# Third-Party Notices

## Rules dependency

- **chess.js**
- Version: 1.4.0
- License: BSD-2-Clause
- Source: https://github.com/jhlywa/chess.js
- Tag: `v1.4.0`
- Commit: `ce1ff9e9fc342984ff75ca475ab39f37888cb28a`

The exact license is preserved at `third_party/chess.js/LICENSE`, and complete
provenance and hashes are recorded in
`third_party/chess.js/SOURCE_VERSION.md`. Published TypeScript and distribution
sources are preserved unchanged under `third_party/chess.js/upstream/`.

The committed QML runtime artifact is reproducibly generated with
`./scripts/build-chess-vendor.sh`. The compatibility transform replaces only
unsupported JavaScript syntax and the internal vendor hash PRNG. Project move
legality remains provided by chess.js, while project-owned `PositionKey.js`
provides repetition identity. Differential and perft tests guard the boundary.

## Project-owned artwork and sound

The assets under `assets/` are original Omarchy Chess project work by Rudy
Rodriguez and contributors, copyright 2026, distributed under this repository's
MIT License. The modern 512 px transparent piece masters were supplied by Rudy
Rodriguez for the project and are integrity-pinned in
`assets/pieces/SHA256SUMS`. The three 1254 px board masters were also supplied
by Rudy Rodriguez for the project; their pixels are preserved while unrelated
container metadata is removed, and they are integrity-pinned in
`assets/boards/SHA256SUMS`. The product and monochrome icons are generated from
the committed source in `assets/generate_assets.py`. The seven short WAV cues
are generated by `scripts/generate-sounds.py` using only standard-library sine
tones and envelopes. No third-party font, sample, commercial chess mark, or
runtime network resource is embedded.

Rebuild and validation commands are documented in `assets/README.md`,
`assets/pieces/README.md`, `assets/boards/README.md`, and
`assets/sounds/README.md`.

## Stockfish

Stockfish is not bundled in V1. A future optional adapter must account for GPL-3.0 distribution obligations.