{"plans":{"starter":{"price":"$1.00/mo","calls":"5,000 calls","savings":"80% vs pay-per-call"},"pro":{"price":"$4.00/mo","calls":"50,000 calls","savings":"92% vs pay-per-call"},"builder":{"price":"$9.00/mo","calls":"Unlimited","savings":"best value"}},"how_to_subscribe":"POST /subscribe/activate?plan=starter&wallet=0xYOUR_WALLET with X-PAYMENT header (USDC on Base)","pay_per_call":"$0.001/call via x402"}