mcp-einvoicing-core

# mcp-einvoicing-core

[English](README.md) | [Francais](README.fr.md) | [Deutsch](README.de.md) | [Italiano](README.it.md) | [Espanol](README.es.md) | [Portugues (Brasil)](README.pt-BR.md) | [العربية](README.ar.md)

<!-- mcp-name: io.github.cmendezs/mcp-einvoicing-core -->

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**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, JWS, none), `OAuthConfig`, `OAuthValues`, `JWSConfig`, `TokenCache`, `AuthMode` |
| `peppol` | `PeppolSMPClient`, `PeppolParticipantId`, `PeppolServiceInfo`, `PeppolLookupResult`, `PeppolEnvironment`, `PEPPOL_BIS_BILLING_30`, `resolve_naptr` (standalone U-NAPTR/SML DNS diagnostic) |
| `peppol.tools` | `register_peppol_tools` (mountable FastMCP plugin: participant lookup, service endpoint, DNS diagnostic, AS4 send, plus 8 eDEC code list tools), `default_id_adapter`, `IdentifierAdapter` (national identifier adapter contract) |
| `peppol.codelists` | `CodeList`, `CodelistNotConfiguredError`, `load_codelist` and the eDEC lookup functions (document types, processes, participant ID schemes, transport profiles, SPIS use cases). Requires `EINVOICING_PEPPOL_CODELIST_DIR`, see Configuration below |
| `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` |
| `schematron_artifacts` | `en16931_base_schematron_validator` (bundled, compiled CEN EN16931 base Schematron — `BR-*` rules only, no Peppol overlay; optional `[xslt2]` extra) |
| `digital_signature` | `BaseDocumentSigner`, `XAdESEPESSigner`, `XAdESSignerConfig`, `XMLDSigSigner`, `XMLDSigSignerConfig`, `load_certificate_der` |
| `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); `extract(filename=None)` tries canonical Factur-X/XRechnung/ZUGFeRD filenames in turn, `identify()` reads XMP to detect a hybrid PDF and its conformance level |
| `pdf_tools` | `register_pdf_tools` (mountable FastMCP plugin: `identify_and_extract_pdf`), `identify_and_extract_pdf` |
| `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) |

## Country packages

| Country | Package | Standard | Scope | Coverage status |
|---------|---------|----------|-------|------------------|
| France | [`mcp-facture-electronique-fr`](https://github.com/cmendezs/mcp-facture-electronique-fr) | NF XP Z12-012 / NF XP Z12-013 / Factur-X / UBL 2.1 / CII | B2B, phased rollout from 1 September 2026 | Live |
| Germany | [`mcp-einvoicing-de`](https://github.com/cmendezs/mcp-einvoicing-de) | ZUGFeRD 2.x / XRechnung 3.x | B2B, phased 2025 to 2028 | Live |
| Belgium | [`mcp-einvoicing-be`](https://github.com/cmendezs/mcp-einvoicing-be) | Peppol BIS 3.0 / PINT-BE | B2B, 1 January 2026 | Live; Peppol-specific overlay rules not checked (EN 16931 base only) |
| Italy | [`mcp-fattura-elettronica-it`](https://github.com/cmendezs/mcp-fattura-elettronica-it) | FatturaPA / SDI | B2G + B2B + B2C, mandatory since 2019 (B2G since 2014) | Live |
| Poland | [`mcp-ksef-pl`](https://github.com/cmendezs/mcp-ksef-pl) | KSeF FA(3) / FA(2) / Peppol BIS 3.0 | B2B, phased February 2026 to January 2027 | Live; batch session flow not implemented |
| Spain | [`mcp-facturacion-electronica-es`](https://github.com/cmendezs/mcp-facturacion-electronica-es) | Factura-e / VeriFactu / SII / FACe | Pending Orden Ministerial, targeted 2026-10-01 | Live for VeriFactu/SII; B2B format wiring blocked on pending Orden Ministerial |
| Brazil | [`mcp-nfe-br`](https://github.com/cmendezs/mcp-nfe-br) | NF-e / NFC-e (modelo 55/65, schema 4.00) / NFS-e Nacional | B2B (NF-e) + B2C (NFC-e), both mandatory since 2008 | Live; IBS/CBS tax reform rollout ongoing through 2033 |

## Installation

```bash
pip install mcp-einvoicing-core
```

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

```bash
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):

```bash
pip install mcp-einvoicing-core[xslt2]
```

## Configuration

| Variable | Used by | Purpose |
|---|---|---|
| `EINVOICING_PEPPOL_CODELIST_DIR` | `peppol.codelists` (and the `peppol.tools` codelist tools) | Local directory containing your own copy of the OpenPeppol eDEC Code Lists. **Not bundled with this package**: the eDEC Code Lists carry no confirmed redistribution grant from OpenPeppol, so core ships only the parser and lookup tools, never the data itself. Download the "as GeneriCode" export for each artifact (Document Types, Participant Identifier Schemes, Processes, Transport Profiles, SPIS Use Case) from [docs.peppol.eu/edelivery/codelists](https://docs.peppol.eu/edelivery/codelists/index.html) and point this variable at the directory containing them. Filenames are matched by prefix, so a version bump (e.g. v9.7 to v9.8) needs no code change. Without this set, the codelist tools return a `configured: false` result with setup instructions rather than raising. |
| `EINVOICING_SMP_ALLOWLIST` | `peppol` (`PeppolSMPClient`, `resolve_naptr`) | Comma-separated hostname suffixes to extend the built-in Peppol Access Point allowlist used when validating a resolved SMP hostname. |

## 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/JWS)
  ├── 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
```

## Plugin registration pattern

Country packages regi