol](/vantage/documentation/skill-designer/document/rule-verification/symbol)                     | A character within the initial text value of a field.            |

### Data and transactions

| Object                                                                                      | Description                                                               |
| :------------------------------------------------------------------------------------------ | :------------------------------------------------------------------------ |
| [Record](/vantage/documentation/skill-designer/document/rule-verification/record)           | A single row from a data catalog, returned by `Context.GetCatalogRecord`. |
| [Transaction](/vantage/documentation/skill-designer/document/rule-verification/transaction) | Transaction parameters for the current run.                               |
| [SourceFile](/vantage/documentation/skill-designer/document/rule-verification/source-file)  | A source file used as input.                                              |

## Related topics

<CardGroup cols={3}>
  <Card title="Business rules automation" icon="code" href="/vantage/documentation/skill-designer/document/rule-verification/business-rules-automation">
    Add scripted rules to a Document skill, configure readable and writable fields, and reference table columns.
  </Card>

  <Card title="Rule verification" icon="circle-check" href="/vantage/documentation/skill-designer/document/rule-verification/rule-verification">
    Use rules to validate, modify, or compute extracted field values in a Document skill.
  </Card>

  <Card title="Sample scripts" icon="file-code" href="/vantage/documentation/skill-designer/document/rule-verification/sample-scripts">
    Working JavaScript samples for common Advanced Script Rule scenarios.
  </Card>
</CardGroup>