FusionX – Ethereum ↔ Cosmos Cross-Chain Swaps with Hashlocks & Timelocks

A Unite DeFi Hackathon project building a fully onchain, bidirectional swap bridge between Ethereum and Cosmos using HTLC (Hash Time Locked Contracts) and 1inch Fusion+ order settlement.

🌉 Project Overview

FusionX enables secure, atomic cross-chain swaps between Ethereum and Cosmos chains. Leveraging 1inch Fusion+ and a CosmWasm-based HTLC, users can trustlessly initiate swaps from one chain and settle on the other—without relying on off-chain infrastructure.

• Ethereum → Cosmos swaps via HTLC & secret reveal
• Cosmos → Ethereum swaps with preimage symmetry
• Powered by Solidity, CosmWasm, and Next.js
• Compatible with MetaMask, Keplr, and Leap wallets

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👥 Team Roles

🔐 Smart Contract Dev

• Solidity HTLC + Fusion+ settlement (FusionOrderSettler.sol, EthereumHTLC.sol)
• CosmWasm HTLC in Rust (CosmosHTLC.rs)
• Deploy to testnets (e.g., Sepolia, Juno, Osmosis)
• Provide ABI and deployment metadata

🖥 Frontend Dev

• Build React/Next.js DApp
• Connect Ethereum (MetaMask) and Cosmos (Keplr/Leap)
• Use Viem, Wagmi, RainbowKit (Ethereum)
• Use CosmJS (Cosmos)
• UI for swap initiation, tracking, claiming

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🔧 Core Components

1. Ethereum Side – Solidity

• FusionOrderSettler.sol: Initiates HTLCs based on 1inch Fusion+ orders
• EthereumHTLC.sol: Locks ETH/ERC20 with hashlock + timelock
• Preimage reveal enables secure claim

2. Cosmos Side – CosmWasm

• CosmosHTLC.rs: Locks ATOM/CW20 with identical hash and timelock
• Claim enabled once preimage is revealed from Ethereum

3. Frontend DApp – Next.js

• Wallet connections: MetaMask (EVM), Keplr/Leap (Cosmos)
• Swap creation UI: amount, chain, hashlock, timelock
• Status tracking:
  • Locked
  • Awaiting secret
  • Claimed / Refunded
• Visuals for Ethereum ↔ Cosmos flow

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🔄 Swap Flow

Ethereum → Cosmos

1. Alice locks ETH in Ethereum HTLC via FusionOrderSettler
2. Bob claims ATOM on Cosmos by revealing the secret
3. Alice uses revealed secret to unlock ETH

Cosmos → Ethereum

1. Bob locks ATOM in Cosmos HTLC
2. Alice claims ATOM by revealing preimage
3. Bob uses revealed preimage to unlock ETH

✅ Hashlock and timelock enforced on both chains for trustless swaps.

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🧱 Tech Stack

Smart Contracts

• Ethereum: Solidity + Foundry
• Cosmos: CosmWasm + Rust

Frontend

• React + Next.js
• Tailwind CSS
• Ethereum: Viem + Wagmi + RainbowKit
• Cosmos: CosmJS + Keplr/Leap

Dev Tools

• GitHub
• Foundry / Hardhat Anvil
• Remix (EVM test)
• Neutron Testnet

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✨ Stretch Goals

Feature	Description
UI/UX Polish	Clean, intuitive design for end users
Partial Fill Logic	Support claiming partial HTLC balances
Relayer Service	Automate claims with offchain script
Resolver Registry	Select best claimant for atomic routing
Realtime OrderBook	Fusion+-style order book display

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✅ Submission Checklist

• Bidirectional HTLCs with hashlock + timelock
• Working Ethereum ↔ Cosmos preimage swap
• Contracts deployed and verifiable
• Frontend DApp with wallet integration
• Demo showcasing full flow (ETH → NTRN)

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📂 Project Structure