RAJA Branch Development

Gitflow Branching Model

The RAJA project uses a simple branch development model based on Gitflow. The Gitflow model is centered around software releases. It is a simple workflow that makes clear which branches correspond to which phases of development. Those phases are represented explicitly in the branch names and structure of the repository. As in other branching models, developers develop code on a local branch and push their work to a central repository.

Persistent, Protected Branches

The main and develop branches are the two primary branches we use. They always exist and are protected in the RAJA GitHub project in that changes to them only occur as a result of approved pull requests. The distinction between the main and develop branches is an important part of Gitflow.

  • The main branch records the release history of the project. Each time the main branch is changed, a new tag for a new code version is made. See Semantic Versioning for a description of the version numbering scheme we use.
  • The develop branch is used to integrate and test new features and most bug fixes before they are merged into the main branch for a release.


Development never occurs directly on the main branch or develop branch.

All other branches in the RAJA repo are temporary and are used to perform specific development tasks. When such a branch is no longer needed (e.g., after it is merged), the branch is deleted typically.

Feature Branches

Feature branches are created off of other branches (usually develop) and are used to develop new features, bug fixes, etc. before they are merged to develop and eventually main. Feature branches are temporary, living only as long as they are needed to complete development tasks they contain.

Each new feature, or other well-defined portion of work, is developed on its own feature branch. We typically include a label, such as “feature” or “bugfix”, in a feature branch name to make it clear what type of work is being done on the branch. For example, feature/<name-of-feature> for a new feature, bugfix/<issue> for a bugfix, etc.


When doing development on a feature branch, it is good practice to regularly push your changes to the GitHub repository as a backup mechanism. Also, regularly merge the RAJA develop branch into your feature branch so that it does not diverge too much from other development on the project. This will help reduce merge conflicts that you must resolve when your work is ready to be merged into the RAJA develop branch.

When a portion of development is complete and ready to be merged into the develop branch, submit a pull request (PR) for review by other team members. When all issues and comments arising in PR review discussion have been addressed, the PR has been approved, and all continuous integration checks have passed, the pull request can be merged.


Feature branches never interact directly with the main branch.

Other Important Branches

Release candidate and hotfix branches are two other important temporary branch types in Gitflow. They will be explained in the RAJA Release Process section.

Gitflow Illustrated

The figure below shows the basics of how branches interact in Gitflow.


This figure shows typical interactions between key branches in the Gitflow workflow. Here, development is shown following the v0.1.0 release. While development was ongoing, a bug was found and a fix was needed to be made available to users. A hotfix branch was made off of main and merged back to main after the issue was addressed. Release v0.1.1 was tagged and main was merged into develop so that it would not recur. Work started on a feature branch before the v0.1.1 release and was merged into develop after the v0.1.1 release. Then, a release candidate branch was made from develop. The release was finalized on that branch after which it was merged into main, and the v0.2.0 release was tagged. Finally, main was merged into develop.