Verifying Your Spins

Verifying Your Spins

You can verify any spin in three ways. All of them run the same math the server used — nothing is trusted, everything is recomputed.

What you need

From the Lucky Spin page (🧾 Spin history & verify), each spin shows:

• Server Seed Hash (commitment) — shown before the spin
• Client Seed — yours
• Nonce — the spin number
• Server Seed — appears only after you press Rotate (which reveals it)

To fully reproduce the segment, you also need the weights (segment odds). These are published in weights.maczo.json and are embedded automatically in the site's Verify ↗ links.

Method 1 — One-click (easiest)

On maczo.co open Lucky Spin → Spin history & verify, press Rotate seed to reveal the server seed, then click Verify ↗ next to any spin. It opens https://verify.maczo.co/ with everything filled in and computes instantly.

Method 2 — Browser, manual

1. Open https://verify.maczo.co/ (or index.html from the repo — works fully offline).
2. Paste Server Seed, Commitment, Client Seed, Nonce, and the weights JSON.
3. Press Verify spin. You'll see:
   • ✅/❌ whether SHA-256(serverSeed) matches the commitment
   • the reproduced segment index and prize

Method 3 — Node.js CLI

git clone https://github.com/maczo-co/lucky-spin
cd lucky-spin

# verify one spin
node verify.js \
  --commit  <serverSeedHash> \
  --server  <revealed serverSeed> \
  --client  <your clientSeed> \
  --nonce   <n> \
  --weights @weights.maczo.json

# confirm the code matches the spec with bundled known-answer vectors
node verify.js --selftest

What "verified" proves

• Commitment match → the server committed to this exact seed before you played; it could not have been chosen after seeing your bet or client seed.
• Reproduced segment → the published result is exactly what the algorithm produces from the seeds and weights — not a number the operator picked.

If either check fails, the result was tampered with. (It won't — that's the point.)