mcp-einvoicing-de 🇩🇪

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MCP server (Model Context Protocol) in Python for German electronic invoicing in ZUGFeRD 2.x and XRechnung 3.x formats (EN 16931, FeRD, KoSIT). Enables AI agents (Claude, IDEs) to create, validate, parse, and convert e-invoices that are fully compliant with the German B2B e-invoicing mandate (effective from 2025, phased enforcement through 2027 to 2028) and the European standard EN 16931.

Introduction

This package is built on mcp-einvoicing-core, a shared base library for European e-invoicing MCP servers. It provides shared models, validation abstractions, XML utilities, and the exception hierarchy.

mcp-einvoicing-core is automatically installed as a transitive dependency, no additional step required.

For developers: pip install -e ".[dev]" installs the base package automatically from PyPI.

Installation

Via PyPI (recommended)

pip install mcp-einvoicing-de

Without prior installation, using uvx:

uvx mcp-einvoicing-de

From source

git clone https://github.com/cmendezs/mcp-einvoicing-de.git
cd mcp-einvoicing-de

python -m venv .venv
source .venv/bin/activate   # Windows: .venv\Scripts\activate

pip install -e ".[dev]"

Optional extras

Configuration

The server does not require external credentials. Available environment variables:

The EUSR/TSR reporting and MLS tools additionally require the [xslt2] extra for Schematron validation.

Claude Desktop integration

Add the following entry to claude_desktop_config.json. No environment variables are required:

{
  "mcpServers": {
    "einvoicing-de": {
      "command": "uvx",
      "args": ["mcp-einvoicing-de"]
    }
  }
}

Cursor integration

Cursor supports MCP servers via stdio. Add the configuration in:

• Global (all projects): ~/.cursor/mcp.json
• Project (this repository only): .cursor/mcp.json

{
  "mcpServers": {
    "einvoicing-de": {
      "command": "uvx",
      "args": ["mcp-einvoicing-de"]
    }
  }
}

Reload the Cursor window (Ctrl+Shift+P then Reload Window) to apply the changes.

Kiro integration

Kiro supports MCP servers via its dedicated configuration file. Two levels are available:

• Global (all projects): ~/.kiro/settings/mcp.json
• Workspace (this repository only): .kiro/settings/mcp.json

{
  "mcpServers": {
    "einvoicing-de": {
      "command": "uvx",
      "args": ["mcp-einvoicing-de"],
      "disabled": false,
      "autoApprove": []
    }
  }
}

The file is automatically reloaded on save. You can also open the config via the command palette (Cmd+Shift+P / Ctrl+Shift+P) then MCP.

Available tools

Peppol network tools

Peppol participant lookup, service-endpoint lookup, a DNS-only diagnostic, AS4 send, Peppol Directory search, and the OpenPeppol eDEC codelist tools are provided by the shared core Peppol tool plugin (mcp_einvoicing_core.peppol.tools.register_peppol_tools), mounted in server.py with a German-specific identifier adapter: a bare USt-IdNr (e.g. 123456789 or DE123456789) is normalized to the 9930:<value> Peppol scheme (DE:VAT); an already scheme-qualified identifier (e.g. 9930:DE123456789, or 0204:<leitweg-id> for Leitweg-ID-routed B2G invoices) passes through unchanged. To send via AS4, first produce XRechnung UBL with invoice_convert (or invoice_create with target_syntax='UBL'), then pass the result to peppol_send.

peppol_send signs outbound messages with a real wsse:Security signature as of mcp-einvoicing-core v1.20.0 (previously computed and discarded — see CHANGELOG.md v0.10.0).

See the mcp-einvoicing-core README for full parameter documentation on these tools.

Peppol reporting and status tools

Added in v0.10.0 via three opt-in core plugins, mounted unconditionally in server.py. Each raises a clear error at call time (not at registration) if its extra or data directory is missing.

See the mcp-einvoicing-core README for full parameter documentation on these tools.

