Start Contributing to Typelevel

Typelevel projects power a large part of the functional Scala ecosystem. They are also complex, long-lived codebases with active communities. Contributing can feel intimidating at first, but even bug reports, small fixes, and documentation updates help move our projects forward!

Become a user of the ecosystem you want to contribute to.

• Use the Typelevel Toolkit to experiment with Cats and Cats Effect.
• Try streaming something with FS2.
• Use http4s for a simple service.
• Build a static site with Laika.

Find something that can be improved

• Look for open issues, especially those labeled good first issue or help wanted.
• Browse the curated good-first-issues board.
• If you're already using the library, improve something that bothered you.
• Documentation and tests are excellent starting points too.

Understand the problem

• Read the issue carefully, understand the current implementation.
• Look for existing PRs or recent comments.
• Check whether a solution was already proposed.

Communication with the community

• Comment on the issue saying you'd like to work on it and briefly describe your idea or approach.
• Ask clarifying questions if anything is unclear.
• If the change is small, you can open a draft PR early to get feedback.

Open a PR and iterate

• Fork the repo, create a branch, and implement the change. Add or update tests where appropriate.
• Open a PR with a clear description of the problem and your solution.
• Expect review feedback, ask questions, adjust your changes, and iterate.

Where to Ask for Help

• Join the Typelevel Discord.
• Ask in #starting-contributing if you're new to contributing.
• Use library-specific channels like #cats, #cats-effect, #fs2, or #http4s for more focused questions.
• You can also ask directly on a GitHub issue if your question is specific to that issue.

Note: This guide emphasises learning and understanding. While most Typelevel projects accept AI written contributions, simply using such tools to fix a bug does not help you learn the codebase and gain the understanding needed to make more significant contributions.