Player and Global Protocol

Protocol

Player protocol

Base: bitworld sprite_v1, unchanged.

Server -> client messages: 0x01 sprite, 0x02 object, 0x03 remove, 0x04 clear, 0x05 viewport, 0x06 layer, 0x07 identity.

Client -> server: the 2-byte input packet [0x84, mask] (0x00 is also accepted for the bitscreen_v1 header). Mask bits: 0 up, 1 down, 2 left, 3 right, 4 A, 5 B, 6 select. At most one direction bit should be set; the server reads them with priority up > down > left > right.

Two additive messages, and only two:

0x90 client -> server, registration

Sent once immediately after connect.

0x90  <u16 len little-endian>  <len bytes UTF-8 JSON>     len <= 4096

Body is either

{"kind": "prompt", "prompt": "<= 1200 runes"}

or

{"kind": "scripted", "baseline": "big_game_hunter"}

A malformed, oversized or non-UTF-8 body is dropped and the seat is treated as {"kind":"scripted","baseline":"big_game_hunter"}. It is never a disconnect.

0x91 server -> client, plan

Sent only to seats that registered kind: "prompt", at most once per planning turn (every 120 ticks).

0x91  <u16 len little-endian>  <len bytes UTF-8 JSON>

{"turn": 7, "intent": "hunt", "target": "stag@13,17", "side": "S",
 "with": ["Cog-A"], "say": "...", "src": "llm"}

src is llm or fallback:<cause>. Scripted seats never receive it, because the bundled bots' parsers reject unknown message types.

Global protocol

The same sprite_v1 stream at world scale (384x384 px viewport, no identity packet), plus the broadcast chrome smuggled as the label of a reserved 1x1 sprite, id 4090, re-emitted every tick. The body is UTF-8 JSON of at most 12 KB (12288 bytes) carrying tick, round, rounds, ticksPerRound, phase, variant, reason, seats[], feed[], beats[] and final.