{
 "id": "x402-payment-payload",
 "name": "x402 Payment Payload",
 "aliases": [
  "X-PAYMENT",
  "PAYMENT-REQUIRED",
  "PAYMENT-RESPONSE"
 ],
 "definition_md": "An **x402 Payment Payload** is the base64-encoded JSON credential carried in the HTTP `X-PAYMENT` (v1) or `PAYMENT-SIGNATURE` (v2) request header when an agent pays for an **HTTP 402 Payment Required** resource under the **x402** protocol. After receiving the server's pricing challenge (`paymentRequirements` specifying scheme, network, asset, amount, and recipient), the agent signs an EIP-3009 `TransferWithAuthorization` or Permit2 authorization and attaches it to the retried HTTP request, which the server or a **Facilitator** verifies and settles before returning the response and `PAYMENT-RESPONSE` receipt. Used by: x402.",
 "step": "pay",
 "related_protocols": [
  "x402"
 ],
 "sources": [
  {
   "url": "https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/http.md",
   "date": "2026-09-05",
   "label": "VERIFIED"
  },
  {
   "url": "https://x402.org/wp-content/uploads/sites/10/2026/06/x402-whitepaper.pdf",
   "date": "2025-05-06",
   "label": "VERIFIED"
  }
 ],
 "part_of": null,
 "group": null,
 "url": "https://agenticweb.wiki/terms/x402-payment-payload/",
 "okf_url": "https://agenticweb.wiki/okf/terms/x402-payment-payload.md",
 "category": "pay",
 "type": "term"
}