Integrate once.
Issue everywhere.

An API and SDK for Brazilian fiscal documents — real SEFAZ transmission, manual tax passthrough, and a dashboard to track every submission.

Create free account Log in

No credit card — free homologation environment.

50 free invoices when you sign upUnlimited homologation tests

View documentation

curl -X POST https://api.stackin.dev/api/v1/invoices \
  -H "Authorization: Bearer stackin_live_••••••••••••" \
  -H "Content-Type: application/json" \
  -d '{
  "document_type": "nfe",
  "client_name": "Buyer Company Ltd",
  "tax_id": "11222333000181",
  "items": [{
    "description": "Rosa Holambra Vermelha",
    "amount": 112.44,
    "product": { "br": { "ncm": "06031100", "cfop": "5102" } }
  }]
}'

Response200 OK

{
  "result": {
    "access_key": "422608...50077",
    "status": "authorized",
    "protocol": "142260000009876",
    "authorized_at": "2026-08-28T09:15:42-03:00"
  }
}

Time: 320ms

Overview30 days

Invoices issued1.414+9,3%

Authorized1.352+10,1%

Rejected62-3,2%

Amount issuedR$ 284.910+12,5%

Issuance over the last 30 days

Document	Recipient	Amount	Status
NFE · a1b2c3d4	Comprador Teste Ltda	R$ 2.622,82	Authorized
NFSE · f9e8d7c6	John Doe	R$ 10.500,00	Rejected
NFE · 5b6a4c3d	Buyer Company Ltd	R$ 112,44	Authorized

Real SEFAZ transmission

Direct, secure communication with every state tax authority.

Taxes and manual passthrough

Compute, break out, and pass through taxes — simple and transparent.

Official SDKs

SDKs for Python, Node.js, PHP, and Java, ready to use.

Full dashboard

Track every submission, look up documents, monitor errors in real time.

Install the SDK. Issue your first invoice.

stackin mirrors the API one-to-one — the same Product/Tax models, the same field names, the same validation.

Install the SDK

pip install stackin

product.py

from stackin.br import Product, Tax, Icms00

product = Product(
    description="Rosa Holambra Vermelha",
    amount=112.44,
    ncm="06031100",
    cfop="5102",
    tax=Tax(icms=Icms00(orig="0", v_bc="112.44",
                         p_icms="18.00", v_icms="20.24")),
)

Three steps from account to authorized invoice.

Configure

Integrate

Call the API with your company's API key, or use stackin.

Ship

Issue in homologation, then production — track every submission.

Start issuing fiscal documents today.

Free homologation environment — no credit card required.