ADR 0004 — NetworkCoordinator is plain TCP, deliberately

Status

Accepted (stopgap; revisit when the upstream noise transport lands).

Context

Multi-host signing needed a transport before the upstream per-party session protocol delivers the noise-transport replacement.

Decision

NetworkCoordinator speaks one-JSON-object-per-line over plain TCP, binary fields hex-encoded, errors returned as {"error": Class, "message": ...}. It is intended for loopback or private networks only. The seam (SigningSession) is positioned so the noise transport replaces the framing without touching session semantics.

Consequences

• Do not expose it on untrusted networks.
• When the noise transport lands, retire the NDJSON framing and this ADR with it.