composer.json
The composer.json file describes your project: name, dependencies, autoloading, and scripts.
PHP
Beginner
3 min read
composer.json Structure
Example
{
"name": "myapp/app",
"require": { "php": "^8.2", "guzzlehttp/guzzle": "^7.0" },
"require-dev": { "phpunit/phpunit": "^10.0" },
"autoload": { "psr-4": { "App\\": "src/" } },
"autoload-dev": { "psr-4": { "Tests\\": "tests/" } },
"scripts": { "test": "phpunit", "lint": "php-cs-fixer fix --dry-run" }
} Pro Tip
The autoload section maps namespace prefixes to directories — run composer dump-autoload after changes.