README
¶
kibitz
Pull up a chair.
kibitz is croc-style pairing for long-lived, end-to-end-encrypted sessions — chat and turn-based games (chess first, backgammon next) instead of file transfer.
- Pair like croc: the host gets a code phrase like
lion-42-maple, plus a share link and QR code. Friends join by clicking or typing. - The relay can't read anything: the phrase seeds a PAKE key exchange; the relay only forwards opaque encrypted frames. Self-host it or use a hosted one — either way it's blind.
- One binary: the relay embeds the whole web client.
kibitz --listen :8080, open a browser, play. - Spectators welcome: sessions hold two players and any number of kibitzers, all in the same encrypted chat.
Status
v0.3 — six games. Chess, backgammon (provably fair commit-reveal dice), checkers, reversi, Connect Four, and Battleship where cheating is cryptographically impossible: each player commits to every cell of their board before the first shot, every reveal is verified by every participant (spectators included), and both full boards are opened and legality-checked at game end — all without any server ever seeing a thing, because the relay only ever forwards ciphertext. Games start on demand from the picker and run side by side in one session; rematches swap colors.
How it works
The relay forwards frames it can never read. The code phrase seeds a PAKE handshake (as in croc); the host wraps a session group key to each joiner; all chat and moves are XChaCha20-Poly1305 envelopes. Games are both-sides-validate: every client runs the same rules engine and checks a position hash on every move — there's no server to cheat past, because the server is blind. Details: docs/THREAT-MODEL.md.
Hosted instance
A public relay runs at https://kibitz-play.fly.dev — open it, start a table, share the phrase. (Remember: the relay is blind either way; you never have to trust it.)
Self-hosting
Grab a release binary (or go install github.com/richardwooding/kibitz/cmd/kibitz@latest) and:
kibitz --listen :8080
Or run the container image:
docker run -p 8080:8080 ghcr.io/richardwooding/kibitz
Put TLS in front with your reverse proxy of choice. That's it — the web UI,
relay, and everything else is in the one binary. Useful flags:
--max-sessions (default 1000), --version.
Development
make serve # build the WASM client and run the relay on :8080
make test # go test -race ./...
License
MIT
Directories
¶
| Path | Synopsis |
|---|---|
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cmd
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kibitz
command
Command kibitz is the relay server.
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Command kibitz is the relay server. |
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kibitz-wasm
command
Native stub so `go build ./...` and `go vet ./...` succeed on the host — the real entrypoint is main.go, built only under GOOS=js GOARCH=wasm.
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Native stub so `go build ./...` and `go vet ./...` succeed on the host — the real entrypoint is main.go, built only under GOOS=js GOARCH=wasm. |
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internal
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crypto
Package crypto is kibitz's security boundary.
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Package crypto is kibitz's security boundary. |
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fairdice
Package fairdice implements commit-reveal dice between untrusting peers.
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Package fairdice implements commit-reveal dice between untrusting peers. |
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phrase
Package phrase generates croc-style code phrases and derives session IDs from them.
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Package phrase generates croc-style code phrases and derives session IDs from them. |
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relay
Package relay implements the kibitz relay server: a blind frame forwarder.
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Package relay implements the kibitz relay server: a blind frame forwarder. |
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service
Package service defines the layered-service abstraction and the mux that routes decrypted envelopes to services.
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Package service defines the layered-service abstraction and the mux that routes decrypted envelopes to services. |
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service/backgammon
Backgammon rules engine — pure logic, no protocol, no I/O. Hand-rolled because no maintained Go backgammon library exists.
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Backgammon rules engine — pure logic, no protocol, no I/O. Hand-rolled because no maintained Go backgammon library exists. |
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service/battleship
The battleship service — kibitz's flagship: hidden ship placement with NO trusted server anywhere.
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The battleship service — kibitz's flagship: hidden ship placement with NO trusted server anywhere. |
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service/chat
Package chat is the simplest layered service: broadcast text messages with a bounded history that late joiners receive via the ctl snapshot.
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Package chat is the simplest layered service: broadcast text messages with a bounded history that late joiners receive via the ctl snapshot. |
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service/checkers
American checkers (English draughts) rules — pure logic, no protocol.
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American checkers (English draughts) rules — pure logic, no protocol. |
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service/chess
Package chess is the first game service, wrapping corentings/chess for rules.
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Package chess is the first game service, wrapping corentings/chess for rules. |
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service/connect4
Connect Four rules — pure logic, no protocol.
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Connect Four rules — pure logic, no protocol. |
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service/game
Package game holds the seat/lifecycle logic every two-player game service shares: who sits where, who may start a game, rematch seat-swapping, and forfeit-on-leave.
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Package game holds the seat/lifecycle logic every two-player game service shares: who sits where, who may start a game, rematch seat-swapping, and forfeit-on-leave. |
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service/reversi
Reversi (Othello) rules — pure logic, no protocol.
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Reversi (Othello) rules — pure logic, no protocol. |
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session
Package session is the client-side engine: it dials the relay, runs the create/join handshake, performs the PAKE + group-key exchange, and moves encrypted service envelopes.
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Package session is the client-side engine: it dials the relay, runs the create/join handshake, performs the PAKE + group-key exchange, and moves encrypted service envelopes. |
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shipcommit
Package shipcommit implements the Battleship hiding scheme: each player commits to all 100 cells of their board before the first shot, then reveals exactly the cells that get shot.
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Package shipcommit implements the Battleship hiding scheme: each player commits to all 100 cells of their board before the first shot, then reveals exactly the cells that get shot. |
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wire
The inner payload layer: what clients put inside Direct/Broadcast Payload fields.
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The inner payload layer: what clients put inside Direct/Broadcast Payload fields. |
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Package web embeds the built browser client.
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Package web embeds the built browser client. |