ElysiaJS

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Quick Start ​

Elysia is optimized for Bun which is a JavaScript runtime that aims to be a drop-in replacement for Node.js.

You can install Bun with the command below:

bash
curl https://bun.sh/install | bash

Automatic Installation ​

We recommend starting a new Elysia server using bun create elysia, which sets up everything automatically.

bash
bun create elysia app

Once done, you should see the folder name app in your directory.

bash
cd app

Start a development server by:

bash
bun dev

Navigate to localhost:3000 should greet you with "Hello Elysia".

TIP

Elysia ships you with dev command to automatically reload your server on file change.

Manual Installation ​

To manually create a new Elysia app, install Elysia as a package:

typescript
bun add elysia
bun add -d @types/bun

This will install Elysia and Bun type definitions.

Open your package.json file and add the following scripts:

json
{
  "scripts": {
    "dev": "bun --watch src/index.ts",
    "build": "bun build src/index.ts --target bun --outdir ./dist",
    "start": "NODE_ENV=production bun dist/index.js",
    "test": "bun test"
  }
}

These scripts refer to the different stages of developing an application:

  • dev - Start Elysia in development mode with auto-reload on code change.
  • build - Build the application for production usage.
  • start - Start an Elysia production server.

If you are using TypeScript, make sure to create, and update tsconfig.json to include compilerOptions.strict to true:

json
{
  "compilerOptions": {
    "strict": true
  }
}

Structure ​

Here's the recommended file structure for Elysia if you don't strictly prefer a specific convention:

  • src - Any file that associate with development of Elysia server.
    • index.ts - Entry point for your Elysia server, ideal place for setting global plugin
    • setup.ts - Composed of various plugins to be used as a Service Locator
    • controllers - Instances which encapsulate multiple endpoints
    • libs - Utility functions
    • models - Data Type Objects (DTOs) for Elysia instance
    • types - Shared TypeScript type if needed
  • test - Test file for Elysia server