# Auditor Fiscal — MCP server on mcp.ai
> Check whether a Brazilian invoice was issued with the right taxes. Send the NF-e line items and get back every divergence between what the invoice declares and what the tax rules require, with the field, the expected value and the arithmetic. Covers ICMS, tax substitution, DIFAL, PIS, COFINS and the new IBS and CBS, plus Simples Nacional effective rate and Fator R. Platform-hosted, no credentials.

By: mcp.ai · official
Page: https://mcp.ai/auditor_fiscal

## Connect (MCP protocol)
Remote MCP endpoint (HTTP, streamable): https://api.mcp.ai/p_auditor_fiscal?ms=1787633220000
Add it as a custom/remote MCP connector, then authenticate when prompted.

## REST API (no MCP client required)
Every tool is also a REST endpoint, authed with a workspace API key.
Discover: GET https://api.mcp.ai/api/auditor_fiscal/_endpoints   # public; lists every endpoint
Call:     POST https://api.mcp.ai/api/auditor_fiscal/<endpoint>
  Authorization: Bearer sk_live_…   # create one at https://mcp.ai/settings/api-keys
  Content-Type: application/json
  Body: { …args }   →   { "ok": true, "tool": "<id>", "result": { … } }

## Developer docs
How to use (MCP or REST), markdown: https://mcp.ai/auditor_fiscal/skill.md
Postman collection (v2.1): https://mcp.ai/auditor_fiscal/postman.json

## Tools
- auditor_fiscal_ajuda() — Explica exatamente o que esta auditoria confere e o que ela NÃO confere, e qual caminho usar por regime tributário. Chame antes da primeira auditoria. Não consome saldo.
- auditor_fiscal_auditar_item(regime_tributario: string, item: object) — Audita UM item isolado. Útil para conferir uma dúvida pontual sem montar a nota inteira.
- auditor_fiscal_auditar_nota(xml?: string, xml_base64?: string, regime_tributario?: string, itens?: object[], totais?: object) — Audita uma NF-e inteira: compara o imposto DECLARADO em cada item com o DEVIDO pela regra tributária, e confere a aritmética da nota.
- auditor_fiscal_consultar_codigo(tipo: string, codigo: string) — Consulta um código fiscal na tabela vigente: NCM (8 dígitos), CEST (7), CFOP (4) ou CST de IBS/CBS da Reforma.
- auditor_fiscal_simples_aliquota(rbt12?: number, receitas_mensais?: number[], meses_de_atividade?: number, anexo?: string, folha_12m?: number) — Simples Nacional: alíquota EFETIVA e Fator R, com a conta aberta.
- auditor_fiscal_simples_fator_r(rbt12?: number, receitas_mensais?: number[], meses_de_atividade?: number, anexo?: string, folha_12m?: number) — Simples Nacional: alíquota EFETIVA e Fator R, com a conta aberta.

## Example prompts
- "What exactly does this audit check, and what does it not check?"
- "Audit this line: NCM 84713012, CFOP 6102, MS to SP, R$1,000, declared ICMS 120"
- "What is the Simples Nacional effective rate for Annex III with a R$1.2M RBT12?"

## Links
Docs: https://mcp.ai/docs/mcps/auditor_fiscal
Website: https://mcp.ai/mcps/auditor_fiscal