Settlement
nanopayments
Nanopayments, in Circle's documents, are gas-free USDC payments down to one millionth of a dollar. The buyer deposits USDC into a Gateway wallet, signs an EIP-3009 authorization, and Gateway verifies it and settles many payments in one batch. Circle presents this as an x402 rail, not as a separate public ledger.
Explanation
Circle's product page describes the flow as an HTTP 402 challenge, an offchain signature, immediate verification against the Gateway balance, and a later onchain batch. The signing guide says USDC uses 6 decimals and that Gateway checks the EIP-3009 signature with public-key recovery, so ERC-1271 contract wallets are outside this path. The blog post announces mainnet support across Gateway's EVM chains.
This index does not keep a second series called nanopayments. Where a Circle facilitator settles x402 USDC on a scanned chain, including Arc, those transfers are already x402. A Gateway-only balance change that never becomes a facilitator transfer on a scanned chain is not imputed. Adding both would either invent volume or count the same transfer twice.
Live data
Related terms
Sources
- Nanopayments — Circle
- Nanopayments powered by Circle Gateway is now live on mainnet — Circle
- Sign EIP-3009 payment authorizations — Circle
- Agent GDP methodology — Agent GDP