Wallets and identity
smart wallet
A smart wallet is an account whose control is defined by code rather than only by a single private key. On Ethereum that is often an ERC-4337 wallet with a paymaster that can sponsor gas. A smart wallet can hold USDC. Some agent-payment signature checks still accept only an ordinary key.
Explanation
ERC-4337 defines UserOperations, bundlers, and paymasters. The wallet's validation logic decides which signatures are valid, which is why ERC-1271 exists for contracts to prove a signature. AP2 and ERC-8004 both allow contract-wallet proofs where their specs say ERC-1271. That is an authorization feature, not a settlement feed.
Circle's Gateway nanopayment path documents the opposite constraint: verification uses public-key recovery on an EIP-3009 signature and does not support ERC-1271. A smart wallet that cannot produce that signature cannot use that path until the verifier changes. x402 facilitators differ by scheme. This index never sees the wallet type. It sees the token transfer and the facilitator sender.
Live data
Related terms
Sources
- ERC-4337: Account Abstraction Using Alt Mempool — Ethereum Improvement Proposals
- ERC-8004: Trustless Agents — Ethereum Improvement Proposals
- Nanopayments — Circle
- Sign EIP-3009 payment authorizations — Circle