--- url: 'https://adk.nht.io/api/@nhtio/adk/exceptions/classes/ValidationException.md' description: Thrown when input fails schema validation. --- # Class: ValidationException Defined in: [lib/utils/validation.ts:69](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/utils/validation.ts#L69) Thrown when input fails schema validation. ## Remarks Carries the full `details` array from the underlying `ValidationError` so callers can surface field-level messages without unwrapping the `cause` manually. ## Extends * [`BaseException`](../../factories/classes/BaseException.md) ## Constructors ### Constructor ```ts new ValidationException(reason: ValidationError): ValidationException; ``` Defined in: [lib/utils/validation.ts:81](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/utils/validation.ts#L81) #### Parameters | Parameter | Type | Description | | --------- | ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `reason` | `ValidationError` | The `ValidationError` thrown by the schema; its `details` are surfaced directly on this exception and its messages are joined to form the human-readable message. | #### Returns `ValidationException` #### Overrides [`BaseException`](../../factories/classes/BaseException.md).[`constructor`](../../factories/classes/BaseException.md#constructor) ## Properties | Property | Modifier | Type | Default value | Description | Overrides | Inherited from | Defined in | | ---------------------------------------- | ---------- | ----------------------- | ------------------------ | --------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- | | `code?` | `public` | `string` | `undefined` | Machine-readable error code for narrowing exception-handling logic. | - | [`BaseException`](../../factories/classes/BaseException.md).[`code`](../../factories/classes/BaseException.md#property-code) | [lib/classes/base\_exception.ts:78](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L78) | | `details?` | `readonly` | `ValidationErrorItem`\[] | `undefined` | The raw field-level error details from the underlying `ValidationError`. | - | - | [lib/utils/validation.ts:75](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/utils/validation.ts#L75) | | `fatal?` | `public` | `boolean` | `undefined` | When `true`, the ADK treats this error as unrecoverable and should halt the agent loop. | - | [`BaseException`](../../factories/classes/BaseException.md).[`fatal`](../../factories/classes/BaseException.md#property-fatal) | [lib/classes/base\_exception.ts:88](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L88) | | `help?` | `public` | `string` | `undefined` | Human-readable guidance for resolving or reporting this error. | - | [`BaseException`](../../factories/classes/BaseException.md).[`help`](../../factories/classes/BaseException.md#property-help) | [lib/classes/base\_exception.ts:73](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L73) | | `name` | `public` | `string` | `undefined` | Name of the class that raised the exception. | - | [`BaseException`](../../factories/classes/BaseException.md).[`name`](../../factories/classes/BaseException.md#property-name) | [lib/classes/base\_exception.ts:68](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L68) | | `status?` | `public` | `number` | `undefined` | HTTP status code associated with this error. | - | [`BaseException`](../../factories/classes/BaseException.md).[`status`](../../factories/classes/BaseException.md#property-status) | [lib/classes/base\_exception.ts:83](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L83) | | `code` | `static` | `string` | `'VALIDATION_EXCEPTION'` | Default machine-readable error code inherited by all instances. | [`BaseException`](../../factories/classes/BaseException.md).[`code`](../../factories/classes/BaseException.md#property-code-1) | - | [lib/utils/validation.ts:71](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/utils/validation.ts#L71) | | `fatal` | `static` | `boolean` | `false` | Whether exceptions of this class are fatal by default. | [`BaseException`](../../factories/classes/BaseException.md).[`fatal`](../../factories/classes/BaseException.md#property-fatal-1) | - | [lib/utils/validation.ts:72](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/utils/validation.ts#L72) | | `help?` | `static` | `string` | `undefined` | Default help text inherited by all instances unless overridden at the throw site. | - | [`BaseException`](../../factories/classes/BaseException.md).[`help`](../../factories/classes/BaseException.md#property-help-1) | [lib/classes/base\_exception.ts:47](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L47) | | `message?` | `static` | `string` | `undefined` | Default message used when no message is supplied to the constructor. | - | [`BaseException`](../../factories/classes/BaseException.md).[`message`](../../factories/classes/BaseException.md#property-message) | [lib/classes/base\_exception.ts:63](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L63) | | `status` | `static` | `number` | `422` | Default HTTP status code inherited by all instances. | [`BaseException`](../../factories/classes/BaseException.md).[`status`](../../factories/classes/BaseException.md#property-status-1) | - | [lib/utils/validation.ts:70](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/utils/validation.ts#L70) | ## Accessors ### \[toStringTag] #### Get Signature ```ts get toStringTag: string; ``` Defined in: [lib/classes/base\_exception.ts:130](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L130) ##### Returns `string` #### Inherited from [`BaseException`](../../factories/classes/BaseException.md).[`[toStringTag]`](../../factories/classes/BaseException.md#tostringtag) ## Methods ### toString() ```ts toString(): string; ``` Defined in: [lib/classes/base\_exception.ts:134](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L134) Returns a string representation of an object. #### Returns `string` #### Inherited from [`BaseException`](../../factories/classes/BaseException.md).[`toString`](../../factories/classes/BaseException.md#tostring) *** ### isBaseException() ```ts static isBaseException(value: unknown): value is BaseException; ``` Defined in: [lib/classes/base\_exception.ts:29](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/classes/base_exception.ts#L29) Returns `true` if `value` is a [BaseException](../../factories/classes/BaseException.md) instance. #### Parameters | Parameter | Type | Description | | --------- | --------- | ------------------ | | `value` | `unknown` | The value to test. | #### Returns `value is BaseException` `true` when `value` is a [BaseException](../../factories/classes/BaseException.md) instance. #### Remarks Performs cross-realm-safe detection: tries `instanceof`, then `Symbol.hasInstance`, then constructor-name comparison. The ADK does not export the `BaseException` class itself as a constructable value — use this guard plus the [BaseException](../../factories/classes/BaseException.md) type for runtime detection and TypeScript narrowing. #### Inherited from [`BaseException`](../../factories/classes/BaseException.md).[`isBaseException`](../../factories/classes/BaseException.md#isbaseexception)