Fairseal 🦭

Provably fair selections for games, loot boxes, and any randomized allocation.

Fairseal creates verifiable receipts (CSRs) proving that a selection was committed before the outcome was knowable. Every loot drop, gacha pull, and randomized selection — independently verifiable, trustlessly.

Try It Now

npx @fairseal/commit

One command. A verifiable gacha pull in your terminal. No setup.

Related MCP server: garl

Quick Start

npm install @fairseal/commit

import { createCommitment, resolveCommitment, createReceipt, verifyReceipt } from '@fairseal/commit';

// 1. Lock your loot table BEFORE the outcome is knowable
const commitment = createCommitment({
  rule: JSON.stringify(LOOT_TABLE),
  inputs: [playerId, pullNumber.toString()],
  revealAfter: 10,
});

// 2. Resolve with verifiable entropy from drand
const resolution = await resolveCommitment(commitment);

// 3. Your algorithm + verifiable entropy = provably fair drop
const drop = yourWeightedPull(LOOT_TABLE, resolution.beaconRandomness);

// 4. Package as a receipt anyone can verify
const receipt = createReceipt(commitment, resolution);
const proof = await verifyReceipt(receipt); // ✅ PARTIAL

How It Works

1. Commit — Lock your drop table + player ID into a hash before the randomness exists

2. Entropy — Wait for a public drand beacon round (Cloudflare + Protocol Labs)

3. Resolve — Derive the selection from beacon entropy + your committed rule

4. Verify — Anyone can re-run every step. drand beacon signatures are BLS12-381-verified; FairSeal receipt signatures use EIP-191 (secp256k1) / Ed25519 — receipts are never BLS-signed. No trust required.

Performance

Client-side. No server. No account. No fees for PARTIAL verification.

Packages

Use Cases

Result Notarization vs. Activity Receipts

Most "agent receipts" today are activity receipts: the platform logs what an agent did, and you trust whoever wrote the log. Fairseal receipts are result notarization — a different trust model:

Related standards: payment-authorization protocols like Google/Mastercard AP2 (mandates), Visa TAP, and OpenAI/Stripe ACP prove that an agent may act and who it is. Fairseal proves what happened — that a result was committed and hasn't been altered since. Fairseal settles micropayments over Coinbase's x402 and does not implement AP2/TAP/ACP; the layers are complementary.

Links

• 🌐 fairseal.io — Landing page

• 📦 npm @fairseal — All packages

• 🔍 verify.fairseal.io — Receipt verifier

• 📖 @fairseal/commit README — Full documentation

Listings

• PayAPI Market — FairSeal Cryptographic Receipts API — verified listing (settled on-chain test payment)

License

MIT — Fairseal