This repository owns the public ArcRelay v1 wire contract. The transport
envelope is in proto/common.proto; feature messages are in
proto/arcrelay.proto.
PROTOCOL_MAJOR, ALPN, the discovery protocol token, protobuf package, and cryptographic domain separators advance together only for an intentionally incompatible release.- Peers advertise an inclusive minor-version range and select the highest common minor. A connection is rejected when the ranges do not overlap.
- Features negotiate their own version independently from the transport version. Adding an optional field or a new feature is a minor-compatible change; changing field meaning is not.
- Published protobuf field numbers, enum numbers, stream-kind bytes, feature
identifiers, and capability tokens are permanent. Removed values must be
marked
reservedand must never be reused. - Every decoder enforces a size limit before allocation. Bulk bytes use a dedicated stream with an exact length, digest, timeout, and one-time ticket.
Run buf lint in this repository for schema style checks. Once the v1 schema
is tagged, run buf breaking --against <last-release-ref> for every protocol
change. Rust and Dart generated sources must both be regenerated from these
canonical schemas; generated files are never edited by hand.
proto/arcrelay.proto exports capability-owned source files: control, input,
clipboard, blob, transfer, files, print, system, media, device, windows, actions
and notifications. status.proto holds shared failures; common.proto owns the
authenticated transport envelope. The package and protocol major remain v1.
This contract is unreleased: every peer must use the same integration revision.
File transfer uses raw file bytes followed by a SHA-256 trailer and FIN after the feature stream header, rather than per-chunk protobuf messages or a prehash. Regenerate Dart with the private mobile repository's generation script; Rust is generated by this crate's build script. Never edit generated client files.