Welcome to Elysia

It’s great to have you here! This playground will help you get started with Elysia interactively.

Unlike traditional backend frameworks, Elysia can run in a browser! Although it doesn’t support all features, it’s a perfect environment for learning and experimentation.

You can open the API docs at any time with the Docs tab at the top of this pane, or by clicking a link in the text.

What is Elysia

Elysia is an ergonomic framework for humans.

Ok, seriously, Elysia is a backend TypeScript framework that focuses on developer experience and performance.

What makes Elysia different from other frameworks is:

Spectacular performance comparable to Golang.
Extraordinary TypeScript support with type soundness.
Built around OpenAPI from the ground up.
Offers End-to-end Type Safety like tRPC.
Uses Web Standards, allowing you to run your code anywhere like Cloudflare Workers, Deno, Bun, Node.js and more.
It is, of course, designed for humans first.

Although Elysia has some framework-specific concepts to learn, once users get the hang of it, many find it very enjoyable and intuitive to work with.

How to use this playground

Playground is divided into 3 sections:

Documentation and task on the left side (what you’re currently reading).
Code editor in the top right
Preview, output, and console in the bottom right

Assignment

For the first assignment, let’s modify the code to make the server respond with "Hello Elysia!" instead of "Hello World!".

Feel free to look around the code editor and preview section to get familiar with the environment.

Assignments

0 of 1 assignments passed

Return "Hello Elysia!"
Not passed yet
Modify the code to make the server respond with "Hello Elysia!" instead of "Hello World!".

You can change the response by changing the content inside the .get method from 'Hello World!' to 'Hello Elysia!'.

import { Elysia } from 'elysia'

new Elysia()
  .get('/', 'Hello World!')
  .get('/', 'Hello Elysia!')
  .listen(3000)

Now Elysia will respond with "Hello Elysia!" when you access /.

One sec, warming things up…

Return "Hello Elysia!"