{"service":"x402 Format Checker","summary":"Format and checksum validation for IBAN, EU VAT, Polish NIP/REGON/PESEL and email, pay-per-call via x402","price":"Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base","network":"eip155:8453","networkName":"Base (mainnet)","asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","payTo":"0xACeaEeBF0Dc8DC7762F2FdE4885f219888e9D045","facilitator":"https://facilitator.payai.network","protocol":"x402 v2 (HTTP 402, PAYMENT-REQUIRED / PAYMENT-SIGNATURE headers), scheme exact","usage":"POST /api/validate/{type} with JSON body {\"value\": \"...\"}. Query-string values are rejected.","privacy":"We never store the values you check; we count requests and public payment data.","docs":{"openapi":"/openapi.json","llms":"/llms.txt","x402":"/.well-known/x402","agentCard":"/.well-known/agent-card.json","mcp":"/mcp","a2a":"/a2a"},"types":[{"type":"iban","description":"IBAN: country length + ISO 13616 mod-97 checksum","price":"$0.001","method":"POST","endpoint":"/api/validate/iban"},{"type":"eu-vat","description":"EU VAT number: per-country format (offline, no VIES); PL also NIP checksum","price":"$0.001","method":"POST","endpoint":"/api/validate/eu-vat"},{"type":"pl-nip","description":"Polish NIP tax id: 10 digits + weighted mod-11 checksum","price":"$0.001","method":"POST","endpoint":"/api/validate/pl-nip"},{"type":"pl-regon","description":"Polish REGON: 9 or 14 digits + mod-11 checksum","price":"$0.001","method":"POST","endpoint":"/api/validate/pl-regon"},{"type":"pl-pesel","description":"Polish PESEL: checksum + encoded birth date and sex","price":"$0.001","method":"POST","endpoint":"/api/validate/pl-pesel"},{"type":"email","description":"Email address syntax (dot-atom local part, LDH domain; no DNS)","price":"$0.001","method":"POST","endpoint":"/api/validate/email"}]}