Synappay

SynapPay is a decentralized cross-chain swapping protocol that enables seamless, secure, and efficient token exchanges between Ethereum and Stellar networks. Built for the 1inch hackathon, our solution leverages 1inch's Fusion+ protocol to provide users with the best possible rates while maintaining the security guarantees of atomic swaps.

Key Features:

• Bidirectional Cross-Chain Swaps: Swap tokens in both directions (Ethereum ↔ Stellar) with a single transaction
• Atomic Swap Security: Implements Hash Time-Locked Contracts (HTLC) on both chains to ensure atomicity
• 1inch Fusion+ Integration: Utilizes 1inch's Fusion+ for optimal pricing and deep liquidity on Ethereum
• Automated Relayer: Handles cross-chain coordination automatically for a seamless user experience
• Partial Fill Support: Enables orders to be filled by multiple counterparties for better liquidity
• Real-time Pricing: Integrates with 1inch API and CoinGecko for accurate, up-to-date exchange rates

Technical Implementation:

• Smart Contracts: Custom HTLC contracts for testnet, with mainnet integration to 1inch's Escrow Factory
• Backend: Node.js service managing cross-chain coordination and transaction monitoring
• Frontend: Intuitive React interface supporting both Ethereum (MetaMask) and Stellar (Freighter) wallets
• Security: Comprehensive audit trail, error handling, and monitoring

Use Cases:

• Cross-chain DeFi: Access Stellar's low fees while maintaining exposure to Ethereum's DeFi ecosystem
• Arbitrage: Capitalize on price differences between chains
• Portfolio Diversification: Easily move assets between chains to optimize for fees and speed
• Merchant Payments: Accept payments on either chain while settling in your preferred currency

The platform is built with a focus on security, user experience, and composability, making it an ideal solution for traders, DeFi users, and anyone looking to move value between Ethereum and Stellar efficiently.

• Synappay is a cross-chain bridge extending 1inch Fusion+ to Stellar.
• It enables atomic and partial fills for cross-chain swaps.
• The system utilizes 1inch under the hood with an HTLC solver on Stellar testnet.
• It supports bidirectional swaps between Ethereum and Stellar.
• The project includes a web UI with MetaMask and Freighter wallet integrations.