Composer vs npm: PHP and Node Dependency Managers in CI
Composer is PHP's dependency manager and npm is Node's - many full-stack repos run both, so the real question is how each behaves in CI.
Composer manages PHP dependencies and autoloading from a composer.json/composer.lock. npm manages Node packages from package.json/package-lock.json. They target different runtimes but share the same lockfile-and-cache pattern.
| Composer | npm | |
|---|---|---|
| Ecosystem | PHP (Packagist) | JavaScript (npm registry) |
| Lockfile | composer.lock | package-lock.json |
| CI install | composer install --no-dev (prod) | npm ci |
| Autoloading | PSR-4 autoloader generation | Module resolution (Node) |
| Reproducibility | From lock | From lock |
In CI
Both want a committed lockfile and a deterministic install command: composer install (often with --no-dev --optimize-autoloader for production) and npm ci. A full-stack app frequently runs both steps in one job - PHP deps via Composer, frontend deps via npm. Each is fast when its cache is warm and slow on a cold install of many native or autoload-heavy packages.
Cache both
Cache Composer's vendor directory (keyed on composer.lock) and npm's node_modules/cache (keyed on package-lock.json) separately. Both installs run on CI runners; faster managed runners shorten whichever cold install dominates.
The verdict
They are not interchangeable - Composer for PHP, npm for Node. In a full-stack pipeline you run both: commit each lockfile, use the deterministic install command, and cache each ecosystem's directory independently.