yaiba-sync

Peer-to-peer replication for yaiba over iroh QUIC — no server in the middle.

This is the transport, not the app. Install yaiba if you want the tool.

How it works

Every instance is a full replica and syncing is symmetric: no peer is authoritative, and none has to be reachable at a fixed address. iroh dials by public key and hole-punches, so peers need outbound UDP and nothing else — no port forwarding, no inbound firewall rule. When hole punching fails the connection falls back to a relay, which forwards already-encrypted QUIC and cannot read what passes through.

Hole punching binds a UDP socket on every interface, which is what a desktop firewall asks about on startup. SyncNode::start_with and Transport::RelayOnly bind no UDP socket at all and let the relay carry everything — slower, but there is no prompt to answer, and on a machine without administrator rights there is nobody who could answer it.

One bidirectional stream carries a three-message exchange that leaves both sides holding the union of each other's writes:

  dialer  ──── Hello { room, vv_a } ────▶  listener
          ◀─── Offer { vv_b, entries } ──          (what A is missing)
          ──── Push  { entries } ───────▶          (what B is missing)

Both directions travel in a single round trip because each side sends its version vector before the other has to decide what to transmit — only the difference crosses the wire, never the whole dataset.

Membership is a shared 32-byte room key carried in the ticket. A peer that can't present it is dropped before any data moves.

License

MIT