Closure Library welcomes patches/pulls for features and bugfixes. For contributors external to Google, follow the instructions given here: Notes on Contributions to Closure Library Google Individual Contributor License In all cases, contributors must sign a contributor license agreement, either for an individual or corporation, before a patch can be accepted. Please fill out the agreement for an individual or a corporation, as appropriate. https://developers.google.com/open-source/cla/individual https://developers.google.com/open-source/cla/corporate If you or your organization is not listed there already, you should add an entry to the AUTHORS file as part of your patch. If you plan to add a significant component or large chunk of code, it is recommended to bring it up on the discussion list for a design discussion before writing code. If appropriate, write a unit test that demonstrates your patch. Tests are the best way to ensure that future contributors do not break your code accidentally. To change the Closure Library source, you must submit a pull request in GitHub. See the GitHub documentation here: https://help.github.com/categories/63/articles Closure Library developers monitor outstanding pull requests. They may request changes on the pull request before accepting. They will also verify that the CLA has been signed. Oftentimes, the pull request will not be directly merged, but patched to the internal Google codebase to verify that unit and integration tests will pass before submitting (and optionally make changes to the patch to match style, fix text, or to make the code or comments clearer). In this case, the issue associated with the pull request will be closed when the patch is pushed to the repository via the MOE (Make Open Easy) system. https://github.com/google/MOE/