0sum

Provably-fair CLI games you play against each other — zero-sum.

0sum is a Rust command-line tool for playing turn-based games against another person, where neither player can secretly cheat. Fairness is not a promise — it's cryptographic. Every move is signed, every game state is a tamper-evident hash-chained log, and the final score is a projection over history that no one can quietly edit.

First game: Farkle (dice). Cards (poker) come later, once the crypto to hide a shared deck from both players is earned.

The christening project of the greytau org.

Phase 1 — work in progress. Hotseat Farkle: the engine, the Game trait, the signed hash-chained state log, and the CLI flow. Plain-text UI. Nothing playable yet — this is the genesis scaffold.

The command builds to a binary named 0sum:

$ 0sum
0sum — provably-fair CLI games (WIP)

The full design brief — CLI flow, the signed-hash-chain state model, the three-tier hidden-state format, phased fairness (commit-reveal dice → mental-poker cards), the stakes/veto layer, and the build phases — lives in docs/DESIGN.md and is tracked canonically in issue #1.

cargo build          # produces target/debug/0sum
cargo run            # prints the WIP banner

Requires a recent stable Rust toolchain.

Dual-licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE)
• MIT license (LICENSE-MIT)

at your option. Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be dual-licensed as above, without any additional terms or conditions.

_{Package name on crates.io: zerosum (Cargo won't take a name with a leading digit — the binary is still 0sum). Fine print: 0sum quietly stands for Protected Randomized Encrypted Gaming — PREGante. That is not its real name. Its real name is 0sum. You didn't read this.}