Look up CNPJ in Python

This guide shows how to look up a CNPJ with the CNPJAPI REST API in Python, using the requests library. The response comes as JSON, with fields in PascalCase (RazaoSocial, SituacaoCadastral, ...).

Prerequisites

Python 3.8+ and the requests library (pip install requests).
An API key from CNPJAPI. Create your account at https://app.cnpjapi.com.br and generate the key (see Authentication).

Simple lookup

import requests

CNPJ = "00776574000156"  # only the 14 digits, without punctuation
API_KEY = "cnpj_sua_chave"

resposta = requests.get(
    f"https://api.cnpjapi.com.br/{CNPJ}",
    headers={"Authorization": f"Bearer {API_KEY}"},
    timeout=10,
)
resposta.raise_for_status()

empresa = resposta.json()
print(empresa["RazaoSocial"])
print(empresa["SituacaoCadastral"]["Descricao"])
print(empresa["AtividadePrincipal"]["Descricao"])

Handling errors and rate limits

When you exceed the per-minute limit or the monthly quota, the API responds 429 with a Retry-After header (seconds). Treat it as recoverable:

import time

resposta = requests.get(
    f"https://api.cnpjapi.com.br/{CNPJ}",
    headers={"Authorization": f"Bearer {API_KEY}"},
    timeout=10,
)

if resposta.status_code == 429:
    espera = int(resposta.headers.get("Retry-After", "60"))
    time.sleep(espera)
    # retry...
elif resposta.status_code == 404:
    print("CNPJ não encontrado na base pública")
elif resposta.ok:
    empresa = resposta.json()
    print(empresa["RazaoSocial"])
else:
    resposta.raise_for_status()

State Registration (IE, premium)

On a plan that includes State Registration (IE), look up a company's IE from the official SEFAZ source. Pass uf for a single state (1 credit) or omit it for the nationwide sweep (3 credits):

resposta = requests.get(
    f"https://api.cnpjapi.com.br/consulta/ie/{CNPJ}",
    params={"uf": "SP"},
    headers={"Authorization": f"Bearer {API_KEY}"},
    timeout=15,
)
resposta.raise_for_status()

for ie in resposta.json()["resultados"]:
    print(ie["uf"], ie["ie"], ie["situacao"])

Full contract (fields, coverage, credits) at Look up the State Registration.

Next steps

Create your free account at https://app.cnpjapi.com.br and make your first lookup in minutes.