x402 Agent Payments: Receipts for Agentic Commerce

Agentic commerce only works if agents can transact without a human at the checkout. That means a payment rail built for machines, not shopping carts — a request for a resource returns a price, the agent pays, and the resource is delivered, all in one automated exchange. x402 is that rail. But a payment that settles and then leaves no verifiable trace is a liability in waiting: when the transaction is later questioned, "it went through" is not the same as "here is proof of what was paid for, and why."

What x402 is

x402 is a machine-to-machine payment pattern: a signed USDC quote settled on Base. An agent asks for something priced, receives a signed quote, and pays in stablecoin — no interactive checkout, no card form, no human step. It is the natural settlement layer for pay-per-call APIs, paid receipts, and agent-to-agent trade.

Why the payment needs a receipt

A settled payment records that value moved. It does not record what the value was for in a way a third party can verify — which model ran, which action was authorized, which agent decided to spend. Pair x402 settlement with a cryptographic receipt and you get both halves: the money moved, and here is signed, offline-verifiable proof of the AI action it paid for. That pairing is what turns raw agentic payments into accountable agentic commerce.

Receipts for economic activity

The same receipt primitive that signs inference and agent actions extends to the economic layer:

• Paid actions — a priced AI action returns both a settlement and a signed receipt of what was delivered.
• Verification stays free — checking any receipt costs nothing; you only pay to mint one. The rail is for producing proof, not gating the reading of it.
• Two-party clarity — buyer and provider each hold a verifiable record of the same transaction.

See it work

The x402 checkout is the canonical, live conversion page: get a real signed USDC quote on Base and run a paid receipt end to end. To see the agent side — where paid actions become part of a signed route — watch a live agent trip, and explore how fleets of agents are organized on the agent fleet page.