intoStellar

intoStellar is a robust cross-chain swap protocol bridging EVM chains with the Stellar network, built with deep interoperability in mind. It fully implements all 7 hashlocks, ensuring atomic, trustless asset swaps. A custom Limit Order Protocol (LOP) smart contract is written and deployed on both EVM and Stellar, enabling true bi-directional swapping between chains.

To ensure security and recoverability, timelocks are preserved across contracts, protecting users from failed or incomplete transactions. All contracts are live on testnets, with addresses and deployment details available in the README.

At the heart of the architecture lies a powerful relayer service, equipped with secure secret-sharing mechanisms to safely manage and reveal preimages only when conditions are met — ensuring integrity across the swap lifecycle.

To onboard new users into the Stellar Chainverse, the Stellar Starter Pack creates, funds, and deploys Stellar wallets automatically for EVM users — making their entry frictionless and instant.

ntoStellar is a comprehensive cross-chain atomic swap platform that enables seamless, trust-minimized token exchanges between Ethereum and Stellar networks. The system is designed around a three-part architecture: a Next.js frontend, a TypeScript-based relayer service, and a suite of smart contracts deployed on both Ethereum and Stellar testnets.

The frontend provides users with a clean interface to initiate swaps, connect wallets (MetaMask for Ethereum and Freighter for Stellar), and monitor swap progress in real-time. All blockchain interactions are abstracted through custom React hooks, enabling consistent UI state management, error handling, and feedback across different transaction stages.

The relayer is the coordination layer between chains. It listens for contract events on both Ethereum and Stellar, manages hashlock secrets using a secure scheme, and ensures atomic execution by enforcing swap conditions across both networks. If a transaction fails on either side, the relayer halts the process to prevent partial execution.

On the Ethereum side, we use Solidity contracts that integrate with 1inch Fusion+, particularly EscrowFactory and EscrowSrc contracts, to lock assets under defined conditions. On the Stellar side, we implemented equivalent Soroban smart contracts in Rust—StellarEscrowFactory and FusionPlusEscrow—which replicate the EVM escrow logic, including immutable deployment parameters and multi-stage timelock functionality to mirror Ethereum’s behavior precisely.

One of the most challenging aspects was dealing with Soroban's authEntry signing across different wallet providers. Wallets like Freighter returned inconsistent formats—ranging from Buffers to serialized objects—which required writing custom format detection and conversion logic. This debugging process involved multiple iterations to handle edge cases in wallet serialization.

Another significant technical task was cross-chain transaction sequencing. Stellar enforces strict sequence numbers, so the system had to ensure that operations are signed, sent, and confirmed in the correct order to prevent txBadSeq errors. To manage this, we built a state machine that tracks the lifecycle of the swap on both chains and keeps the UI accurately synchronized with blockchain state.

Additionally, a Stellar Starter Pack feature automatically creates and funds Stellar wallets for new EVM users, allowing for a frictionless onboarding experience into the Stellar ecosystem without manual setup.

Overall, intoStellar brings together advanced blockchain integration techniques, consistent multi-wallet support, and precise control over atomic operations, forming a reliable foundation for secure, bi-directional cross-chain swaps.