The x402 protocol standardizes machine-to-machine payments over HTTP. When an agent requests a protected API endpoint, the server responds with HTTP 402 and payment parameters in the PAYMENT-REQUIRED response header.
MOI uses @x402/fetch and @x402/evm to parse payment requirements, verify that the purchase cost falls within the mandate’s serviceSpendPerCallAtomic cap, sign an onchain payment authorization, and retry the request seamlessly.