cnpjaberto

Python SDK and Model Context Protocol (MCP) server for cnpjaberto.com.br, the open registry of Brazilian companies (CNPJ). It allows for company lookups, partner graphs, joins by address and contact, CNAE statistics, and national/annual overviews.

pip install cnpjaberto          # apenas SDK
pip install cnpjaberto[mcp]     # SDK + servidor MCP para Claude Desktop e similares

Quick start with the SDK

from cnpjaberto import Client

with Client() as cnpj:                       # lê CNPJABERTO_API_KEY do ambiente
    empresa = cnpj.lookup("18.236.120/0001-58")
    print(empresa["razao_social"])

    achados = cnpj.search("nubank", per_page=5)
    for h in achados["results"]:
        print(h["cnpj"], h["razao_social"])

    snap = cnpj.panorama_year(2024)
    print(f"{snap['abertas']:,} abertas, {snap['fechadas']:,} fechadas em 2024")

Anonymous calls work, subject to public rate limits. For the Pro plan daily quota, generate a key at cnpjaberto.com.br/planos and export it:

export CNPJABERTO_API_KEY=sua_chave_aqui

Related MCP server: brdata-mcp

MCP Server (Claude Desktop, Cursor, Cline)

Install the extra and add this config to your client.

pip install cnpjaberto[mcp]

~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "cnpjaberto": {
      "command": "cnpjaberto-mcp",
      "env": { "CNPJABERTO_API_KEY": "sua_chave_aqui" }
    }
  }
}

Restart Claude Desktop. Now you can ask things like:

• "Look up CNPJ 18.236.120/0001-58 and tell me when it was founded."

• "How many Brazilian companies opened in 2024 vs 2023? Which states grew the most?"

• "Find companies where 'Maria Silva' appears as a partner, grouped by state."

• "What other companies are registered at the same address as the Magazine Luiza headquarters?"

Exposed Tools

Typed errors

from cnpjaberto import Client, NotFoundError, RateLimitError, AuthError

with Client() as cnpj:
    try:
        cnpj.lookup("00000000000000")
    except NotFoundError:
        ...
    except RateLimitError as e:
        print("Cota diária:", e.payload)
    except AuthError:
        ...

Data source

All data comes from the public CNPJ dump from the Federal Revenue Service, updated monthly. cnpjaberto.com.br ingests, indexes, and serves with sub-second lookups, plus value-added joins (partner graph, shared addresses, CNAE aggregates) covering about 70 million establishments and 67 million companies.

License

MIT.