Provably-fair verification

Every result on Haddzy is a deterministic function of four public inputs: server seed, client seed, nonce, and game name. Once a server seed is rotated, it is revealed forever — you can paste it here and reproduce any result, or run the same algorithm yourself in any language.

Verify a result

Algorithm

This is the exact source running on our servers. Copy it, paste it anywhere, and confirm we are not lying about your results.

JavaScript (Node.js)

import { createHmac } from 'node:crypto';

export function* hmacFloatStream(serverSeed, clientSeed, nonce, gameName) {
  let cursor = 0n;
  while (true) {
    const input = `${clientSeed}:${nonce}:${gameName}:${cursor}`;
    const hmac = createHmac('sha256', serverSeed).update(input).digest();
    for (let i = 0; i < 8; i++) {
      yield hmac.readUInt32BE(i * 4) / 0x1_0000_0000;
    }
    cursor++;
  }
}

Python 3

import hmac, hashlib

def hmac_float_stream(server_seed: str, client_seed: str, nonce: int, game_name: str):
    cursor = 0
    while True:
        msg = f"{client_seed}:{nonce}:{game_name}:{cursor}".encode()
        digest = hmac.new(server_seed.encode(), msg, hashlib.sha256).digest()
        for i in range(8):
            chunk = digest[i*4:(i+1)*4]
            yield int.from_bytes(chunk, 'big') / (1 << 32)
        cursor += 1