MCP Nfe Br

mcp-nfe-br 🇧🇷

English | Portugues (Brasil)

Introduction

mcp-nfe-br is an MCP (Model Context Protocol) server providing tools for issuing and validating Brazilian electronic fiscal documents: NF-e (modelo 55), NFC-e (modelo 65), NFS-e Nacional (ADN), and CT-e (modelo 57). This server is part of the mcp-einvoicing-* / mcp-*-* family, built on mcp-einvoicing-core, which provides the base data model, HTTP/OAuth2 utilities, and shared MCP server infrastructure.

Current status (v0.6.5): NF-e/NFC-e (modelo 55/65, schema 4.00) and NFS-e Nacional (ADN, schema v1.01) generation, ICP-Brasil signing, XSD validation, and gated SEFAZ/ADN submission are implemented. NF-e/NFC-e now also covers the 010e_v.1.02 schema delta (DANFE Simplificado Tipo 2 — tpImp=6, cIndOp, ISUFEmit, and the SEFAZ alert-message response group) and the 010f_v.1.04 delta (NT 2026.007 — emit/IE optional for taxpayers exclusively subject to IBS/CBS, produção 2026-11-03) on top of the PL_010d base. CT-e (modelo 57) generation/signing/validation and SEFAZ event submission (cancelamento, Carta de Correção) were added starting v0.6.0 — v1 scope is intentionally narrow: modal rodoviário only, ICMS CST 00 only, and no bundled/verified CT-e webservice endpoint table (every SEFAZ CT-e call requires an explicit endpoint_override). See the "CT-e (modelo 57)" tools section below for the full field-level reference.

Installation

Requirements

• Python ≥ 3.11
• mcp-einvoicing-core (installed automatically as a dependency)

Using uv (recommended)

uv add mcp-nfe-br

Using pip

pip install mcp-nfe-br

From source

git clone https://github.com/cmendezs/mcp-nfe-br.git

cd mcp-nfe-br uv sync --all-extras

Configuration

This server needs no credentials to run. The environment variables below are optional safety/logging toggles:

Environment variables

Claude Desktop integration

To use this server with Claude, add this configuration to your claude_desktop_config.json file:

{

"mcpServers": { "nfe-br": { "command": "uvx", "args": ["mcp-nfe-br"] } } }

For a local development install:

{

"mcpServers": { "nfe-br": { "command": "uv", "args": ["run", "mcp-nfe-br"], "cwd": "/path/to/mcp-nfe-br" } } }

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": { "nfe-br": { "command": "uvx", "args": ["mcp-nfe-br"] } } }

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": { "nfe-br": { "command": "uvx", "args": ["mcp-nfe-br"], "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

br__validate_cpf

Validates a CPF (Cadastro de Pessoas Físicas), the individual taxpayer identification number, using the Receita Federal modulo 11 algorithm.

Returns a TaxIdValidationResult with valid=True and the cleaned value (11 digits) on success, or valid=False with an error message in Portuguese.

br__validate_cnpj

Validates a CNPJ (Cadastro Nacional da Pessoa Jurídica), the business taxpayer identification number. Accepts both the traditional numeric format (14 digits) and the alphanumeric format introduced by NT 2026.004 (PL_010d), effective in homologation from 2026-06-01 and in production from 2026-07-01.

Returns a TaxIdValidationResult with valid=True and the cleaned value (14 characters) on success, or valid=False with an error message in Portuguese.

⚠️ [Unverified]: the check-digit algorithm for the alphanumeric CNPJ format was implemented based on secondary sources, as the primary source ("NT Conjunta DFe 2025.001") is not yet available locally.

br__generate_nfe

Generates an unsigned NF-e/NFC-e 4.00 document ( … ) from a BRInvoice object.

Returns {"xml": ..., "chave_acesso": ..., "warnings": [...]}. The warnings in Portuguese remind that the document is not signed (ICP-Brasil) and was not transmitted to SEFAZ. Both steps are the responsibility of a separate process.

