ChainMate

ChainMate is a trustless P2P chess wagering platform that eliminates the need for centralized escrow services. Players create wagers on one blockchain and opponents can accept from any chain using Avail Nexus for seamless cross-chain bridging. Game outcomes are automatically verified using Reclaim Protocol's zero-knowledge proofs, which cryptographically prove Chess.com results without exposing private session data. All transactions are tracked in real-time via Blockscout SDK integration, providing complete transparency. Smart contracts handle escrow and settlement automatically, with winners receiving funds instantly after verification. Built with Hardhat 3, featuring 95%+ test coverage and deployed on Base Sepolia and Arbitrum Sepolia.

Built with Next.js frontend, Node.js backend, and Solidity smart contracts developed using Hardhat 3's new EDR runtime and Viem testing framework. Integrated Avail Nexus SDK to enable cross-chain wager acceptance - users can accept wagers on Base using funds from Arbitrum in one transaction. Blockscout SDK provides real-time transaction toast notifications and history popups for complete transparency. Backend service runs automated verification using Reclaim Protocol to generate zkTLS proofs of Chess.com game outcomes, which are verified on-chain by our ReclaimVerifier contract. Notable challenge: Fixed critical winner determination bug where we had to parse Chess.com's result format ("1-0", "0-1") and match winning color to player usernames to determine correct wallet address. Used Hardhat 3's chain type specification to optimize gas costs for L2 deployments. All four partner technologies work together seamlessly to create a truly trustless, cross-chain wagering experience.