API Documentation v0.1.0

Authentication

Include your API key in every request using the Authorization header.

Authorization: Bearer <your-api-key>

For sandbox/testing, use the test key: fm_test_key_acme_12345

Amounts

All monetary amounts are in cents (integer). R$ 100,00 = 10000.

Charges

PIX

{
  "method": "pix",
  "amount": 10000,
  "customer": {
    "name": "João Silva",
    "document": "12345678900"
  }
}

Credit Card

{
  "method": "card",
  "amount": 25000,
  "installments": 3,
  "capture": true,
  "customer": { "name": "Maria Souza", "document": "98765432100" },
  "card": {
    "number": "4111111111111111",
    "holderName": "MARIA SOUZA",
    "expirationMonth": 12,
    "expirationYear": 2028,
    "cvv": "123"
  }
}

Boleto

{
  "method": "boleto",
  "amount": 5000,
  "dueDate": "2026-05-30",
  "customer": { "name": "Carlos Lima", "document": "11122233344" }
}

created → awaiting_payment → paid
         ↘ cancelled
                            → refunded
                            → chargeback

{
  "amount": 5000
}

Omit amount for a full refund.

Webhooks

Webhook payloads are signed with HMAC-SHA256. Verify the x-webhook-signature header.

{
  "event": "payment.confirmed" | "payment.refunded" | "payment.chargeback",
  "gatewayId": "fake_...",
  "chargeId": "uuid",
  "amountCents": 10000,
  "timestamp": "2026-05-14T00:00:00.000Z"
}

Sandbox Admin Sandbox only

Simulate gateway events in the test environment without waiting for real payment confirmations.

Infrastructure