NestJS main.ts

This bootstrap registers Query Kit's query parser, structured fields errors, validation, and Swagger documentation in a Nest application.

import { ValidationPipe } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
import { FieldsExceptionFilter, QueryTransformPipe } from '@querry-kit/nest';
import { AppModule } from './app.module.js';

async function bootstrap(): Promise<void> {
  const app = await NestFactory.create(AppModule);

  app.useGlobalPipes(
    new QueryTransformPipe(),
    new ValidationPipe({
      transform: true,
      whitelist: true,
      forbidNonWhitelisted: true,
    }),
  );

  app.useGlobalFilters(new FieldsExceptionFilter());

  const config = new DocumentBuilder()
    .setTitle('Books API')
    .setDescription('Example API using @querry-kit/nest resource queries and fields projection.')
    .setVersion('1.0.0')
    .addBearerAuth()
    .build();

  const document = SwaggerModule.createDocument(app, config);
  SwaggerModule.setup('docs', app, document, {
    swaggerOptions: {
      persistAuthorization: true,
    },
  });

  const port = Number(process.env.PORT ?? 3000);
  await app.listen(port);
}

void bootstrap();

Notes

QueryTransformPipe normalizes query strings before DTO validation and service calls.
ValidationPipe handles DTO validation and transformation.
FieldsExceptionFilter serializes invalid fields query values as structured HTTP 400 responses.
SwaggerModule.createDocument works with ApiPaginatedResponse, ApiErrorResponses, and the DTO metadata used by fields schema generation.
Configure PORT when the application should listen on a port other than 3000.