eu-einvoice: a Claude skill for European e-invoices

中文说明 · PyPI: eu-einvoice

A Claude skill (packaged as a Claude Code plugin) that creates, validates, reads and converts European structured e-invoices following EN 16931: XRechnung (UBL and CII), Peppol BIS Billing 3.0, ZUGFeRD / Factur-X hybrid PDFs, and plain UBL 2.1 or UN/CEFACT CII.

Ask Claude in plain words, for example "make this an XRechnung for the city of Köln", "why was my Peppol invoice rejected with BR-CO-15?", or "what's in this xrechnung.xml my supplier sent?". Claude then uses the bundled tooling instead of writing XML by hand:

• Amounts are computed, not typed. Line totals, the VAT breakdown per category and rate, document totals, prepayments and allowances are calculated to the cent, the way EN 16931 (BR-CO-10..17) and Peppol (R040, R120) require. Arithmetic is the most common reason e-invoices get rejected.
• It is validated with the official rules, the same ones receiving platforms use: XSD, CEN EN 16931 Schematron, KoSIT XRechnung and OpenPeppol BIS 3.0. They run in pure Python through Saxon-HE (saxonche), so no Java is needed. Rule sets are pinned to exact releases and SHA-256 verified.
• Errors come with fixes. Each finding shows the official rule ID, its message, the location and a hint written in terms of the invoice data.
• It checks what the official rules miss: check digits of Leitweg-IDs, SIREN, SIRET, French and Belgian VAT numbers and GLN/GTIN. A typo there gives an invoice that validates but can't be routed.
• It reads and converts invoices. Received XML or Factur-X/ZUGFeRD PDFs become JSON, or a readable HTML/PDF with labels in the seller's language (de/fr/nl/it/es/en). Conversions (UBL ↔ CII, ZUGFeRD → XRechnung, …) keep the source amounts.
• It makes Factur-X / ZUGFeRD PDFs: PDF/A-3 with embedded fonts, an sRGB OutputIntent, Factur-X XMP metadata and the embedded factur-x.xml. It can also embed the XML into your own PDF layout.

Install

Claude Code (plugin marketplace):

/plugin marketplace add uulucky/claude-skill-eu-einvoice
/plugin install eu-einvoice@uulucky-skills

claude.ai / Claude desktop app: download eu-einvoice.skill from the latest release and upload it as a skill (drag it into a chat and click "Save skill", or upload it in the Skills settings).

Manual: copy plugin/skills/eu-einvoice/ to ~/.claude/skills/eu-einvoice/.

Without Claude (Python library and command line):

pip install eu-einvoice
eu-einvoice template xrechnung-b2g > invoice.json   # edit, then:
eu-einvoice create invoice.json -o invoice.xml      # computes totals, writes XML, validates it

Requirements: Python 3.9+. On first use the skill creates a virtual environment from plugin/skills/eu-einvoice/requirements.txt (lxml, saxonche, factur-x, pypdf, reportlab). The official rule sets are downloaded on the first validation into ~/.cache/eu-einvoice/rules (set EINVOICE_RULES_DIR to change the location).

What you can ask

The same commands work without Claude (pip install eu-einvoice):

eu-einvoice template                                  # list example scenarios
eu-einvoice check invoice.json -p xrechnung-ubl       # computed lines, VAT breakdown, problems
eu-einvoice create invoice.json -p peppol -o out.xml
eu-einvoice validate received.xml                     # or a Factur-X / ZUGFeRD PDF
eu-einvoice extract received.pdf -o data.json
eu-einvoice convert in.xml --to xrechnung-cii -o out.xml
eu-einvoice render received.xml -o view.pdf

Profiles and rule sets

Rule-set updates come out about twice a year. einvoice_cli.py rules check-updates reports newer releases, and plugin/skills/eu-einvoice/references/maintenance.md explains how to bump the pins.

Quality

• All 35 official CEN example invoices round-trip (parse → regenerate as UBL and as CII → validate), 70/70.
• The bundled examples (B2G XRechnung, Peppol reverse charge, French Factur-X, credit note, intra-EU supply) are all valid.
• Six eval cases live in evals/; see docs/benchmark.md for with-skill vs. without-skill results. You can run them yourself with claude plugin eval plugin --eval-dir evals.

Limits

• It produces and checks documents; it does not send them. Peppol needs an access point, and German B2G portals need an upload or a Peppol channel.
• PDF/A-3 output is built to the spec, but the formal glyph-level check needs veraPDF.
• Not covered: non-EN 16931 national formats (Italy FatturaPA/SDI, Poland KSeF, Spain Verifactu/Facturae, Hungary NAV, Greece myDATA, India GST/IRN), the Factur-X MINIMUM/BASIC WL/EXTENDED profiles, France's EXTENDED-CTC-FR flows, and the XRechnung extension profile.
• This is not tax advice. Choosing a VAT category or exemption is a tax decision, so check with your accountant.

Third-party components

Python dependencies: factur-x (BSD), which provides the XSDs, the Factur-X schematron and PDF embedding; saxonche (Saxon-HE, MPL-2.0); lxml; pypdf; reportlab. The validation artefacts are not bundled. They are downloaded at run time from their publishers under the publishers' terms: CEN/TC 434 EN 16931 validation artefacts, KoSIT XRechnung schematron (Apache-2.0), OpenPeppol BIS Billing 3.0, and SchXslt, which compiles the Peppol schematron.

License

MIT, see LICENSE.