Augur uses x402 for per-call payment. The flow is HTTP-native: request the resource, receive payment requirements, sign the payment, retry the same request, receive JSON.
GET https://augurrisk.com/analyze?address=0x4200000000000000000000000000000000000006.402 Payment Required with a base64-encoded Payment-Required header describing the exact USDC payment on Base.PAYMENT-SIGNATURE header.If the address is missing, malformed, or has no bytecode on Base mainnet, Augur returns 422 before the x402 paywall. That prevents paying for EOAs or undeployed contracts.
# First request GET https://augurrisk.com/analyze?address=0x4200000000000000000000000000000000000006 # Retry after signing payment GET https://augurrisk.com/analyze?address=0x4200000000000000000000000000000000000006 PAYMENT-SIGNATURE: <x402-payment-proof>
Integration references: