We very much appreciate any contributions to the project, you don't even necessarily need to do any coding! There's really good blog post how to contribute here.
For code submissions we accept GitHub pull requests to the develop branch. If the update will force users to change their configuration, or take any other manual actions, the pull request should be made against the next branch (though you may need to bug us in chat if that branch isn't up to date with develop at the moment.)
You can find a guide here for forking a repo and making a pull request. Feel free to mark a PR as a work in progress and submit it early, a PR is a good place to follow progress and get feedback.
If you really want to make us happy, make sure your changes pass PEP8 guidelines. We have task for checking them. You can run it via
bin/flake8
Any & additional unit tests are also huge bonus.
GitHub repo is located at:
https://github.com/Flexget/Flexget
Development tutorials and documentation:
https://flexget.readthedocs.org/en/latest/
Feel free to drop in to IRC to discuss any ideas, #flexget on freenode. You can also visit the forum at http://discuss.flexget.com