{
  "class": "invalid_payload",
  "raw_reason": "invalid_payload: Both paymentPayload and paymentRequirements are required",
  "hint": "Facilitator rejected the payment payload as malformed. Send both paymentPayload and paymentRequirements. A successful pay is not invented.",
  "title": "Sig Class Sample",
  "next": {
    "name": "sigclass",
    "title": "Sig Class",
    "price": "$0.03",
    "method": "GET",
    "url": "https://openclawproductions.com/api/v1/sigclass"
  },
  "note": "Frozen OpenX402 empty-POST facilitator string (2026-09-03): invalid_payload plus Both paymentPayload and paymentRequirements are required. Classification is from that text only. A tx hash is never invented. A successful pay is never invented. Distinct from decscale (on-chain decimals decode) and settleproof (observed on-chain settles). Next paid GET is Sig Class at $0.03."
}