supernova

Supernova is a novel extension of 1inch Fusion+ that enables trustless cross-chain swaps between Ethereum and Stellar, expanding the protocol beyond EVM-compatible ecosystems. The project integrates directly with the 1inch Limit Order Protocol on the Ethereum side using fillOrderArgs, implementing hashlock and timelock functionality to ensure secure, atomic execution. On Stellar, a complementary escrow contract mirrors this logic through Hashed Timelock Contracts (HTLCs), allowing bidirectional swaps where users can seamlessly move assets between Ethereum and Stellar. The system guarantees that either both sides of the swap complete successfully or funds are safely refunded after the timelock expires, preserving user security. By connecting Ethereum’s deep liquidity with Stellar’s fast and low-cost transaction network, Supernova demonstrates how Fusion+ can evolve into a universal cross-chain liquidity layer, serving as a blueprint for future integrations with other non-EVM blockchains.

Our project is built with a combination of Solidity, Soroban, and Next.js, carefully pieced together to extend Fusion+ beyond EVM. On the Ethereum side, we developed a Solidity contract that directly integrates with the 1inch Limit Order Protocol using fillOrderArgs, ensuring compatibility with Fusion+’s existing swap flow. This contract implements hashlock and timelock logic to enforce atomicity. For Stellar, we used Soroban, Stellar’s smart contract platform, to build a complementary Hashed Timelock Contract (HTLC) that mirrors the EVM contract, enabling secure bidirectional swaps. The frontend was built with Next.js, providing a simple interface for users to initiate cross-chain swaps and visualize the transaction process. To design this solution, we studied the existing Solidity implementation within Fusion+, then adapted the core logic to make it work across two fundamentally different blockchain environments. The hacky part came in bridging the differences between the EVM and Soroban programming models, particularly in how state and contract calls are handled, but this experimentation allowed us to align both sides to a shared hash/timelock flow. Using Soroban as a partner technology gave us a direct way to bring Stellar into the cross-chain swap ecosystem, and integrating with 1inch’s Limit Order Protocol ensured that our work slots directly into Fusion+ without reinventing its architecture.