ckUSDT is a digital twin of USDT on the Internet Computer Protocol network. Fully backed 1:1 by USDT, ckUSDT is powered by Chain-key technology which allows for cross chain interoperability without centralized intermediaries or bridges. Canister smart contracts on ICP can integrate with the Ethereum network using a combination of replicated HTTPS outcalls to a known set of public Ethereum nodes to read state and submit transactions, and chain-key ECDSA (ckECDSA) signatures, an enhanced version of threshold ECDSA, to sign those submitted transactions. Building upon this integration framework, ckUSDT is a pair of canister smart contracts that utilize HTTPS outcalls and ckECDSA services. The ckETH minter and ckUSDT ledger contracts work together to enable users and smart contracts to send and receive USDT value within seconds with negligible transaction fees, and no gas fees, while also always allowing users and smart contracts to send and receive USDT value to and from the Ethereum network. ckUSDT exposes ICRC-1 and ICRC-2 ledger interfaces (the fungible token standards of ICP), making it simple for all wallets on the Internet Computer to offer ckUSDT support.