Contributing to detectron2


We use GitHub issues to track public bugs and questions. Please make sure to follow one of the issue templates when reporting any issues.

Facebook has a bounty program for the safe disclosure of security bugs. In those cases, please go through the process outlined on that page and do not file a public issue.

Pull Requests

We actively welcome your pull requests.

However, if you’re adding any significant features (e.g. > 50 lines), please make sure to have a corresponding issue to discuss your motivation and proposals, before sending a PR. We do not always accept new features, and we take the following factors into consideration:

  1. Whether the same feature can be achieved without modifying detectron2. Detectron2 is designed so that you can implement many extensions from the outside, e.g. those in projects. If some part is not as extensible, you can also bring up the issue to make it more extensible.

  2. Whether the feature is potentially useful to a large audience, or only to a small portion of users.

  3. Whether the proposed solution has a good design / interface.

  4. Whether the proposed solution adds extra mental/practical overhead to users who don’t need such feature.

  5. Whether the proposed solution breaks existing APIs.

When sending a PR, please do:

  1. If a PR contains multiple orthogonal changes, split it to several PRs.

  2. If you’ve added code that should be tested, add tests.

  3. For PRs that need experiments (e.g. adding a new model or new methods), you don’t need to update model zoo, but do provide experiment results in the description of the PR.

  4. If APIs are changed, update the documentation.

  5. Make sure your code lints with ./dev/

Contributor License Agreement (“CLA”)

In order to accept your pull request, we need you to submit a CLA. You only need to do this once to work on any of Facebook’s open source projects.

Complete your CLA here:


By contributing to detectron2, you agree that your contributions will be licensed under the LICENSE file in the root directory of this source tree.