Building a Custom Checkout with NoPOS API

Learn how to build a custom checkout experience that perfectly matches your brand and business requirements using the NoPOS API.

Prerequisites

Before starting, ensure you have:

• NoPOS API credentials
• Node.js 18+ installed
• Basic knowledge of REST APIs
• A payment gateway account (Stripe, Square, etc.)

Step 1: Initialize the Transaction

First, create a new transaction with the items being purchased:

const response = await fetch('https://api.nopos.dev/v1/transactions', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    items: [
      {
        product_id: 'prod_123',
        quantity: 2,
        price: 29.99
      }
    ],
    customer_id: 'cust_456'
  })

const transaction = await response.json(); `

Step 2: Calculate Tax and Totals

The API automatically calculates taxes based on your location and settings:

const totals = transaction.totals;
console.log('Subtotal:', totals.subtotal);
console.log('Tax:', totals.tax);
console.log('Total:', totals.total);

Step 3: Process Payment

Integrate with your payment provider:

const paymentResponse = await fetch(
  `https://api.nopos.dev/v1/transactions/${transaction.id}/payment`,
  {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer YOUR_API_KEY',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      payment_method: 'stripe',
      payment_token: stripeToken,
      amount: totals.total
    })
  }
);

Step 4: Handle Payment Confirmation

Listen for payment confirmation and update your UI:

if (paymentResponse.ok) {
  const result = await paymentResponse.json();
  
  // Update inventory automatically
  // Send receipt to customer
  // Show confirmation page
  
  console.log('Order confirmed:', result.order_id);
}

Advanced Features

Split Payments

Support multiple payment methods in a single transaction:

const splitPayment = {
  payments: [
    { method: 'card', amount: 50.00 },
    { method: 'gift_card', amount: 25.00 }
  ]
};

Loyalty Points

Apply loyalty points during checkout:

const withLoyalty = {
  customer_id: 'cust_456',
  apply_loyalty_points: true,
  loyalty_points_to_redeem: 500
};

Error Handling

Always implement robust error handling:

try {
  const response = await processTransaction();
  
  if (!response.ok) {
    throw new Error(`Payment failed: ${response.statusText}`);
  }
} catch (error) {
  console.error('Transaction error:', error);
  // Show user-friendly error message
  // Log for debugging
}

Next Steps

• Explore [payment webhooks](https://developer.nopos.dev/webhooks) for real-time updates
• Implement [refunds and returns](https://developer.nopos.dev/refunds)
• Add [subscription billing](https://developer.nopos.dev/subscriptions) for recurring payments

Check out the full API documentation for more details.