fantom → sonic ($s) token migration
Token migration smart contract & claims dApp for one of the largest L1 rebrands of 2024.
the brief
Fantom's transition into Sonic ($S) was one of the most consequential L1 rebrands of the year — billions of dollars in $FTM held by hundreds of thousands of wallets needed to migrate cleanly to the new $S token. The window was tight. The audit bar was enterprise-grade. Any bug in the migration contract or claims dApp could brick funds permanently. There was no margin for error.
the work
Migration smart contract. Audit-grade Solidity handling 1:1 $FTM → $S conversion with reentrancy guards, pausable circuit breakers, and emergency withdrawal paths. Deployed to mainnet with multi-sig admin keys.
Claims dApp. Production Next.js + Ethers.js frontend that wallet-connects, reads on-chain balances, signs the migration transaction, and walks users through a clean four-step UX. Built for users who'd never touched a contract before.
Wallet support matrix. MetaMask, Rabby, WalletConnect v2, Coinbase Wallet, and hardware wallets — all tested, all documented.
Transaction monitoring. Real-time pending/confirmed/failed states, gas-price awareness, retry logic for dropped txs, and a live migration counter for the community.
Internationalization. The dApp shipped in English, Mandarin, Korean, and Japanese on day one — Fantom's largest holder communities.
the result
The migration moved hundreds of millions in token value with zero on-chain incidents. The claims interface was praised by the Fantom community as the smoothest L1 migration experience to date, and continued to serve late claimers for months after launch.
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