Usage examples

Example 1: Validate an invoice

1. invoice_validate(
     xml_base64="...",   # Base64-encoded ZUGFeRD XML
     strict=True
   )
   → {
       "is_valid": true,
       "profile": "EN_16931",
       "syntax": "CII",
       "error_count": 0,
       "warning_count": 2,
       "errors": [],
       "warnings": [...],
       "validator_used": "local_schematron"
     }

Example 2: Query German tax rules

2. tax_rules(query="reverse_charge", context="Bauleistungen")
   → {
       "results": [
         {
           "paragraph": "§13b Abs. 2 Nr. 5 UStG",
           "description_en": "Construction services (building contractor rule)",
           "vatex_code": "VATEX-EU-AE",
           "invoice_note": "Steuerschuldnerschaft des Leistungsempfängers (§13b UStG)"
         }
       ],
       "legal_disclaimer": "..."
     }

Example 3: Check Peppol registration

3. peppol_lookup_participant(
     identifier="123456789",   # bare USt-IdNr, normalized to 9930:DE123456789
     environment="production"
   )
   → {
       "is_registered": true,
       "participant_id": "9930:DE123456789",
       "supported_document_types": ["urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0"],
       "smp_hostname": "b-...iso6523-actorid-upis.edelivery.tech.ec.europa.eu"
     }

Example 4: Parse invoice data

4. invoice_parse(xml_base64="...", include_raw_xml=False)
   → {
       "profile": "XRECHNUNG",
       "syntax": "CII",
       "invoice_number": "RE-2025-001",
       "invoice_date": "2025-01-15",
       "seller_name": "Muster GmbH",
       "buyer_name": "Käufer AG",
       "tax_inclusive_amount": "119.00",
       "currency_code": "EUR"
     }

Architecture

mcp-einvoicing-de (this package, standalone MCP server)
├── ZUGFeRDInvoice / XRechnungInvoice  ← Pydantic models (all profiles)
├── SchematronValidator                ← EN 16931 + KoSIT BR-DE-* rules
├── KoSITValidator                     ← Remote validation tool (optional)
└── Tools: create / validate / parse / convert / datev_export / tax_rules
    (+ core Peppol tool plugin, mounted separately: lookup / send / DNS / codelists)

        ↑ extends
mcp-einvoicing-core (shared base, installed as dependency)
├── BaseDocumentGenerator / Validator / Parser
├── BaseInvoice, BaseParty … (Pydantic)
├── xml_utils, exceptions
└── EInvoicingMCPServer

Vendor neutrality

This server implements the standard itself: it builds, validates, and signs the document locally. It is not a client for a commercial invoicing platform, and your signing keys and credentials never leave your own infrastructure.

A Peppol access point is optional: transmission via peppol_send is one available channel, and any accredited access point speaks the same AS4 profile, so switching providers is a configuration change, not a code change. This package does not implement direct submission to a German B2G state portal (ZRE/OZG-RE).

Supported standards

Note: ZUGFeRD 2.x and XRechnung 3.x share the same CII XML syntax at the EN 16931 profile level. Conversion between both formats is therefore possible without data loss. The EXTENDED profile is specific to ZUGFeRD and has no XRechnung equivalent.

Tests

# Install development dependencies
pip install -e ".[dev]"

# Run the full test suite
pytest tests/ -v

# With coverage report
pytest --cov=mcp_einvoicing_de --cov-report=term-missing

# Model tests only
pytest tests/test_models.py -v

Contributing

Contributions are welcome. Please open an issue before submitting a pull request for significant changes.

git clone https://github.com/cmendezs/mcp-einvoicing-de.git
cd mcp-einvoicing-de
pip install -e ".[dev]"
pytest
make audit

Other e-invoicing MCP servers

License

This project is licensed under the Apache 2.0 License. See the LICENSE file for details. For the full version history, see CHANGELOG.md.