Asset: USDC (6 decimals)
Network: eip155:8453 — Base
Scheme: x402 / exact (EIP-3009, payer pays no gas)
Pay to:
On a paid call, the server responds 402 Payment Required with a PAYMENT-REQUIRED header. Agents read it, sign, settle — and get the markdown with a settlement receipt.
(challenge payload — JSON, base64 in header)