MCP E-Invoicing Core

io.github.cmendezs/mcp-einvoicing-core

Documentation

mcp-einvoicing-core

Topics: mcp mcp-server e-invoicing electronic-invoicing python fastmcp peppol en16931 ubl fatturapa xp-z12-013 nfe xml base-library

Base package for electronic invoicing MCP servers.

Provides shared Pydantic models, EN 16931 invoice tree, UBL/CII wire format serializers, an OAuth2 HTTP client, Peppol SMP lookup, digital signature primitives, and a compliance audit framework so country-specific packages share a common foundation without duplicating code.

What this package provides

Module	Contents
`models`	`InvoiceDocument`, `InvoiceParty`, `InvoiceLineItem`, `PartyAddress`, `VATSummary`, `PaymentTerms`, `DocumentValidationResult`, `TaxIdentifier` (per-country tax ID validators: IT, FR, DE, BE, ES, PL, BR), `TaxIdValidationResult`
`en16931`	`EN16931Invoice`, `EN16931Party`, `EN16931LineItem`, `EN16931Address`, `EN16931Tax`, `EN16931AllowanceCharge`, `EN16931PaymentMeans`
`credit_note`	`EN16931CreditNote` (type codes 381/383/384/385), `BillingReference`
`wire_formats`	`EN16931UBLSerializer`, `EN16931UBLParser`, `EN16931CIISerializer`, `EN16931CIIParser`, `UBL_NSMAP`, `CII_NSMAP`
`convert`	`Syntax` (UBL, CII), `convert_wire_format` (auto-detect source, serialize to target)
`base_server`	`EInvoicingMCPServer`, `BaseDocumentGenerator`, `BaseDocumentValidator`, `BaseDocumentParser`, `BaseLifecycleManager`, `BasePartyValidator`, `SubmitResult`, `assert_not_read_only`, `scrub`
`http_client`	`BaseEInvoicingClient` (OAuth2, mTLS, bearer, API key, none), `OAuthConfig`, `OAuthValues`, `TokenCache`, `AuthMode`
`peppol`	`PeppolSMPClient`, `PeppolParticipantId`, `PeppolServiceInfo`, `PeppolLookupResult`, `PeppolEnvironment`, `PEPPOL_BIS_BILLING_30`
`peppol.transport`	`AS4MessageEnvelope`, `AS4TransportClient`, `AS4ReceiptHandler`, `PeppolTransmitter`, `AS4Receipt`, `AS4Credentials` (Peppol AS4 outbound transmission)
`schematron`	`SchematronValidator` (XSLT 1.0), `SaxonSchematronValidator` (XSLT 2.0/3.0, optional `[xslt2]` extra), `load_schematron_validator` (auto-dispatch factory), `get_xslt_version`, `BaseStructuredValidator`, `BaseXSDValidator`, `BaseJSONValidator`, `ValidationMessage`, `ValidationResult`
`digital_signature`	`BaseDocumentSigner`, `XAdESEPESSigner`, `XAdESSignerConfig`, `XMLDSigSigner`, `XMLDSigSignerConfig`
`endpoints`	`BaseEnvironmentEndpoints`, `EndpointSet`, `EndpointEnvironment` (sandbox/production URL routing)
`routing`	`RoutingIdentifier` (static validators: `validate_de_leitweg`), `RoutingIdValidationResult`
`profile_registry`	`ProfileEntry`, `ProfileRegistry`, `profile_registry`, `set_profile_registry`
`pdf`	`PDFEmbedder` (PDF/A-3 XML embedding)
`qr`	`generate_qr_png_base64`
`xml_utils`	`format_amount`, `format_quantity`, `xml_element`, `xml_optional`, `validate_date_iso`, `validate_iban`, `resolve_xml_input`, `mark_untrusted`, `mark_untrusted_fields`, `filter_empty_values`, `format_error`
`download_rules`	`DownloadSpec`, `download_artefacts`
`testing`	`InvoiceFixtureFactory` (shared pytest fixtures)
`audit_log`	`AuditLog`, `AuditAction`, `get_audit_log`
`confirmation`	`ConfirmationGate`, `ConfirmationStore` (human-in-the-loop gate)
`exceptions`	`EInvoicingError`, `ValidationError`, `PartyValidationError`, `XSDValidationError`, `SchematronValidationError`, `DocumentGenerationError`, `AuthenticationError`, `PlatformError`
`logging_utils`	`setup_logging`, `get_logger`
`audit`	Compliance audit framework: `AuditReport`, `CheckResult`, `CheckFinding`, severity constants, `make_report`, `render_summary_table`, `parse_audit_args`, `run_check_core_coverage`, `run_check_version_compatibility`, `run_check_known_shared_helpers`, `TaxRate`, `load_rates` (optional `[audit]` extra)

