Cheat Sheet
Here are a quick overview for a common Elysia patterns
Hello World
A simple hello world
typescript
import { Elysia } from 'elysia'
new Elysia()
.get('/', () => 'Hello World')
.listen(3000)Custom HTTP Method
Define route using custom HTTP methods/verbs
See Route
typescript
import { Elysia } from 'elysia'
new Elysia()
.get('/hi', () => 'Hi')
.post('/hi', () => 'From Post')
.put('/hi', () => 'From Put')
.route('M-SEARCH', '/hi', () => 'Custom Method')
.listen(3000)Path Parameter
Using dynamic path parameter
See Path
typescript
import { Elysia } from 'elysia'
new Elysia()
.get('/id/:id', ({ params: { id } }) => id)
.get('/rest/*', () => 'Rest')
.listen(3000)Return JSON
Elysia converts response to JSON automatically
See Handler
typescript
import { Elysia } from 'elysia'
new Elysia()
.get('/json', () => {
return {
hello: 'Elysia'
}
})
.listen(3000)Return a file
A file can be return in as formdata response
The response must be a 1-level deep object
typescript
import { Elysia, file } from 'elysia'
new Elysia()
.get('/json', () => {
return {
hello: 'Elysia',
image: file('public/cat.jpg')
}
})
.listen(3000)Header and status
Set a custom header and a status code
See Handler
typescript
import { Elysia } from 'elysia'
new Elysia()
.get('/', ({ set, error }) => {
set.headers['x-powered-by'] = 'Elysia'
return error(418, "I'm a teapot")
})
.listen(3000)Group
Define a prefix once for sub routes
See Group
typescript
import { Elysia } from 'elysia'
new Elysia()
.get("/", () => "Hi")
.group("/auth", app => {
return app
.get("/", () => "Hi")
.post("/sign-in", ({ body }) => body)
.put("/sign-up", ({ body }) => body)
})
.listen(3000)Schema
Enforce a data type of a route
See Validation
typescript
import { Elysia, t } from 'elysia'
new Elysia()
.post('/mirror', ({ body: { username } }) => username, {
body: t.Object({
username: t.String(),
password: t.String()
})
})
.listen(3000)File upload
See Validation#file
typescript
import { Elysia, t } from 'elysia'
new Elysia()
.post('/body', ({ body }) => body, {
body: t.Object({
file: t.File({ format: 'image/*' }),
multipleFiles: t.Files()
})
})
.listen(3000)Lifecycle Hook
Intercept an Elysia event in order
See Lifecycle
typescript
import { Elysia, t } from 'elysia'
new Elysia()
.onRequest(() => {
console.log('On request')
})
.on('beforeHandle', () => {
console.log('Before handle')
})
.post('/mirror', ({ body }) => body, {
body: t.Object({
username: t.String(),
password: t.String()
}),
afterHandle: () => {
console.log("After handle")
}
})
.listen(3000)Guard
Enforce a data type of sub routes
See Scope
typescript
import { Elysia, t } from 'elysia'
new Elysia()
.guard({
response: t.String()
}, (app) => app
.get('/', () => 'Hi')
// Invalid: will throws error, and TypeScript will report error
.get('/invalid', () => 1) )
.listen(3000)Custom context
Add custom variable to route context
See Context
typescript
import { Elysia } from 'elysia'
new Elysia()
.state('version', 1)
.decorate('getDate', () => Date.now())
.get('/version', ({
getDate,
store: { version }
}) => `${version} ${getDate()}`)
.listen(3000)Redirect
Redirect a response
See Handler
typescript
import { Elysia } from 'elysia'
new Elysia()
.get('/', () => 'hi')
.get('/redirect', ({ redirect }) => {
return redirect('/')
})
.listen(3000)Plugin
Create a separate instance
See Plugin
typescript
import { Elysia } from 'elysia'
const plugin = new Elysia()
.state('plugin-version', 1)
.get('/hi', () => 'hi')
new Elysia()
.use(plugin)
.get('/version', ({ store }) => store['plugin-version'])
.listen(3000)Web Socket
Create a realtime connection using Web Socket
See Web Socket
typescript
import { Elysia } from 'elysia'
new Elysia()
.ws('/ping', {
message(ws, message) {
ws.send('hello ' + message)
}
})
.listen(3000)OpenAPI documentation
Create interactive documentation using Scalar (or optionally Swagger)
See swagger
typescript
import { Elysia } from 'elysia'
import { swagger } from '@elysiajs/swagger'
const app = new Elysia()
.use(swagger())
.listen(3000)
console.log(`View documentation at "${app.server!.url}swagger" in your browser`);Unit Test
Write a unit test of your Elysia app
See Unit Test
typescript
// test/index.test.ts
import { describe, expect, it } from 'bun:test'
import { Elysia } from 'elysia'
describe('Elysia', () => {
it('return a response', async () => {
const app = new Elysia().get('/', () => 'hi')
const response = await app
.handle(new Request('http://localhost/'))
.then((res) => res.text())
expect(response).toBe('hi')
})
})Custom body parser
Create custom logic for parsing body
See Parse
typescript
import { Elysia } from 'elysia'
new Elysia()
.onParse(({ request, contentType }) => {
if (contentType === 'application/custom-type')
return request.text()
})GraphQL
Create a custom GraphQL server using GraphQL Yoga or Apollo
See GraphQL Yoga
typescript
import { Elysia } from 'elysia'
import { yoga } from '@elysiajs/graphql-yoga'
const app = new Elysia()
.use(
yoga({
typeDefs: /* GraphQL */`
type Query {
hi: String
}
`,
resolvers: {
Query: {
hi: () => 'Hello from Elysia'
}
}
})
)
.listen(3000)Contributors
saltyaom
macabeus
Dale Seo
Anthony Morris
Suvan Gowri Shanker
Jevon Thompson
andi hakim arif
Tom Zaiger
bogeychan
Kitpipat Jaritwong
Mousa Aboubaker