1、安装
下载swagger

npm install --save @nestjs/swagger swagger-ui-express

按照官网的介绍进行配置
main.ts文件

import { NestFactory } from '@nestjs/core';
import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
import { AppModule } from './app.module';

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

  const config = new DocumentBuilder()
   // 标题
    .setTitle('NestJs博客API')
    // 描述
    .setDescription('我的第一个NestJs项目')
    // 版本
    .setVersion('1.0')
    //标签
    .addTag('cats')
    .build();
  const document = SwaggerModule.createDocument(app, config);
   // 接口文档路径
  SwaggerModule.setup('api-docs', app, document);
  // 监听端口号3000
  await app.listen(3000);
}
bootstrap();

2、添加标签

import { Controller, Get, Post } from '@nestjs/common';
import { ApiOperation, ApiTags } from '@nestjs/swagger';

@Controller('posts')
//添加标签
@ApiTags('帖子')
export class PostsController {
  @Get()
  //添加描述
  @ApiOperation({summary:'显示博客列表'})
  index() {
    return [
      {id:1111},
      {id:13},
      {id:14},
      {id:1},
      {id:37},
      {id:26},
    ];
  }

  @Post()
  create(){
    return{
      success:true
    }
  }

  @Get(':id')
  detail(){
    return{
      id:1,
      title:'aaaaa'
    }
  }
}