Every pull is provably fair

This is the core of @edgeplays/gleipnir-sdk, the same fairness engine the server runs, published to npm so you can install it and check any round for yourself.

// Lootwin's fairness is the exact code the server runs, shipped as an npm
// package you can audit and run yourself:
//   npm i @edgeplays/gleipnir-sdk
//   import { ByteStream, nextInt, commit } from "@edgeplays/gleipnir-sdk/fair";
// The recipe below is that library's core, verbatim — HMAC-SHA256, nothing else.
import { hmac } from "@noble/hashes/hmac";
import { sha256 } from "@noble/hashes/sha256";

// A deterministic byte stream KEYED BY THE SERVER SEED. Each 32-byte block is
// HMAC-SHA256(serverSeed, "clientSeed:nonce:cursor"); ":rep" is appended when a
// single draw needs more than one block. Same inputs -> same bytes, forever.
function block(serverSeed, clientSeed, nonce, cursor, rep) {
  const msg = rep === 0
    ? `${clientSeed}:${nonce}:${cursor}`
    : `${clientSeed}:${nonce}:${cursor}:${rep}`;
  return hmac(sha256, serverSeed, msg); // 32 bytes
}

// Your winning ticket: a uniform int in [0, 999999] by rejection-sampling four
// bytes at a time (no modulo bias). It maps to exactly one item's ticket range.
function ticket(serverSeed, clientSeed, nonce) {
  const span = 1_000_000, MAX = 0x1_0000_0000, cut = MAX - (MAX % span);
  for (let rep = 0, cursor = 0; ; rep++) {
    const b = block(serverSeed, clientSeed, nonce, cursor, rep);
    for (let i = 0; i + 4 <= b.length; i += 4) {
      const v = b[i] * 2 ** 24 + b[i + 1] * 2 ** 16 + b[i + 2] * 2 ** 8 + b[i + 3];
      if (v < cut) return v % span;
    }
  }
}

// Before the bet you were shown  serverSeedHash = commit(serverSeed) = sha256(serverSeed).
// After you rotate seeds the server reveals serverSeed: check the hash matches,
// then recompute ticket() and confirm it lands on the item you actually got.