Phase 1 coverage for per-item tax groups:

[NEED: IBS/CBS/Imposto Seletivo — Grupo UB/W03 (NT 2025.002-RTC) not yet modeled].

br__validate_nfe_xml

Validates an NF-e/NFC-e 4.00 XML document against the official PL_010d XSD, patched with the PL_010e_v.1.02 and PL_010f_v.1.04 deltas (local "unsigned" variant, see note below).

\* Exactly one of xml_content/xml_base64 must be provided.

Returns {"valid": bool, "errors": [...], "metadata": {"schema_version": ...}}.

[Inference]: the official XSD (nfe_v4.00.xsd/leiauteNFe_v4.00.xsd, PL_010d) requires as a mandatory child of . Since Phase 1 generates unsigned documents, this tool validates against a local derived copy (nfe_v4.00_unsigned.xsd) where has been made optional (minOccurs="0"). Validation of signed documents (future phase) should use the official XSD without modifications.

br__build_access_key

Builds an access key (chNFe, 44 characters) with a modulo 11 check digit, from the components cUF, dhEmi, issuer CNPJ, model, series, and document number.

Returns {"chave_acesso": ..., "cnf": ...}.

CT-e (modelo 57) tools

CT-e (Conhecimento de Transporte Eletrônico) coverage started at v0.6.0. v1 scope is intentionally narrow: modal rodoviário only (other modais raise an error), ICMS CST 00 (tributação normal) only, and no bundled/verified SEFAZ CT-e endpoint table — every SEFAZ call below requires an explicit endpoint_override. Since v0.7.0, br__generate_cte also accepts the Reforma Tributária do Consumo (IBS/CBS) fields introduced by NT 2026.002 — imp/IBSCBS, emit/ISUFEmit, and ide/tpPagAnt+gPagAntecipado — with the NT's self-contained business rules enforced at the model layer; rules that require a live SEFAZ database lookup are not checked.

br__generate_cte

Generates an unsigned CT-e 4.00 document ( … ) from a BRCTeDocument object.

Returns {"xml": ..., "chave_acesso": ..., "warnings": [...]}.

br__validate_cte_xml

Validates a CT-e 4.00 XML document against the bundled PL_CTe_400 XSD (auto-selects the unsigned or official signed schema based on presence).

\* Exactly one of xml_content/xml_base64 must be provided.

br__consult_cte_sefaz_status

Checks SEFAZ CT-e webservice availability (CTeStatusServicoV4). Read-only, no confirmation required.

br__consult_cte

Queries a CT-e's status by access key (CTeConsultaV4). Read-only, no confirmation required — it queries one already-known document, not a bulk data pull.

br__submit_cte

Submits a signed CT-e to SEFAZ authorization (CTeRecepcaoSincV4, synchronous). The payload is automatically GZip-compressed and Base64-encoded before transmission, per the CT-e MOC. Gated with a two-step confirmation (ConfirmationGate) and BR_CTE_READ_ONLY.

br__cancel_cte

Requests cancellation of an authorized CT-e (event 110111, CTeRecepcaoEventoV4). cStat=135 indicates the cancellation was homologated. Gated.

br__correct_cte

Issues a Carta de Correção Eletrônica (event 110110, CTeRecepcaoEventoV4). Per Art. 58-B of CONVÊNIO/SINIEF 06/89, a CC-e cannot alter tax values, party registration data, or the issue/departure date. Gated.

Not yet implemented: br__distribute_cte_dfe (CTeDistribuicaoDFe) — the bundled specification confirms the request payload shape but not the webservice's method name, WSDL namespace, or message-wrapper element.

Architecture

mcp-nfe-br/

├── src/ │ └── mcp_nfe_br/ │ ├── init.py │ ├── server.py # MCP entry point and tool registration │ ├── models/ │ │ ├── init.py │ │ └── invoice.py # BRInvoice, BRInvoiceLine, NFeModelo, TipoOperacao │ ├── standards/ │ │ ├── init.py │ │ └── nfe_generator.py # NFeGenerator — generates unsigned NF-e/NFC-e 4.00 │ ├── validator