PHP Attributes: What, Why, How and When

PHP attributes (introduced in PHP 8) are typed, structured metadata attached to classes, methods, properties, parameters, and more. They don't execute code themselves — a consumer must read them via the Reflection API and turn them into behavior. The post covers how to define attributes with target restrictions and constructor arguments, how to build a practical webhook handler registry using reflection, performance best practices (reflect at boot, use plain data at runtime), Laravel examples like #[Scope] and #[Config], testing strategies, and a clear decision checklist for when attributes are appropriate versus when interfaces, configuration, or explicit code are better choices.