harn relay

harn relay serve [--port 8787]

Runs the presence relay on this machine — the self-host counterpart to the Cloudflare Durable Objects worker in relay/worker/ (the reference public deployment is wss://relay.harnery.com). Same wire protocol: one in-memory room per opaque 32-hex room id, a warm-join cache replaying the last frame per sender, fan-out to every other socket in the room, and per-socket rate limits.

Point clients at it via the host repo’s .harnery/config.jsonc:

{ "presence": { "relay": "ws://your-host:8787" } }

The relay is blind by design: room ids and sender ids are opaque derivations and every payload is AES-GCM ciphertext end-to-end (see harn presence and decision record 0016), so hosting one requires no trust from its users beyond availability.

Bun-only (Bun.serve WebSockets) — like harn tunnel, it fails fast with a clear message on a Bun-free host. Limits: 16KB per frame, 64 sockets per room, 10-frame burst / 1 frame per 2s per socket, 15-minute warm-join cache TTL.