FriendSwap
Decentralized P2P Cross-Chain Swap Protocol
About
The problem it solves # FriendSwap Miniapp - P2P Cross-Chain Token Swaps ## Project Overview **Name**: FriendSwap **Title**: Decentralized P2P Cross-Chain Token Exchange on Farcaster **Category**: DeFi Infrastructure / Cross-Chain Protocol ## Description FriendSwap is a peer-to-peer cross-chain token swap protocol that enables users to exchange tokens directly across different blockchain networks without relying on centralized exchanges or bridges. Built as a Farcaster Mini App, it combines the social aspect of Farcaster with trustless cross-chain DeFi functionality, allowing users to discover and fulfill swap requests within their social network. The protocol implements atomic cross-chain swaps using hashlock and timelock mechanisms, ensuring that either both parties receive their tokens or the swap fails completely - eliminating counterparty risk. ## What We're Solving ### 1. **Peer-to-Peer Token Exchange Risk** - People hold different tokens but have no safe way to exchange them directly - Example: Alice has USDC and needs ETH, Bob has ETH and needs USDC - Current solutions involve centralized exchanges with custody risks and fees - No trustless platform for direct one-to-one token swaps between individuals ### 2. **Cross-Chain Liquidity Fragmentation** - Traditional DEXs are limited to single chains - Users must use complex bridge protocols with high fees and risks - Limited liquidity across different blockchain ecosystems ### 3. **Centralized Exchange Dependencies** - Users rely on CEXs for cross-chain trades - Custody risks and regulatory concerns - High fees and withdrawal limits ### 4. **Social Discovery Gap** - No easy way to find trusted counterparties for OTC trades - Lack of social context in DeFi transactions - Difficulty in discovering fair swap opportunities ### 5. **Complex User Experience** - Multi-step bridge processes - High technical barriers for cross-chain operations - Poor mobile/social media integration ## How It Works ### Core Protocol Architecture  ### Step-by-Step Process 1. **Request Creation**: Asker creates a swap request specifying: - Source token and amount (what they're offering) - Destination token and amount (what they want) - Source and destination chains - Expiration time 2. **Source Escrow Deployment**: Asker deploys and funds the source escrow contract with their tokens 3. **Discovery**: Other users browse available swaps on the Farcaster Mini App 4. **Fulfillment**: Fulfiller deploys destination escrow with their tokens matching the request 5. **Secret Revelation**: The relayer reveals the secret, enabling both parties to claim their tokens atomically 6. **Completion**: Both escrows release tokens to the respective recipients ### Security Mechanisms - **Hashlock**: Cryptographic commitment ensuring only the secret holder can unlock funds - **Timelock**: Time-based expiration allowing refunds if swaps aren't completed - **Deterministic Addresses**: Predictable contract addresses for verification - **Access Control**: Only authorized parties can deploy and interact with escrows ## Why This Product Matters ### 1. **Democratizing Cross-Chain DeFi** - Removes technical barriers for average users - Social context makes DeFi more accessible and trustworthy - Mobile-first approach reaches broader audience ### 2. **True Decentralization** - No central authority or custody - Peer-to-peer discovery and execution - Trustless atomic swaps ### 3. **Cost Efficiency** - Direct swaps without intermediate bridges - Minimal gas costs through optimized contracts - No trading fees beyond platform maintenance ### 4. **Social Layer Innovation** - First P2P cross-chain protocol integrated with social media - Leverages social graphs for counterparty discovery - Community-driven liquidity provision ### 5. **Native Notification System** - Farcaster provides built-in notification infrastructure - Users get real-time alerts when new swap opportunities match their interests - Push notifications for swap fulfillment requests directly in their social feed - Perfect platform for discovering time-sensitive trading opportunities within your network Smart Contract Address(es) ## Contract Addresses ### Sepolia - **Factory**: `0x543046076dE28686b3A6BEb34a29C747F26fBA23` - **EscrowSrc**: `0x976708a30358649CbFaDcFb4583518556bb4699E` - **EscrowDst**: `0x8DCB7fC8e4BB2bb5c5cB70b5F1a22035d6D79FFe` ### Base Sepolia - **Factory**: `0xEC9f35Dc7B6bC272Dc874Ae016554FcEBce5f68b` - **EscrowSrc**: `0xE80a47Ff3C587087Ac2809b82C5ca1d29196cc24` - **EscrowDst**: `0x4951715141dED8b45a01529e98dC26d24B3da5a0`
How it's made
Challenges we ran into ## Technical Challenges Overcome ### 1. **Cross-Chain State Synchronization** **Challenge**: Ensuring atomic operations across different blockchains with different finality times. **Solution**: Implemented hashlock-timelock pattern with deterministic contract addresses and event-driven relayer coordination. ### 2. **Minimal Proxy Gas Optimization** **Challenge**: Deploying individual escrow contracts for each swap is expensive. **Solution**: ERC-1167 minimal proxy pattern reduces deployment costs by ~90% while maintaining isolated state. ### 3. **Factory Initialization with Clones** **Challenge**: Constructor parameters don't work with cloned contracts. **Solution**: Implemented initialize() pattern with factory address setting during first call to maintain access control.