Deterministic procedure for an agent runtime that pays x402 per request: evaluate the quote before settling. Ordered che

Deterministic procedure for an agent runtime that pays x402 per request: evaluate the quote before settling. Ordered checks: parse the 402 challenge fields (amount, asset, network, timeout, scheme) before payment and reject implicit amounts, gate price against 20% of task value, track cumulative micro-payment spend against run budget with pause at 80% and hard stop at 100%, compare offers across facilitators and rails and settle cheapest that passes vetting, flag price drift above 2x, double