{"x402_version":1,"environment":"production","asset":"USDC","decimals":6,"network":{"name":"base","chain_id":8453},"token_address":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","authorization_type":"TransferWithAuthorization (EIP-3009)","signature_scheme":"EIP-712","eip712_domain":{"name":"USD Coin","version":"2","chainId":8453,"verifyingContract":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"},"challenge_ttl_seconds":300,"custody":"none","recipient":"0x417da74cdc0d3babf6adc851b6e5c638574c0d58","price_minor":"590","free_tier":"20 calls/day per client","settlement":"facilitator (gas-sponsored, on-chain, non-custodial)","notes":"The 402 challenge body is authoritative for recipient, amount, chain, nonce. Payer->seller direct; the rail never holds funds."}