GembaPay

Unified payment gateway for crypto, cards, and PayPal.

Accept ETH, BNB, POL, USDC, USDT, credit cards (via Stripe), and PayPal through a single API. Non-custodial crypto payments — funds go directly to your wallet via smart contract.

Features

• One API, three payment methods — Crypto, Stripe (cards/Apple Pay/Google Pay), PayPal
• Non-custodial crypto — Payments route directly to your wallet via smart contracts
• 86+ currencies — Price in any fiat currency, settle in crypto or fiat
• Multi-chain — Ethereum, BNB Smart Chain, Polygon
• Test mode built-in — Testnets + sandbox environments for development
• TypeScript support — Full type definitions included
• Zero dependencies — Uses only Node.js built-in modules

Install

npm install gembapay

Quick Start

const GembaPay = require('gembapay');

const gembapay = new GembaPay({
  apiKey: 'gembapay_test_your_key',  // test key for development
  webhookSecret: 'your_webhook_secret'
});

// Create a payment
const payment = await gembapay.createPayment({
  orderId: 'ORDER-123',
  amount: 100.00,
  currency: 'EUR'
});

console.log(payment.paymentUrl);
// → https://payment.gembapay.com/checkout/ORDER-123

console.log(payment.allowedMethods);
// → ['crypto', 'stripe', 'paypal']

Usage

Create Payment

const payment = await gembapay.createPayment({
  orderId: 'ORDER-456',
  amount: 49.99,
  currency: 'USD',
  description: 'Premium Plan'
});

// Redirect customer to unified checkout
res.redirect(payment.paymentUrl);

Check Status

const status = await gembapay.getPaymentStatus('ORDER-456');

console.log(status.status);   // 'completed'
console.log(status.network);  // 'bsc', 'stripe', 'paypal', etc.

Webhook Verification

const express = require('express');
const app = express();

app.post('/webhooks/gembapay', express.json(), 
  gembapay.webhookHandler(async (event) => {
    if (event.event === 'payment.completed') {
      console.log(`✓ Order ${event.payment.orderId} paid`);
      console.log(`  $${event.payment.usdAmount} via ${event.payment.network}`);
      await fulfillOrder(event.payment.orderId);
    }
  })
);

Or verify manually:

app.post('/webhooks/gembapay', express.json(), (req, res) => {
  const signature = req.headers['x-gembapay-signature'];
  
  if (!gembapay.verifyWebhook(req.body, signature)) {
    return res.status(401).send('Invalid signature');
  }
  
  const { event, payment, testMode } = req.body;
  // Process event...
  
  res.json({ received: true });
});

Transactions & Stats

const transactions = await gembapay.listTransactions();
const stats = await gembapay.getStats();

Test Mode

Use test API keys (gembapay_test_...) for development. Test mode automatically uses:

| Method | Test Environment | |--------|-----------------| | Crypto | Sepolia, BSC Testnet, Polygon Amoy | | Stripe | Test cards (4242 4242 4242 4242) | | PayPal | Sandbox accounts |

// SDK detects test mode from your API key
const gembapay = new GembaPay({
  apiKey: 'gembapay_test_your_key'
});

console.log(gembapay.isTestMode); // true

Claim free test tokens at Developer Resources.

Express.js Example

const express = require('express');
const GembaPay = require('gembapay');
const app = express();

const gembapay = new GembaPay({
  apiKey: process.env.GEMBAPAY_API_KEY,
  webhookSecret: process.env.GEMBAPAY_WEBHOOK_SECRET
});

// Create payment endpoint
app.post('/api/checkout', express.json(), async (req, res) => {
  const { orderId, amount, currency } = req.body;
  
  try {
    const payment = await gembapay.createPayment({ orderId, amount, currency });
    res.json({ paymentUrl: payment.paymentUrl });
  } catch (err) {
    res.status(err.statusCode || 500).json({ error: err.message });
  }
});

// Webhook endpoint
app.post('/webhooks/gembapay', express.json(),
  gembapay.webhookHandler(async (event) => {
    if (event.event === 'payment.completed') {
      await fulfillOrder(event.payment.orderId);
    }
  })
);

app.listen(3000);

API Reference

new GembaPay(options)

| Option | Type | Required | Description | |--------|------|----------|-------------| | apiKey | string | ✓ | API key from Merchant Dashboard | | webhookSecret | string | | Webhook signing secret | | baseUrl | string | | Custom API URL (default: https://api.gembapay.com) | | timeout | number | | Request timeout in ms (default: 30000) |

Methods

| Method | Description | |--------|-------------| | createPayment(params) | Create payment request → returns paymentUrl | | getPayment(orderId) | Get payment details | | getPaymentStatus(orderId) | Check payment status | | listTransactions(params?) | List merchant transactions | | getStats() | Get merchant statistics | | verifyWebhook(payload, signature) | Verify webhook signature | | parseWebhook(req) | Parse & verify Express request | | webhookHandler(fn) | Express webhook middleware |

Fee Structure

| Method | Fee | |--------|-----| | Crypto (ETH, BNB, POL, USDC, USDT) | 1% | | Stripe (Cards, Apple Pay, Google Pay) | 1% + €0.20 + Stripe fees | | PayPal (Balance, Bank, Pay Later) | 1% + €0.20 + PayPal fees |

Links

• Documentation
• Merchant Dashboard
• Integration Guide
• GitHub
• Developer Resources

Support

• Email: [email protected]
• GitHub Issues: github.com/ivanovslavy/gembapay/issues

License

MIT © GEMBA EOOD