# How to Contribute

We'd love to accept your patches and contributions to Pigweed. There are just a
few small guidelines you need to follow.

## Contributor License Agreement

Contributions to this project must be accompanied by a Contributor License
Agreement. You (or your employer) retain the copyright to your contribution;
this simply gives us permission to use and redistribute your contributions as
part of the project. Head over to <https://cla.developers.google.com/> to see
your current agreements on file or to sign a new one.

You generally only need to submit a CLA once, so if you've already submitted one
(even if it was for a different project), you probably don't need to do it
again.

## Code reviews

All Pigweed development happens on Gerrit, following the [typical Gerrit
development workflow](http://ceres-solver.org/contributing.html).

In the future we may support GitHub pull requests, but until that time we will
close GitHub pull requests and ask that the changes be uploaded to Gerrit
instead.

## Community Guidelines

This project follows [Google's Open Source Community
Guidelines](https://opensource.google/conduct/).

## Source Code Headers

Every Pigweed file containing source code must include copyright and license
information. This includes any JS/CSS files that you might be serving out to
browsers.

Apache header for C and C++ files:

```javascript
// Copyright 2019 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
```

Apache header for Python and GN files:

```python
# Copyright 2019 The Pigweed Authors
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.
```