# Contributing to Halkyon

## Licences

Contributions are accepted under the licence of the package they change (see
`LICENSE.md`): `AGPL-3.0-or-later` for the apps, the client packages and the shared
Flutter and Dart packages, `SSPL-1.0` for the servers and the server module. Halkyon
Todo's packages have no licence yet; contributions to them wait until they have one.
There is no copyright assignment and no contributor licence agreement: every
contributor keeps the copyright of their work.

## Sign-off

Every commit carries a `Signed-off-by` line with your name and email address. With it
you certify the Developer Certificate of Origin below: that you wrote the change, or
otherwise have the right to submit it under the package's licence. `git commit -s` adds
the line, or `git config format.signoff true` for every commit.

## Before you push

`dart run tool/check.dart` runs the format check, the analyzer and every package's tests
that don't need a running server. In a fresh clone,
`ln -s ../../tool/pre-push .git/hooks/pre-push` makes every push run it. Keep a change
focused, with its tests. How the code is organised, and the rules it follows, are in
`AGENTS.md` and each app's own `AGENTS.md`.

## Developer Certificate of Origin

```text
Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.

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.
```