Contributing Guidelines

Branching Strategy

SecureDrop uses a branching model based on git-flow. The master branch always points to the latest stable release. Use this branch if you are interested in installing or auditing SecureDrop. Development for the upcoming release of SecureDrop takes place on develop, which is the default branch. If you want to contribute, you should branch from and submit pull requests to develop.

Automated Testing

When a pull request is submitted, we have Travis CI automatically run the SecureDrop test suites, which consist of:

  1. Unit tests of the Python SecureDrop application code.
  2. Functional tests that use Selenium to drive a web browser to verify the function of the application from the user’s perspective.
  3. Tests of the system configuration state using testinfra.

Before a PR can be merged, these tests must all pass. If you modify the application code, you should verify the tests pass locally before submitting your PR. If you modify the server configuration, you should run the testinfra tests. Please denote in the checklist when you submit the PR that you have performed these checks locally.

Code Style

We use code linters to keep a consistent code quality and style. These linters also run in CI and will produce build failures. To avoid this, we have included a git pre-commit hook. You can install it with the following command run at the root of the repository:

ln -sf ../../git/pre-commit .git/hooks/pre-commit


The code linters are installed automatically on the Development VM, but for the pre-commit hook to work, you will need to install the linting tools locally on your host machine. From the root of the repo you can run the following:

pip install -r securedrop/requirements/develop-requirements.txt


All Python code should be flake8 compliant. You can run flake8 locally via:

make flake8


All Shell code (e.g. bash, sh) should be shellcheck compliant. You can run shellcheck locally via:

make shellcheck

For reference, consult the shellcheck wiki for detailed explanations of any reported violations.


HTML should be in compliance with Google’s HTML style guide. We use html-linter to lint our HTML templates in securedrop/source_templates and securedrop/journalist_templates. Run the HTML linting options we use via:

make html-lint


The Ansible configuration is specified in YAML files, including variables, tasks, and playbooks. All YAML files in the project should pass the yamllint standards declared in the .yamllint file at the root of the repository. Run the checks locally via:

make yamllint

Git History

We currently use an explicit merge strategy to merge feature branches into develop. In order to keep our git history as clean as possible, please squash your commits to package up your changes into a clear history. If you have many unnecessary commits that do not add information to aid in review, they should be removed. If you are unfamiliar with how to squash commits with rebase, check out this blog post.


Dedicated contributors to SecureDrop will be granted extra privileges such as the right to push new branches or to merge pull requests. There is no formal process at the moment but the general idea is that any contributor with the right technical and social skills is entitled to ask. The people who have the power to grant such privileges are commited to do so in a transparent way to avoid any dispute.

Other Tips

  • To aid in review, please write clear commit messages and include a descriptive PR summary. We have a PR template that specifies the type of information you should include.
  • To maximize the chance that your PR is merged, please include the minimal changes to implement the feature or fix the bug.
  • If there is not an existing issue for the PR you are interested in submitting, you should submit an issue first or comment on an existing issue outlining how you intend to approach the problem.