Gasless Payments with ERC-4337 Account Abstraction

The Gas Problem

Traditional EVM payments require users to hold two tokens: the payment token (USDT) and the native gas token (ETH, MATIC, etc.). This creates friction — users who receive USDT can't spend it without first acquiring gas tokens through an exchange or bridge.

For mainstream adoption, users should only need to think about the payment amount. They have USDT, they want to pay — everything else should be invisible.

ERC-4337: Account Abstraction

ERC-4337 introduces a new transaction flow that separates who initiates a transaction from who pays for gas:

Key components:

• UserOperation: A pseudo-transaction that describes what the user wants to do
• Bundler: Collects UserOps and submits them as real transactions
• Paymaster: A contract that sponsors gas fees (can be repaid in ERC-20 tokens)
• EntryPoint: The singleton contract that validates and executes UserOps

T402 Gasless Flow

T402 integrates ERC-4337 through the @t402/wdk-gasless package. The flow wraps a standard EIP-3009 TransferWithAuthorization inside a UserOperation:

flowchart TD
  A["1. Client signs EIP-3009 authorization
  (off-chain, free)"]
  B["2. Wrapped in UserOperation"]
  C["3. Paymaster agrees to sponsor gas"]
  D["4. Bundler submits UserOp to EntryPoint"]
  E["5. EntryPoint validates & executes"]
  F["5a. Paymaster pays gas"]
  G["5b. Token transfer via transferWithAuthorization"]
  H["6. USDT moves payer → payee"]
  I["7. Gas deducted from paymaster
  (or charged to user in USDT)"]

  A --> B --> C --> D --> E
  E --> F & G
  F --> H
  G --> H
  H --> I

The user experience is simple: sign one message, payment complete. No ETH, no gas estimation, no stuck transactions.

Implementation

Supported Chains

Gasless payments are available on all EVM chains where ERC-4337 infrastructure is deployed:

Trade-offs