FluxPay Developer Docs

curl -X POST https://fluxpay.online/api/v1/payments \
  -H "Authorization: Bearer sk_test_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 99.99,
    "currency": "USD",
    "description": "Order #1234",
    "customer": {
      "email": "customer@example.com",
      "firstName": "John",
      "lastName": "Doe",
      "phone": "+12125551234",
      "ip": "203.0.113.42",
      "billing": {
        "address": "123 Main Street",
        "city": "New York",
        "state": "NY",
        "country": "US",
        "postalCode": "10001"
      }
    },
    "metadata": { "orderId": "ORD-1234" },
    "successUrl": "https://yoursite.com/payment/success",
    "failureUrl": "https://yoursite.com/payment/failure"
  }'

// curl -o fluxpay.cjs.js https://fluxpay.online/sdk/v1/fluxpay.cjs.js
const { FluxPayClient } = require('./fluxpay.cjs.js');

const fluxpay = new FluxPayClient({
  apiKey: process.env.FLUXPAY_API_KEY, // sk_test_... or sk_live_...
});

const { FluxPayClient, FluxPayError } = require('./fluxpay.cjs.js');
const fluxpay = new FluxPayClient({ apiKey: process.env.FLUXPAY_API_KEY });

try {
  const { payment } = await fluxpay.createPayment({
    amount: 49.0,
    currency: 'EUR',
    customer: { email: 'customer@example.com', firstName: 'Jane', lastName: 'Smith' },
    successUrl: 'https://yoursite.com/payment/success',
    failureUrl: 'https://yoursite.com/payment/failure',
  });
  console.log(payment.paymentUrl);

  const { payment: latest } = await fluxpay.getPayment(payment.id);
  console.log(latest.status);
} catch (err) {
  if (err instanceof FluxPayError) console.error(err.statusCode, err.message);
}

{
  "methods": [
    {
      "method": "CREDIT_CARD",
      "currencies": ["EUR", "USD", "GBP"],
      "countries": ["DE", "FR", "ES"],
      "fxConversion": false
    }
  ],
  "cardBrands": ["VISA", "MASTERCARD", "AMEX", "DISCOVER", "JCB", "DINERS", "UNIONPAY"],
  "checkoutMode": "HOSTED",
  "checkoutModeCountry": "DE",
  "threeDS": {
    "controlAllowed": false,
    "preference": "auto",
    "modes": ["auto", "always", "never"]
  }
}

POST https://yoursite.com/webhooks/fluxpay

Headers
  Content-Type: application/json
  X-Webhook-Event: payment.success
  X-Webhook-Signature: <HMAC-SHA256 of the raw body, hex>
  X-Transaction-Id: cm4h1abc123def456
  X-Test-Mode: false          (first attempt only)
  X-Retry-Attempt: 2          (retries only)

Body
{
  "paymentId": "cm4h1abc123def456",
  "transactionId": "cm4h1abc123def456",
  "reference": "cm4h1def456ghi789",
  "amount": 99.99,
  "currency": "USD",
  "status": "COMPLETED",
  "customerEmail": "customer@example.com",
  "testMode": false,
  "metadata": { "orderId": "ORD-1234" },
  "timestamp": "2026-10-15T10:35:00.000Z"
}

const crypto = require('crypto');

// Use the RAW body. Parsing and re-encoding the JSON breaks the signature.
app.post('/webhooks/fluxpay', express.raw({ type: 'application/json' }), (req, res) => {
  const expected = crypto
    .createHmac('sha256', process.env.FLUXPAY_WEBHOOK_SECRET)
    .update(req.body)
    .digest('hex');
  const received = req.get('X-Webhook-Signature') || '';

  if (received.length !== expected.length ||
      !crypto.timingSafeEqual(Buffer.from(received), Buffer.from(expected))) {
    return res.status(401).end();
  }

  const event = req.get('X-Webhook-Event');
  const payment = JSON.parse(req.body);
  if (event === 'payment.success') {
    // Mark order payment.metadata.orderId as paid
  }
  res.status(200).end();
});