NestJS

Accords NestJS docs:

https://docs.nestjs.com/first-steps#platform

There are two HTTP platforms supported out-of-the-box: express and fastify. You can choose the one that best suits your needs.

• platform-express: Express is a well-known minimalist web framework for node. It's a battle tested, production-ready library with lots of resources implemented by the community. The @nestjs/platform-express package is used by default. Many users are well served with Express, and need take no action to enable it.
• platform-fastify: Fastify is a high performance and low overhead framework highly focused on providing maximum efficiency and speed. Read how to use it here.

The NestJS is platform-agnostic, so we can choose which platform we will use. By default, I always use express but if in your company you use fastify, it's okay too.

So, to add support to NestJS, we have two ways:

Express

index.ts

import { NestFactory } from '@nestjs/core';
import { ExpressAdapter } from '@nestjs/platform-express';
import { LazyFramework } from '@h4ad/serverless-adapter/frameworks/lazy';
import { ExpressFramework } from '@h4ad/serverless-adapter/frameworks/express';
import { AppModule } from './app.module';

async function bootstrap() {
  const nestApp = await NestFactory.create(AppModule, new ExpressAdapter());

  // we need to wait until it initializes
  await nestApp.init();

  // then we get the instance of http adapter, it will be express
  const app = nestApp.getHttpAdapter().getInstance();

  return app;
}

const expressFramework = new ExpressFramework();
// the initialization of nestjs is asynchronous, so you can use the lazy framework.
const framework = new LazyFramework(expressFramework, bootstrap);

export const handler = ServerlessAdapter.new(null)
  .setFramework(framework)
  // continue to set the other options here.
  //.setHandler(new DefaultHandler())
  //.setResolver(new PromiseResolver())
  //.addAdapter(new AlbAdapter())
  //.addAdapter(new SQSAdapter())
  //.addAdapter(new SNSAdapter())
  // after put all methods necessary, just call the build method.
  .build();

Fastify

index.ts

import { NestFactory } from '@nestjs/core';
import { FastifyAdapter } from '@nestjs/platform-fastify';
import { LazyFramework } from '@h4ad/serverless-adapter/frameworks/lazy';
import { FastifyFramework } from '@h4ad/serverless-adapter/frameworks/fastify';
import { AppModule } from './app.module';

async function bootstrap() {
  const nestApp = await NestFactory.create(AppModule, new FastifyAdapter());

  // we need to wait until it initializes
  await nestApp.init();

  // then we get the instance of http adapter, it will be fastify
  const app = nestApp.getHttpAdapter().getInstance();

  return app;
}

const fastifyFramework = new FastifyFramework();
// the initialization of nestjs is asynchronous, so you can use the lazy framework.
const framework = new LazyFramework(fastifyFramework, bootstrap);

export const handler = ServerlessAdapter.new(null)
  .setFramework(framework)
  // continue to set the other options here.
  //.setHandler(new DefaultHandler())
  //.setResolver(new PromiseResolver())
  //.addAdapter(new AlbAdapter())
  //.addAdapter(new SQSAdapter())
  //.addAdapter(new SNSAdapter())
  // after put all methods necessary, just call the build method.
  .build();

tip

Need to deal with CORS? See CorsFramework which helps you to add correct headers.