# Contributing to Psalm The following is a set of guidelines for contributing to Psalm, which is hosted in the [Vimeo Organization](https://github.com/vimeo) on GitHub. Make sure to check out the [Contributing to Open Source on GitHub](https://guides.github.com/activities/contributing-to-open-source/) guide. ## Submitting Issues You can create an issue [here](https://github.com/vimeo/psalm/issues/new), but before you do, follow these guidelines: * Make sure that you are using the latest version (`master`). * It’s by no means a requirement, but if it's a bug, and you provide demonstration code that can be pasted into https://psalm.dev, it will likely get fixed faster. ## Pull Requests [Here’s a guide to the codebase you may find useful](docs/how_psalm_works.md). Before you send a pull request, make sure you follow these guidelines: * Make sure to run `composer tests` and `./psalm` to ensure that Travis builds will pass * Don’t forget to add tests!