# Contributing to Flectar Mail

Thank you for helping improve Flectar Mail. Keep changes focused, reviewable,
and safe for a mail client that handles private user data.

## Before starting

- Search existing issues and pull requests before opening a duplicate.
- Open an issue before substantial features, architecture changes, new
  dependencies, protocol changes, or user-visible licensing changes.
- Never submit real mailbox contents, credentials, OAuth tokens, signing
  material, or personal fixture data. Use reserved `.example` domains.

## Contributor License Agreement

Every contributor must accept the
[`Flectar Contributor License Agreement`](CLA.md) before a pull request can be
merged. Contributors retain copyright. The CLA permits Flectar to maintain the
AGPL project and provides an explicit patent grant; it does not make accepted
client contributions proprietary. This purpose is also described in
[`LICENSING.md`](LICENSING.md).

If an employer or another organization owns your work, an authorized
representative must approve the contribution. A personal checkbox cannot grant
rights owned by your employer. Maintainers may request a separate corporate
agreement before review is completed.

## Pull requests

- Keep one logical change per pull request.
- Explain the problem, the chosen solution, tests, and user-visible effects.
- Add or update tests for behavior changes.
- Disclose material use of generative tools. You remain responsible for every
  submitted line and for confirming that generated material has valid
  provenance and compatible licensing.
- Preserve third-party copyright and license notices.
- Do not add dependencies or copied assets without documenting their source,
  version, license, and required notices.

## Local validation

Run the checks relevant to your change:

```bash
cargo fmt --all -- --check
cargo clippy --workspace --all-targets --locked -- -D warnings
cargo test --workspace --locked
slint-viewer --check ui/app.slint
```

UI changes must be rendered and inspected in light and dark themes. Responsive
changes must also be checked at the documented phone and tablet preview sizes.
Use fictional data in screenshots.

## Licensing of accepted contributions

Accepted contributions are published as part of Flectar Mail under
`AGPL-3.0-only`, unless a file is explicitly identified as third-party material
under another compatible license. The CLA does not remove the AGPL rights that
recipients receive for published releases.