a0flow Launches Live x402 Payment Rails for Pay-Per-Call APIs

Summary

a0flow is a live service offering website audits and x402 payment integration for APIs. Its audits cost $29-$99: the service provides a prioritized fix list at the $29 tier and ready-to-paste patches at the $99 tier, with a stated refund guarantee if it does not identify three real, fixable issues. Its integration service costs $150-$400 and can add payment gating to one endpoint on a Cloudflare Worker or configure multi-tier pricing, a facilitator, and documentation. Payments use USDC on Base, with no accounts or invoices and on-chain proof for both sides. The site says its x402 implementation is running in production across three domains and exposes a free status and price list, live demonstrations, and an on-chain revenue counter. The payment flow is described as a GET request returning HTTP 402, followed by a USDC payment and a retry carrying an X-PAYMENT header. For AI agents, the site provides a machine-readable JSON manifest when the homepage is requested with a non-HTML Accept header; the manifest includes endpoints, prices, and payment requirements. The service identifies ultravioletadao.xyz as its facilitator and lists updatesbyai.com, an AI digest with free and paid tiers, as one of its demonstrations.