Getting Started

Getting Started with ARO

This guide walks you through installing ARO and creating your first application.

Installation

Prerequisites

• macOS 13.0+ or Linux
• Swift 6.0 or later

Building from Source

git clone https://github.com/KrisSimon/aro.git
cd aro
swift build -c release
sudo cp .build/release/aro /usr/local/bin/

Your First ARO Application

Step 1: Create a Project Directory

mkdir HelloWorld
cd HelloWorld

Step 2: Create main.aro

(Application-Start: Hello World) {
    <Log> "Hello, World!" to the <console>.
    <Return> an <OK: status> for the <startup>.
}

Step 3: Run Your Application

aro run ./HelloWorld

Creating a Web API

ARO uses contract-first HTTP development. Define routes in openapi.yaml:

Directory Structure

HelloAPI/
├── openapi.yaml      # Required: Defines HTTP routes
├── main.aro          # Application lifecycle
└── handlers.aro      # Feature sets matching operationIds

openapi.yaml

openapi: 3.0.3
info:
  title: Hello API
  version: 1.0.0

paths:
  /hello:
    get:
      operationId: sayHello
      responses:
        '200':
          description: Success

main.aro

(Application-Start: Hello API) {
    <Log> "Hello API starting..." to the <console>.
    <Keepalive> the <application> for the <events>.
    <Return> an <OK: status> for the <startup>.
}

handlers.aro

(sayHello: Hello API) {
    <Create> the <response> with { message: "Hello, World!" }.
    <Return> an <OK: status> with <response>.
}

CLI Commands

aro run ./MyApp       # Run the application
aro check ./MyApp     # Syntax validation
aro build ./MyApp     # Compile to native binary

Next Steps

• A Tour of ARO
• HTTP Services
• Events