Open-Source Libraries and Tools

Inofficial page on free Factur-X, Order-X and Deliver-X (and XRechnung) libraries and tools.

ZUGFeRD/Factur-X is a standard to embed machine readable XML in electronic invoice PDFs.

Libraries

Akretion’s factur-x is a BSD-licensed library.
Raphael Michel created a APL library for python.
Early dev of FX parsing and generation library https://github.com/zfutura/pycheval
Fintom8 Document Anonymizer: automated PII and Sensitive Data Masking for pdf invoices & e-invoices.

@gp has a factur-x library for PHP
horstoeko has MIT licensed PHP projects for ZUGFeRD, Order-X and e.g. a Visualizer
dealerweb/einvoice MIT licensed PHP library (pure PHP, no Java) to read, validate, visualize and create XRechnung, ZUGFeRD/Factur-X and Peppol BIS invoices in UBL and CII. Validates with the XML schemas and the Schematron rules of EN 16931, XRechnung and ZUGFeRD/Factur-X, and with the Peppol BIS 3.0 rules in an own implementation; reads the XML out of a ZUGFeRD/Factur-X PDF and writes the PDF/A-3 with the XML embedded.

Ghostscript, in it’s core a C++ library, can be used in a way that it actually produced proper PDF/A-3 Factur-X

Konik GPL Java and C# library for ZUGFeRD 1
invoice4j is a modern permissive library for Java
Mustang is a old fashioned Java library and command line tool to extract, combine and validate and convert. It’s open-source REST API has been continued commercially.
Writing XRechnung in Java https://github.com/codebarista-de/gallop

E-invoice EU Typescript and CLI
@attestwire/en16931 TypeScript library (MIT, zero dependencies) to validate and generate EN 16931 XML: XRechnung in UBL and CII, Peppol BIS 3, and the Factur-X/ZUGFeRD CII payload. Reads the XML out of a Factur-X PDF; does not write the PDF.

Ghostscript can also be used to create PDF/A files from ordinary PDF
COS-Viewer: iText RUPS can be used, along with a good hex editor to inspect the PDF internal structure, a generic GUI+CLI solution or a Windows-only alternative
MuPDF for windows and linux, mutools show can display simple internal structures
loca Open source AI/invoice recognition and ZUGFeRD/FX review+generation https://github.com/kyr0/easy-erechnung/
Open source AI/invoice recognition InvoiceNet
Open source OCR/pattern based invoice recognition invoice2data

FNFE uses a odoo plugin which is based on VeraPDF and the CEN Schematron
The ZUGFeRD-community online validation is based on Mustang and embeds VeraPDF and the CEN Schematron as well
Philip Helgers open-sourve-validator Phive can validate almost any invoice XML, including XRechnung, unfortunately not covering PDF-hybrid formats. Plus he has published the Kaltblut Factur-X/ZUGFeRD Validator
The DealerWeb online validator (German, free) for XRechnung, ZUGFeRD/Factur-X and Peppol BIS is based on dealerweb/einvoice; it shows a readable view of the invoice and does not store the file. For a PDF it checks the embedded XML, not the PDF itself.
VeraPDF, validates PDF-A,
Exiftool allows to quickly check PDF/A meta data,

The ZUGFeRD Infopaket includes schema and schematron, example files, specs, codelist and a refererence (called technical appendix)
The CEN Schematron can be used to validate ZUGFeRD/Factur-X XML

The open source accounting application Fakturama
Mustang based
- Andreas Rudolphs ZUGFeRD-Manager and
- Robert Grosskopfs LibreOffice Base XRechnung
Factur-X extension for LibreOffice is a LibreOffice extension to generate Factur-X invoices from LibreOffice Calc published under the GPL licence (video tutorial)
The Gate (g8) is a factur-x producing android app https://github.com/gatesuperapp/g8-invoicing

The XRechnung XSLT can be used to convert ZUGFeRD/Factur-X to HTML
Ultramarin Viewer is a freeware viewer for XRechnung based on these XSLTs, additionally
OpenXRechnungToolbox is an open source cross platform XRechnung viewer as well as
Quba-Viewer, a open source cross platform multi format viewer (also displaying ZUGFeRD/Factur-X PDF and XML)

Andreas Starkes original little python utility to remove personal data/anonymize invoices
Valitool’s https://github.com/valitoolorg/zebra and it’s online version http://zebra.valitool.org/
Philip Helgers XSLT based https://github.com/phax/ph-redact

Additional data is a python project to support extensions for certain industries like logistics, adding additional information to structured invoices (e.g. the invoice is for kilometres and the additional data contains the amount of miles)
Swiss army knife conversion tool, use e.g. it’s commandline tool EIGOR to convert interchangably between CII, UBL and FatturaPA
Philip Helger published a java library to convert UN/CEFACT CII to UBL
Auratech published a tool cii to ubl and vice versa https://github.com/Auratechcom/converter_ubl_cii_invoice_xml
There is a OpenXRechnungToolbox to visualize and validate XRechnung and Leitweg-IDs
There is an interesting parser for the EN16931 specification documents
And there is a MIT licensed parser for the Factur-X/ZUGFeRD Spec https://github.com/S2-Industries/FactoorSharp.FacturXDocumentationParser publishing to http://doc.factoorsharp.com/
xpdf has a interesting pdfdetach command line tool to extract the XML from the PDF
There is a corpus of samples, with german B2B samples in the XML-Rechnung subdirectory