# Contributing to Map

Map is one of the [Transaction Science open standards](../README.md). The wire
format and the right to fork are public; Transaction Science is the steward, not
the proprietor.

## Ground rules

- **Reference code** (`map-rs/`) is Apache-2.0. **Specification text** (`SPEC.md`,
  `spec/`, `vocab/`) is CC-BY-4.0.
- Rust toolchain is pinned by the repo `rust-toolchain.toml`. `cargo test
  --workspace` MUST pass and `cargo clippy --workspace --all-targets` MUST be
  warning-free.
- Any change to a wire structure requires regenerating and committing
  `conformance/v1/` (`cargo run -p map-conformance --bin gen-vectors`) and a note
  in `CHANGELOG.md`.

## The smallest valuable contributions

- **Conformance:** adversarial negatives (a directory whose root disagrees with
  its entries, a revision-chain fork, a viewport whose range planner over-fetches),
  and independent implementations certifying against `conformance/v1/`.
- **Substrate port:** real `map-index` (S2 + 4D), `map-tiles` (MVT / raster / 3D
  Tiles), `map-orbital` (SGP4), `map-route` — see [`ROADMAP.md`](ROADMAP.md).
- **Measured energy:** backends feeding the receipt's `HwShunt` path (RAPL/SMC)
  so a resolver reports measured joules instead of the estimator.
- **Codecs:** new tile payload codecs registered behind the `Tile` cargo, with
  conformance vectors per codec.

Issues and PRs scope by the `map` subdirectory tag.