API para envio automático de correspondências

curl https://api.cartaflow.com.br/v1/letters \
  -H "Authorization: Bearer $CARTAFLOW_API_KEY" \
  -H "Idempotency-Key: fatura-2026-10-0042" \
  -F "to[name]=Destinatário Exemplo" \
  -F "to[address_line1]=Rua Exemplo, 128" \
  -F "to[address_line2]=Ap. 52" \
  -F "to[district]=Centro" \
  -F "to[city]=São Paulo" \
  -F "to[state]=SP" \
  -F "to[cep]=01001-000" \
  -F "color=true" \
  -F "file=@fatura-outubro.pdf"

import { readFile } from 'node:fs/promises';

const form = new FormData();
form.append('to[name]', 'Destinatário Exemplo');
form.append('to[address_line1]', 'Rua Exemplo, 128');
form.append('to[address_line2]', 'Ap. 52');
form.append('to[district]', 'Centro');
form.append('to[city]', 'São Paulo');
form.append('to[state]', 'SP');
form.append('to[cep]', '01001-000');
form.append('color', 'true');
form.append('file', new Blob([await readFile('fatura-outubro.pdf')]), 'fatura-outubro.pdf');

const res = await fetch('https://api.cartaflow.com.br/v1/letters', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.CARTAFLOW_API_KEY}`,
    'Idempotency-Key': 'fatura-2026-10-0042',
  },
  body: form,
});
const letter = await res.json();

import os
import requests

letter = requests.post(
    "https://api.cartaflow.com.br/v1/letters",
    headers={
        "Authorization": f"Bearer {os.environ['CARTAFLOW_API_KEY']}",
        "Idempotency-Key": "fatura-2026-10-0042",
    },
    data={
        "to[name]": "Destinatário Exemplo",
        "to[address_line1]": "Rua Exemplo, 128",
        "to[address_line2]": "Ap. 52",
        "to[district]": "Centro",
        "to[city]": "São Paulo",
        "to[state]": "SP",
        "to[cep]": "01001-000",
        "color": "true",
    },
    files={"file": open("fatura-outubro.pdf", "rb")},
).json()

{
  "id": "ltr_8Kq2wX4m",
  "object": "letter",
  "status": "received",
  "pages": 2,
  "to": {
    "name": "Destinatário Exemplo",
    "cep": "01001-000",
    "city": "São Paulo",
    "state": "SP"
  },
  "created_at": "2026-10-13T14:20:00Z"
}