Installation

pip install mcp-einvoicing-core

For the compliance audit framework (used by country package CI):

pip install mcp-einvoicing-core[audit]

For XSLT 2.0/3.0 Schematron validation (SaxonSchematronValidator — needed for Schematron rule sets using XPath 2.0+ constructs, e.g. FNFE-MPE Factur-X 1.08 / ZUGFeRD):

pip install mcp-einvoicing-core[xslt2]

Architecture

Country packages subclass the core abstractions and register their tools on a shared or standalone MCP server:

mcp-einvoicing-core
  ├── EN16931Invoice / InvoiceDocument  ← canonical invoice models
  ├── EN16931CreditNote                 ← credit note (type codes 381/383/384/385)
  ├── EN16931UBL/CII Serializer/Parser  ← wire format round-trip
  ├── convert_wire_format               ← CII ↔ UBL conversion
  ├── BaseDocumentGenerator/Validator/Parser/LifecycleManager
  ├── BaseEInvoicingClient              ← async HTTP (OAuth2/mTLS/bearer/API key)
  ├── PeppolSMPClient                   ← participant lookup via SMP/SML
  ├── PeppolTransmitter                 ← AS4 outbound transmission
  ├── BaseDocumentSigner                ← XAdES-EPES / XMLDSig
  ├── BaseEnvironmentEndpoints          ← sandbox/production URL routing
  ├── RoutingIdentifier                 ← country-specific routing ID validation
  ├── EInvoicingMCPServer               ← plugin registry wrapping FastMCP
  └── Audit framework                   ← per-package compliance checks

Country packages

Country	Package	Standard
France	`mcp-facture-electronique-fr`	NF XP Z12-012 / NF XP Z12-013 / Factur-X / UBL 2.1 / CII
Germany	`mcp-einvoicing-de`	ZUGFeRD 2.x / XRechnung 3.x
Belgium	`mcp-einvoicing-be`	Peppol BIS 3.0 / PINT-BE
Italy	`mcp-fattura-elettronica-it`	FatturaPA / SDI
Poland	`mcp-ksef-pl`	KSeF FA(3) / FA(2) / Peppol BIS 3.0
Spain	`mcp-facturacion-electronica-es`	Factura-e / VeriFactu / SII / FACe
Brazil	`mcp-nfe-br`	NF-e / NFC-e (modelo 55/65, schema 4.00) / NFS-e Nacional

Plugin registration pattern

Country packages register their tools on a shared or standalone FastMCP instance:

# Standalone
from fastmcp import FastMCP
mcp = FastMCP(name="mcp-fattura-elettronica-it", instructions="...")
register_header_tools(mcp)
register_body_tools(mcp)
register_global_tools(mcp)

# Multi-country (optional EInvoicingMCPServer)
from mcp_einvoicing_core import EInvoicingMCPServer
server = EInvoicingMCPServer(name="mcp-einvoicing-eu", instructions="...")
server.register_plugin(register_header_tools, "it-header")
server.register_plugin(register_flow_tools, "fr-flow")
server.run()

Claude Desktop / Cursor / Kiro compatibility

Existing configurations for country packages require no changes: tool names, signatures, environment variables, and entry points (server:main) are fully preserved.

License

Apache 2.0 -- see LICENSE.