Mom Factura Payments Integration

Process payments for Angolan payment methods with automatic SAFT-AO invoice generation.

Base URL: https://api.momenu.online

Authentication

All requests require the x-api-key header.

Content-Type: application/json
x-api-key: <MERCHANT_API_KEY>

Payment Methods

1. Multicaixa Express (MCX) - Immediate

POST /api/payment/mcx

Immediate payment. Creates order as PAID and generates invoice on success.

Required body:

• paymentInfo.amount (number) - Kwanzas
• paymentInfo.phoneNumber (string) - Format: 244XXXXXXXXX
• instantWithdraw (boolean) - Must be true. Auto-payout (amount minus 2%) to the merchant's verified bank account on confirmation. See Instant Withdrawal.

Optional body:

• products (array) - Items for detailed invoice
• products[].id (string), products[].productName (string), products[].productPrice (number), products[].productQuantity (number)
• products[].iva (number) - IVA rate 0-14, default 14
• customer (object) - name (string), nif (string), phone (string)
• simulateResult (string) - QA only: success, insufficient_balance, timeout, rejected, invalid_number

Example body:

{
  "paymentInfo": { "amount": 5000, "phoneNumber": "244923456789" },
  "instantWithdraw": true
}

Success (200):

{
  "success": true,
  "transactionId": "abc123...",
  "invoiceUrl": "https://invoice-momenu.toquemedia.net/invoices/..."
}

2. Bank Reference - Deferred

POST /api/payment/reference

Generates bank reference. Client pays via ATM or Internet Banking.

Required: paymentInfo.amount, instantWithdraw: true (see Instant Withdrawal) Optional: products, customer (same as MCX)

Success (200):

{
  "success": true,
  "operationId": "op-123...",
  "referenceNumber": "123456789",
  "entity": "12345",
  "dueDate": "2024-01-20"
}

Amount Validation

If both paymentInfo.amount and products are provided, they must match:

• total = SUM(productPrice * productQuantity) for all products
• Mismatch returns error AMOUNT_MISMATCH
• Providing only one is valid (amount OR products)
• Providing neither returns AMOUNT_MISMATCH

Webhook (Payment Confirmation)

Deferred Bank Reference payments are confirmed via webhook. Configure the webhook URL in your apiConfigs document.

When a payment is confirmed, the API sends two sequential events:

Event 1: payment.confirmed — Sent immediately after order status is updated to PAID:

{
  "event": "payment.confirmed",
  "merchantTransactionId": "abc123...",
  "ekwanzaTransactionId": "EKZ456...",
  "operationStatus": "1",
  "operationData": { ... }
}

Event 2: invoice.created — Sent after invoice PDF is generated and uploaded:

{
  "event": "invoice.created",
  "merchantTransactionId": "abc123...",
  "ekwanzaTransactionId": "EKZ456...",
  "operationStatus": "1",
  "operationData": { ... },
  "invoiceUrl": "https://invoice-momenu.toquemedia.net/invoices/..."
}

Non-paid events (operationStatus 3, 4, 5) are sent without the event field for backward compatibility.

operationStatus values: "1" Paid · "3" Cancelled/Expired · "4" Failed/Refused · "5" Error

Fallback (status endpoint):

Reference: GET /api/payment/reference/status/:operationId - Returns payment.status

When paid, both return invoiceUrl.

Instant Withdrawal

instantWithdraw is required and must be true on /api/payment/mcx and /api/payment/reference. The payment value — minus the 2% fee — is transferred automatically (via KWiK) to the merchant's verified bank account as soon as the payment is confirmed.

• Applies to: Multicaixa Express (/api/payment/mcx) and Bank Reference (/api/payment/reference).
• Requires a verified (approved) bank account for the merchant. Without it, the payment request is rejected.
• The flag is read only from the order created at payment time — it cannot be forced later via the status/polling request.
• Amounts above the per-withdrawal ceiling stay in the merchant balance for a manual withdrawal.

⚠️ Required (since 2026-06-22): requests to /api/payment/mcx and /api/payment/reference that omit instantWithdraw (or send false) are rejected with INSTANT_WITHDRAW_REQUIRED (HTTP 400). Always send "instantWithdraw": true.

Error Codes

| Code | Description | |------|-------------| | MISSING_API_KEY | x-api-key header missing | | INVALID_API_KEY | Key invalid or inactive | | DOMAIN_NOT_ALLOWED | Origin not registered | | INVALID_AMOUNT | Invalid amount | | AMOUNT_MISMATCH | amount != SUM(products) | | INSTANT_WITHDRAW_REQUIRED | instantWithdraw required and must be true (MCX/Reference) | | MISSING_PHONE | Phone required (MCX) | | MISSING_RESTAURANT_ID | Merchant not identified | | RATE_LIMIT_EXCEEDED | 100 req/min exceeded | | PAYMENT_RATE_LIMIT_EXCEEDED | 20 payment req/min exceeded | | INTERNAL_ERROR | Server error |

Error format: { "success": false, "error": "message", "code": "ERROR_CODE" }

Fees

2% processing fee on all payments: feeAmount = totalAmount * 0.02

Notes

• Phone format: 244XXXXXXXXX (12 digits)
• IVA defaults to 14%. Use 0 for exempt.
• Invoice PDFs hosted on CDN, returned as invoiceUrl
• MCX is immediate; Reference is confirmed via webhook (status polling as fallback)