{"service":"Web4 World Store","support":{"contact":{"email":"158969666@qq.com","response_sla_hours":24,"languages":["zh","en"]},"refund_policy":{"delivery_failed":"full refund (on-chain tx hash as proof)","content_corrupted":"full refund (on-chain tx hash as proof)","delivered_ok":"no refund (digital content); free certificate reissue","how_to_request":"email 158969666@qq.com with your tx hash + product id"},"faq":{"delivery_format":"JSON envelope: {product_id, title, content_markdown, certificate}","certificate":"ECDSA anti-counterfeit cert (X-Web4-Certificate header on local gateway; embedded in JSON on edge)","verify_certificate":"compare certificate JSON signature against signer 0xd29D93F0A5E161F1F286F5Cd5Afeb718837C15E1","batch_purchase":"buy per-product; bulk endpoints planned (email for volume pricing)","payment_failed":"402 error includes detail.reason; retry with fresh signature (nonce reuse rejected)","networks":"Base mainnet USDC (eip155:8453) via x402 v2 exact scheme"},"note":"AI agent 请先读 faq 与 refund_policy；其他问题邮件联系。"}}