Getting Started

This guide will get you up and running with your first API in just a few minutes.

Prerequisites

Before we begin, make sure you have:

• Node.js (version 18 or higher), Deno, or Bun - YasuiJS works on all runtimes
• npm, pnpm, yarn, or your preferred package manager
• Basic knowledge of TypeScript

You can check your runtime version with:

node --version  # Node.js
deno --version  # Deno
bun --version   # Bun

This guide uses Node.js, but the same code works on:

• Traditional runtimes: Node.js, Deno, Bun
• Edge runtimes: Cloudflare Workers, Vercel Edge, Netlify Edge, Deno Deploy
• Serverless: AWS Lambda, Vercel Functions, Netlify Functions

Quick Start

Let's create your first YasuiJS API in 3 simple steps.

Step 1: Install YasuiJS

Create a new directory and install YasuiJS:

mkdir my-yasui-api
cd my-yasui-api
npm init -y
npm install yasui
npm install -D typescript @types/node

Step 2: Configure TypeScript

Create a tsconfig.json file:

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "commonjs",
    "strict": true,
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  }
}

Step 3: Create Your First API

Create app.ts:

import yasui, { Controller, Get } from 'yasui';

@Controller('/')
export class AppController {
  @Get('/')
  hello() {
    return { message: 'Hello World!' };
  }
}

yasui.createServer({
  controllers: [AppController]
});

Step 4: Run Your API

Add scripts to your package.json:

{
  "scripts": {
    "build": "tsc",
    "start": "node dist/app.js",
    "dev": "tsc && node dist/app.js"
  }
}

Build and run your API:

npm run dev

Visit http://localhost:3000 and you'll see:

{ "message": "Hello World!" }

Congratulations! You have a working YasuiJS API.

Need Help?

If you encounter any issues:

1. Make sure your tsconfig.json has experimentalDecorators: true
2. Check that you're using the correct import syntax
3. Verify your TypeScript and Node.js versions
4. Look at the console output for detailed error messages