[](https://packagist.org/packages/vimeo/psalm) [](https://packagist.org/packages/vimeo/psalm) [](https://travis-ci.org/vimeo/psalm/branches) [](https://coveralls.io/github/vimeo/psalm)  Psalm is a static analysis tool for finding errors in PHP applications, built on top of [PHP Parser](https://github.com/nikic/php-parser). It's able to find a [large number of issues](https://github.com/vimeo/psalm/blob/master/docs/running_psalm/issues.md), but it can also be configured to only care about a small subset of those. [Try a live demo](https://psalm.dev/), or install it in your project by following the Quickstart Guide below. ## Psalm documentation Documentation is available on [Psalm’s website](https://psalm.dev/docs), generated from the [docs](https://github.com/vimeo/psalm/blob/master/docs) folder. ## Quickstart Guide Install via [Composer](https://getcomposer.org/): ```bash composer require --dev vimeo/psalm ``` Add a config: ```bash ./vendor/bin/psalm --init ``` Then run Psalm: ```bash ./vendor/bin/psalm ``` The config created above will show you all issues in your code, but will emit `INFO` issues (as opposed to `ERROR`) for certain common trivial code problems. If you want a more lenient config, you can specify the level with ```bash ./vendor/bin/psalm --init [source_dir] [level] ``` You can also [learn how to suppress certain issues](https://github.com/vimeo/psalm/blob/master/docs/running_psalm/dealing_with_code_issues.md). ## How Psalm Works A basic rundown of Psalm’s internals can be found in [docs/how_psalm_works.md](https://github.com/vimeo/psalm/blob/master/docs/how_psalm_works.md). ## Acknowledgements The engineering team [@vimeo](https://github.com/vimeo) for encouragement and patience, especially [@nbeliard](https://github.com/nbeliard), [@erunion](https://github.com/erunion) and [@nickyr](https://github.com/nickyr).