How a payment works

When an agent pays for an x402 call on credit, the money comes from the credit vault, not the agent. This article follows one payment from request to ledger.

The vault is the payer

Each paid call is an ordinary x402 exact payment in USDC whose payer is the credit vault. The merchant is paid from the vault's float. Nothing passes through the agent's wallet.

Two signatures

1. The agent asks the credit co to prepare the payment. The credit co reserves the amount against the agent's line.
2. The agent signs the payment.
3. The credit co co-signs it.

The vault approves a payment only when both have signed. A stolen agent key alone cannot spend, and neither can a stolen co-signing key.

Limits on a payment

A payment has to fit inside the agent's line and the vault's caps, and it cannot take the vault below its reserve. It is valid for a short window, shown on the Terms page.

Settling

Any facilitator that supports smart contract (EIP-1271) payers can settle the payment with no change on its side. Which facilitators accept a contract payer is still being tested.

Recording the spend

After USDC settles the payment, anyone can record it with recordSpend, which proves the spend from USDC's own record. A netting job then writes it onto the ledger as debt. See Reading the figures for how this shows on the pages.