{"usage":"GET /v1/vat?value=ATU12345678","required":{"value":"EU VAT identification number, country prefix included"},"optional":{"vies":"true (default) also queries the live EU VIES register"},"auth":"header X-API-Key (get one free at /kaufen, 100 calls included)","returns":["format_valid","registered","name","address","checked_at"],"example":"https://api.eucompliance.tools/v1/vat?value=ATU16170006","free_alternative":"no key needed: /free/... endpoints, 5 calls a day","catalog":"https://api.eucompliance.tools/.well-known/x402"}