cnpj-mcp

An MCP server for analytical questions over Brazil's open company registry (CNPJ), built from Receita Federal's monthly open-data dump. It is made for questions about many companies at once, not for looking up a single number:

• How many MEIs were opened per month in Minas Gerais since 2023?
• Which municipalities in Mato Grosso have the most active soy and grain companies?
• Which companies share one address, and who are their partners?
• How many companies closed each year, and for what reason?

Single-CNPJ lookup is included, but free APIs already do that well.

What is in it

Every establishment, company, partner and Simples/MEI record in Receita's dump, joined and typed for fast queries. Values stay in Portuguese, exactly as Receita publishes them. See dataset_info for the loaded snapshot month and row counts.

Source: Receita Federal, Dados Abertos CNPJ, https://www.gov.br/receitafederal/pt-br/acesso-a-informacao/dados-abertos/cadastros

Use it

Hosted endpoint (streamable HTTP): listed in the MCP registry as io.github.bnovarini/cnpj-mcp.

Or run it yourself:

pip install "cnpj-mcp[ingest]"
cnpj-mcp ingest 2026-09 ./raw          # streams Receita's zips straight to Parquet, about 7 GB downloaded
cnpj-mcp build 2026-09 ./raw ./data    # joins and types them
CNPJ_DATA_DIR=./data cnpj-mcp          # MCP server over stdio

ingest needs curl and unzip on the PATH. It never writes the zip or the CSV to disk, so disk use is only the Parquet output (about 8 GB). It skips files that are already done, so you can re-run it after an interruption. The build step needs about 20 GB of free space for sorting and the swap.

Tools: dataset_info, search_companies, count_companies, get_company, list_partners, search_partners, companies_at_address, lookup_codes.

Read this before quoting numbers

• The registry shows the current state only. A company's earlier addresses, activities and capital are not kept.
• About half of all records are closed (situacao baixada). Filter by situacao when you mean active companies.
• Counts are establishments (one per CNPJ) unless you pass unit='empresas', which counts companies (matriz only).
• Capital social is what the company declared, in BRL. It is not a measure of real assets.
• Receita's data is only as good as what companies and registries report. Opening dates, CNAE codes and addresses can be wrong or stale.
• MEI and Simples flags show the current option, with dates when it started or ended.

Personal data and LGPD

Receita publishes partner names, and this project includes them. Under LGPD that is still personal data, even though it is public:

• Receita masks CPFs before publishing (only the 6 middle digits are shown), and this project keeps them masked. Do not try to re-identify people from them.
• Names alone can match different people. Do not treat a name match as proof that two records are the same person.
• Use partner search for legitimate purposes, such as due diligence, journalism or research. Do not use it for profiling people, harassment or unsolicited marketing.
• Contact details (email, phone) are published by Receita too. They are only returned when you ask for them with include_contacts.

Checks

Counts are reconciled to the source and to the government's own figures. See docs/AUDIT.md, including numbers that do not match and why.

License

MIT for the code. The data comes from Receita Federal's open-data program; check Receita's current terms for reuse.