Execute agentic USDC payments using the x402 HTTP payment protocol — sign EIP-3009 authorizations, settle payments, and verify receipts. Use when an agent needs to pay for API access or when building pay-per-call services.
x402 is an HTTP-native payment protocol that lets AI agents pay for API access using USDC on Ethereum. It extends HTTP 402 Payment Required into a machine-readable payment flow.
Agent → GET /api/resource → 402 Payment Required (with payment details)
Agent → Signs EIP-3009 transferWithAuthorization
Agent → Retries request with X-PAYMENT header
Server → Forwards to Facilitator for settlement
Facilitator → Settles USDC on-chain
Server → Returns the resource
The agent never needs to hold ETH for gas. EIP-3009 transferWithAuthorization allows gasless USDC transfers where the facilitator pays the gas and deducts it from the payment.