---
type: Glossary Term
title: "x402 Payment Payload"
description: "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."
resource: "https://agenticweb.wiki/terms/x402-payment-payload/"
tags: ["glossary", "pay"]
status: stable
generated: { by: agenticweb-builder/1.0, at: 2026-10-23T00:00:00Z }
verified: { by: process:agenticweb-engine, at: 2026-10-23T00:00:00Z }
stale_after: 2026-11-22T00:00:00Z
sources:
  - id: ref-1
    resource: "https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/http.md"
    last_modified: 2026-09-05T00:00:00Z
  - id: ref-2
    resource: "https://x402.org/wp-content/uploads/sites/10/2026/06/x402-whitepaper.pdf"
    last_modified: 2025-05-06T00:00:00Z
---

# x402 Payment Payload

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.

# Knowledge Graph

* **Related standards**: [x402](/okf/protocols/x402.md)

[^ref-1]: https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/http.md (https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/http.md)
[^ref-2]: https://x402.org/wp-content/uploads/sites/10/2026/06/x402-whitepaper.pdf (https://x402.org/wp-content/uploads/sites/10/2026/06/x402-whitepaper.pdf)