Proposes an extension to the x402 protocol to add first-class support for smart contract wallets (account abstraction) and EIP-4337 style 'UserOperation's, enabling clients using smart wallets to generate and submit payment payloads.
# Enable EIP-4337 Smart Wallet / UserOperation Support in x402 Protocol ## **1. Summary** We propose an extension to the x402 protocol that adds first-class support for smart contract wallets (account abstraction) and EIP-4337 style `UserOperation`s. This enhancement enables clients using smart wallets (rather than simple EOAs) to generate and submit payment payloads conforming to x402 flows, including verification and settlement of UserOperations, thus making x402 compatible with next-gen wallet models and on-chain UX patterns. ## **2. Motivation** Currently, x402 supports payments via “wallet signing” of a payment payload, typically by an externally-owned account (EOA) transferring tokens via a facilitator. While effective, this model does not fully support smart contract wallets, meta-transactions, account abstraction flows, or bundler/Paymaster models. With the rise of smart wallets (e.g., those created via SDKs like Alchemy Account Kit and Coinbase Smart Accounts) and the bro