Introduction

Sweepster is a gasless, cross-chain token sweep service. The one-line pitch:

Sign once, move any ERC-20 from any supported EVM chain to any wallet on any supported chain — even when the source wallet holds zero native gas token.

The paymaster/relayer fronts gas on both ends. All costs — gas, bridge fees, and the Sweepster protocol fee — are skimmed atomically from the assets in motion.

What makes it different

Most gasless solutions stop at meta-transactions. Sweepster's defensibility is the source-side atomicity invariant: the transaction that moves the user's funds also pays Sweepster in the same atomic call. There is no state where value has been advanced and repayment can be revoked or front-run.

The off-chain product is EIP-7702-only. To run a sweep, the user signs two things off-chain — no gas, no on-chain approval, no token allowance:

1. The order — an EIP-712 typed-data signature over the SweepDelegate SweepOrder. This becomes the bytes signature passed to sweep().
2. An EIP-7702 authorization delegating their EOA to the per-chain SweepDelegate implementation contract.

A relayer (Kryard) then broadcasts the EIP-7702 type-4 "set-code" transaction and pays the gas. The sweep runs as the user's own EOA (now temporarily behaving like a smart account), pulls and swaps the token, skims fees, and delivers — all in one atomic transaction. The user never holds native gas; a wallet with only ERC-20s and zero native token can sweep.

The on-chain SweepRouter / Permit2 contracts still exist but are not used by the product — Permit2 requires an on-chain approve, which costs gas. See Gasless Settlement.

What Sweepster is not

• Not custodial. Users sign two off-chain authorizations. No assets are held by Sweepster at any time.
• Not audited yet. A full external audit and bug bounty program are planned before mainnet value moves.
• Not a static token list. Any ERC-20 is accepted at quote time, subject to the Token Risk Engine screen.

Supported chains (target)

Ethereum · Base · Arbitrum · Optimism · Polygon · BNB Smart Chain

Key concepts

• Gasless Settlement — how gas is sponsored and recovered
• Source-Side Atomicity — the repayment invariant
• Fee Model — layered fee policy
• Token Risk Engine — any-ERC-20 gating
• Supported Chains — current and planned

For builders

If you're integrating Sweepster into your wallet, exchange, or app, start with the Builder Quickstart.