File-based plugins

Psalm can be extended through plugins to find domain-specific issues.

Plugins may implement one of (or more than one of) Psalm\Plugin\Hook\* interface(s).

class SomePlugin implements \Psalm\Plugin\Hook\AfterStatementAnalysisInterface

Psalm\Plugin\Hook\* offers six interfaces that you can implement:

An example plugin that checks class references in strings is provided here.

To ensure your plugin runs when Psalm does, add it to your config:

        <plugin filename="src/plugins/SomePlugin.php" />

Composer-based plugins

Composer-based plugins provide easier way to manage and distribute your plugins.

Using composer-based plugins

Discovering plugins

Plugins can be found on Packagist by type=psalm-plugin query:

Installing plugins

composer require --dev plugin-vendor/plugin-package

Managing known plugins

Once installed, you can use psalm-plugin tool to enable, disable and show available and enabled plugins.

To enable the plugin, run psalm-plugin enable plugin-vendor/plugin-package. To disable it, run psalm-plugin disable plugin-vendor/plugin-package. psalm-plugin show (as well as bare psalm-plugin) will show you the list of enabled plugins, and the list of plugins known to psalm-plugin (installed into your vendor folder)

Authoring composer-based plugins


Composer-based plugin is a composer package which conforms to these requirements:

  1. Its type field is set to psalm-plugin
  2. It has extra.psalm.pluginClass subkey in its composer.json that reference an entry-point class that will be invoked to register the plugin into Psalm runtime.
  3. Entry-point class implements Psalm\Plugin\PluginEntryPointInterface

Using skeleton project

Run composer create-project weirdan/psalm-plugin-skeleton:dev-master your-plugin-name to quickly bootstrap a new plugin project in your-plugin-name folder. Make sure you adjust namespaces in composer.json, Plugin.php and tests folder.

Upgrading file-based plugin to composer-based version

Create new plugin project using skeleton, then pass the class name of you file-based plugin to registerHooksFromClass() method of the Psalm\Plugin\RegistrationInterface instance that was passed into your plugin entry point's __invoke() method. See the conversion example.

Registering stub files

Use Psalm\Plugin\RegistrationInterface::addStubFile(). See the [sample plugin] (

Stub files provide a way to override third-party type information when you cannot add Psalm's extended docblocks to the upstream source files directly.