"Target" matching MCP connectors:

402xAgent is the check an agent calls before paying any x402 endpoint. It probes the endpoint's 402 without paying and returns a pay / skip / recheck verdict with a reason. Every check leaves a public receipt. It never pays the target.

Payments and pricing math sellers do weekly, computed deterministically over MCP: processor_fees breaks down payment costs with editable presets, charge_to_net answers what to charge to net a target amount, invoice_total validates and totals line items, with discount_stack, proration, and installment_plan in the premium tier.