Know an invoice will be rejected before it leaves

// 1. In any browser with WebMCP support (auto-registered on page load):
// The FacturGate tools are mounted on navigator.modelContext:
//   • validate_einvoice ($0.10/call)
//   • convert_invoice_to_facturx ($0.25/call)
//   • check_eu_vat_id ($0.05/call)

const report = await navigator.modelContext.executeTool("validate_einvoice", {
  invoice: JSON.stringify({
    invoice: { number: "INV-2026-001", issueDate: "2026-10-01", currency: "EUR" },
    seller: {
      name: "Acme SAS",
      vatId: "FR83404833048",
      country: "FR",
      postalCode: "75001",
      city: "Paris",
      street: "10 Rue de la Paix"
    },
    buyer: {
      name: "Client GmbH",
      vatId: "DE123456789",
      country: "DE",
      postalCode: "10115",
      city: "Berlin",
      street: "Musterstr. 1"
    },
    lines: [
      { description: "Consulting", quantity: 1, unitPrice: 1000, vatRate: 20, vatCategory: "S" }
    ]
  }),
  target_country: "FR",
  target_format: "facturx"
});

console.log("Readiness Score:", report.score); // 100 (score)
console.log("Verdict:", report.verdict); // "ready"
console.log("Reconciliation Delta:", report.reconciliation?.delta); // 0.00
console.log("Emitted XML Length:", report.emitted?.xml.length);