How does Sweepster's gasless sweep work?

Sweepster is a gasless cross-chain token sweep built on EIP-7702: your wallet temporarily gains smart-account behavior for one transaction, so a relayer can pay the gas while your tokens still move atomically — pulled, swapped, fee-skimmed, and delivered in a single transaction that either fully succeeds or fully reverts.

The flow, step by step

1. Your wallet signs two things off-chain: an EIP-712 typed-data order (what to sweep, where it goes, the fee) and an EIP-7702 authorization delegating your EOA to Sweepster'sSweepDelegate contract for this transaction.
2. Sweepster's relayer submits a type-4 transaction carrying both the signed order and your 7702 authorization — you never send a transaction or hold native gas yourself.
3. For the duration of that transaction, the SweepDelegate code runs AS your EOA (that's what the 7702 authorization grants) — it acts with your account's own balance and approvals, not as a separate contract holding custody.
4. In that one transaction, the delegate code pulls the source token, swaps it if needed, skims the gas reimbursement plus fee, and delivers the remainder — same-chain or bridged cross-chain. Every step is inside the same reverting transaction: partial execution isn't possible.

Why this needs no native gas

Because the relayer submits the transaction and is reimbursed out of the swept value itself, your wallet never needs ETH (or any native gas token) to sweep — even a wallet holding only a stray ERC-20 and zero native gas can sweep.