import { IsString, MaxLength } from 'class-validator'; import { ApiProperty } from '@nestjs/swagger'; export class HeartbeatDto { @ApiProperty({ example: 'inst_abc123', maxLength: 128 }) @IsString() @MaxLength(128) installId: string; @ApiProperty({ example: '1.2.0', maxLength: 32 }) @IsString() @MaxLength(32) appVersion: string; }