Psalm can be extended through plugins to find and fix domain-specific issues.
Psalm plugins are distributed as composer packages.
You can find a list of plugins on Psalm’s own website, and also on Packagist. Alternatively you can get a list via the CLI by typing composer search -t psalm-plugin '.'
composer require --dev <plugin-vendor/plugin-package>
Once installed, use the psalm-plugin tool to enable, disable and show available and enabled plugins.
To enable a plugin, run vendor/bin/psalm-plugin enable plugin-vendor/plugin-package.
To disable a plugin, run vendor/bin/psalm-plugin disable plugin-vendor/plugin-package.
vendor/bin/psalm-plugin show will show you a list of all local plugins (enabled and disabled).
Is there no plugin for your favourite framework / library yet? Create it! It's as easy as forking a repository, tweaking some docblocks and publishing the package to Packagist.
Consult Authoring Plugins chapter to get started.