Generate a ZUGFeRD 2.x or XRechnung 3.x invoice in XML (CII or UBL) format. Supports all ZUGFeRD profiles: MINIMUM, BASIC_WL, BASIC, EN_16931, EXTENDED. For XRechnung, set profile to XRECHNUNG and choose CII or UBL syntax. PDF/A-3 hybrid output is planned for v0.2.0.

Validate a ZUGFeRD 2.x or XRechnung 3.x invoice XML against EN 16931 rules and German KoSIT Schematron rules (BR-DE-* business rules). Returns a structured validation report with errors and warnings. Supports all ZUGFeRD profiles (MINIMUM through EXTENDED) and XRechnung (CII and UBL syntax). Profile and syntax are auto-detected if not specified.

Extract structured data from a ZUGFeRD 2.x or XRechnung 3.x invoice. Accepts raw XML (CII or UBL), base64-encoded XML, or base64-encoded PDF (ZUGFeRD hybrid — the XML is extracted from the PDF/A-3 attachment). Returns a structured JSON object matching the invoice data model.

Convert a ZUGFeRD or XRechnung invoice to a different profile or syntax. Supports ZUGFeRD profile upgrades and downgrades, ZUGFeRD ↔ XRechnung conversion, and CII ↔ UBL syntax transformation (XRechnung only). Profile downgrades may result in data loss; set allow_data_loss=True to permit this.

Verify whether a German company is registered on the Peppol network and can receive electronic invoices via AS4. Performs a live DNS + SMP lookup using the participant's Peppol ID (Leitweg-ID, GLN, or VAT number). Returns registration status, supported document types, and AS4 endpoint URL.

Query German VAT rules for e-invoicing. Returns structured information about VAT rates (19%, 7%), VAT category codes, reverse charge rules under §13b UStG, zero-rate and exemption provisions (§4 UStG), intra-community supply rules, and VATEX exemption reason codes. For use when building invoice creation logic or validating VAT treatment.