Thanks for your interest in contributing! This document outlines how to build, test, and submit changes.

• Use meaningful, descriptive names for variables, functions, and types in all languages.
• Write short docstrings for public modules, classes, and functions.
• Write clear, easy-to-read, and maintainable code.
• Keep code warnings and linter errors to a minimum.
• In general, prefer clarity over clever tricks, and keep the codebase friendly for contributors.

C++

• Use C++20.
• Format C++ with clang-format.

Python

• Follow PEP 8 for style.
• Use type annotations (PEP 484) and prefer formatted string literals (PEP 701, f-strings).

We use pre-commit to run Python linters and formatters (including Ruff) before commits. If you are using uv like us, install the tools and hooks as follows:

uv tool install ruff
uv tool install pre-commit
pre-commit install

After that, pre-commit runs automatically on git commit. To run on all files manually:

SKIP=check-copyright-year pre-commit run --all-files

To run only Ruff (check + fix and format):

ruff check . --fix
ruff format .

We use REUSE to enforce SPDX license headers on source files. Pre-commit runs reuse lint-file on changed files (e.g. .py, .cpp, .md, .yaml):

1. Required fields: Each file must have SPDX-FileCopyrightText and SPDX-License-Identifier.
2. License: SPDX-License-Identifier must be Apache-2.0 (full text in LICENSES/Apache-2.0.txt).

Example header:

# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0

To add or fix headers, install the reuse tool

uv tool install reuse

and run for example:

reuse annotate -t compact -l Apache-2.0 --skip-unrecognised -r path/to/file

REUSE does not auto-update the copyright year when you touch a file; include the current year when adding or editing headers.

GitHub Actions builds the default targets and runs tests.

1. Create a feature branch
2. Ensure builds pass locally and in CI
3. Describe motivation, changes, and testing in the PR
4. Link related issues

• Your contributions are under the repository’s license unless stated otherwise

• We require that all contributors "sign-off" on their commits. This certifies that the contribution is your original work, or you have rights to submit it under the same license, or a compatible license.

  • Any contribution which contains commits that are not Signed-Off will not be accepted.

• To sign off on a commit you simply use the --signoff (or -s) option when committing your changes:

  $ git commit -s -m "Add cool feature."

  This will append the following to your commit message:

  Signed-off-by: Your Name <your@email.com>
  

• Full text of the DCO:

    Developer Certificate of Origin
    Version 1.1
  
    Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
    1 Letterman Drive
    Suite D4700
    San Francisco, CA, 94129
  
    Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
  

    Developer's Certificate of Origin 1.1
  
    By making a contribution to this project, I certify that:
  
    (a) The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or
  
    (b) The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or
  
    (c) The contribution was provided directly to me by some other person who certified (a), (b) or (c) and I have not modified it.
  
    (d) I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved.