Status ​

A status code is an indicator of how the server handles the request.

You must have heard of the infamous 404 Not Found when you visit a non-existing page.

That's a status code.

By default, Elysia will return 200 OK for a successful request.

Elysia also returns many other status codes depending on the situation like:

• 400 Bad Request
• 422 Unprocessable Entity
• 500 Internal Server Error

You can also return a status code by returning your response using the status function.

import { Elysia } from 'elysia'

new Elysia()
	.get('/', ({ status }) => status(418, "I'm a teapot"))
	.listen(3000)

The status code can be a number or a string status name. These are equivalent:

status(418, "I'm a teapot")
status("I'm a teapot", "I'm a teapot")

String status names provide TypeScript autocompletion for all valid HTTP statuses.

See Status.

Redirect ​

Similarly, you can also redirect the request to another URL by returning the redirect function.

import { Elysia } from 'elysia'

new Elysia()
	.get('/', ({ redirect }) => redirect('https://elysiajs.com'))
	.listen(3000)

See Redirect.

Headers ​

Unlike status code and redirect, which you can return directly, you might need to set headers multiple times in your application.

That's why instead of returning a headers function, Elysia provides a set.headers object to set headers.

import { Elysia } from 'elysia'

new Elysia()
	.get('/', ({ set }) => {
		set.headers['x-powered-by'] = 'Elysia'

		return 'Hello World'
	})
	.listen(3000)

Because headers represents request headers, Elysia distinguishes between request headers and response headers by prefixing set.headers for response.

See Headers.

Assignment ​

Let's exercise what we have learned.

import { Elysia } from 'elysia'

new Elysia()
	.get('/', ({ status, set }) => {
		set.headers['x-powered-by'] = 'Elysia'

		return status(418, 'Hello Elysia!')
	})
	.get('/docs', ({ redirect }) => redirect('https://elysiajs.com'))
	.listen(3000)