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MARKO DOCS

Your First Application

This guide walks you through building a simple “Hello World” web application with Marko, introducing key concepts along the way.

1. Create the Project

Section titled “1. Create the Project”
Terminal window
composer create-project marko/skeleton hello-marko
cd hello-marko

2. Register Your Module

Section titled “2. Register Your Module”

Create an app/foo directory for your local module. It needs a composer.json to be recognized as a module:

app/foo/composer.json
{
    "name": "app/foo",
    "type": "marko-module",
    "autoload": {
        "psr-4": {
            "App\\Foo\\": "src/"
        }
    },
    "extra": {
        "marko": {
            "module": true
        }
    }
}

3. Create a Controller

Section titled “3. Create a Controller”

Controllers handle HTTP requests. Create one using PHP attributes to define routes:

app/foo/src/Controller/GreetingController.php
<?php


declare(strict_types=1);


namespace App\Foo\Controller;


use Marko\Routing\Attributes\Get;
use Marko\Routing\Http\Response;


class GreetingController
{
    #[Get('/hello/{name}')]
    public function greet(string $name): Response
    {
        return new Response(
            body: "Hello, {$name}! Welcome to Marko.",
        );
    }
}

4. Start and Test

Section titled “4. Start and Test”
Terminal window
marko up
marko open

If marko isn’t installed yet, run composer global require marko/cli first. See Installation for details.

This opens the site up in your browser. Then, just navigate to http://localhost:8000/hello/World and you’ll see:

Hello, World! Welcome to Marko.

5. Add a JSON Endpoint

Section titled “5. Add a JSON Endpoint”

Marko makes JSON responses simple:

app/foo/src/Controller/ApiController.php
<?php


declare(strict_types=1);


namespace App\Foo\Controller;


use Marko\Routing\Attributes\Get;
use Marko\Routing\Http\Response;


class ApiController
{
    #[Get('/api/hello/{name}')]
    public function greet(string $name): Response
    {
        return new Response(
            body: json_encode(['message' => "Hello, {$name}!", 'framework' => 'Marko']),
            headers: ['Content-Type' => 'application/json'],
        );
    }
}

What You’ve Learned

Section titled “What You’ve Learned”
  • Modules are Composer packages with marko.module: true
  • Routes are defined with PHP attributes (#[Get], #[Post], etc.)
  • Controllers are plain classes — no base class inheritance required
  • Marko auto-discovers modules in app/, modules/, and vendor/

Next Steps

Section titled “Next Steps”