ThunderPortal

Thunder Portal enables trustless atomic swaps between Bitcoin and Ethereum without bridges or wrapped tokens. We extended 1inch Fusion+ protocol to support native Bitcoin through a custom HTLC service written in Rust.

Key features:

• True atomic swaps with cryptographic guarantees
• No intermediary tokens or bridges required
• Real testnet transactions on Bitcoin testnet3 and Ethereum Sepolia
• Order chunking for improved liquidity matching
• CLI demo and live testnet swap functionality

Our solution solves the trust problem in cross-chain swaps by using Hash Time Locked Contracts (HTLCs) on both chains, ensuring either both transactions complete or neither does.

Thunder Portal consists of three main components:

1. Bitcoin HTLC Service (Rust): Custom service that creates and manages Bitcoin HTLCs, handles script generation, and monitors the Bitcoin testnet3 network.

2. Ethereum Smart Contracts (Solidity): Factory pattern for deploying escrow contracts that implement HTLC logic on Ethereum Sepolia.

3. Thunder Portal CLI (TypeScript): Orchestrates the atomic swap process, manages order chunking, and provides user interface.

We extended the 1inch Fusion+ architecture by adding Bitcoin support through our HTLC service. The system ensures atomicity by using the same preimage hash on both chains - revealing the preimage claims both sides of the swap simultaneously.

Notable technical achievements:

• Real Bitcoin script generation for HTLCs
• Atomic guarantee without trusted intermediaries
• Live testnet deployment with verifiable transactions