Invoicenow Sg MCP server

mcp-invoicenow-sg 🇸🇬

English

<!-- mcp-name: io.github.cmendezs/mcp-invoicenow-sg -->

Introduction

mcp-invoicenow-sg is an MCP (Model Context Protocol) server for Singapore electronic invoicing over InvoiceNow, the national e-invoicing platform operated by IMDA. It builds and validates PINT-SG v1.4.1 and SG Peppol BIS Billing 3.0 sent invoices (originally-issued invoices, not the received/purchase side). It is part of the mcp-einvoicing-* family of country-specific servers, all built on mcp-einvoicing-core, which provides the shared validation engine, EN 16931 abstractions, and Peppol network utilities.

Supported standards

senders.

• PINT-SG v1.4.1 (urn:peppol:pint:billing-1@sg-1) — the recommended profile for new

mcpeinvoicingcore.en16931.EN16931Invoice.

• SG Peppol BIS Billing 3.0 — legacy profile, predates the PINT programme.
• Both are EN 16931-conformant; the invoice model extends

government artifact, e.g. it flags a missing buyer/seller UEN. As of v0.2.0, PINT-SG's own jurisdiction Schematron rules (e.g. the invoiceuuid requirement) are not** checked — see "Not yet supported" below.

• Validation runs IRAS's own C5 acceptance layer (nonpeppoldoc_validation) — a first-party

Not yet supported (see specs/README.md for full detail):

self-compiled derivative of OpenPeppol's PINT-SG jurisdiction Schematron with no confirmed redistribution rights; it was removed in v0.2.0 (2026-08-28). The shared, properly-licensed core CEN EN16931 base validator is wired but not yet activated for SG — SGInvoice's IRAS GST category codes have no sourced crosswalk to the UNCL5305 code list that validator requires. See EN16931BASEUNAVAILABLEWARNING in every validateinvoice_sg result (tracked as [CORE-EN16931-BASE-SG-CROSSWALK-1]) for what would unblock it.

• CEN EN16931 base and PINT-SG jurisdiction Schematron validation. v0.1.0 bundled a

Order Balance.

• The Peppol Ordering message family (Order, OrderResponse, etc.) and IMDA's SG-specific

package's own test suite (a test-only fixture, not shipped in the wheel), but not wired into the validateinvoicesg tool: the OASIS UBL 2.1 schema files needed carry no locally-confirmed redistribution grant.

• UBL 2.1 XSD structural validation. Proven correct against a real UBL 2.1 schema in this

distinct from generic Peppol AS4 transport, which the Peppol tools below do support) — no publicly available document states an IMDA-accredited Access Point's actual API base URL or authentication flow.

• IRAS's own Invoice Data Submission API (the 5th-corner "C5" copy specifically, as

• SG Peppol BIS Billing 3.0 Schematron validation — no rule set is bundled for this profile.
• The received/purchase-side invoice model (LocalTaxInvoice, TX2_Annex Annex B Type 1B).

Installation

Requirements

automatically as a dependency)

• Python ≥ 3.11
• mcp-einvoicing-core (installed

validateinvoicesg to run. The bundled IRAS C5 stylesheet requires XSLT 2.0.

• Optional: the xslt2 extra (pip install mcp-invoicenow-sg[xslt2]) — required for

Using uvx (recommended)

uvx mcp-invoicenow-sg

Using uv

uv add mcp-invoicenow-sg

From source

Shortened. The full README is on GitHub.