How does Stable enable free USDT transfers? @stable is building a digital nation for USDT, offering a wide range of USDT native features, and also delivering end-to-end scalability optimizations across RPC, Consensus, Execution, and DB. Among the USDT-specific features, the most notable is free USDT transfers. But how does Stable actually make this possible? "The secret lies in ERC-4337 and EIP-7702." [ERC-4337] ERC-4337 is the leading account abstraction standard in the Ethereum ecosystem. It implements account abstraction without changing the core Ethereum protocol by introducing: - EntryPoint - Bundler - Paymaster In ERC-4337, users sign a separate object called a UserOp instead of a traditional transaction, and send it to a dedicated off-chain mempool (UserOperation mempool) rather than Ethereum’s public mempool. While traditional mempool transactions are validated by validators, in ERC-4337 Bundlers validate UserOps from users, package them into a single bundle transaction, and send it to the EntryPoint smart contract. The EntryPoint is the core contract of ERC-4337. It verifies and executes UserOps, and processes gas settlement in one step. Here, the Paymaster can be optionally used — a smart contract that pays gas fees on behalf of the user or allows fees to be paid in an alternative token. If a UserOp specifies a Paymaster and includes the required extra data, the EntryPoint will process it so the user either pays no gas fee or can settle the fee in another token. [EIP-7702] Although ERC-4337 introduced an innovative account abstraction standard, it faced adoption challenges. A key issue was that to use account abstraction, end-users had to transfer funds from their existing EOA to a newly created CA. This added friction to the user experience and slowed widespread adoption. EIP-7702 solves this. Introduced with the Ethereum Pectra upgrade, it allows an EOA to temporarily act like a CA. This means users can keep their existing EOA address and UX while immediately using account abstraction features like ERC-4337. To make this possible, EIP-7702 introduces a new transaction type. In addition to regular transaction fields, it includes an authorization_list, which contains signatures approving which contract code can be temporarily delegated to the account. This signature essentially says, “I allow my EOA to temporarily run the code from this smart contract address.” When the EOA executes the transaction, the delegated smart contract logic runs. After the transaction completes, the delegation is automatically revoked, and the EOA returns to its original state. [Gas-free USDT Transfer] By combining ERC-4337 and EIP-7702, Stable’s secret recipe is complete: 1. The user signs a USDT transfer transaction from an account enabled with EIP-7702. 2. The signed UserOp is sent to the Bundler network. 3. The Bundler includes the transaction in a bundle and sends it to the EntryPoint, coordinating with the Paymaster to prepare gas payment. 4. The Paymaster covers the gas cost for executing the transaction, and the EntryPoint executes it — resulting in a completely free USDT transfer for the user. Additionally, Stable enables users to pay gas fees in USDT through ERC-4337 and EIP-7702.