About Fairplay
Fairplay is a commit–reveal pool engine for USDC on Base. Creators configure a pool, participants enter at a fixed price, and a winner is drawn using revealed salts plus a block hash. No external VRF required, with an optional sentinel for extra neutrality.
How it works
- Create: The creator commits to a secret salt (its hash is stored on-chain), sets entry price, timing windows, and fees. (Optional) A sentinel also commits.
- Enter: Participants approve USDC and buy entries at a flat price during the entry window.
- Reveal: After entries close, the creator (and optional sentinel) reveal their salts before the reveal deadline(s).
- Draw: The contract derives a random word from the revealed salts + block hash and pays the winner instantly. Unpaid fees accrue to designated recipients.
Fairness & security model
Commit–reveal ensures the randomness seed is fixed before anyone knows the reveal time block hash. Using a sentinel (a second independent commit) makes the combined seed harder to bias.
- Bonds: Creator and (optionally) sentinel post refundable bonds. Missed or late reveals can be slashed to discourage griefing.
- No VRF dependency: Randomness is derived from on-chain data (salts + block hash); fewer moving parts, lower cost.
- Deadlines: Entry and reveal windows are strict to remove ambiguity and race conditions.
Roles
- Commits to a secret salt and sets pool parameters.
- Posts a bond and must reveal on time.
- Receives the builder fee (if configured).
- Provides a second, independent commit.
- Posts a bond; must reveal on time.
- Improves neutrality of the seed.
- Approves USDC and enters at a fixed price.
- Awaits draw after reveals.
- Receives prize instantly if selected.
Fees
Fees are set in basis points (bps) at pool creation. For example, 200 bps = 2%. Fees are split between the builder and protocol recipients configured in the contract. If you build on top of Fairplay via our SDK, you can designate your own builder recipient.
Accessibility & UX
- Clear language and tooltips explain pool parameters.
- High-contrast palette and large touch targets on mobile.
- Keyboard accessible navigation and focus states.
Roadmap
- Curated templates and presets for popular pool types.
- Hosted sentinel service with APIs.
- Expanded analytics and public leaderboards.
- SDK examples (Next.js, pure viem, server actions).
Disclaimer
Fairplay is experimental software. Use at your own risk. Nothing here is financial advice. Check local laws and regulations before operating prize pools or games of chance in your jurisdiction.