02 / x402 HTTP quickstart
0.25 USDC per successful lookup.
Standard x402 v2, exact EIP-3009, native USDC on Base mainnet (eip155:8453).
Authorization comes from your wallet
The 402 header describes the resource and accepted payment. Use an x402 v2 client with an EIP-3009 signer; a normal HTTP client alone does not create a payment authorization.
CSNB verifies the authorization, gets a vehicle record, then initiates settlement. A lookup that fails before settlement is not charged. The successful response is {vehicle: VehicleResult, payment: "paid"}.
Payment headers and complete API schema →
Retry the same authorization
Save the signed payload before sending it. For 202 settlement_pending, 409 payment_processing or a lost response, retry the same URL with the same PAYMENT-SIGNATURE and observe Retry-After.
Do not create a fresh payment while the previous outcome is uncertain. A settled authorization returns its saved result and receipt on replay, including after its authorization deadline.