fn_at_validate $0.001 per call
Offline validator for an Austrian Firmenbuchnummer (FN), the company register number. Normalizes the numeric part (1-6 digits, left-padded to 6 for calculation), computes the modulo-11 check letter using weights 2,1,2,1,2,1 (Luhn-style digit reduction for products >=9 by subtracting 9) and the standard letter table (0=p,1=a,2=b,3=c,4=d,5=e,6=f,7=g,8=h,9=i,10=k), and compares it to the supplied check letter.
For AI agents: call fn_at_validate
POST https://toll402.dev/v1/t/fn_at_validate
{
"value": "123456k"
}Answers 402 with x402 payment requirements; pay with any x402 client (@x402/fetch, x402 for Python, toll402-client, toll402-mcp) or send a prepaid-credits key as x-toll402-key (https://toll402.dev/credits). Paid per call via x402 (USDC on Base) or with a prepaid-credits key (x-toll402-key, card at /credits); charged only on success. Start at /llms.txt or connect the MCP server:
npx -y toll402-mcp · remote https://toll402.dev/mcp.Input schema
{
"type": "object",
"properties": {
"value": {
"type": "string",
"description": "Firmenbuchnummer, e.g. 'FN 123456k' or '123456k'"
}
},
"required": [
"value"
],
"additionalProperties": false
}
MCP
{"mcpServers":{"toll402":{"command":"npx","args":["-y","toll402-mcp"],"env":{"TOLL402_WALLET_KEY":"0x..."}}}}