The first production ready,
and most loved Bun framework
Our Principle
Design for Humans
Our goal is to design an ergonomic, sensible, and productive framework that even beginners can use easily
Designed to avoid unnecessary complexity and type complexity for you to focus on building
A framework that feels just like JavaScript
import { Elysia, file } from 'elysia'
new Elysia()
.get('/', 'Hello World')
.get('/image', file('mika.webp'))
.get('/stream', function* () {
yield 'Hello'
yield 'World'
})
.ws('/realtime', {
message(ws, message) {
ws.send('got:' + message)
}
})
.listen(3000)The Next Level of Type Safety
import { Elysia } from 'elysia'
new Elysia()
.get('/id/:id', ({ params, set }) => {
set.headers.a
return 'Su'
})
.get('/optional/:name?', ({ params: { name } }) => {
return name ?? 'Pardofelis'
})
.listen(3000)Your own documentation in 1 line
It's not magic
With deep integration with OpenAPI schema
Elysia can generate Swagger documentation for your API out of the box
import { Elysia } from 'elysia'
import swagger from '@elysiajs/swagger'
new Elysia()
.use(swagger())
.use(character)
.use(auth)
.listen(3000)11.88ms
POST /character/:id/chat
Playback
For DevOps
OpenTelemetry
Elysia has 1st party support for OpenTelemetry. Instrumentation is built-in, so you can easily monitor your services on regardless of the platform.
import { treaty } from '@elysiajs/eden'
import type { App } from './server'
const api = treaty<App>('api.elysiajs.com')
const { data } = await api.profile.patch({
age: 21
})For Frontend
End-to-end Type Safety
Like tRPC, Elysia provides type-safety from the backend to the frontend without code generation. The interaction between frontend and backend is type-checked at compile time.
21x
faster than Express
6x
faster than Fastify
Elysia Bun
2,454,631 reqs/sGin Go
676,019
Spring Java
506,087
Fastify Node
415,600
Express Node
113,117
Nest Node
105,064
Measured in requests/second. Result from TechEmpower Benchmark Round 22 (2023-10-17) in PlainText
Test with Confidence
Type safe with auto-completion
Elysia provides a type-safe layer to interact with and test your server, from routes to parameters.
With auto-completion, you can easily write tests for the server without any hassle.
import { treaty } from '@elysiajs/eden'
import { app } from './index'
import { test, expect } from 'bun:test'
const server = treaty(app)
test('should handle duplicated user', async () => {
const { error } = await server.user.put({ username: 'mika',
})
expect(error?.value).toEqual({
success: false,
message: 'Username already taken'
})
}) Powered by love
from the community
Aqueel
@AqueelMiq
Jetfuel on bun at X! @shlomiatar who built the framework has an eye for picking the right tools for the job.
Shlomi Atar
@shlomiatar
also a shoutout to @saltyAom and the phenomenal Elysia js that is powering our server driven UI. Incredible work.
htmx.org
@htmx_org
htmx works great w/ @bunjavascript, @elysiaJS and @tursodatabase btw
Marc Laventure
@MarcLaventure
both engineering+monetary contributions are paramount for OSS we proudly sponsor dozens of projects: @elysiaJS @LitestarAPI @honojs @daveshanley @kevin_jahns @MarijnJH & help maintain repos+contribute to OSS at blistering cadence. it's @scalar's ethos to be a catalyst for OSS
Jarred Sumner
@jarredsumner
You can use Express with Bun, but often we see people using Elysia, Hono, or Bun.serve() directly.
Runyasak Ch. 💚
@runyasak
Started using @elysiaJS to create a Discord Bot and found the type system beautifully easy. DX is fantastic and coding is fun! Use @DrizzleORM with PostgreSQL. So much easier than I've used before. ElysiaJS has proved to me that great performance and DX can live together. 😎
Herrington Darkholme
@hd_nvim
Was introduced to @elysiaJS today and it looks pretty solid. end-to-end type safety/guard/swapper are killer features of the modern web! (and it's fast)
scalar.com
@scalar
so excited to be part of the amazing @elysiaJS community!
José Donato 🦋
@josedonato__
handling tables with ~350k rows like it's nothing. Working on allowing @ag_grid server side row model when connecting a custom backend to @openbb_finance Terminal Pro. Backend in @elysiaJS + @bunjsproject.
pilcrowonpaper
@pilcrow
Just in time for Bun 1.0 - Lucia 2.5 now supports @elysiajs out of the box!! You can also use Bun.serve() directly as well. This release also comes with 2 new OAuth providers, Strava and AWS Cognito!
MikroORM
@MikroORM
I've been playing a bit with @bunjavascript and @elysiaJS, need to do a few more tweaks before the release, but next version should work more natively with bun when it comes to TS support detection, e.g. the CLI works without ts-node installed.
Made possible by you
Elysia is not owned by an organization, but is driven by the community.
Elysia development is only possible thanks to your support.
Thank you for making Elysia possible
To summarize
Only the best
for the bold
For builders, inventors, and visionaries
We spent years studying the strengths and weaknesses of JavaScript frameworks, all to deliver an exceptional experience
At the speed of light
Up to 21x faster than Express
Supercharged by Bun,
Elysia is one of top performing JavaScript frameworks
Maximum Type Safety
Dynamic type safety
Built from type to runtime
Elysia learns from your codebase, adapts, and enforces your types
Productive in a reach
The best experience of today
Ergonomically designed for humans, prioritizing DX. No technical nonsense