@metanet-games/chainseed

Verifiable deterministic randomness from a Bitcoin (BSV) block hash. Zero dependencies.

A block hash is a public, un-riggable random beacon: nobody picks it, everybody can read it, and it's fixed forever once mined. chainseed turns it into an unlimited stream of independent, reproducible draws — each selected by a path string — so two parties derive the same value and a third can audit it. Trustless because it's reproducible, not because you trust anyone.

import { seed } from "@metanet-games/chainseed";

const s = seed(blockHash);          // blockHash: lowercase big-endian hex, as explorers show it
s.unit("loot:sword");               // float in [0,1)
s.int("spawn:3", 6);                // integer 0..5
s.pick("event", ["rain","fog"]);    // uniform pick
s.chance("crit", 0.1);              // true 10% of the time

Every draw is HMAC-SHA256(key = blockHash, message = path) under the hood. Same block + same path ⇒ same value, anywhere.

Not a secret RNG — outputs are public and predictable to anyone who knows (beacon, path). Don't derive keys or secrets from it.

See SPEC.md for the language-agnostic derivation and conformance test vectors.

Apache-2.0 © metanet.games