⚠️ v0.1 ALPHA — Offline beacon only. NOT production-ready. This version uses a simulated beacon (crypto.randomBytes), not real drand. Verification proves internal hash consistency only — it does NOT prove the operator couldn't have chosen a favorable seed. Real drand integration comes in v0.2. Do not use v0.1 for production provably fair claims.

Game API scaffold for RGS studios — Seed Commitment Model.

Install

npm install @fairseal/game

Quick Start

import { createSession, deriveSpin, closeSession, verifySession } from '@fairseal/game';

// Create a provably fair session
const session = await createSession({
  mode: 'provably-fair',
  serverSeed: 'your-secret-seed',
  clientSeed: 'player-seed',
  gameId: 'my-slot-game',
  paytableHash: 'abc123',
});

// Derive spin results (pure computation — zero latency)
const spin = deriveSpin(session, 0);
console.log(spin.entropy); // Use to derive game result

// Free spins, cascades, bonuses — unlimited sub-paths
const freeSpin = deriveSubResult(session, 0, 'freespin', 0);

// Close session and get verifiable receipt
const receipt = await closeSession(session);
const result = verifySession(receipt);
console.log(result.valid); // true

Modes

provably-fair (Mode A): Full player verifiability. Client seed participates in derivation.
audit-only (Mode B): GLI-19 safe. Client seed recorded as witness only.

API

Function	Description
`createSession(config)`	Create a new game session with committed seed
`awaitSession(session)`	Wait for beacon resolution (0-3s)
`deriveSpin(session, index)`	Derive spin result — pure HMAC, zero latency
`deriveSubResult(session, parent, type, index)`	Derive sub-event (free spin, cascade, etc.)
`mapEntropy(entropy, range)`	Map 256-bit entropy to `[0, range)`
`closeSession(session)`	Close session, reveal seed, generate receipt
`rotateClientSeed(session, newSeed)`	Atomic seed rotation (Mode A only)
`verifySession(receipt)`	Client-side receipt verification
`computeMerkleRoot(leaves)`	Merkle tree construction