Getting Started

Install

bun add nestjs-platform-elysia @nestjs/common @nestjs/core elysia

For CORS:

bun add @elysiajs/cors

For WebSocket gateways:

bun add @nestjs/websockets

Bootstrap

import { NestFactory } from '@nestjs/core';
import { ElysiaAdapter, type NestElysiaApplication } from 'nestjs-platform-elysia';
import { AppModule } from './app.module';

async function bootstrap() {
  const app = await NestFactory.create<NestElysiaApplication>(
    AppModule,
    new ElysiaAdapter(),
  );

  app.enableCors();

  await app.listen(3000);
}

bootstrap();

That’s it. Write controllers and providers exactly as you would in a normal NestJS app — guards, pipes, interceptors, exception filters all flow through the same pipeline.

A minimal controller

import { Body, Controller, Get, Param, ParseIntPipe, Post } from '@nestjs/common';

@Controller('cats')
export class CatsController {
  @Get()
  list() {
    return [{ id: 1, name: 'Mia' }];
  }

  @Get(':id')
  one(@Param('id', ParseIntPipe) id: number) {
    return { id, name: 'Mia' };
  }

  @Post()
  create(@Body() body: { name: string }) {
    return { id: 2, name: body.name };
  }
}

What you get for free

Full Nest DI, modules, guards, pipes, interceptors, exception filters
HTTP method coverage including WebDAV verbs (PROPFIND, PROPPATCH, MKCOL, etc.)
URI / Header / Media-Type / Custom versioning via app.enableVersioning(...)
CORS via app.enableCors() (lazy-loads @elysiajs/cors)
MiddlewareConsumer.apply().forRoutes() Express-style middleware
app.inject(new Request(...)) for testing without binding a port
app.register(plugin) to mount Elysia plugins (e.g. swagger(), bearer())
app.mount(path, fetchHandler) to mount sub-apps

Continue with Route Decorators to see how to attach Elysia schemas and lifecycle hooks to your controller methods.