Handover

Handover makes a whole wallet sellable without trusting the seller. Today, selling a wallet (a funded address, a project's treasury) means handing over a seed phrase, and the seller keeps a copy. In Handover the wallet is an NFT: each token controls its own Ethereum (Sepolia) address through NEAR Chain Signatures, and no private key exists. Only the current owner can get a signature, and the contract builds every transaction itself as a plain ETH transfer with no calldata, so no token approval can ever be signed. Every signature goes into a public, sequential log, listing freezes signing, and a clean check anyone can run compares that log with the Sepolia nonce to prove no signed transaction is left over. buy() moves the NFT and pays the seller in one call, bound to the state the buyer checked. The contract has no admin or upgrade path, and its keys are deleted. NEAR is the core: Chain Signatures let a NEAR contract control the Ethereum address, and NEP-171 makes it a transferable token. Deployed and locked on NEAR testnet (handover.handover-alpha.testnet) with a hosted demo. The full sale, a caught pre-signed transaction and the old owner's refused request are committed as on-chain evidence in the repo.