PDF-zu-ZUGFeRDAPI

# Organisationen abrufen
curl https://vellonode.de/api/v1/organizations \
  -H "Authorization: Bearer vk_live_abc123..."

# Rechnung konvertieren
curl -X POST "https://vellonode.de/api/v1/invoices/convert?organizationId=org_123" \
  -H "Authorization: Bearer vk_live_abc123..." \
  -F "[email protected]" \
  -F "format=zugferd,json" \
  -F "direction=incoming"

{
  "id": "conv_a1b2c3d4e5f6...",
  "data": {
    "invoiceNumber": "RE-2026-0042",
    "invoiceDate": "2026-05-15",
    "currency": "EUR",
    "seller": {
      "name": "Muster GmbH",
      "vatId": "DE123456789",
      "address": {
        "street": "Musterstraße 1",
        "postalCode": "10115",
        "city": "Berlin",
        "country": "DE"
      }
    },
    "buyer": {
      "name": "Beispiel AG",
      "vatId": "DE987654321"
    },
    "lines": [
      {
        "description": "Softwarelizenz Enterprise",
        "quantity": 1,
        "unit": "C62",
        "unitPrice": 2500.00,
        "vatRate": 19,
        "netAmount": 2500.00
      },
      {
        "description": "Technischer Support",
        "quantity": 10,
        "unit": "HUR",
        "unitPrice": 150.00,
        "vatRate": 19,
        "netAmount": 1500.00
      }
    ],
    "taxBreakdown": [
      { "rate": 19, "taxableAmount": 4000.00, "taxAmount": 760.00 }
    ],
    "totals": {
      "netTotal": 4000.00,
      "vatAmount": 760.00,
      "grossTotal": 4760.00
    }
  },
  "validation": {
    "valid": true,
    "profile": "EN16931",
    "errors": []
  },
  "files": {
    "zugferd": {
      "url": "https://vellonode.de/api/v1/files/d4e5f6..."
    },
    "json": {
      "url": "https://vellonode.de/api/v1/files/f6g7h8..."
    }
  },
  "stored": {
    "status": "saved",
    "documentId": "clx1234567890",
    "invoiceIds": ["clx0987654321"],
    "archived": true
  },
  "usage": { "used": 42, "limit": 500 }
}