nestjs-platform-elysia

NestJS HTTP adapter for Elysia on Bun.

📚 Full documentation →

⚠️ Bun runtime only. Elysia uses Bun.serve() internally and does not run on Node.js.

Why

NestJS gives you DI, modules, guards, pipes, interceptors, exception filters. Elysia gives you Bun-native performance, end-to-end type safety, TypeBox/Zod validation at the framework level, lifecycle hooks, and a plugin ecosystem.

This adapter lets you keep both: write Nest controllers as usual while still being able to register Elysia plugins, attach TypeBox schemas, mount sub-apps, and use app.handle() for testing — without losing what makes Elysia worth choosing.

Install

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

Quick start

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

const app = await NestFactory.create<NestElysiaApplication>(
  AppModule,
  new ElysiaAdapter(),
);
await app.listen(3000);

Guides

| Guide | What's inside | |---|---| | Getting Started | Install, bootstrap, project layout | | Route Decorators | @RouteSchema, @RouteHook, @RouteConfig, @RouteDetail | | Body Parsing | rawBody, custom parsers, size limits | | Server-Sent Events | @Sse() over Web Streams, backpressure, disconnects | | File Uploads | Native multipart, @UploadedFile(), @UploadedFiles() | | Static Assets | useStaticAssets(), Range requests, traversal protection | | Trust Proxy | X-Forwarded-* resolution, Express-compatible hop count | | WebSockets | @WebSocketGateway on the same Bun server, hardening config | | Testing | app.inject() patterns, fixtures | | API Reference | Adapter, request, reply, interfaces |

What's supported

• All HTTP methods, route params, query, body, default status codes
• Full Nest pipeline: Guards, Pipes, Interceptors, Exception Filters
• @RouteSchema with TypeBox/Zod for framework-level validation
• Versioning: URI, Header, Media-Type, Custom
• CORS via @elysiajs/cors
• MiddlewareConsumer.apply().forRoutes() (Express-style middleware)
• Server-Sent Events (@Sse()) streamed over Web Streams, with client-disconnect cleanup
• File uploads via native multipart — @Body(), @UploadedFile(), @UploadedFiles() yield Web File objects (no multer)
• Static file serving via useStaticAssets(root, { prefix }), backed by Bun.file with path-traversal protection
• Hybrid apps: HTTP server + Nest microservices (TCP validated)
• app.register(plugin) for Elysia plugins (swagger, bearer, openapi, etc.)
• app.mount(path, handler) for sub-apps and fetch handlers
• app.inject(Request) for programmatic testing
• WebSocket gateways on the same Bun server (no second port)

Known limitations

• setViewEngine() / @Render() — not implemented (no SSR templating support).
• @Req() / @Res() — receive ElysiaRequest / ElysiaReply wrappers, not Express request/response. Express-only APIs like .is(), .accepts(), .signedCookies are not exposed.
• Microservice transports are runtime-dependent — each transport must support Bun (TCP validated; others untested).

Versioning

Pre-1.0. APIs may change between minor versions. See CHANGELOG.md.

Releasing

Releases are cut by pushing a v*.*.* tag — see .github/workflows/release.yml. The workflow runs bun run check, verifies the tag matches package.json#version, publishes to npm via OIDC Trusted Publishing with provenance, and creates a GitHub Release.

License

MIT