Credits and licences
Last updated 2026-10-21
Our own code
The readable invoice view, the invoice creator, the Schematron rule runner and the page layouts are written for this site. Every file listed below is hosted on this site; the pages make no requests to other servers.
Official rule files (EUPL-1.2 and Apache-2.0)
The EN 16931 validation artefacts of CEN/TC 434 are published under the European Union Public Licence 1.2 (EUPL-1.2). We distribute the rule files unmodified, in their own folder, with the licence text (LICENSE-EUPL-1.2.txt) and a list of SHA-256 checksums of the upstream files (SHA256SUMS); our engine reads them as they are. The KoSIT XRechnung rules and validator configuration are published under the Apache License 2.0 and are likewise shipped unmodified with their licence.
Factur-X / ZUGFeRD profile rule files (FNFE-MPE / FeRD) are not distributed by this site.
Third-party material
| Name | Used for | Licence |
|---|---|---|
| EN 16931 validation artefacts 1.3.17 (CEN/TC 434) | Official EN 16931 business rules (Schematron, UBL and CII), shipped unmodified in /rules/en16931-*-1.3.17/ with the licence text and SHA256SUMS | EUPL-1.2 |
| XRechnung Schematron 2.6.0 (KoSIT) | Official XRechnung 3.0.2 national rules (BR-DE-…), shipped unmodified in /rules/xrechnung-3.0.2-schematron-2.6.0/ | Apache-2.0 |
| KoSIT validator configuration XRechnung (release 2026-08-31) | Scenario logic (which rules apply to which specification identifier) and the bundled XML schemas | Apache-2.0 |
| OASIS UBL 2.1 XML schemas | Syntax check of UBL invoices; unmodified, with the OASIS notice in /rules/…/ubl/2.1/OASIS-UBL-2.1-NOTICE.txt | OASIS copyright notice (copying and distribution permitted with the notice) |
| UN/CEFACT Cross Industry Invoice D16B XML schemas | Syntax check of CII invoices and of the XML inside ZUGFeRD / Factur-X PDFs; unmodified, notice in the file headers | UN/CEFACT copyright notice (copying and distribution permitted with the notice) |
| fontoxpath 3.34.0 | XPath 3.1 / XQuery engine that evaluates every rule; bundled with a small patch for exact decimal arithmetic (licences in /engine/THIRD-PARTY-LICENSES.txt) | MIT |
| xspattern, prsc, whynot | Libraries used by fontoxpath (XML Schema regular expressions, parser combinators) | MIT |
| xmllint-wasm 5.3.0 (libxml2) | XML schema (XSD) validation in a Web Worker, loaded on the first check | MIT |
| PDF.js 6.4.299 | Reads the XML embedded in ZUGFeRD / Factur-X PDFs and the PDF text; loaded only when you open a PDF | Apache-2.0 |
| @cantoo/pdf-lib 2.11.1 | Writes the invoice PDFs (ZUGFeRD / Factur-X PDF/A-3 with the embedded XML; XRechnung as readable PDF), bundled in /engine/pdfgen-*.js, loaded only when a PDF is made | MIT |
| @cantoo/fontkit 2.0.12 (with restructure, dfa, brotli, base64-js) | Embeds and subsets the font in generated PDFs (bundled in /engine/pdfgen-*.js) | MIT |
| culori, fflate, tslib, node-html-better-parser, html-entities | Dependencies of @cantoo/pdf-lib, bundled in /engine/pdfgen-*.js; licence texts in /engine/pdfgen-THIRD-PARTY-LICENSES.txt | MIT / 0BSD |
| Noto Sans Regular and Bold (Latin subset) | Font embedded in generated PDFs (PDF/A needs embedded fonts); subset with fontTools, in /vendor/fonts/noto-sans/ with the licence | SIL Open Font License 1.1 |
| Noto Sans JP, KR, TC and Arabic (Regular and Bold) | Fonts for Japanese, Korean, Chinese and Arabic names and labels in generated PDFs; static instances subset with fontTools, in /vendor/fonts/noto-sans-jp|kr|tc|arabic/ with the licence; downloaded only when an invoice uses these scripts | SIL Open Font License 1.1 |
| sRGB2014.icc (International Color Consortium) | Colour profile of the PDF/A output intent in generated PDFs, unchanged, /vendor/icc/ with its terms | ICC: may be copied, distributed and embedded without restriction |
| PKI.js 3.4.3 (with asn1js, pvtsutils, pvutils, bytestreamjs, @noble/hashes) | Opens .p7m files (CMS SignedData) and checks the signature with WebCrypto, bundled in /engine/p7m-*.js | BSD-3-Clause / MIT |
| swissqrbill 4.4.2 (with svg-engine) | Draws and checks the Swiss QR-bill (payment part and receipt), bundled in /engine/qrbill-*.js | MIT |