Elysia - Ergonomic Framework for Humans

Elysia is an ergonomic framework for Humans.
With end‑to‑end type safety and great developer experience.
Elysia is familiar, fast, and has first‑class TypeScript support with well‑thought integration between services whether it’s tRPC, Swagger or WebSocket.

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See why developers love Elysia

The first production ready, and most loved Bun framework

Trusted by team at

• X / Twitter – using Elysia for Jetfuel
• CS Money – high RPS
• Tiptap – moved from Hono Node to Elysia Bun
• Bank for Agriculture and Agricultural Cooperatives Thailand – internal website
• Abacatepay – stripe alternative
• ConnexTickets – performance improvement
• Decidable – Business Intelligence platform

Made for Humans

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)

Summary

Benchmark

Measured in requests/second. Result from https://www.techempower.com/benchmarks/#hw=ph&test=plaintext§ion=data-r22 Round 22 (2023‑10‑17).

Your code, your runtime

• Elysia is optimized for Bun but not vendor‑lock‑in.
• Built on Web‑Standard – run Elysia anywhere.

Type Safety

Best in Class – Type Safety

import { Elysia, t } from 'elysia'

new Elysia()
	.post('/user', ({ body }) => {
		return body, {
			body: t.Object({
				name: t.Literal('SaltyAom'),
				age: t.Number(),
				friends: t.Array(t.String())
			})
		}
	})

Bring your own Validator

Elysia offers a built‑in validator, but you can also bring your favorite validator, like Zod, Valibot, ArkType, Effect, and more.

Code examples

TypeBox

import { Elysia, t } from 'elysia'

new Elysia()
	.post('/user', ({ body }) => {
		return body, {
			body: t.Object({
				name: t.Literal('SaltyAom'),
				age: t.Number(),
				friends: t.Array(t.String())
			})
		}
	})

Zod

import { Elysia } from 'elysia'
import { z } from 'zod'

new Elysia()
	.post('/user', ({ body }) => {
		return body, {
			body: z.object({
				name: z.literal('SaltyAom'),
				age: z.number(),
				friends: z.array(z.string())
			})
		}
	})

Valibot

import { Elysia } from 'elysia'
import { validator } from '@valibot/valibot'

new Elysia()
	.post('/user', ({ body }) => {
		return body, {
			body: validator({
				name: validator.string().equals('SaltyAom'),
				age: validator.number(),
				friends: validator.array(validator.string())
			})
		}
	})

ArkType

import { Elysia } from 'elysia'
import { z } from 'arktype'

new Elysia()
	.post('/user', ({ body }) => {
		return body, {
			body: z({
				name: 'SaltyAom',
				age: z.number(),
				friends: z.string().array()
			})
		}
	})

Effect

import { Elysia } from 'elysia'
import { t } from '@effect/schema/Schema'

new Elysia()
	.post('/user', ({ body }) => {
		return body, {
			body: t.struct({
				name: t.literal('SaltyAom'),
				age: t.number,
				friends: t.array(t.string)
			})
		}
	})

Other Sections (placeholders for the rest of the page)

• Further documentation, tutorials, API reference, and advanced features would follow in the same format, with headings, paragraphs, code blocks, and interactive snippets converted into Markdown.