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. When the buyer is a German VAT-registered business (DE-prefixed VAT id), the Wachstumschancengesetz B2B mandate (effective 2025-01-01, §14 Abs. 2 UStG) requires a structured EN 16931 invoice. Non-XML output is rejected unless transitional_period_opt_in is set to True (allowed only 2025-2026 with the buyer's written consent).

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 cross-syntax CII ↔ UBL transformation. 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.

Send a ZUGFeRD invoice to a German Peppol participant via AS4. The invoice is serialized to UBL (Peppol BIS 3.0) and transmitted using the core PeppolTransmitter. Requires signing credentials configured via EINVOICING_DE_PEPPOL_CERT_PATH and EINVOICING_DE_PEPPOL_KEY_PATH environment variables.

Export a ZUGFeRD invoice to DATEV CSV format (EXTF 700, Buchungsstapel). Produces a CSV file importable by DATEV Belegtransfer or DATEV Rechnungswesen. Maps invoice line items to DATEV booking records with configurable accounts.

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.