Contributing to ALPS

ALPS is an open-source project and welcomes contributions at every level — from a bug report or tutorial fix to a new simulation method or library. This page describes how to get involved. The full technical details are in CONTRIBUTING.md in the ALPS repository.

Ways to contribute

You do not need to start at the bottom — jump in wherever your skills and interests fit.

Students new to the project may also want to read the Onboarding Statement for Students, which describes each level in more detail and explains what to expect from the collaboration.

Before you start

For bug reports, feature requests, and documentation fixes, you can open an issue or pull request directly on GitHub without any prior contact.

For new simulation applications or libraries (Level 4), please reach out to a member of the Governing Council before starting significant work. This avoids duplication of effort and ensures the new code fits the ALPS architecture and maintenance model.

If you are unsure where to start, drop a message on Discord — the community is friendly and happy to point you in the right direction.

The contribution workflow

The full workflow is documented in CONTRIBUTING.md. In brief:

1. Fork the ALPS repository and clone your fork locally.
2. Build and test to confirm everything works on your machine before making changes.
3. Create a branch for your change (fix/, feat/, or docs/ prefix by convention).
4. Make your change, adding or updating tests as appropriate.
5. Open a pull request against the master branch. Fill in the pull request template — in particular, describe how the change was tested and, for simulation code, how results were validated against known reference values.
6. Respond to review comments. Core maintainers will review your PR; acceptance requires either consensus approval or no objections within six weeks.

What we look for in a pull request

• CI passes on all platforms (Linux and macOS).
• No new compiler warnings (-Wall -Wextra for C++ code).
• New or modified behaviour is covered by tests.
• Simulation results are validated against a published reference or known analytic result.
• Commit messages are descriptive and written in the imperative mood.

Recognition

ALPS releases are accompanied by a peer-reviewed publication. Active contributors are added as co-authors. The Governing Council decides the author list for each release, taking into account contributions to code, documentation, tutorials, testing, and community support.

Contributing at Level 2 or above — that is, improving documentation and tutorials, fixing bugs, or adding new features — with sustained effort is the typical threshold for co-authorship consideration.

Getting help