# Contributing¶

MESA welcomes contributions from the user community. Please note that contributing code to MESA (e.g., acceptance of a pull request) does not entitle one to co-authorship of a MESA instrument paper.

## Bug Reports¶

We welcome bug reports about MESA. However, bug reports must describe specific, actionable issues. An undiagnosed difficulty with a MESA model should not be treated as a bug.

If you are encountering problems with your MESA models, user support occurs through the mesa-users@lists.mesastar.org mailing list. Send a message describing the problem and including enough detail (e.g., MESA version, inlists, saved models) such that anyone can reproduce it. Other users and the MESA developers can help you understand if your problem represents a bug.

## Code Changes / Pull Requests¶

Proposed changes will be carefully reviewed by the MESA developers. Simple bugfixes or improvements to documentation are likely to be readily accepted. Modifications that can be easily realized via hooks may be more appropriate for mesa-contrib and the MESA developers may suggest adding your changes there.

User contributions are expected to follow the standard technical guidelines for MESA developers. We strongly recommend against undertaking any significant development effort without first emailing mesa-developers@lists.mesastar.org with an outline of your anticipated changes.

New contributions must be proposed through GitHub’s pull request (PR) system. The process is roughly:

1. fork the mesa repo (click Fork in the top-right of the GitHub interface),
3. create a new branch for your additions (e.g. git switch -c my-new-hook),
5. open a PR against the main branch.