Byte layouts

#Conventions

• Fixed integers are big-endian (u16, u32, u64).
• Varints are unsigned LEB128 and must be minimal: 00 is 0, e8 07 is 1000. A longer encoding of the same number is rejected, so every message has exactly one byte form.
• Magic tags open every signed message (PSREC001, PSCHAL01, PSCERT01 ...). A signature for one kind of message can never verify as another, and a new layout gets a new tag.
• Hashes are SHA-256, signatures Ed25519 (64 bytes), verified under ZIP-215 rules.

#A move on the wire

White's first move, 1. e4, exactly as it travels from White's phone to Black's: sequence 1, nothing seen yet, signed 1000 ms after START, move code 13.

Black's acknowledgement is the same shape with op 230 (ACK) and seen = 1:

#What gets signed

The receiver rebuilds the body from its own chain and the wire bytes, hashes it, and checks the signature over the header.

#A head

The header's variable parts plus its signature. The genesis is known to everyone involved, so this is all an anchor needs, and it still commits to the whole game.

#A server verdict

Server records carry two seen values, one per player. This one is VERDICT_RESULT (op 242) with the result, the termination and both final clocks as varints.

#Device certificate

The server certifies each device key while the device is online. Valid 30 days, renewed silently.

#Rules profile

A name and numbered key/value pairs, both varints. This is whitepawn/1 for a 3+2 rated blitz game online, so it has no key 14 (link_settle): only games with peer clocks carry it, two bytes more.

#Genesis messages

Three messages start a game; see Genesis for the handshake. CHALLENGE carries the challenger's certificate and the rules profile in full.

#Anchor receipt

The server's signed answer to an anchor: the highest heads it holds for both players, its clock, and the hash of its previous receipt for this game.

#Ping and pong

Peer games exchange pings four times a second on every link that carries the records, inside that link's session. They are unsigned and never stored: they only feed the live checks.

#Heartbeat

While a game with peer clocks runs, each device adds a signed heartbeat to a PING, as its optional last field, at least once a second on every open link: "at my clock at, my newest record was head_seq". A record that contradicts it is a fork (see Clocks).

#Link hello

The first message on a direct link, one from each side. After it every frame on that link is sealed with ChaCha20-Poly1305 under a key per direction, derived from the two hellos, with the frame counter as the nonce (see Links).

#Sizes at a glance