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Open Factura provides two core functions for creating electronic invoices that comply with Ecuador’s SRI requirements.

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Overview

The invoice generation process involves two steps:
  1. Generate the invoice object with generateInvoice() - Creates the complete invoice structure and calculates the access key
  2. Convert to XML with generateInvoiceXml() - Transforms the invoice object into XML format required by SRI

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Generating an Invoice

1

Import the required functions

import { generateInvoice, generateInvoiceXml } from 'open-factura';
2

Prepare your invoice data

Create an InvoiceInput object with all required tax, invoice, and detail information:
const invoiceData = {
  infoTributaria: {
    ambiente: "1", // 1 = Testing, 2 = Production
    tipoEmision: "1",
    razonSocial: "Mi Empresa S.A.",
    nombreComercial: "Mi Empresa",
    ruc: "1234567890001",
    codDoc: "01", // 01 = Invoice
    estab: "001", // Establishment code
    ptoEmi: "001", // Emission point
    secuencial: "000000001", // Sequential number
    dirMatriz: "Av. Principal 123",
  },
  infoFactura: {
    fechaEmision: "15/03/2026",
    dirEstablecimiento: "Av. Principal 123",
    obligadoContabilidad: "SI",
    tipoIdentificacionComprador: "04",
    razonSocialComprador: "Cliente ABC",
    identificacionComprador: "0987654321001",
    direccionComprador: "Calle Secundaria 456",
    totalSinImpuestos: "100.00",
    totalDescuento: "0.00",
    totalConImpuestos: {
      totalImpuesto: [
        {
          codigo: "2", // IVA
          codigoPorcentaje: "2", // 12%
          baseImponible: "100.00",
          tarifa: "12.00",
          valor: "12.00",
        },
      ],
    },
    propina: "0.00",
    importeTotal: "112.00",
    moneda: "DOLAR",
    pagos: {
      pago: [
        {
          formaPago: "01", // Cash
          total: "112.00",
        },
      ],
    },
  },
  detalles: {
    detalle: [
      {
        codigoPrincipal: "PROD001",
        descripcion: "Product Description",
        cantidad: "1.000000",
        precioUnitario: "100.000000",
        descuento: "0.00",
        precioTotalSinImpuesto: "100.00",
        impuestos: {
          impuesto: [
            {
              codigo: "2",
              codigoPorcentaje: "2",
              tarifa: "12.00",
              baseImponible: "100.00",
              valor: "12.00",
            },
          ],
        },
      },
    ],
  },
};
The claveAcceso (access key) is automatically generated based on the invoice data. You don’t need to provide it manually.
3

Generate the invoice object

Call generateInvoice() to create the invoice structure and access key:
const { invoice, accessKey } = generateInvoice(invoiceData);

console.log('Access Key:', accessKey);
// Access Key: 1503202601123456789000110010010000000011234567891
The function returns:
  • invoice: Complete invoice object with XML structure
  • accessKey: 49-digit unique identifier for the invoice
4

Convert to XML format

Transform the invoice object into XML string required by SRI:
const invoiceXml = generateInvoiceXml(invoice);

console.log(invoiceXml);
// <?xml version="1.0" encoding="UTF-8"?>
// <factura id="comprobante" version="1.0.0">
//   <infoTributaria>
//     ...
//   </infoTributaria>
//   ...
// </factura>
The XML is formatted with pretty printing for readability.

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Access Key Generation

The access key is automatically generated using the following components:
ComponentDescriptionSource
DateEmission date (DDMMYYYY)infoFactura.fechaEmision
Document CodeType of document (01 for invoice)infoTributaria.codDoc
RUCTax identification numberinfoTributaria.ruc
EnvironmentTesting (1) or Production (2)infoTributaria.ambiente
EstablishmentEstablishment codeinfoTributaria.estab
Emission PointPoint of emissioninfoTributaria.ptoEmi
SequentialSequential numberinfoTributaria.secuencial
Numeric CodeRandom 8-digit numberAuto-generated
Emission TypeAlways “1”Fixed
Verification DigitModulus 11 checksumCalculated

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Complete Example

Here’s a minimal working example: 
import { generateInvoice, generateInvoiceXml } from 'open-factura';

const { invoice, accessKey } = generateInvoice({
  infoTributaria: {
    ambiente: "1",
    tipoEmision: "1",
    razonSocial: "My Company",
    nombreComercial: "My Store",
    ruc: "1234567890001",
    codDoc: "01",
    estab: "001",
    ptoEmi: "001",
    secuencial: "000000001",
    dirMatriz: "Main Street 123",
  },
  infoFactura: {
    fechaEmision: "15/03/2026",
    dirEstablecimiento: "Main Street 123",
    obligadoContabilidad: "SI",
    tipoIdentificacionComprador: "04",
    razonSocialComprador: "Customer Name",
    identificacionComprador: "0987654321001",
    direccionComprador: "Customer Address",
    totalSinImpuestos: "100.00",
    totalDescuento: "0.00",
    totalConImpuestos: {
      totalImpuesto: [{
        codigo: "2",
        codigoPorcentaje: "2",
        baseImponible: "100.00",
        tarifa: "12.00",
        valor: "12.00",
      }],
    },
    importeTotal: "112.00",
    moneda: "DOLAR",
    pagos: {
      pago: [{ formaPago: "01", total: "112.00" }],
    },
  },
  detalles: {
    detalle: [{
      codigoPrincipal: "PROD001",
      descripcion: "Product Name",
      cantidad: "1.000000",
      precioUnitario: "100.000000",
      descuento: "0.00",
      precioTotalSinImpuesto: "100.00",
      impuestos: {
        impuesto: [{
          codigo: "2",
          codigoPorcentaje: "2",
          tarifa: "12.00",
          baseImponible: "100.00",
          valor: "12.00",
        }],
      },
    }],
  },
});

const invoiceXml = generateInvoiceXml(invoice);

console.log('Generated access key:', accessKey);
console.log('XML ready for signing:', invoiceXml.substring(0, 100) + '...');

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Next Steps

Sign the Document

Learn how to digitally sign the XML with your P12 certificate

Submit to SRI

Submit the signed document to SRI’s reception endpoint

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API Reference

For detailed type information and all available fields:

Invoice Types

View complete type definitions for InvoiceInput and Invoice

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