Includes a decision guide for greenfield vs legacy codebases (PHPStan level + baseline strategy, Rector's withPhpSets()/withPhpLevel(), PHP-CS-Fixer rule sets), plus ready-to-copy templates for phpstan.neon, rector.php, .php-cs-fixer.dist.php, and a composer-scripts CI pipeline.

Do NOT use this skill on Laravel projects — Laravel uses Pint (a thin wrapper over PHP-CS-Fixer) and Larastan instead, both owned by laravel-expert. Do NOT use it for test framework setup (php-testing) or language syntax questions (php-language-modern).

PHP Quality Tooling

Three complementary tools. PHPStan finds type bugs, Rector rewrites code (upgrades + refactors), PHP-CS-Fixer formats to a coding standard. They do not overlap — run all three.

Agent Workflow (MANDATORY)

Before ANY implementation, spawn 3 agents in parallel, one Agent call each with a name: