Pay $0.01 USDC on Base mainnet to exercise the full
x402 protocol flow
against the /ping demo endpoint. Your Phantom wallet handles the EIP-3009
transferWithAuthorization signature; settlement clears through the
Coinbase CDP facilitator. Real products (risk-score $1.00, sanctions $0.50,
tx-trace $3.00, etc.) live under /x402/api/address/....
Endpoint:
Network: Base mainnet (chainId 8453)