Elysia
A TypeScript web framework for building HTTP servers, designed to run on Bun.
- Stars
- 19.3k
- Forks
- 611
- Licence
- MIT
- Language
- TypeScript
- Last update
- 8 days ago
- Type
- Framework
What it is
Elysia is a TypeScript framework for building web servers and HTTP APIs. Its README emphasizes end-to-end type safety and a developer-friendly experience, and says it is built to run on the Bun JavaScript runtime. Developers use it to define routes and handlers in TypeScript with types shared across the code.
- Build a JSON HTTP API with typed routes
- Create a small web server with TypeScript handlers
- Share types between a server and a frontend client
Great for
- TypeScript developers building HTTP APIs or web servers
- Teams already using or willing to adopt the Bun runtime
- Projects that want type safety shared between server and client code
Not ideal for
- Developers who need to run on Node.js only, since the README ties the framework to Bun and this is not verified here
- Beginners new to both TypeScript and backend development, who may find the setup and concepts a lot to learn at once
- Projects that need a long track record of stability, given the pre-2.0 version number in the latest release
How to get it
- 1
Install with a package manager
You'll need: Bun
Create a new app with the Elysia template
bun create elysia app - 2
Run it
- Install Bun following its own instructions
- Run bun create elysia app to scaffold a project
- Follow the prompts and start the dev server as the generated project instructs
- Read the documentation at elysiajs.com for the first route
- 3
Get the most out of it
- Use the official documentation at elysiajs.com for routing, validation and plugin details
- Join the Discord community linked in the README for questions
- Check the GitHub sponsors and contributing guide if you want to contribute
Downloads
Strengths
- Written in TypeScript with a focus on end-to-end type safety
- Documentation is hosted separately at elysiajs.com with links from the README
- Active project with a recent push and an MIT license
Trade-offs
- The README is short and defers most detail to external documentation
- Positioned around the Bun runtime, which limits the setup choices
- Some README claims, such as performance comparisons, are only summarized in a hidden image and are not verified here
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| elysia (this) | 19.3k | Framework | intermediate | 8 days ago | TypeScript developers building HTTP APIs or web servers |
| hono | 32.8k | Library | beginner | 5 days ago | Developers writing TypeScript or JavaScript HTTP APIs |
| fastify | 37.3k | Library | beginner | 4 days ago | Node.js developers building JSON APIs or backend services |
| express | 69.6k | Framework | intermediate | 4 days ago | Developers building JavaScript or Node.js back-end servers |
| trpc | 40.8k | Library | intermediate | 4 days ago | TypeScript teams building a web app where the frontend and backend are both written in TypeScript |
| vapor | 26.2k | Library | intermediate | 4 days ago | Swift developers who want to build backend services in the same language as their iOS or macOS apps |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.