Lesson 14 / 33

Custom Decorators

Create your own decorators for reusable parameter or class-level logic.

Parameter decorator

Extract specific values from the request using a custom decorator.

import { createParamDecorator, ExecutionContext } from '@nestjs/common';

export const User = createParamDecorator(
  (data: unknown, ctx: ExecutionContext) => {
    const request = ctx.switchToHttp().getRequest();
    return request.user;
  }
);

// usage
@Get('profile')
getProfile(@User() user) {
  return user;
}

Method decorator

Mark methods with custom logic—e.g. @Public() to skip guards, or @Roles() for role-based access.

export const Public = () => SetMetadata('isPublic', true);
export const Roles = (...roles: string[]) => SetMetadata('roles', roles);

@Public()
@Get('health')
health() {
  return { status: 'ok' };
}