Look up CNPJ in Node.js

This guide shows how to look up a CNPJ with the CNPJAPI REST API in Node.js, using native fetch (Node 18+). The response comes as JSON, with fields in PascalCase (RazaoSocial, SituacaoCadastral, ...).

Prerequisites

Node.js 18+ (fetch is native; on earlier versions, use node-fetch or undici).
The examples use top-level await, so run them as an ES module (a .mjs file, or "type": "module" in package.json). In CommonJS, wrap the code in an async function.
An API key from CNPJAPI. Create your account at https://app.cnpjapi.com.br and generate the key (see Authentication).

Simple lookup

const CNPJ = "00776574000156"; // only the 14 digits, without punctuation
const API_KEY = "cnpj_sua_chave";

const resposta = await fetch(`https://api.cnpjapi.com.br/${CNPJ}`, {
  headers: { Authorization: `Bearer ${API_KEY}` },
});

if (!resposta.ok) {
  throw new Error(`Falha na consulta: HTTP ${resposta.status}`);
}

const empresa = await resposta.json();
console.log(empresa.RazaoSocial);
console.log(empresa.SituacaoCadastral.Descricao);
console.log(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:

const resposta = await fetch(`https://api.cnpjapi.com.br/${CNPJ}`, {
  headers: { Authorization: `Bearer ${API_KEY}` },
});

if (resposta.status === 429) {
  const espera = Number(resposta.headers.get("Retry-After") ?? 60);
  await new Promise((r) => setTimeout(r, espera * 1000));
  // retry...
} else if (resposta.status === 404) {
  console.log("CNPJ não encontrado na base pública");
} else if (resposta.ok) {
  const empresa = await resposta.json();
  console.log(empresa.RazaoSocial);
}

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):

const resposta = await fetch(
  `https://api.cnpjapi.com.br/consulta/ie/${CNPJ}?uf=SP`,
  { headers: { Authorization: `Bearer ${API_KEY}` } },
);

if (!resposta.ok) {
  throw new Error(`IE lookup failed: HTTP ${resposta.status}`);
}

const { resultados } = await resposta.json();
for (const ie of resultados) {
  console.log(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.