> Source: https://builder-docs.ema.ai/agent-reference/core/rule-validation
> Title: Rule Validation Agent

# Rule Validation Agent

The Rule Validation agent validates documents or data against a defined set of rules. Each rule is evaluated independently, and the agent returns a pass/fail result for each rule along with an overall verdict.

## Use Cases

-   You need to check whether a document or dataset complies with a set of business rules.
-   A compliance workflow requires systematic rule-by-rule evaluation.
-   You want structured pass/fail output for auditing purposes.

## Inputs

Input

Type

Description

`document`

Document

The document to validate against the rules.

`text`

Text

(Alternative) Plain text to validate.

`data`

JSON

(Alternative) Structured data to validate.

## Outputs

Output

Type

Description

`overall_result`

Boolean

`true` if all rules pass, `false` if any rule fails.

`rule_results`

JSON

Per-rule results with rule name, pass/fail, and explanation.

## Configurations

Parameter

Description

Default

`rules`

List of rules to evaluate. Each rule has a name, description, and evaluation criteria.

Required

`fail_on_any`

Whether to fail the overall result if any single rule fails.

`true`

### Deterministic Validation

The Rule Validation agent supports **deterministic validation** -- conditions that evaluate extracted data against rules without using an LLM. This is useful for exact checks like "does the PO amount match the invoice amount?" or "is the date within range?" You can define deterministic validations in two modes:

#### Condition Mode

A visual rule builder where you define conditions using extracted variables:

-   **LHS (Data field)** -- reference extracted fields using double curly braces: `{{field_name}}`. Chain methods on fields: `{{field_name}}.method1(arg1).method2(arg2)`.
-   **Operator** -- compatible operators are shown based on the field type.
-   **RHS (Value)** -- a fixed value, another variable, or a static function like `$now()`.

Examples:

```
{{PO Amount}} == {{Invoice Amount}}
{{Invoice Date}}.plus(30, "days") > $now()
{{Vendor Name}}.lower() == "acme corp"
{{PO Quantity}} >= {{Invoice Quantity}}
```

> [INFO]
> Currently, you can chain conditions with either ANDs or ORs, but not both in the same rule.

**Supported operators by type:**

Type

Operators

Boolean

`==`, `!=`

Number

`==`, `!=`, `>`, `>=`, `<`, `<=`, `in`, `not in`

String

`==`, `!=`, `substring`, `not substring`, `contains substring`, `does not contain substring`, `in`, `not in`, `substring in any of`, `substring not in any of`

Datetime

`>`, `>=`, `<`, `<=`, `in`, `not in`

**Available functions:**

Function

Returns

Description

`$now()`

Datetime

Current date and time

`.day()`

Number

Day of the month (1-31)

`.month()`

Number

Month of the year (1-12)

`.year()`

Number

The year

`.hour()`

Number

Hour of the day (0-23)

`.plus(n, interval)`

Datetime

Adds a duration (seconds, minutes, hours, days, weeks, months, years)

`.minus(n, interval)`

Datetime

Subtracts a duration

`.plus(n)` (number)

Number

Adds n to the number

`.minus(n)` (number)

Number

Subtracts n from the number

`.lower()`

String

Converts to lowercase

#### Code Mode

For more complex validation logic, switch to the Code tab for a JavaScript editor:

-   Extracted fields are available as `inputs.field_name`.
-   For **boolean** rules: return `"true"` or `"false"` as a string.
-   For **numerical** rules: return a number.
-   Use `log.info()`, `log.warning()`, or `log.error()` for Show Work visibility.

```javascript
// Boolean validation with tolerance
function main(inputs) {
 var poAmount = inputs.PO_Amount;
 var invoiceAmount = inputs.Invoice_Amount;

 if (poAmount === undefined || invoiceAmount === undefined) {
 log.warning("Missing amount fields");
 return "false";
 }

 var tolerance = 0.01;
 var passed = Math.abs(poAmount - invoiceAmount) <= tolerance;
 log.info(passed ? "Amounts match" : "Mismatch: PO=" + poAmount + ", Invoice=" + invoiceAmount);
 return passed ? "true" : "false";
}
```

```javascript
// Numerical scoring
function main(inputs) {
 var score = 0;

 if (inputs.PO_Amount === inputs.Invoice_Amount) score += 40;
 if (inputs.PO_Quantity === inputs.Invoice_Quantity) score += 30;
 if (inputs.PO_Unit_Price === inputs.Invoice_Unit_Price) score += 30;

 log.info("Validation score: " + score);
 return score;
}
```

## How to Use This Agent

Validate an insurance claim document against policy rules:

```
document_trigger -> rule_validation -> [pass] -> intelligent_actions("Approve claim")
 -> [fail] -> human_collaboration -> workflow_output
```

## Related Agents

-   [Response Validator](/legacy-docs/agent-reference/core/response-validator) -- for validating AI-generated responses specifically.
-   [Extract Entities](/legacy-docs/agent-reference/core/extract-entities) -- for extracting data from documents before rule validation.
-   [Custom Code Agent](/legacy-docs/agent-reference/core/custom-code-agent) -- for standalone JavaScript logic outside of rule validation context.