PHP Version Upgrade Planner (8.1–8.3 to 8.4 or 8.5)

An evidence-first procedure for moving any Composer-based PHP codebase (plain PHP, Laravel, Symfony, WordPress, Drupal, Magento) from PHP 8.1, 8.2 or 8.3 to PHP 8.4 or 8.5. PHP 8.1 is already end of life and PHP 8.2 loses security support on 31 Dec 2026, so most teams need this upgrade now.

What the agent does

• Inventories the runtime, extensions and every place the PHP version is pinned (Composer, Docker, CI, hosting, IaC).
• Finds Composer packages and extensions that block the target version before anything changes.
• Scans code with a bundled read-only scanner, PHPCompatibility and PHPStan/Psalm, then maps findings to the official PHP 8.2–8.5 deprecations and breaking changes.
• Applies mechanical fixes with Rector in a separate commit, then prioritizes the remaining manual fixes (P0–P3).
• Runs tests on both versions with deprecations treated as failures, and plans a staged rollout with a rollback path.

What you get

• An upgrade report: target recommendation, effort estimate, version pins, dependency blockers, file:line change list, and a rollout checklist.
• Reference tables of every high-impact change in PHP 8.2, 8.3, 8.4 and 8.5 with replacements, sourced from the official php.net migration guides.
• Ready-to-use configuration for Rector, PHPCompatibility, PHPStan, PHPUnit, GitHub Actions and Docker.

Requires a terminal and Python 3 for the optional scanner script; PHP and Composer for the project itself.