# ValidationPipeOptions

**Kind:** Interface

**Source:** [`packages/common/pipes/validation.pipe.ts`](https://github.com/nestjs/nest/blob/master/packages/common/pipes/validation.pipe.ts#L26)

**Part of:** [Common](subsystem-packages-common)

`ValidationPipeOptions` configures how NestJS's `ValidationPipe` validates incoming request data and transforms payloads into typed DTO instances. It controls validation behavior, error responses, class-transformer integration, and optional custom validator or transformer package implementations.

## Properties

| Property | Type |
|---|---|
| `transform` | `boolean` |
| `disableErrorMessages` | `boolean` |
| `transformOptions` | `ClassTransformOptions` |
| `errorHttpStatusCode` | `ErrorHttpStatusCode` |
| `exceptionFactory` | `(errors: ValidationError[]) => any` |
| `validateCustomDecorators` | `boolean` |
| `expectedType` | `Type<any>` |
| `validatorPackage` | `ValidatorPackage` |
| `transformerPackage` | `TransformerPackage` |

## Diagram

```mermaid
graph LR
  Request[Incoming request payload] --> Pipe[ValidationPipe]
  Pipe --> Transform{transform enabled?}
  Transform -- Yes --> DTO[Transform payload to DTO instance]
  Transform -- No --> Validate[Validate raw payload]
  DTO --> Validate
  Validate --> Valid{Validation succeeds?}
  Valid -- Yes --> Handler[Route handler]
  Valid -- No --> Factory[exceptionFactory]
  Factory --> Error[HTTP error response]

  Options[ValidationPipeOptions] --> Pipe
  Options --> Transform
  Options --> Validate
  Options --> Factory
```

## Usage

```ts
import {
  BadRequestException,
  ValidationPipe,
  ValidationError,
} from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);

  app.useGlobalPipes(
    new ValidationPipe({
      transform: true,
      transformOptions: {
        enableImplicitConversion: true,
      },
      disableErrorMessages: false,
      validateCustomDecorators: true,
      exceptionFactory: (errors: ValidationError[]) => {
        return new BadRequestException({
          message: 'Request validation failed',
          errors,
        });
      },
    }),
  );

  await app.listen(3000);
}

bootstrap();
```

## AI Coding Instructions

- Enable `transform` when controllers expect DTO instances or typed primitive conversion, and configure `transformOptions` for behaviors such as implicit conversion.
- Use DTO validation decorators from `class-validator`; set `validateCustomDecorators` when custom decorators must be evaluated by the pipe.
- Provide an `exceptionFactory` when the application requires a consistent validation-error response format.
- Avoid enabling detailed error messages in production when validation errors could expose internal request or DTO details; use `disableErrorMessages` where appropriate.
- Use `validatorPackage` and `transformerPackage` only when integrating compatible custom implementations of `class-validator` or `class-transformer`.