Introduction

zPredict is a shielded prediction market on Zcash, built for ZECATHON 2026 (Private Markets track). Everyone sees the odds. Nobody sees who bet.

• Orders are split in your browser into three XOR shares, one per relayer. A single share is uniformly random.
• Matching happens inside 3-party MPC (polytune): the relayers cross YES against NO at the midpoint and check your balance and your account credential in-circuit. Only your fill (to you) and one public clearing price per market come out.
• Collateral sits in a FROST 2-of-3 escrow on Zcash's Ironwood shielded pool. Withdrawals are batched into one shielded transaction, and every signer re-derives what it signs.
• Outcomes come from Zcash mainnet block data (or, for mirrored markets, from Polymarket), are FROST-signed by the relayers, and are verified in your browser.

Reading orders needs all three relayers to collude; moving funds needs two. The hosted demo runs all three on one VM behind Cloudflare, so read it as a working protocol, not a working trust split. See Privacy and Status.

Try itCopy Anchor Link

1. Open app.zpredict.site and press Judge mode. You get mock testnet collateral without a deposit (it can never be withdrawn).
2. Pick a market and place an order. Trading alone? Tick Take the other side (demo) to add a labelled self-trade, so you see a fill.
3. Open the Relayer View (/trade/): three panels of noise, with your own shares lit.

Where to go nextCopy Anchor Link

SourceCopy Anchor Link

Everything is in one MIT-licensed monorepo, zpredict/zpredict. The protocol is specified in DESIGN.md and audited in PRIVACY.md; these pages are written from them and from the code, and link to both.