Where

Read, write, validate and/or convert electronic invoices using the commandline version (download on the commandline page) or read how to embed the java library in your software.

What

Mustangproject is a open source Java (Jar or Maven) and a command-line tool, and provides a server with a REST API. Mustangproject 2.16.0 was released on 10.01.2025 and supports ZUGFeRD 2.3.2, ZUGFeRD 1, Factur-X 1 as well as UN/CEFACT CII XRechnung 3.0.1.

2.16.0

2025/10/01

Mustangproject, the open-source e-invoicing toolkit, released it’s version 2.16.0 today, January 10th, 2025. This version adds support to parse charges/allowances (#651), allows allowance and charge reasoncodes also on document level (#657), allows multiple invoice referenced documents (#631) and supports a PDF validation report output (#356, using --log-as-pdf, it’s currently not yet documented anywhere). Further fixes […]

Mustangserver 1.6.0

2024/30/12

Today, Monday, December 30th we released a new version of our E-Invoice-Rest-API Mustangserver which supports conversion to and from CII, UBL and FatturaPA based on a open source project called EeISI. Additionally, it now also supports writing embedded files. As usual, Mustangserver 1.6.0 is not yet the default version for all requests but can be […]

2.15.2

2024/19/12

Mustangproject version 2.15.2 was published today, December 19th, 2024, and brought minor improvements in the fields of Parsing #618 import BT-20 correctly import additional referenced documents into invoice/corrected setting of attachments from jackson corrected parseException structure Validation allow 1p0 as potential xmp version number and Writing correcly write charge reason codes also for non-Xrechnung #617 […]

Chat under the christmas tree

2024/18/12

In order to mutually ask and answer questions Jochen suggests to just meet at the matrix.org #facturx room the next three Thursdays (19.12., 26.12. and 02.01.) between 16:00 and 17:00 CET. This chat “room” already exists and is open 24h/day at https://app.element.io/#/room/#facturx:matrix.org and you can already ask questions now. Matrix may require an account but […]

2.15.1

2024/07/12

Mustangproject version 2.15.1, released December 7th, 2024, now also reads lineId and IncludedNotes on item- as well as InvoiceReferencedDocument and IncludedNotes, lineTotalAmount, TaxBasisAmount, duePayableAmount and prepaidamount on document level as well as classes like DirectDebit from both CII and UBL to/from JSON. Error IDs are now logged in validation, fatal errors may no longer appear […]

Mustangserver 1.5.1

2024/02/12

On Saturday, November 30th we released a new Mustangserver version which, simply put, supports more fields when reading and writing, incuding e.g. IncludedNotes. The difference between reading CII and UBL has been practically eradicated and e.g. prepaidamount is now supported. As usual, Mustangserver 1.5.1 is not yet the default version for all requests but can […]

Mustangserver 1.5.0

2024/20/11

Today, November 20th, 2024, we released Mustangserver 1.5.0, which is based on Mustang 2.15.0 and brings support for ZUGFeRD 2.3.2, with a corrected XML to PDF/A output, removal of uneccessary null values, more and improved UBL reading, validation of UBL credit notes, and support for validation warnings, not only errors and notices. The new version […]

2.15.0

2024/18/11

Today, November 18th, 2024, we released version 2.15.0 of our open source e-invoice toolkit “Mustangproject”. This release fixes some errors and supports Factur-X/ZUGFeRD 2.3.2 (#531), it uses its UBL compatible InvoiceImporter as basis for the ZUGFeRDimporter convenience methods (#435), additionally fixes a PDF/A validation issue #538, converts UBL and CII to validated PDF/A #523, now […]

2.14.2

2024/14/10

Today, October 14th, 2024, version 2.14.2 of the Open Source e-invoicing toolkit Mustangproject was released without any new features but fixing also parse BICs in InvoiceImporter not only IBANs #509 CLI currently does not write a logfile #505 crash after invoking ZUGFeRD2PullProvider #506 Fix POM missing dependencies

Where to get community support?

2024/10/10

Fora If you are looking for community support for ZUGFeRD or XRechnung, apart from the obvious Stackoverflow you e.g. might The ZUGFeRD Community Forum the There is english Google group or, for quick questions, a chat, i.e. the [#facturx] Room in Matrix Associations Industry association-wise in Germany there is not only the Forum elektronische Rechnung […]

News archive

Features

  • Read, write and validate ZUGFeRD 2/Factur-X, ZUGFeRD 1 and XRechnung
  • Convert PDF/A1 to PDF/A3
  • Embeddable java library based on PDFbox
  • Permissive license (APL2, free for use in commercial and noncommercial applications)
  • The Mustangproject library
    • is available via Maven Central supporting Maven and Gradle
    • can be embedded in your Java software
  • Command line tool
    • Runs on Linux, Mac OS and Windows with JRE 1.8
    • Add ZUGFeRD XML to PDF
    • Extract ZUGFeRD XML from PDF
    • Convert CII to UBL
    • Migrate ZUGFeRD 1 to 2 (experimental)
    • Convert PDF/A-1 to PDF/A-3
    • Find out how many PDFs are ZUGFeRD
  • Mustang Server
    • Reads, writes and validates ZUGFeRD 2/Factur-X and XRechnung
    • Converts CII to UBL
    • is a OpenAPI/Swagger REST API and uses oAuth
    • Phive-Validation of other formats and UBL
    • Converts any PDF to PDF/A-3

A Mustang Library .net Version is currently in Beta.

Screenshot of Acrobat Adobe PDF Reader showing a ZUGFeRD invoice with open file attachments tab
At the right you see a sample PDF containing Factur-X/ZUGFeRD metadata generated with the Mustang library. If you open it in Adobe Acrobat Reader just click on the paperclip symbol to see the embedded ZUGFeRD XML structure. It has been created using the invoice class. Which you can also use to create a XRechnung.