Ed's Agentic Finance Rails

x402

An open payment standard built on the HTTP 402 Payment Required status. A server asks for payment inside the web request, and the client pays and retries. Coinbase for Agents uses it.

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x402

x402 is an open payment standard built on HTTP. It lets a client, such as an agent, pay for something it asks a website for.12

How it works

  1. The client asks for a resource.
  2. If no valid payment is attached, the server replies with a “payment required” signal and its payment terms.2
  3. The client sends the request again with a payment.
  4. A facilitator, a service that checks and settles payments, can handle verification and settlement on a blockchain.2

The spec names several payment schemes, including exact, upto and batch-settlement.2 The project says it aims to support both crypto and traditional payment networks, and forms of value including stablecoins.1

x402 is a standard, not a hosted service, so there is no single endpoint.

Where it shows up

  • Coinbase for Agents lets an agent pay for data and research with x402 from a USDC balance.3 See Coinbase.

Unknown

What a person approves before an x402 payment depends on the agent or wallet. The spec sources do not say. No cited source confirms it, so the wiki says unknown.

All programs: Payments.

Sources

Suggest a correction (opens a GitHub issue)

Footnotes

  1. GitHub - x402-foundation/x402: A payments protocol for the internet. Built on HTTP. · GitHub. x402 Foundation (GitHub), official, retrieved 2026-11-12. ↩ ↩2

  2. x402 specification v2. x402 Foundation (GitHub), official, retrieved 2026-11-12. ↩ ↩2 ↩3 ↩4

  3. Coinbase MCP - Coinbase Developer Documentation. Coinbase Developer Platform, official, retrieved 2026-11-12. ↩

Last verified 2026-11-14

Suggest a correction (GitHub issue)

Source file: payments/x402.md

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