Money that moves like a message
Press Send and race $50 on Base against ACH, SWIFT and a card. Then pay for one API request and one coffee.
- BaseLive—
About 200 ms to a preconfirmation, about 2 s to a block
- Same Day ACH—
Settles at the next FedACH window
- SWIFT gpi—
Most arrive within 30 min; nearly all within 24 h
- Card—
Merchant funded within ~48 h of daily settlement (Visa)
Different milestones: a preconfirmation is not final settlement, a card authorization is not merchant funding.
- No requests yet
This server speaks x402's headers. The payment leg is simulated: no USDC moves.
No account, no card form, no subscription. Two calls.
import { createPublicClient, createWalletClient, custom, erc20Abi, http, parseUnits, type Address } from 'viem'import { base } from 'viem/chains'const USDC = '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913' // native USDC on Base, 6 decimalsconst wallet = createWalletClient({ chain: base, transport: custom(window.ethereum!) })const client = createPublicClient({ chain: base, transport: http() })export async function send(to: Address, dollars: string) { const [account] = await wallet.requestAddresses() // Dry-run the transfer first: it fails here, not onchain, if the balance is short. const { request } = await client.simulateContract({ account, address: USDC, abi: erc20Abi, functionName: 'transfer', args: [to, parseUnits(dollars, 6)], }) // The wallet asks the sender to confirm, then broadcasts. const hash = await wallet.writeContract(request) // Preconfirmed in about 200 ms, included in a 2 s block. return client.waitForTransactionReceipt({ hash })}Gas for a USDC transfer
Measured on Base
Flashblock interval measured in this tab, nearest 10 ms
Block interval
Token
USDC, native on Base
Protocol
x402 is an open standard under the Linux Foundation's x402 Foundation.
PAYMENT-REQUIRED
- scheme
- —
- network
- —
- amount
- —
Send a request to see the PAYMENT-REQUIRED header
Gas for a USDC transfer
Gas for a USDC transfer
The two calls
- pay()
- in the browser
- getPaymentStatus()
- on your server
Nothing on this page moves money. The transfer, the paid request and the checkout are simulated; the fee, the block and the preconfirmation time are measured on Base as you watch. Bank, card and SWIFT timings are published figures for different milestones, linked above.