apipj MCP server: Brazilian CNPJ lookup (API CNPJ)

Remote Model Context Protocol server for looking up and validating Brazilian companies by CNPJ, using the open data that Receita Federal publishes every month. Works in Claude, ChatGPT, Claude Code, Cursor, VS Code and any MCP client that supports Streamable HTTP.

https://apipj.com.br/mcp

This repository holds the public documentation and the MCP Registry manifest (server.json, name br.com.apipj/cnpj). The server itself is hosted by apipj; there is nothing to install or run.

Tools

All tools are read-only (readOnlyHint: true, destructiveHint: false).

Related MCP server: Cadastro PJ Básico

Authentication

• OAuth 2.1 (recommended): clients that support MCP authorization (Claude, ChatGPT, Claude Code, Cursor, VS Code) open the apipj sign-in page the first time a tool needs an account. Sign in with Google (or e-mail and password) and click Autorizar. The server supports Client ID Metadata Documents and Dynamic Client Registration, with PKCE S256.

• API key: clients without OAuth can send Authorization: Bearer apipj_live_.... Create a free account and a key at apipj.com.br/criar-conta.

Each lookup counts toward the per-minute limit and the monthly quota of your apipj account. See plans.

Connect

Claude (claude.ai, Desktop, mobile): Customize → Connectors → Add custom connector → URL https://apipj.com.br/mcp. Leave the OAuth client fields empty.

ChatGPT: Settings → Apps & Connectors → enable Developer mode → Add custom MCP server → URL https://apipj.com.br/mcp, authentication OAuth.

Claude Code:

claude mcp add --transport http apipj https://apipj.com.br/mcp

Cursor: use the install button above, or the apipj Cursor plugin, or add to .cursor/mcp.json:

{ "mcpServers": { "apipj": { "url": "https://apipj.com.br/mcp" } } }

VS Code: use the install button above, or add to .vscode/mcp.json:

{ "servers": { "apipj": { "type": "http", "url": "https://apipj.com.br/mcp" } } }

Cline: add the server to cline_mcp_settings.json as described in llms-install.md.

Other clients (with an API key):

{
  "mcpServers": {
    "apipj": {
      "type": "http",
      "url": "https://apipj.com.br/mcp",
      "headers": { "Authorization": "Bearer YOUR_API_KEY" }
    }
  }
}

Example prompts

• "What is the registration status and address of CNPJ 11.378.117/0001-20?"

• "Who are the partners of CNPJ 11.378.117/0001-20, and is it in Simples Nacional?"

• "Is the CNPJ 12.ABC.345/01DE-35 valid?"

• "Which month of Receita Federal data does apipj have loaded?"

Data and limits

• Source: Receita Federal open data (CNPJ), loaded monthly. Data may be out of date and is not an official certificate.

• Partner CPF numbers are masked exactly as Receita Federal publishes them; the server never reveals full CPF numbers.

• Transport: Streamable HTTP, stateless, protocol versions 2025-11-25, 2025-06-18 and 2025-03-26.

• Server status: apipj.com.br/status.

Em português

Servidor MCP remoto do apipj para consultar CNPJ e validar CNPJ (inclusive o CNPJ alfanumérico) direto no Claude, no ChatGPT, no Cursor e em outros assistentes, com os dados abertos da Receita Federal (carga mensal). A consulta usa uma conta apipj: na primeira vez, o assistente pede para conectar; entre com o Google e clique em Autorizar. Validação e status funcionam sem conta. Guia completo: apipj.com.br/guias/consultar-cnpj-ia-mcp.

Links

• Documentation: https://apipj.com.br/docs

• MCP guide: https://apipj.com.br/guias/consultar-cnpj-ia-mcp

• JavaScript/TypeScript client: apipj/apipj-js · Python client: apipj/apipj-py · n8n node: apipj/n8n-nodes-apipj

• Terms: https://apipj.com.br/termos · Privacy: https://apipj.com.br/privacidade

• Support: brunogalizzi@masterbi.com

Operated by MASTER BI TECNOLOGIA LTDA (CNPJ 35.659.589/0001-19). Documentation licensed under MIT.